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Full text of "Applied Anatomy: Designed for the Use of Osteopathic Students and Practitioners as an Aid in the Anatomical Exploration of Disease from an Osteopathic Viewpoint"

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APPLIED ANATOMY 




APPLIED ANATOMY 



DESIGNED FOR THE USE OF OSTEOPATHIC STUDENTS AND 

PRACTITIONERS AS AN AID IN THE ANATOMICAL 

EXPLANATION OF DISEASE FROM AN 

OSTEOPATHIC VIEWPOINT. 



-BY- 



MARION EDWARD CLARK, D. O., 

Pro fessor of Applied Anatomy, Gynecology, Obstetrics and Diseases of Children, 
in the American School of Osteopath}', Kirksville, Mo. 



Illustrated With 175 Engravings, of Which Several are in 
Color, and Many Halftones from Photos. 



1 906 



/I4U 



U)S f/fd.JffO 




Copyrighted 1906, by II. E. Clark. 




iluurnal 
printing (to.. 

Kirltiiliillr. iHu. 



APPLIED ANATOMY. 



PREFACE 



Realizing the close relation existing between anatomy and osteo- 
pathic therapeutics, that the science is built on anatomical and physio- 
logical knowledge, I in 1901 outlined a course in a subject that I chose 
to call, Applied Anatomy. This book is the outgrowth of that attempt 
to anatomically explain the signs, cause and treatment of disease. 

The object of this work is to place osteopathy on a scientific basis 
by offering anatomical and physiological proof that our etiology of dis- 
ease is correct; to demonstrate that disturbance of function is, as a rule, 
due to structural changes, and to point out the significance of anatomical 
changes; and to furnish the practitioner a ready reference for the explain- 
ing of lesions and their effects. Anatomical details have been avoided 
unless of importance in the explanation of the subject. 

I am fully aware that many will differ with me in some of the state- 
ments made, also that errors unintentional and unavoidable, have crept 
into the text. Having no precedent, this being a practically new work 
along its line, it was found hard to avoid repetition and present the sub- 
ject in an interesting and at the same time, an instructive and correct 
way. 

In the arrangement of it I have followed my notes used in the pre- 
sentation of the subject to my classes. The articulations of the body are 
first studied, this being followed by a consideration of the regions of the 
body, the nervous system and the viscera. 

The scope of the work is not confined entirely to anatomy, but use 
is made of physiology, pathology and physical diagnosis in the inter- 
pretation of the signs of lesions and disease. In fact, it is almost as 
much of a work on applied physiology as it is of applied anatomy. 

The illustrations have been taken from various sources. Many 
are from drawings of dissections, some adapted from the standard works, 
some reproduced, and others from photographs of cases seen and treated 
by the writer. Due credit is given when the illustration is not original. 






10 APPLIED ANATOMY. 

They are designed to elucidate the text and on this account have 
been arranged so that they come at or near the part of the text that they 
are intended to illustrate. 

In the preparation of the work, I consulted many authorities, but 
I especially used the following: Gray, Quain, Morris, Cunningham, 
Gerrish, Eisendrath, Spalteholz, McClellan, Deaver, McLachlin, Taylor, 
Eckley, Landois, Schafer, Howell, Brubaker, Mouillan, Lovett and Hare. 
Credit has been attempted in all quotations from the above. 

Much dissection has been done in order to ascertain course of nerves, 
relations of viscera, pathological conditions and their causes, and to the 
better understand lesions, their kinds and effects. The greater part of 
the material has been taken from the writer's extensive experience in 
the diagnosis and treatment of disease, having been a teacher and oper- 
ator in the American School of Osteopathy since 1899. Many of the 
conclusions drawn have been from actual cases treated, and we take it 
that we have as much right to draw conclusions from clinical observa- 
tions that are as accurate as those drawn from experiments on animals, 
when cases are diagnosed, lesions found and on the removal of them the 
patient recovers. 

The majority of the illustrations were drawn by Dr. Wm. Most, 
and I am glad to express my appreciation of his efficient work. I am 
indebted to D. Appleton & Co., for electrotypes from Dr. Kelly's splen- 
did work. 

I am especially indebted to Messrs. Pratt and Sullivan, senior stu- 
dents in the A. S. 0. for the preparation of the index. 

I am also indebted to my co-laborers in the A. S. O. for many val- 
uable suggestions. 

It is the desire of the writer that this work will be of material aid 
to the practitioner, in the understanding of the human body, that it will 
stimulate the student to a closer study of the wonderful mechanism, 
and it is his regret that it is so imperfect, that there are so many things 
that he is unable to make entirely clear, since, as yet, many of the func- 
tions of the body are mere speculations. 

M. E. C. 
402 Osteopathy Ave., Kirksville, Mo. 

May, 1906. 



APPLIED ANATOMY. 1 1 



INTRODUCTION 



Disease, in the average ease, is due to disturbance of structure. 
Even in cases of disease resulting from abuse, there is often found some 
structural change. In all diseases, whether from abuse or other causes, 
there are to be found structural changes, peculiar to the disease. These 
structural changes, are in a general way, called lesions. Lesions there- 
fore, may be muscular, ligamentous, visceral or bony. A bony lesion 
is one in which the function of the articulations of the bone are im- 
paired. Anything that disturbs the function of a joint, causes a bony 
lesion. The usual form is the result of displacement of the bone. This 
displacement is very slight in the average case. A muscular contrac- 
ture, a ligamentous shortening, an exostosis, or most important and com- 
mon of all, an inflammatory deposit around the articulation, constitute 
bony lesions. The function of a joint is movement. Ligaments and 
muscles restrict this movement. If force is applied, this restriction is in 
a measure, overcome and consequently the tissues around the joint are 
injured. Nature sends out an exudate, which forms a splint, the lig- 
aments become thickened, in short, we have a typical lesion. This con- 
stitutes a sprain, the most common form of bony lesion. The contrac- 
ture of these tissues injured by the excessive movement, holds the bone 
in abnormal position, thus forming the slight displacement or sublux- 
ation, so often spoken of in osteopathic literature. These conditions more 
often follow trivial injuries than they do severe trauma. A person in 
walking over an uneven sidewalk, may unexpectedly step in a depression 
and twist the spine. There is a momentary pain and soon it is forgotten. 
The injured place remains sore. The tissues become thickened. The 
patient is not aware that it is tender until some osteopathic physician 
presses directly on the spot. The movement of the joint is practically 
lost, the foramina partly closed, and there is disturbance of function of 
everything in relation. Physical culture is not a substitute for osteo- 
pathic treatment since the movements of the spine take place in the 
normal parts, while the place of injury is not moved at all. To reduce 
such a lesion, passive movement must be directed to the injured joint. 
By doing this, the function is temporarily restored, the circulation through 
the part bettered and absorption of the deposits begins. This is followed 



12 APLLIUU ANATOMT. 

by restoration of function of the joint and the adjacent tissues. Such 
conditions predispose to visceral disease. From this one can see that a 
knowledge of anatomy is absolutely necessary in order to locate the lesion, 
to explain the effects and to remove the cause. 

Since disease is caused or characterized by structural derangement, 
and these derangements "produce or maintain the functional disorder," 
the object of osteopathic examination and treatment is to locate 
and correct these structural disturbances. Osteopathy, then, is the 
science of locating and correcting by manipulation, structural disorders 
that cause or maintain functional disturbances or disease, and the use 
of common sense regarding the care of the body. Any one can become 
an invalid by disobeying the laws of nature, consequently structural 
disorders are not the primary causes of all diseases, yet in such cases 
there are structural changes that maintain the disturbances which must 
be corrected before normal function will be regained. 

In lesions of the spinal column, there is, in practically all cases a 
deposit around the joint and a thinning of the intervertebral discs. The 
object to be attained in the treatment of the spine is to restore normal 
function, that is movement, to the spinal articulations. This can be 
accomplished by adjusting the articular surfaces and by stretching the 
inflammatory tissues deposited around the injured joint. 

The essential cause of bony lesions producing disease is pressure. 
This pressure is exerted on nerves, vessels and other tissues, principally 
at the intervertebral foramina. The pressure is from the displaced 
bone or is the result of the inflammatory deposits around the injured 
joint. On account of this, the nerve connections between the spinal 
cord and the rest of the body are interrupted, the blood-vessels supply- 
ing and draining the spinal cord compressed, the lymphatic vessels im- 
paired and as a result of this, the nutrition of the cord disturbed, the 
originating of impulses interfered with as well as the transmission of 
them. Normal circulation to the spinal cord is essential to proper func- 
tioning of it; the condition, that is, the mobility of the various vertebral 
articulations, determines this. 

The writer appreciates the fact that there are many exciting causes 
of disease such as abuse of function, exposure, neuroses and inherited 
weakness but the underlying cause of all disease is a structural derange- 
ment of some part of the body and most important is a derangement of 
the framework; the spinal column and the ribs in particular. 



APPLIED ANATOMY. 13 



TABLE OF CONTENTS 



Page. 

The atlas 17 

The axis 53 

The third cervical vertebra G7 

The fourth cervical vertebra 76 

The fifth cervical vertebra : 84 

The sixth cervical vertebra 97 

The seventh cervical vertebra 104 

The region of the neck 11.5 

The thoracic vertebr.e 127 

The first thoracic vertebra 127 

The second thoracic vertebra 138 

The third thoracic vertebra 146 

The fourth thoracic vertebra 156 

The fifth thoracic vertebra ]67 

The sixth thoracic vertebra 179 

The seventh thoracic vertebra 192 

The eighth thoracic vertebra 202 

The ninth thoracic vertebra 211 

The tenth thoracic vertebra 217 

The eleventh thoracic vertebra 225 

The twelfth thoracic vertebra 234 

The first lumbar vertebra 241 

The second lumbar vertebra 251 

The third lumbar vertebra 261 

The fourth lumbar vertebra 274 

The fifth lumbar vertebra 287 



14 applied anatomy. 

The innominate 301 

The sacrum 327 

The back as a region 332 

The spinal cord 367 

The ribs 379 

The first rib 384 

The second rib 390 

The third rib 395 

The fourth rib 398 

The fifth rib • 403 

The sixth rib 405 

The seventh rib 408 

The eighth rib 410 

The ninth rib 413 

The tenth rib 414 

The eleventh rib 415 

The twelfth rib 418 

The thorax 420 

The abdomen 435 

The temporo-maxillary articulation .• 448 

The hyoid bone 451 

The sterno-clavicular articulation 452 

The acromioclavicular articulation 453 

The shoulder-joint 454 

The elbow-joint 459 

The wrist-joint 459 

The hand 461 

The upper extremity as a region 461 

The hip-joint 469 

The knee-joint 477 

The ankle-joint 483 

The lower extremity as a region 486 



applied anatomy. 15 

The cranial nerves 494 

The olfactory nerve 494 

The optic nerve ■ 495 

The third cranial nerve 496 

The fourth cranial nerve 498 

The fifth cranial nerve 498 

The sixth cranial nerve 505 

The seventh cranial nerve 506 

The eighth cranial nerve 508 

The ninth cranial nerve 510 

The tenth cranial nerve 512 

The eleventh cranial nerve 519 

The twelfth cranial nerve 520 

The brain 522 

The medulla oblongata 527 

The cerebellum 532 

The eye 550 

The ear 556 

The nose 560 

The mouth 563 

The pharynx 569 

The larynx 571 

The thyroid gland 575 

The trachea 579 

The bronchi 580 

The lungs 582 

The heart 589 

The stomach 598 

The liver 60S 

The pancreas 616 

The spleen 620 

The small intestine 622 



16 applied anatomy. 

The large intestine 628 

The kidneys 639 

The bladder 647 

The supra-renal capsules 651 

The ovaries 652 

The testes 655 

The spermatic cord 661 

The vesicle seminales 663 

The prostate gland 663 

The uterus 669 

The external genitalia 674 

The mammae 674 



Hpplied Hnatomy. 



THE ATLAS. 

The Atlas is the most peculiar of vertebra?. It is the uppermost 
of the vertebrae forming the spinal column and supports the head. For 
an object to be well supported, there must be little motion between the 
part supporting and the part supported. This is true of the atlas and 
occiput, the atlanto-occipital articulation being to all intents and pur- 
poses immovable, very little motion at least, taking place at this 
joint in movements of the head. On this account lesions of this artic- 
ulation are rare as compared with other vertebral articulations, using 
the term lesion in its usually accepted meaning. In the better use of 
this term, that is including all affections of the articulation, especially 




Fig. 1. — The atlas showing the superior aspect. Note the shape and depth of the 

articular facets. 

sprains of the ligaments, a lesion of this articulation is quite com- 
mon. 

The atlas is peculiar in that the body is absent, it being supposedly 
usurped by the odontoid process of the axis. This is of interest since 
complete dislocations result in pressure on the spinal cord by the odon- 
toid process from breaking of the transverse ligament, and paralysis of 



18 APPLIED ANATOMY. 

all parts below follows. if pressure is constant and long"continued. The 
absence of the body of the atlas makes it thinner, thus permitting of 
freer motion of the head on the spinal column, in accordance with the 
general rule that the smaller the vertebra the greater the arc of mobility. 

The posterior spinous process, which is developed in all the other 
vertebra?, is absent or, at least, poorly developed in the case of the atlas. 
There is a rudimentary process or tubercle that takes its place, and to 
which is attached the small posterior recti muscles. Ordinarily, it can- 
not be palpated even though the neck be in extreme flexion, but in some 
cases it is possible to distinctly palpate it. If it can be palpated it de- 
notes either (1) an abnormal development of the tubercle; (2) an anterior 
condition of the occiput on the atlas; or (3) a posterior condition of the 
atlas, the atlas and occiput being displaced posteriorly on the spinal 
column. The diagnosis is based on (1) tenderness over and around the 
tubercle and (2) disturbance of function of the articulations involved. 
If there is no tenderness in or around the articulations of the atlas and 
the function is unimpaired, the prominence of this tubercle is not 
pathological but only a peculiarity. 

At the junction of the anterior arches is another tubercle. It is of 
interest only in that the longus colli muscles and the anterior verte- 
bral ligament are attached to it, hence in lesions of the atlas flexion of 
the head and neck may be impaired indirectly, by affecting these muscles 
through their nerve supply or attachment and directly, by derangement 
of the articular facets. , 

The superior articular facets are peculiar on account of their shape, 
size and the directions that they face. These facets are oval shaped, 
deeply concave from before backward, converge in front and incline 
obliquely inward. They are often indented, in which cases they are 
divided into two unequal parts, thus lessening the mobility of the joint. 
They receive the condyles of the occipital bone, thus forming a rather 
secure articulation. On account of the depth of the concavity of the 
superior facets of the atlas and the prominent convexity of the occipital 
condyles, dislocation of this articulation either partial or complete, is 
rare. Also the facets act as inclined planes, thus assisting spontaneous 
reduction if the condyles were forced slightly upward on the facets. 
By muscular contracture the occiput and atlas are approximated, this 
of itself lessening the mobility of the occipito-atlantal articulation. If 
in addition, an inflammatory exudate is present from meningitis, la- 



APPLIED ANATOMY. 



19 



grippe or other causes, mobility of this articulation is still further less- 
ened. The principal movement of this joint is an antero-posterior one, 
thus permitting of a nodding movement of the head. 

Another peculiarity is the fact that the articular facets of the atlas, 
like those of the axis, are anterior to the place of exit op the spinal 
nerves; the facets being posterior in the other vertebrae. 

There is a circular facet on the posterior surface of the anterior arch 
for articulation with the odontoid process of the axis. This indentation 
or facet is called fovea dentalis. On account of this articulation a dis- 
placement of the atlas directly backward is impossible unless it carries 
the axis with it. 




Fig. 2. — Inferior surface of the atlas. Compare with superior, Fig. 1. 



The inferior facets are smaller and more nearly circular than the 
superior, but like them, concave. They face inwards and downwards 
and are more subject to abnormal movement than are the superior. 
This is because of the freedom of movement and the leverage exerted 
on it by the atlas and occiput. 

The movements of the atlanto-occipital articulation are not very 
well marked, they consisting principally of a rocking movement of the 
occipital condyles on the superior facets of the atlas. This has been 
described as of a ginglymoid character. Morris says: "There is also 
a slight amount of gliding movement, either directly lateral, the outer 
edge of one condyle sinking a little within the outer edge of the socket 
of the atlas, and that of the opposite condyle projecting to a corres- 



20 APPLIED ANATOMY. 

ponding degree. The head is thus tilted to one side, and it is even 
possible that the weight of the skull may be borne almost entirely on 
one joint, the articular surfaces of the other being thrown out of 
contact. Or the movement may be obliquely lateral, when the lower 
side of the head will be a trifle in advance of the elevated side. "* 

The head is so poised on the superior articular surfaces of the atlas 
that it requires little muscular effort to keep it balanced. If the occiput 
or atlas become changed in position as a result of a subluxation, the 
balancing of the head becomes more difficult, that is, more muscular 
effort is required to keep the head in a normal position. Since the cervi- 
cal ligaments have little or nothing to do with the balancing of the head, 
and since the muscles connecting the head with the spinal column are 
the principal factors concerned in holding the head erect, it follows 
that any disorder of these muscles or the joint itself, will interfere with 
this function, that is the head is drawn too far to one side or else the 
balance is lost so that it moves to and fro. Many of the cases charac- 
terized by a constant nodding movement of the head are due to some 
affection of either the joint itself or the mechanism moving the joint so 
that the muscles are constantly drawing the head out of balance, that 
is it is drawn too far forward or backward in the attempts of the cervi- 
cal muscles to keep it poised. If the lesion exists for sometime, the 
irritation is not overcome by assuming the prone posture but as a rule 
the movement is decidedly lessened in the worst cases and is stopped 
entirely in the mild cases. If the prone posture is assumed for several 
hours as in sleep, the attempts of the muscles to balance the head cease. 
The above is the principal cause of nodding of the head, the other ones 
being of less importance. 

The first cervical nerves making their exit in relation with the atlas, 
pass along a groove over the posterior arch instead of through a foramen, 
this groove being occasionally converted into a foramen. The vertebral 
vessels also pass along with the first cervical nerve. 

The transverse processes are unusually large and rough and extend 
farther outward than those of the other vertebra?. They are perforated 
by a foramen through which pass the vertebral vessels and vertebral 
plexus of nerves. Numerous muscles are attached to the transverse 
processes, in contractured conditions of which the position of the pro- 
cesses is changed. These processes are quite superficial, hence tender 

*Morris Human Anatomy, p. 204. 



APPLIED ANATOMY. 21 

on pressure. Use is occasionally made of this fact in treating hysterical 
cases, pressure on the transverse processes producing such pain that the 
patient forgets about the other trouble. The direction and position of 
the processes vary in different individuals. Theoretically they should 
point directly outward and be midway between the angle of the jaw and 
the mastoid process. The position of the bone is partly determined by 
the relation of the tip of the transverse process to the above named 
landmarks, but it does not necessarily follow that a lesion exists if it is 
nearer one than the other. 

The position of the head is sometimes indicative, if not diagnostic, 
of, a lesion of this articulation. If the chin is drawn in abnormally 
far, the chances are that the head sets too far back on the spinal column, 
that is on the atlas; if the chin protrudes unusually far, the opposite con- 
dition exists. The sterno-mastoid muscles are put on a tension in the 
first, and relaxed in the second condition. 

The ligaments binding the atlas to the occiput are arbitrarily divided 
into anterior occipito-atlantal, posterior occipito-atlantal, two capsular 
and two anterior oblique. They are band-like, elastic and densely woven 
ligaments and, if not diseased, hold the superior facets of the atlas and 
the occipital condyles securely in apposition. 

The anterior occipito-atlantal ligament is composed of very strong 
dense fibers that radiate upward and slightly outward from the anterior 
arch to the anterior border of the foramen magnum. It is in close re- 
lation with the anterior common, the capsular and the atlanto-axoidean 
ligaments. 

The posterior occipito-atlantal is incomplete on both sides for the 
passage of the vertebral vessels and the suboccipital nerve. 

It extends from the upper part of the posterior arch of the atlas 
to the posterior border of the foramen magnum. It is not very strong, 
is not stretched very tightly and does not to a great extent limit motion. 
Being weaker than the anterior, extreme flexion is more likely to pro- 
duce a serious effect than is extreme extension. Because of the greater 
strength of the anterior ligament the front part of the articulation is 
held the more securely in place than is the posterior thus the latter 
would respond to a force more quickly than would the former. The 
capsular do not materially strengthen the joint since they are quite lax. 
They entirely surround and enclose the occipito-atlantal articulation. 
They are reinforced and strengthened by the anterior oblique ligaments. 



22 APPLIED ANATOMY. 

These ligaments are affected in various ways by bony and mus- 
cular lesions of the neck. However, the principal effects are those of 
relaxation and contraction or shortening. If the lesion is irritative the 
ligaments are likely to become' thickened, less elastic and shorter, and 
thus draw the head quite firmly down on the atlas. In the anemic and 
malnourished, relaxation takes place with increased mobility. 

The blood supply to these ligaments comes principally from the ver- 
bral while a few twigs are given off by the ascending pharyngeal. The 
innervation is from the anterior division of the first cervical nerve. In 
subluxations of the occiput, these ligaments are injured, either torn or 
badly stretched. This results in a thickening of the ligaments and de- 
posits around the injured part. These conditions interfere with the 
function of the joint, the blood-vessels, the nerves in relation, the mus- 
cles attached and the intervertebral foramina that is the space between 
the posterior arch of the atlas and the axis. 

The brain has a pulsation in the direction where the resistance is 
least. This is seen best in babies before the fontanelles close. The 
diastole and systole of the brain are in part made possible in the un- 
yielding box of the cranium by the ebb and flow of the cerebro-spinal 
fluid. Hill says: "The occipito-atlantal and other vertebral ligaments 
extend in cerebral diastole, and allow the fluid to escape from the cranial 
cavity, while in systole, through the elasticity of these ligaments com- 
ing into play, it is driven back. "* This then is an important factor in 
the circulation of the brain. Lesions of the occipito-atlantal articula- 
tion affect the ligaments and thus interfere with their elasticity. 
Since in all vertebral lesions the ligaments in relation are always af- 
ected, the direct relation of spinal lesions and especially cervical, to 
brain disorders, becomes the better understood. 

The ligaments uniting the atlas to the axis are the anterior and 
posterior atlanto-axoidean, capsular and the atlanto-odontoirl. 

The muscles attached to the atlas are the recti capiti minores and 
laterales, longus colli, obliqui, splenitis colli, levator anguli scapulae and the 
intertransversales. Most of these are attached to the transverse processes. 
On account of the length of these processes, the number of muscles attached 
and the mobility of the articulations, torsion of the atlas and occiput on 
the axis from muscular contractions often occurs. These muscles con- 
tract from thermic influences. This form of stimulation most often 

*Schaffer's phys. p. 143. 



APPLIED ANATOMY. 



23 



affects the neck. Nature provides against this by giving man hair 
which, covering the neck, protects it against exposure. Fashion has 
decreed that the hair should be worn closely cropped and as a result one 
of nature's defenses is weakened. In the male the throat is protected 
in a similar manner by hair from the face. 

These muscles, on account of the thermic stimulation, fail to return 




Fig. 3. — Showing the small deep muscles at the base of the occiput that are 
always affected in lesions of the atlanto-occipital and atlanto-axoidean articulations. 
In the average case of headache these muscles are tender and contractured. 

to their normal length and thickness. Landois, in speaking of a con- 
tracture says: "This is especially well marked in muscles that have been 
previously subjected to strong, direct stimulation, or are greatly fatigued, 
or more strongly acid, or approaching a condition of rigor or have been 
obtained from animals poisoned with veratin. " In man, these con- 



24 APPLIED ANATOMY. 

tfactures come, in the neck, from thermic stimuli, as mentioned above; 
toxemia, by which the cells are over stimulated; and from lesions of the 
neck by which the nerve trunks are stimulated, the nerve cells irritated 
and the muscles put on a stretch on account of change in position of the 
origin or insertion. It seems that a muscle undergoes a change in struc- 
ture as a result of prolonged stimulation of its nerve, which condition is 
readily recognized on palpation and is called a muscular contracture. 

When these muscles remain contraetured for any great length of 
time the vertebrae are abnormally approximated, hence the interverte- 
bral foramina are smaller, the circulation through the muscle impaired 
and consequently the blood supply to the cervical spinal cord, medulla 
and pons Varolii interfered with. The nerve filaments passing through 
and in relation with, the contraetured muscle are also, affected. On 
the other hand, lesions affecting the innervation of these muscles pro- 
duce contracture., which in turn produces the above effects. 

The upper two or, three segments of the cervical spinal cord are in 
relation with the atlas but provision is made against pressure from move- 
ments of the head and neck. This provision is a very large foramen in 
the atlas portion of the spinal canal. If pressure is exerted on the 
spinal cord in this region the lesion must necessarily be a complete dis- 
location. Partial dislocations of vertebrae affect structures attached 
to the bone and those in the spinal foramina more readily than those in 
the canal. 

The structures affected by vertebral lesions in order of frequency 
are the ligaments, veins, arteries, nerves and muscles. 

The veins in relation with the atlas are the vertebral and rami 
spinales which collect the blood from the upper cervical segments of the 
spinal cord and the spinal column. In lesions of t he atlantal articulation 
there is pressure on these veins since they are in close relation with it. 
The vertebral, at this level, drains the recti and obliqui muscles in rela- 
tion, pericranium, and, through the lateral spinal, the upper cervical 
spinal cord. Often, these veins, by means of an emissary vein through 
the posterior condyloid foramen, are brought in relation with the lateral 
sinus. The blood from the pons Varolii, medulla oblongata and a part of 
the upper part of the spinal cord passes into the sinuses of the brain 
that are in relation. 

The rami spinales veins drain a part of the cord, its coverings and 
the vertebrae. The result then of a lesion would necessarily be a venous 



APPLIED ANATOMY. 



25 



disturbance in the parts drained by the vessels that are compressed. 
This venous congestion affects nutrition of nerve cells located in the 
affected segments, hence an atlas lesion, by affecting drainage of the 
first and second cervical segments, disturbs the function of the nerves 
arising from them. 

The arteries in relation with the atlas are the vertebral and its lateral 
spinal branches which go to the cervical spinal cord. The vertebral, 
after passing up through the foramen in the transverse process of the 
atlas/makes an abrupt change in its direction by curving backward and 



RECTUS CAPITIS 
LATERALIS 



,BASILAR ARTFRY 
'RIGHT LEFT VERTEBRAL ABTCRY 




STYLOID PROCESS 
FrRSTCERVlCAt N 
SECOND CERVICAL N 
THIRD CERVICAL H 
VERTEBRAL VEIN 



RECTUS CAPITIS 
POSTICUS m'n 



RTERU PRINCEPS 
CE RYIC1S ART 

SEMISPINALS 



Fig. 4. — Showing the course of the vertebral artery. Note the curve around the 
superior articular process of the atlas on account of which lesions at the occipito- 
atlantal articulation readily affect it. 

inward behind the articular process. It passes through a foramen 
formed by the posterior occipito-atlantal ligament into the spinal canal. 
It then becomes intra-cranial by passing up through the foramen mag- 
num. It joins with its fellow and forms the basilar. Before uniting 
to form the basilar there is given off the rami spinales, posterior men- 
ingeal, anterior and posterior spinal and the posterior inferior cerebellar. 
The rami spinales supply the muscles and spinal cord. The posterior 
meningeal supplies the bone and dura mater of the occipital fossa. The 
anterior spinal joins the corresponding artery on the opposite side and 



26 



APPLIED ANATOMY. 



runs the entire length of the spinal cord, being reinforced by branches 
from the vertebral, ascending cervical, intercostal, lumbar, ilio-lumbar 
and lateral sacral which follow the corresponding nerves into the spinal 
canal and accompany the nerve roots into the substance of the cord. 
The posterior spinal remain separate, extend the entire length of the 
spinal cord and are similarly reinforced. Church says that the arterial 



RECTUS CAPITIS 
POST. MINOR 

RECTUS CAPITIS 
POST. MAJOR 



TRACHE.LO MASTOID 




SUR OBLIQUE 
INT OBLIQUE 



.* SPLENIUS CAPITIS 



Fig. 5. — Showing deep muscles of back of neck. These muscles are commonly 
contractured in upper cervical lesions and can be palpated as cord-like bodies which 
are tender on pressure. The vertebra are approximated by such contracture. 

twigs from these arteries entering the cord are of the "terminal variety 
and therefore do not anastomose. " The posterior inferior cerebellar 
supplies the medulla oblongata, a part of the cerebellum and the fourth 
ventricle, internal ear and cerebrum especially the occipital and tem- 
pero-sphenoidal lobes. 

The vertebral arteries are affected by a lesion of the occipito-atlantal 
articulation. Pressure on these arteries is the most common effect. 
As a result the parts supplied by the artery are likely to be affected un- 
less the anastomosis is complete, which thing is almost impossible on 



APPLIED ANATOMY. 



27 



CQMPLE XUS 



-RECT. CAP POST. WN. 



\ RECT. CAP POST. M J 



ANASTOMOTIC wrr H GRT. OCC I PITA L 
INT. AND EXT. CAROTID BRAS. 




ANT N 



SUP. CERV. 
GANGLION 
LARYrt66AL BRAHC 
2? CERVICAL 

! CARDIAC BRA. 

LOOP 



BRA.TOMASTOID 
AND 

To OCCIPITO-ATLANTO ART'N 
ERTEBRAL PLEXUS 

R C.A.WN 

VAGUS 

PHARYN6EAL.BRA. 
'stOSSAL 
-/-RECT CAP. 
LATERALIS 

GLOSSOPHARYNGEAL 

HYPOGLOSSAL 

BRA.TOGLOSSO- 
r, PHARYNGEAL 

GENIO- 



DESCENDENS >■ 

DESCENDENS 
HYPOCLOSSI 



ANSA CERVICALIS 



OMOHYOID 




THYRO HYOID, 
(STERNOHYOID 




Fig. 6. — First cervical segment of the spinal cord showing branches and 

connections. 



28 APPLIED ANATOMY. 

account of the branches being end arteries. The parts to suffer are the 
spinal cord and its coverings, medulla, pons, cerebellum and quite a 
large part of the cerebrum, especially the centers for vision. Recalling 
the function of these parts one can readily see an explanation for dis- 
turbances of the eye and other parts whose nerves have their cells of 
origin here. Vaso-motor nerves accompany and control the size of 
these arteries. The source of the nerve energy transmitted by these 
nerves is a point below perhaps in the upper thoracic segments of the 
spinal cord. 

The nerves directly in relation with the atlas are the cerebro-spinal 
nerves and their branches and communications coming from the first 
and second cervical segments, the sympathetic gangliated cord with 
some of its branches and communications, and the vertebral plexus. 
The anterior and posterior divisions and grey ramus with the vaso-motor 
nerves of the lateral spinal arteries carry impulses that pass through the 
intervertebral foramen between the occiput and atlas while the gangliated 
cord with its ganglia and branches are in relation with the transverse process. 

In all lesions affecting the occipito-atlantal articulation the sub- 
occipital nerve is involved. This nerve supplies the recti capiti, ob- 
liquii, complexi, genio-hyoid and infra-hyoid muscles. It supplies the 
mastoid process of the temporal bone, the occipito-atlantal articulation 
and, in some cases, sensation to the back part of the head. Some say 
that it helps to supply the meninges of the brain. It communicates 
directly with the second cervical nerve, ninth and twelfth cranial, superior 
cervical ganglion and the vertebral plexus around the vertebral artery 
in relation. 

In all lesions involving the atlanto-axial articulation the second 
cervical nerve with its branches is involved. 

A lesion at the occipito-atlantal articulation affects the grey ramus 
which connects the gangliated cord with the suboccipital nerve. This 
nerve carries vasomotor and secretory impulses. A filament is given 
off which joins the recurrent nerve which is distributed in the interior 
of the spinal canal. Langley says "Intermixed with the pale fibers in 
the grey rami communicantes there are also a few medullated fibres of 
varying size, even in regions where distinct white rami do not exist." 

The superior cervical ganglion may be affected by an atlas lesion 
but not so readily as by lesions lower in the neck. This ganglion is sit- 
uated in relation with the anterior part of the transverse .process of 



APPLIED ANATOMY. 29 

the second and third, sometimes the first cervical vertebra. Clinically 
an atlas lesion readily affects this ganglion, judging from the various 
conditions and effects ordinarily attributed to such lesion. Anatomically 
the superior cervical ganglion is affected either by direct pressure from 
the displaced bone or indirectly from contracture of muscles or tighten- 
ing of tissues, or through interference with ascending branches which 
are in relation with the upper cervical vertebrae. 

The ganglion being located anteriorly to the transverse process, it is 
the exception for it to be affected by direct pressure, but common for 
its functions to be disturbed by a tightening of tissues in relation with 
it. These tissues are always irritated and put on a tension by sublux- 
ations of the upper cervical vertebrae. This tightened condition affects 
the ganglion by direct pressure on it, pressure on its branches and com- 
munications, and by pressure on the blood-vessels supplying and drain- 
ing it. 

This ganglion gives off ascending branches which divide into an 
external or carotid plexus and an internal or cavernous plexus. The 
external connects with, or send filaments to, the fifth and sixth cranial 
nerves, external carotid artery, dura mater, Gasserian ganglion, the 
tympanic plexus through the small deep petrosal, and the sphenopala- 
tine ganglion. The internal connects with, or sends filaments to, the 
third, fourth, ophthalmic division of fifth cranial nerves, internal carotid, 
ophthalmic and central artery of retina, ciliary ganglion and the pitui- 
tary body. The internal branches of this ganglion send filaments to 
the ninth and tenth cranial, superior and external laryngeal, pharyngeal 
plexus and superior cardiac. The inferior branches connect with the 
middle cervical ganglion. The anterior sends filaments to the carotid 
artery and its branches, sub-maxillary ganglion and the middle meningeal 
artery. Its branches connect with the ninth, tenth and twelfth cranial 
and help to supply the nose, tonsils, brain, meninges, medulla, spinal 
cord and heart. 

The function of the superior cervical ganglion seems to be that of a. 
relay station for impulses reaching it from points below. Langley says: 
"The upper part of the thoracic spinal cord sends out fibers by the an- 
terior roots of the spinal nerves of this region. The fibers make no halt 
at the ganglia until they reach the superior cervical ganglion. This is 
a relay station for the sympathetic nerve supply of the whole of the 
head; in it all the nerve fibers form nerve endings each nerve 



ACCOMPANYING BRANCHES OF [NT. CARO'iiU ARTERY 
TO SIXTH 



TO CILIARY GANGLION 
TO FIFTH N. 



TO TYMPANIC BRA.OF GLOSSOPHARYNGEAL 



to ganglion of root of vagus 

to petrosal ganglion of 
glosso-pharyngeal 

from first cervical nerve 
from second cerv. im. 
from third cerv. n 
from fourth cerv.n. 
from fifth cerv.n 
From sixth cerv. im. 
from seventh cerv.n 

plexus surrounding 
vertebral art. '-^ 

from eighth cerv.n 

plexus sur 

rounding 
subclavian art 
ano its branches 

from fl rst thoracic 'n 

fromsecondtho.n 



VIDIAN N.TOSPHENO- 

- PALATINE GANGLION 



"TO THIRD N 

TO GANG. OFTRUNKpr VAGUS LARGESUP PETROSAL FROM FACIAL 
■— -TOHYPOGLOSSAL 



UNITING WITH BRANCHES OF VAGUS 

ANO GLOSSO-PHARYNOEALTO 
FORM THE PHARYNGEAL PLEXUS 




CARDIAC BRANCHES FROM VAGUS 
AND RECURRENT LARYNGEAL 



NFERIOR CARDIAC 



. TO LEFTANT 
( \_si? PULMONARY 
NERVES 



CARDIAC PLEXUS 



FROM SEVENTH 
THORACIC N. =?As 



Fig. 7. — Scheme of the cervical sympathetica with their connections, (.after Flower). 



APPLIED ANATOMY. 31 

cell sends off a nerve fiber, which runs to the periphery, where it branches 
and supplies a group of unstriated muscles or gland cells. On the course 
of a nervous impulse from the spinal cord to the periphery, there are 
then two nerve cells, one with cell body in the spinal cord, the other 
with cell body in the local sympathetic ganglion. " Few if any impulses 
are generated in the superior cervical ganglion; most if not all of them 
so far as it can be determined, come from the upper thoracic and lower 
cervical spinal cord. Without doubt there is a nerve line of communica- 
tion existing between the various parts of the head and face and the 
upper thoracic spinal cord and the superior cervical ganglion, and the 
ganglion acts as a relay station, it being on the line of communication. 
According to Langley, stimulation of thesuperiorcervicalganglioninthe 
cat produces the following effects: (1) dilatation of the pupil, (2) re- 
traction of the nictitating membrane, (3) contraction of the blood-ves- 
sels of the skin and mucous membrane of the head and of the salivary 
and other glands, it being marked in the conjunctiva, the iris, and in 
most animals in the skin and adjoining mucous membrane of the nose 
and lips and in the mucous membrane of the hard palate; and (4) secre- 
tion from the salivary glands, the lachrymal glands, the glands of the 
mucous membrane of the mouth, nose and pharynx, and from the sweat 
glands of the skin where these occur. This ganglion also exerts a tonic 
effect on the vaso-constrictor fibers, the pupillo-dilator and the motor 
to the non-striated muscle fibers which it supplies." 

Clinically, an atlas or upper cervical lesion produces effects in the 
parts mentioned above; that is, there are vasomotor, secretory, motor, 
or trophic disturbances in some part supplied by fibers coming from 
the superior cervical ganglion. This lesion may be irritative. In such 
cases it can be substituted for the means used in experiments in which 
the ganglion is stimulated or inhibited. At any rate the lesion -breaks 
or otherwise impairs the line of communication existing between the 
base of supply, the nerve cells, and the periphery, some part above. 
The blood-vessels of the head, face and throat, the involuntary muscles, 
and the glands' and secretory membranes all receive their impulses 
almost, if not entirely, from or rather by way of, the superior cervical 
ganglion. 

The vertebral plexus of nerves surrounds the vertebral artery and 
is affected in atlas lesions. This plexus is formed by the lowest cervical 
and first dorsal ganglia which give off slender grey branches which ascend 



32 APPLIED ANATOMY. 

along the vertebral artery furnishing to it and its branches and the 
basilar arteries, vasomotor impulses. Since this artery supjjlies the 
spinal cord, medulla, pons Varolii, cerebellum and part of the cerebrum, 
especially the center for vision, and since the amount of blood passing 
through it is controlled by the size of the vessel and the vertebral plexus 

POST CERERRAL V POST. COMMIh MIDDLE CEREBRAL ^ 

llCATING / IB' 

SUPCERESELLA V / ANT CEREBRAL /.%gj ? SUPRAORBITAL 

RASILAR \\\ //OPHTHALMIC -^^^^fSif .FRONTAL 
^g&Sj^^^ KB!Efc5f .---"^\ B'^- NASAL 

■>■■;■■ • s«i»L-. 

vJ^SZZTk -~ff- J$P* ! si\\S -WjP^^^X^-^i 36 ^' FACIAL 

VERTEBRAL- - .. _ LWLi^^^ba^^/'. : ^\,\-5N&"\ 'w/]?5Bfe- -?$% 

*$§& '£?" ASCG PALATINE 

profunda j v^s^/ ■■/^"i'li^r^^s^r^ 

\WIv-<* ' /W-/' IKPWSSS 55 ^ P^S&lJil I ■! K'M — • POST AURICULAR 

'''faiKM ' *LjT^$l**Ji^L-L l-lh — — occipital 

' '"/ l^^RSk-Ti " :v - ^5-" FACIAL 

\«\t\/W''lJ^Bt^ = *Ci>»*TJliE_^-i- -^^""Vl — LINGUAL 

VvJ £V„ J /rt ?Bt«--'-*-- --flff ^— COMMON CAUUi 

I (, ig. 8. — Showing the arteries of the cervical region. Note their relation to the 

vertebra?. 

controls its size, it therefore; follows that many disorders of the above 
mentioned structures will arise in case the vertebral plexus is disturbed. 
It is disturbed by all atlas lesions, since it passes through the fora- 
men and bends around the articular process, therefore being subject to 
pressure in all deviations of the atlas. 




APPLIED ANATOMY. 33 

The writer has noted in dissections of this artery that it is surrounded 
by connective tissue that is closely adherent to it and the parts of the 
atlas with which it is in relation. Any irritation of this connective tissue 
therefore, as in sprains or other lesions of the neck, would affect this 
artery. 

Branching from the anterior division of the suboccipital nerve and 
the ramus communicans are two filaments which unite to form the 
recurrent or meningeal nerve. It enters the spinal canal through the 
intervertebral foramen where it is distributed to the vertebrae and lig- 
aments, to the blood-vessels of the cord and to the dura mater (Luschka). 

In lesions of the atlas the recurrent nerve in relation is affected, 
this in turn producing trouble with the parts supplied, viz., the atlas 
and its ligaments, the dura mater in that part of the canal and the blood- 
vessels of the spinal cord in relation. 

The first cervical segment of the spinal cord is likely to be affected 
by an atlas lesion since this lesion interferes with its nutrition, drainage 
and vaso-motor nerve supply, the vessels and nerves being in relation 
with the atlas. This segment contains the cells which give rise to nerve 
impulses that supply the recti capiti, obliqui, complexi, genio-hyoid and 
infra-hyoid muscles. A disturbance of this segment would cause atony 
or contracture of some or all of the above named muscles. Every mus- 
cle fibre has a cell in the spinal cord which supplies it with tone. If 
this cell is inhibited there is loss of muscular tone; if this cell is stimulated 
there is increased tone or contracture. An altered circulation to the 
cell will cause some pathological effect in the muscles supplied. This 
segment furnishes a pathway over which impulses pass to or 
from the upper part of the neck, occipito-atlantal articulation, and the 
various blood-vessels in relation that supply the muscles, ligaments, 
vertebra?, meninges and spinal cord. The vaso-motor nerves connect 
with predominant center in the bulb. 

A great many muscles attaching below the atlas connect the head 
and spinal column. By their contracture the head is drawn tightly down 
on the spinal column. As a result the tissue between the head and atlas 
is thinned and the foramina lessened in size, thus impinging on some or 
all of the structures passing over the posterior arch of the atlas. Such 
a lesion is diagnosed by the tightened condition of the muscles, absence 
of irregularity at the atlas, and by approximation of the head and atlas. 
Tenderness is usually present in and around the joint. 



34 APPLIED ANATOMY. 

The atlas is subject to lesions similar in character to lesions of any 
vertebra. In nearly all cases the occipito-atlantal articulation is not 
involved, but the head and atlas are abnormally moved on the axis; 
that is, the lesion in atlas subluxations is in the atlanto-axial articula- 
tion. It is the exception for there to be any relative change between 
the atlas and occiput other than approximation. 

Torsion is the most common atlas lesion. This may come from 
sudden or abnormal movement of the head or it may follow muscular 
contracture, especially that of the splenitis capitus. This form of lesion 
is diagnosed by tenderness at the articulation, irregularity of the trans- 
verse processes, they not being symmetrical, and by impairment of 
mobility of the joints involved, that is the patient has trouble in ex- 
tending the neck or rotating the head through an arc of 180 degrees. 

Posterior luxations of the atlas are practically impossible except 
to a very slight degree, such being prevented by the odontoid process of 
the axis. Anterior luxations are fairly common. Such are diagnosed 
by the way the patient holds the head and by palpation of the trans- 
verse and articular processes. 

"The relation of the pharynx to the cervical vertebrae makes it 
possible to diagnosticate vertebral fractures and dislocations by inspec- 
tion and palpation through the oral cavity; for example, from the rela- 
tion of the anterior arch of the atlas to the posterior pharyngeal wall, 
it is clear that when the atlas is dislocated anteriorly it may be recognized 
as a hard prominence in the posterior pharyngeal wall. It will also be 
readily understood that diseases of the cervical vertebra? (such as caries) 
may lead to retropharyngeal abscess or to perforation and the extrusion 
of jDieces of bone into the pharynx."* 

This does not apply so well to the minor subluxations of the upper 
cervical vertebra?, but even in such cases it is possible to palpate, by way 
of the oral cavity, the irregularity caused by an anterior subluxation of 
the atlas or other cervical vertebra? but not advisable in the average 
case. 

The transverse processes are abnormally near the angle of the jaw 
and the articular processes quite tender, with undue prominence of 
tissue over them. 

Lateral deviations are unusual, and in case one transverse process 
is more prominent than its fellow it is probably due to its greater length, 
the two rarely being of the same length. Such a luxation is diagnosed 

*Schu]tze's Applied Anat. p. 58. 



APPLIED ANATOMY. 



35 



partly by the prominence of the process and partly by the tenseness of 
tissues in relation. 

Approximation of the head and atlas is very frequent. In such 
cases the lesion is commonly at a point distant from the atlas. 

Atlas lesions result from trauma, especially sudden and unexpected 
twists of the head, muscular contractures and from Injury during birth. 
Anything that carries the head or neck beyond the normal range of move- 
ment will produce a lesion of some or all of the cervical articulations. 
There is often found as a complication, a sprained condition of the lig- 
aments of the affected joint and contracture of the muscles in relation. 

Pain is present to some degree in all cases but varies in amount in 
different cases on account of the difference in the degree of the injury 



CRT.OCCIPITAL 
TRAPEZ 



.„' V-'«sif4»- ^".-V. v^f: MF^^Ww, '£ ■ Jt— BRANCH-TO 




VERTEBRAL ARTERY cu 
POST PRIM.DIV. FIRST CE 
INFERIOR OBLIQUE ^ 
RECTUS CAR POST- MJ 



COMPLEXUS cur 
CREAT OCCIPITAL 
POST. PRIM.DIV FIRSTCERVICAL 
NASTOMOTIC 
■THIRD CERVICAL 
THIRD OCCIPITAL 
INFERIOR OBLIQUE 



Fig. 9. — Showing course of great occipital nerves. (After Testut) 
on this nerve is often effective in the relief of headaches. 



Pressure 



and manner of its occurrence. In the average case, nature soon 
overcomes most of the acute effects and the condition settles into a 
chronic state. Almost any form of disease of any or every viscus or 
structure above the point of lesion may occur, the effects coming on 
gradually in most instances, that is, the lesion acts as the predispos- 
ing cause while the abuse is the exciting one. In lesions involving the 
occipito-atlantal and occipito-axoidal articulations there will be some 
impairment of practically all the structures of the head and face, 



36 



APPLIED ANATOMY. 



but the eye and its appendages are most frequently and noticeably 
affected. 

The eye affections follow such lesions as a result of the disturbance 
of the various nerves that carry motor, trophic, sensory and secretory 
impulses to and from the eye and the upper spinal segments. These 

CLOBEOFTHEEYE 
CILIARY NERVES 
OPTIC NERVE 

CILIARY 

OPHTHALMIC OR 
LENTICULAR GANG, 

CASSERIAN GANG, 



UPPER 
LOWER 
BRANCH 




CAVERNOL 
'LEXUS 



1 S1XTH OR ABDUCENT M 
INT. CAROTID PLEXUS 



CERVICAL GANGLION- 



FIG. 10. — Showing nerve pathway from superior cervical ganglion to the eye 
and to the second, third, fifth and sixth cranial nerves. 

impulses, that is the motor, secretory, trophic and vaso-motor impulses 
arise as low in the spinal cord as the third dorsal segment and pass to 
the eye via the gangliated cord, superior cervical ganglion,, ascending 



APPLIED ANATOMY. 37 

branches thence over the various connecting fibers to the eye and its 
appendages. 

Motor disturbances of the eye and its appendages result from 
lesions that hinder the origin of the motor impulses or their transmission 
to the eye. These impulses arise in the spinal cord and pass to the eye 
by way of the vertebral plexus and superior cervical ganglion. Atlas 
lesions interfere with the line of communication existing between the 
upper segments of the spinal cord and consequently the muscle fibers 
become weakened. The point of obstruction is the result of direct 
pressure from the subluxated bone but more commonly from a tightening 
of the adjacent tissues. It has not been satisfactorily demonstrated 
that motor impulses pass from the spinal cord to the voluntary muscles 
of the head and face yet it has been demonstrated that some of the 
cranial nerves derive at least some of their impulses from the spinal 
cord. It has been satisfactorily demonstrated that trophic impulses 
travel from the spinal cord to the different parts of the head and face 
and in this way the motor effects can be explained. 

Strabismus follows a weakening of one of the ocular muscles thus 
permitting the unopposed muscles to draw the eye to the opposite side. 

Convergent squint is due to a paralysis or other impairment of the 
sixth cranial nerve. This nerve receives a part of its impulses from 
the cavernous plexus. These impulses are principally trophic in charac- 
ter but according to some, they are partly motor as well. Judging from the 
immediate effects of certain forms of lesions on the eye, the writer 
is of the opinion that motor as well as trophic impulses reach the 
sixth nerve. by way of the cavernous plexus. 

The common forms of strabismus are due to disturbances of the 
oculo-motor nerve which receives impulses directly from the spinal cord 
by way of the cavernous plexus. Paralysis of the fourth cranial nerve 
permits the drawing of the eye-ball up and inward; this being an unusual 
type of strabismus. Since the cavernous plexus acts as a medium of 
transmission of trophic and other impulses from the spinal cord to the 
above named cranial nerves, it follows that any lesion affecting it will 
cause disturbances in the parts supplied by its branches and communica- 
tions. A lesion of the atlanto-occipital or atlanto-axoidal articulations 
will interfere with this transmission of impulses. 

The most frequent bony lesion that affects the origin and exit of 
these impulses is an upper thoracic one. It is a well known fact that 



38 



APPLIED ANATOMY. 



often a blow on or other injury of this part of the spinal column, will 
produce strabismus almost instantly. A case was reported to the writer 
in which the physician could produce at will a convergent squint by 
pressure at the spine of the second thoracic vertebra. 




Fig. 11. — Showing the vertebral arches and occipital bone cut away, exposing 
the cord, etc.; 6th C. G., Ganglion on 6th cerv. n.; S. A. N., Spinal Accessory n.; 
V. A., Vertebral Artery; V., Vagus n.; G., Ninth n.; Tri., Fifth n.; T., Trochlearis; 
C. Q., Corp. Quad.; L., Lingula C'erebelli; F. & A., Facial and Auditory; H., Hypo- 
glossus; 2nd C. G., ganglion on 2nd n.; L. D., Lig. Denticulatum. 



APPLIED ANATOMY. 39 

Myopia and hypermetropia in acquired cases, are similarly ex- 
plained that is they are due principally to trophic disturbances caused 
by neck lesions. Accommodation of the eye is controlled by the action 
of the ciliary muscles. Contraction of these muscles increases the con- 
vexity of the crystaline lens. If this is of such a degree that the rays 
are focussed before they reach the retina, it is called myopia. If ac- 
quired it is the result of an irritative lesion that causes contraction of the 
ciliary muscles but if congenital, it is due to the marked convexity of 
the lens from faulty development. If these muscles become weakened, 
the lens becomes flattened and the rays of light are focussd behind the 
retina or rather they are not focussed soon enough and the patient has 
trouble in adapting the eyes to near-by objects. In either myopia or 
hypermetropia little can be done aside from the wearing of lenses, if 
the condition is a congenital one, but if acquired, the conditions can be 
benefitted by the neck treatment in quite a large majority of all cases. 
It has been noted by the writer that many patients treated for other 
disorders caused by neck lesions, have had to change their lenses, the eyes 
becoming remarkably stronger under the neck treatment. This effect 
applies better to, or rather is more common in cases in which the eyes 
are weak but in some apply to cases of near and far sight edness. This 
clinical fact demonstrates that neck lesions affect the eye, that impulses 
pass from the spinal cord to the eye, and that almost any acquired dis- 
ease of the eye may be benefitted by appropriate neck treatment in 
which adjustment of the vertebral articulations is secured. 

Astigmatism, which is commonly characterized by an unequal curva- 
ture of the corneal meridians, can be explained in a similar way, if it is 
an acquired case. The ciliary nerves supply the cornea and crystalline 
lens. These nerves may be affected by atlas lesions in that impulses 
to them pass through the superior cervical ganglion, which is involved 
in lesions of the upper cervical vertebrae. These impulses are carried 
by way of the ascending internal branch of the superior cervical ganglion. 
The plexus thus formed (cavernous) sends a branch to, or rather forms 
a root of, the ciliary ganglion. 

The branches of the ciliary nerves supply the cornea forming a 
plexus around the periphery and forming in the substance of the cornea 
the stroma plexus. The function of these nerves is not well known but 
it is supposed that they exert a trophic and motor effect on the cornea, 
thus controlling its degree of curvature. Morris says that the cornea is 



40 APPLIED ANATOMY. 

richly supplied with nerves, particularly in its most superficial layers. 

Abnormal dilation of the pupil, mydriasis, may come from the 
same cause and is similarly explained. 

McLachlin in his applied anatomy says in speaking of the relation 
of the sympathetic nerve to the eye: "In addition to the ordinary vaso- 
motor action, the sympathetic is the motor nerve to the dilator pupillae 
and also to Muller's muscle — a layer of non-striped muscular tissue 
bridging across the sphenoidal fissure. The center is probably situ- 
ated in the medulla, but the fibers pass down the cord some little dis- 
tance (cilio-spinal region) leaving it through the last cervical or the 
first two dorsal nerves and entering the corresponding ganglia of the 
sympathetic trunk, up which they pass to the base of the skull, then 
along the plexus around the internal carotid artery (carotid and cavern- 
ous plexuxes), pass along the sixth nerve and then join the ophthalmic 
division of the'fifth, forming part of its nasal branch, and thence through 
the long ciliary twigs of the nasal nerve to the radiating fibers of the 
iris. " An upper cervical lesion will interrupt or disturb in some way the 
passing of these impulses, since they go by way of the cervical sym- 
pathetic, which is in relation with the cervical vertebra?. Clinically it 
is not unusual for dilatation or contraction of the pupil to accompany 
neck and upper thoracic lesions. 

The opposite of mydriasis which is called myosis, follows from in- 
hibition or paralysis of the sympathetic or irritation of the third cranial. 
Myosis is usually divided into irritation myosis and paralytic myosis. 
Irritation myosis most frequently comes from diseases of the brain and 
meninges. The paralytic form comes from cervical lesions and lesions 
of the cord above the dorsal vertebra. These effects are explained by 
the relations and connections of the superior cervical ganglion with the 
third cranial nerve. Deaver says "Ligation of the vertebral produces 
dilation of pupil on same side. " If ligature of this artery and plexus 
produces an effect on the pupil, lesions which affect the vertebral artery 
or its plexus will also have an effect. Clinically we are warranted to 
make the statement that atlas lesions affect the vertebral artery and 
plexus. 

Ptosis follows paralysis of the third cranial nerve. This paraly- 
sis comes from neck lesions which involve the superior cervical ganglion 
or vertebral plexus. The internal division of the ascending branches 



APPLIED ANATOMY. 41 

of the superior cervical ganglion transmits impulses to the third nerve 
with which it is directly connected. 

Blepharospasm, which consists of a spasmodic contraction of the 
orbicularis palpebrarum muscle, may be caused by an atlas or other 
cervical lesions affecting the anterior branches of the superior cervical 
ganglion, which connect directly with the seventh nerve. 

This condition is usually accompanied by choreic symptoms, such 
as a histrionic spasm and some jerking of the head, that is, of the parts 
supplied by the seventh cranial nerve which is the principal one involved. 

Vaso-motor troubles of the eye and appendages are explained by 
the fact that the superior cervical ganglion either contains the vaso- 
motor centers, or transmits vaso-motor impulses, for the head and face. 
Upper cervical lesions affect this .ganglion, either increasing or decreas- 
ing the impulses, and therefore disturb the size of the blood-vessels of 
the eye and eye-lids since it is controlled by the condition of this ganglion. 

Pterygium consists of a dilated condition of the vessels of the con- 
junctiva often resulting in its thickening, most frequently at the inner 
canthus. 

This dilated condition comes from some interference with the trans- 
mission of vaso-motor impulses to these vessels. Conjunctivitis is 
caused in a similar way. Granulated lids, an advanced form of con- 
junctivitis, and characterized by the formation of minute abscesses, 
occurs in chronic eases. A sty or hordeolum is a slightly different form 
of vascular disturbance but it may come from a similar lesion; most 
cases however come from infection at the point of a diseased hair follicle. 
This infection acts as the exciting cause, the lesion being the predis- 
posing cause. The vaso-motor impulses to the above parts of the eye 
are carried by way of the plexus around the ophthalmic artery, the 
branches of which supply blood to the eye. This plexus is derived from 
the cavernous plexus which in turn is derived from the superior cervical 
ganglion, at least the impulses pass through this ganglion. Contrac- 
tured muscles of the neck cause congestion of the eye. The patient 
says that he has cold in the eye. The explanation is like that mentioned 
above, that the vaso-motor impulses to the eye are inhibited by con- 
tracture of the cervical muscles hence a slowing of the current of the 
blood and increase in size of the lumen of the vessels. 

The ophthalmic artery through its branches almost entirely con- 
trols the amount of blood to the eye and its appendages. The inner- 



42 APPLIED ANATOMY. 

vation of its branches comes from the cavernous plexus, which surrounds 
the artery and sends off filaments with each of its branches. Conges- 
tion of one part is commonly accompanied by congestion of other parts; 
for example, the eye-lids are usually red and slightly inflamed in cases 
of congestion of the eye ball, as in cases of headache from overuse of the 
eye. In cases of alcoholic intoxication, the eyes and the tip of the nose 
become red on account of the action of the alcohol on the vaso-motor 
nerves, which is an inhibitory one. 

Nutritional disorders of the eye, such as cataract, keratitis and spots 
before the eye or muscae volitantes, occur from cervical lesions, since the 
fibres which carry trophic impulses to the eye pass through the superior 
cervical ganglion. Atrophy of the optic nerve is brought about in a 
similar way. The optic nerve is pierced by an artery called the arteria 
centralis retinae which artery is innervated by the principal terminal 
branch of the "cavernous plexus. 

Secretory disturbances, such as lacrymation, follow disturbances 
of the ophthalmic division of the fifth nerve. This nerve receives im- 
pulses from and is more closely connected with the cervical sympathetic 
than any other of the cranial nerves. These impulses pass by way of 
the superior cervical ganglion and over both the internal and external 
divisions of the ascending branches. 

Summary of eye. Atlas lesion disturb the function of the superior 
cervical ganglion. This ganglion possibly originates some and trans- 
mits mo'st, if not all, of the impulses to the eye by way of its ascending 
and anterior brandies. These branches connect with the second, third 
and fourth, ophthalmic division of the fifth, sixth and seventh cranial 
nerves, which nerves have to do with the eye and its appendages. The 
vertebral plexus of nerves is affected by atlas lesions. This nerve con- 
trols, or at least has to do with, the nutrition of the floor of the fourth 
ventricle at which place are located the cells of origin of nearly all the 
nerves of the eye. Also this plexus controls nutrition of the occipital 
lobe of the brain in which is the center for vision. 

Cervical lesions, and particularly lesions of the articulations of the 
atlas and axis, produce ear disturbances. Earache or otalgia is caused 
by a disturbance of the sensory innervation of the external auditory 
meatus, which is supplied to a great extent by the auriculo-temporal 
branches of the fifth cranial and the auricular branches of the vagus. 
Pain is most commonly due to pressure. In earache the 'pressure is 



APPLIED ANATOMY. 



43 




CAROTID ARTERY 

SUP. CERVICAL GANGLION 

SMALL OCCIPITAL 

GREAT AURICULAR 

PHRENIC 

MIDDLE CERVICAL GANGLION 

INT. CERVICAL GANGLION 

F1RSTTHORACIC GANGLION 

VERTEBRAL PLEXUS 



ANSA VIEUSSEUII^ 
Fig. 12. — Showing cervical nerves and their sympathetic connections. 



44 APPLIED ANATOMY. 

most frequently a vascular one, that is congestion of the auditory canal, 
especially of its nerves. Exposure, which so often in children results in 
contracture of the cervical muscles, is in this way responsible for many 
cases. These muscular contractures affect the cervical sympathetic 
ganglia which are directly connected with the fifth and tenth cranial, 
which supply sensation to the affected part, the fifth by way of the 
ascending branches which connect with the Gasserisji ganglion; the 
tenth by direct filaments that go from the superior cervical ganglion to 
the vagus. Atlas and other cervical lesions predispose to muscular 
contractures, after which the exciting cause, such as exposure, the more 
readily affects the part. There are other causes, viz., decayed teeth 
and a dislocated inferior maxilla, in which the fifth nerve is involved. 
Hilton cites cases in which a decayed tooth produced chronic earache. 
All vascular disturbances of this part of the ear are very painful on ac- 
count of the almost inelastic lining of the external auditory canal. In 
acute attacks heat applied to the back of neck will relieve, sometimes cure, 
if the trouble is entirely due to contracture of cervical muscles, which is 
the exception. The correction of neck lesions will cure most chronic 
cases since these lesions are responsible for the trouble. 

Tinnitus aurium is a condition in which the tympanum is in a state 
of too great tension which results in constant vibration. The impulses 
generated by the passing of the blood through the internal carotid artery, 
which is in relation, set in motion the tightened ear drum. The tone 
of the ear drum is controlled by the tensor tympani muscle. Patholog- 
ically, the desiccation of cerumen or contracture of this muscle results 
in an increased tension. The stopping of the Eustachian tube, which 
prevents the entrance of air into the middle ear, allows the external 
air pressure to force the ear drum inward thus interfering with normal 
vibration. Sound is supposed to be carried by waves. These waves 
strike the ear drum and set it in motion. If the ear drum is unusually 
tense it will vibrate longer and more easily than it otherwise would. 
Neck lesions affect the superior cervical ganglion which, by way of its 
ascending branches, connects with the fifth nerve, which by way of the 
Otic ganglion sends filaments for innervation of the muscle that con- 
trols the degree of contraction of the tympanum, the tensor tympani 
muscle. The stapedius is supplied by the seventh, which connects with 
the superior cervical ganglion by way of its anterior branches. This 



APPLIED ANATOMY. 45 

connection is probably only a vasomotor one by which the nerve is 
nourished. 

The mucous membrane of the ear is supplied by the tympanic 
plexus which is formed by filaments from the ninth, carotid plexus, 
great superficial petrosal and small superficial petrosal (Morris). The 
superior cervical ganglion directly connects with nearly all the above 
nerves. In vascular or secretory disturbances of the mucous mem- 
brane of the ear the tympanic plexus is implicated, usually it is at fault, 
and since its vaso-motor and secretory impulses pass through or arise 
in the superior cervical ganglion a lesion of the atlas or axis may cause 
catarrh of the ear, a lessened or increased secretion, otitis media, or 
even abscess. 

The auditory nerve, as far as we can ascertain, has no direct connec- 
tion with the superior cervical ganglion. In the aqueductus Fallopii 
' it connects with the seventh and its blood supply is in a measure regu- 
lated by the vertebral plexus. The internal auditory artery, a branch 
of the basilar, supplies the internal ear. The vertebral plexus supplies 
the basilar artery and its branches. Lesions of the upper cervical ver- 
tebrae affect the vertebral plexus, hence would in many cases affect the 
blood supply of the internal ear. Vascular disturbances of the middle 
ear come from lesions affecting the innervation of its arteries, which 
are: the tympanic branch of the internal maxillary, petrosal of the 
middle meningeal, and stylo-mastoid of the posterior auricular. The 
vaso-motor nerves of these arteries come by way of the superior cervical 
ganglion by way of its anterior and superior branches. The anterior 
sends filaments to the middle meningeal artery and its branches; the 
ascending branches supply the carotid and its branches. 

Deafness, partial or complete, may come from impairment of the 
mechanism receiving the sound impulses or from an impairment of the 
mechanism conveying them. The first is due to disease of the auditory 
nerve, the second usually to disturbance of the tympanum or ossicles. 
Neck lesions, as pointed out above, affect both. To differentiate be- 
tween the two, use the sound test. If the patient can hear at all the 
auditory nerve is not paralyzed ; if patient can not hear watch or tuning 
fork, when placed in relation with the ear but can hear it when placed 
between teeth or against mastoid, the trouble is in the sound-conveying 
mechanism. 

Summary. Sensory disturbances of the ear follow cervical lesions 



46 APPLIED ANATOMY. 

affecting directly or indirectly the vagus or fifth cranial; disturbances 
of the tympanum from lesions affecting the fifth, seventh or ninth cranial 
nerves; disturbances of the inner ear from cervical lesions affecting the 
vaso-motor supply which comes from the vertebral and carotid plexuses. 

The nose may be affected as a result of atlas or other cervical 
lesions. Catarrh of the nasal mucous membranes is the most common 
affection. 

Catarrh is a condition characterized by congestion of a mucous 
membrane with disturbed secretions. This congestion is most frequently 
the result of vaso-motor inhibition which permits an increase in size of 
the blood-vessels affected. This vaso-motor disturbance in the head 
and face comes from neck lesions. The connection is traced through 
the ascending branches of the superior cervical ganglion and their con- 
nection with the fifth cranial, the branches of which supply the nasal 
mucous membrane. The ophthalmic and internal maxillary arteries 
through their branches supply most of the nasal mucous membrane, 
and these arteries are supplied by the cavernous plexus and anterior 
branches of the superior cervical ganglion. A simple experiment would 
clinically prove the connection between the neck and nose. Expose 
the back of the neck to a draught. Within a few minutes the nose will 
begin to feel stopped and coryza sets in. The thermic stimulation 
causes the cervical muscles to contract. This contraction interferes 
with the passing of vaso-motor impulses through the sympathetic. 
Since the nose gets its vaso-motor supply from this source its mucous 
membrane necessarily suffers. If the atlas or axis is displaced there is 
chronic congestion of the nasal mucous membrane and we call it chronic 
catarrh. These lesions predispose to muscular contracture of the neck, 
that is, the muscles more easily contract, hence a very slight thermic 
stimulation would readily affect them. On this account a case with 
cervical lesions and in a bad climate is hard to cure. 

Hay fever, being a vaso-motor disease, is explained in a similar way. 
The cervical lesions impair the passing of nervous impulses to the nasal 
mucous membrane. It becomes diseased, thus more irritable, and 
certain kinds of stimuli affect it more readily than others. The pollen 
of flowers acts as an exciting cause, the lesion being the predisposing 
cause. Change of climate may relieve because the exciting cause is 
removed, or rather the patient is removed from the exciting cause, but 
not cured. As in other cases in which cures are effected, the predis- 



APPLIED ANATOMY. 47 

posing cause, the bony lesion, must be corrected. This lesion is most 
often found at the articulations of the atlas and axis. In general, all 
vaso-motor and secretory disturbances in this region are similarly ex- 
plained. 

Anosmia may come as a result of disturbance of the fifth nerve 
since a certain amount of secretion is necessary to the normal sense of 
smell. 

Enistaxis may also come from neck lesions. The application of 
cold to the back of the neck will often stop it, this indicating a connection 
between the neck and the nose. The explanation is that the cold has a 
tonic effect on the vaso-motor nerves controlling the blood-vessels of the 
nose. 

The various affections of the brain most often come from neck le- 
sions. This is explained by the fact that the vaso-motor supply arises 
in or passes through the cervical sympathetic. These impulses thus 
generated follow the plexuses around the arteries, viz., vertebral and 
carotid arteries and their branches. The amount of blood in these ves- 
sels is controlled by their size. Their size is controlled by the condition 
of the vaso-motor nerve supply to them. If lesions exist which dis- 
turb this there must be some effect in the part supplied. Cervical le- 
sions do affect these vaso-motor nerves, hence the vascular and sensory 
disturbance. Although many cerebral troubles come from other sources, 
such as abuse, many come from lesions in the neck. Apoplexy, cerebral 
softening, congestive headache, motor and sensory disturbance, such as 
spasms and pain, depend on the amount and character of the blood 
sent to the brain. 

According to Langley,it has not been definitely demonstrated that 
the blood-vessels of the brain have vaso-motor nerves but according to 
the observations of many, there seems to be no doubt about it. In 
speaking of the blood-vessels of the pia mater Landois says: "The blood- 
vessels of the pia mater are naturally in part under the influence of the 
vaso-motor nerves accompanying them; in part their size may be in- 
fluenced from remote parts of the body. Irritation of the sympathetic 
affects only the vessels of the same side, but does not alter the blood 
pressure upon the other side. Paralysis of the vaso-motor nerves, also 
by means of narcotics, causes dilatation of the vessels. The vessels 
contract strongly in death. " From observations made in clinic cases 
it seems to be demonstrated beyond a doubt that the vessels of the 



48 



APPLIED ANATOMY. 



meninges and possibly those of the brain substance have nerves which 
have their origin in the spinal cord, at least lesions of the spine affect 
the circulation of blood through these vessels. 

The vaso-motor,motor and secretory supply to the face comes from 
or is controlled to a great extent by the cervical sympathetic. The 
vaso-motor impulses travel by ■nay of the superior cervical ganglion, 
anterior and ascending branches, to the carotid artery, thence over 




Fig. 13. — Showing connections of superior cervical ganglion; the upper cer- 
vical; and 9, 11 and 12 cranial nerves with the carotid arteries and the pharynx. 
1, 2. 3, 4, first four cervical nerves; II hypoglossus; V., vagus; G. P. , glosso-pharyngeal ; 
I-C, internal carotid; E. C, external carotid; G., superior cervical ganglion. (After 
Cunningham). 

facial branches to the face. Sometimes we are inclined to the belief 
that the nuclei of the seventh nerve are affected by vascular changes, 
these following neck lesions affecting the vertebral artery. 

Since it has not been conclusively demonstrated that any motor 
impulses pass to the voluntary muscles of the head and face by way of 



APPLIED ANATOMY. 49 

this ganglion, or at least the physiologists disagree about it, we are 
forced to the conclusion that these motor effects that undoubtedly come 
from neck lesions, are the results of vaso-motor disturbances that affect 
the nutrition of the nerve cells or as stated above, the nuclei of origin 
of the seventh nerve. 

In regard to the passing of motor impulses to voluntary muscles of 
the eye Landois says: "The motor fibers for the unstriated muscles of 
H. Muller in the orbit and the lids and for the external rectus, pass in 
part through the dorsal nerves from the first to the fifth (in the cat)." 
These impulses pass by way of the superior cervical ganglion; that is 
according to this, it does send, by way of its ascending branches, im- 
pulses to voluntary muscle fibers, since the external rectus is a volun- 
tary muscle. 

Sensory disturbances follow lesions affecting the fifth cranial nerve. 
These sensory disturbances are explained by (1) the effect of lesion 
on the blood supply or nutrition of the cells of origin of the fifth cranial 
nerve and (2), disturbance of its long or descending root which is sensory 
and runs as low in the spinal cord as the third cervical segment. The 
cervical lesion affects the circulation in the cervical spinal cord where 
the cells of this root of the fifth cranial nerve are disturbed. 

Under vaso-motor disorders of the face we have classed eruptions, 
blotches, pathological blushing and anemia. Under motor disturbances, 
Bell's paralysis, tic douloureux and histrionic spasms. Under sensory 
affections, facial neuralgia, toothache and sensory paralysis. 

The above mentioned nervous and vascular distribution and con- 
nections explain these various troubles since atlas and other cervical 
lesions affect all the nerves mentioned. This has been proven clinically 
as well as anatomically. Secretory disturbances may follow cervical 
lesions, the most striking being hemidrosis, that is sweating of a lateral 
half of the face. The fifth cranial is supposed tocontrol secretion of sweat 
of the head and face. This nerve connects with the cervical sympathetic. 

The writer has treated a few cases of hemidrosis and with uniform 
success. In all the cases, there was found a lesion at the atlanto-axoidean 
articulation. In some of these cases, only a few treatments were neces- 
sary to reduce the lesion and thus effect a cure. 

The pharynx is supplied with blood by the ascending pharyngeal, 
ascending palatine branch of facial, and the posterior palatine from 
the internal maxillary. The nerves, vaso-motor, motor and sensory, 



50 APPLIED ANATOMY. 

are derived from the pharyngeal plexus which is formed by the vagus, 
glosso-pharyngeal and branches from the cervical sympathetic. The 
principal disease is pharyngitis which consists of an inflammation of 
its mucous membrane. Most frequently the congestion preceding and 
accompanying the inflammation is from a vaso-motor disturbance. 
This comes from a variety of causes, but the cervical lesions are most 
important in chronic sore throat. Referring to the arteries, it is 
seen that the vaso-motor supply would be affected by cervical lesions 
since the vaso-motor impulses arise in or pass through the cervical 
sympathetic, thence to the pharynx by way of the ninth and tenth 
cranial nerves. Dysphagia and "sore throat" are secondary to the 
inflammation. 

The tonsils are often affected by neck lesions, either through their 
nerve or blood supply. Their nerve supply is from the ninth cranial 
and Meckel's 'ganglion. Both of these nerves are connected with the 
superior cervical ganglion. The ninth cranial gets most of its motor 
impulses from the upper spinal cord. The nerves following the arteries 
are. many, since the tonsil is exceptionally vascular. The external 
carotid by way of the ascending pharyngeal, the facial, through the 
tonsillar and ascending palatine, the lingual and the internal maxillary 
send branches to them. These arteries are supplied with vaso-motor 
impulses through the superior cervical ganglion, by way of the ninth 
cranial hence vascular disturbances in the tonsil when this ganglion is 
affected. , 

The larynx, which forms the entrance to the respiratory tract and 
is the organ for the formation of the voice, is affected by cervical lesions. 
The nerve supply to the larynx is through the superior and recurrent 
or inferior laryngeal nerves. These connect by way of the vagus with 
the superior cervical ganglion and cervical nerves. 

The innervation of the hyoid muscles comes almost entirely from 
the upper three cervical segments by way of the cervical plexus. These 
muscles when contractured draw the hyoid bone out of normal position 
and the voice is affected. The blood supply comes from the superior 
and inferior thyroid arteries. The superior is a branch of the external 
carotid, hence is innervated by branches of the cervical sympathetic. 
The inferior thyroid is a branch of the thyroid axis and is innervated by 
the inferior cervical and stellate ganglia. The veins, the superior, 
middle and inferior thyroid, empty into the internal jugular. 



APPLIED ANATOMY. - 51 

The salivary glands may be affected by cervical lesions. The 
parotid gland is innervated by the facial, great auricular, glosso-pharyn- 
geal, by way of the auriculo-temporal branch of the fifth and the carotid 
plexus. All these nerves connect with or are supplied by impulses 
from the cervical sympathetic system. 

Some secretory impulses arise in the upper thoracic spinal cord, 
pass out over the anterior nerve roots, common nerve trunk, anterior 
division and white ramus, into the gangliated cord, thence upward by 
way of the superior cervical ganglion. 

It also may be affected through its blood supply or drainage. 

The other salivary glands are in a similar way affected by a neck 
lesion. 

The mastoid cells are innervated by a branch from the suboccipital 
nerve. Lesions of the occipito-atlantal articulation always involve this 
nerve, hence the effect on the mastoid cells. 

Atlas lesions often irritate the nerve innervating the rotator muscles 
of the head. This results in chorea or other forms of disease character- 
ized by spasmodic contractions of the cervical muscles. It is a well 
known fact that chorea or some form of tic, comes oftenest from lesions 
in the upper cervical region. The explanation is that the lesion inter- 
feres, by pressure or other means, with the regular transmission of motor 
impulses to the muscles of the neck. There being a spasmodic trans- 
mission of these nerve impulses, there is a spasmodic effect characterized 
by irregular muscular contractions. 

Spasms may also be caused by atlas lesions. In such cases, per- 
haps the medulla is affected as a result of the lesion interfering with its 
blood-supply which is controlled by the vertebral vessels and plexus of 
nerves. 

Epilepsy may come from a similar cause if the higher centers are 
involved. The circulation to the brain is governed to a certain extent 
by the superior cervical ganglion hence any vascular disturbance, of 
which epilepsy is one, may come from a lesion involving it. 

Summary of the atlas. Lesions of the atlas involve the atlanto- 
axoidal articulation oftener than the occipito-atlantal. When this 
articulation is disturbed the cervical sympathetic system is impaired. 
The superior cervical ganglion sends filaments to, or communicates 
with, all the cranial and upper four cervical nerves, hence the varied 
effect of a lesion involving it. This ganglion is in relation with the 



52 



APPLIED ANATOMY. 



atlantoaxial articulation and would be affected by a lesion of it. The 
vertebral plexus is also in relation and would necessarily be involved 
by a lesion. As a result the spinal cord, medulla, pons, cerebellum, 
pituitary body, fourth ventricle and a part of the cerebrum would be 
disturbed by an atlas lesion. 

Vaso-motor effects occur from atlas lesions in all parts supplied by 
the superior cervical ganglion and vertebral plexus, since these impulses 
pass through the ganglion and possibly the plexus. Motor effects in 
the involuntary muscles, that is the smooth muscle fibers, result from 
effect of lesions on the superior cervical ganglion through which these 
impulses pass on their way from the spinal cord to the muscles. The 
motor effects on the voluntary muscles are best explained by the dis- 
turbance of circulation to the motor cells in the brain. . In proportion 



Articular Surface 
for Ant. Arch of Atlas 




Fig. 14. — Showing front view of axis. Note the superior articular surfaces. 

to the trophic disturbance of these cells, so is the effect on the muscles 
supplied. The vaso-motor nerves control the amount of blood to, hence 
the trophic condition of, the cells. Some of the secretory and probably 
all vaso-motor effects from atlas lesions, are explained by disturbance 
of the superior cervical ganglion, since the secretory and vaso-motor 
impulses to the glands above, pass through this ganglion. The trophic 
effects are explained by the vaso-motor disturbances. The sensory ef- 
fects are explained by the disturbance of nutrition of the sensory cells 
of origin of the long or descending root of the fifth cranial, and by the 
fact that the ascending branches of the superior cervical ganglion con- 
nect with the Gasserian ganglion and thus the pain is a referred one. 
As in motor disorders the effect on the sensory nerves is explained by 
the trophic disturbances of the cells giving origin to those nerves. 



APPLIED ANATOMY. 53 

In the explanation of the effects of an upper cervical lesion we 
assume that the superior cervical ganglion is affected. Clinically there 
is no doubt about it. If the lesion affects this ganglion the. rest of the 
explanation is simple. In all cases of lesions of the articulations of the 
atlas, the adjacent tissues are affected and I believe that the best ex- 
planation of the distal effects is that the tightening of the tissues dis- 
turbs the function of the ganglion. The continued drawing of the mus- 
cles and ligaments interferes with the function of all structures in rela- 
tion. 

THE AXIS. 

The axis, so named because it forms a pivot upon which the head 
and atlas rotate, is the strongest and next to the atlas the most peculiar 
vertebra in the cervical region. The most striking peculiarity is the 
odontoid process which represents the displaced body of the atlas. 
The check ligaments, which limit rotation of the head, are attached to 
it. This process is of interest in that in hanging or in dislocation from 
any cause it is thrown directly against the spinal cord, the transverse 
ligament being broken. The lamina? are exceptionally strong, being 
thick and prismatic on cross section. The spinous process is very large, 
markedly bifid and deeply grooved on its under surface. This process 
forms an important osteopathic landmark of the neck. The superior 
facets are placed over the pedicles and the anterior root of the transverse 
processes. They are nearly circular, slightly convex and face upward 
and outward. The second nerve passes out posterior to the facet which 
is true only of the atlas and axis. The inferior facet is not directly 
beneath the superior as in other vertebrae but posterior, thus resulting 
in the weight of the head being transmitted through an angle instead 
of a straight line. The transverse processes are short, sometimes 
rudimentary, and are perforated by the foramen for the passage of the 
vertebral artery. 

The atlanto-axoidal articulation permits of nearly all movements, 
the facets being very shallow. Rotation of the head and atlas on the 
axis is the most important and most marked. In a supposed lesion of 
this articulation a test of mobility should be made, there being some 
restriction to the normal degree of rotation of the head if a lesion exists. 

The principal landmark of the axis is the bifid spinous process. It 
is ordinarily the first bone to be palpated below the occiput in the median 



54 



APPLIED ANATOMY. 



line of the neck. The articular processes can quite distinctly be out- 
lined and particularly so if a lesion of the atlanto-axoidal articulation is 
present. In such cases there is a prominence of the joint, which is best 
palpated midway between the spinous and transverse processes, which 
is partly the result of the irregularity and partly the result of a thicken- 
ing of the muscles and ligaments over it. 

The ligaments involved by an axis lesion are those uniting the axis 
to the atlas, the occiput and the third cervical. 

Those uniting the atlas and axis are the anterior and posterior 




POST. COMMON LIGT. 

OCCIPITO AXOID LIGT. 

i -MIDDLE ODONTOID LIGT. 

— ODONTOID OR CHECK 

VERTICAL PORTION OF 

■TRANSVERSE OR 
CRUCIA.LLIGT. 

ACCESSORY BANDOF ATLANTO 
AXIAL CAPSULAR LIGT. 



Fig. 15. — Showing the vertebral arches cut away exposing the ligaments connect- 
ing the axis and atlas and occiput. 

atlanto-axoidean, two capsular, the transverse ligament and the atlanto- 
odontoid. 

The atlanto-axoidean ligaments are thin, but strong, elastic mem- 
branes. In that strength with mobility is necessary, these ligaments 
are well adapted. 

The posterior atlanto-axoidean is attached above to the lower edge 
of the posterior arch of the atlas and inferiorly to the upper edge of 
the lamina of the axis. It has a layer of elastic tissue in it. It is in 
relation with the inferior oblique muscles and is perforated by the sec- 
ond cervical nerve. This is of interest in that in subluxations of the 



APPLIED ANATOMY. 55 

axis this ligament is more or less involved hence a disturbance of this 
nerve as it passes through the ligament. 

The anterior atlanto-axoidean is in its middle portion, a continu- 
ation upward of the anterior common spinal ligament, and it in turn is 
continued upward and helps to form a part of the anterior atlanto- 
occipital ligament. 

The important ligaments uniting the occiput with the axis are the 
check or lateral occipito-odontoid and the central odontoid or sus- 
pensory. 

The capsular are important in that they are necessarily injured in 
all dislocations since they completely surround the atlanto-axoidean 
articulation. 

The most important of these ligaments is the transverse, so far as 
the life of the individual is concerned. It is attached on either side to 
a tubercle on the lateral mass of the atlas and passes behind the odon- 
toid process, thus dividing the spinal foramen into two parts, the an- 
terior containing the odontoid process and the posterior, the spinal cord, 
if this ligament were to become broken, the odontoid process would 
be forced into the spinal cord and instant death result. Posteriori}', 
there is found a vertical portion which is attached above to the anterior 
margin of the foramen magnum, and on this account it is called the 
crucial ligament. ■&• 

This latter ligament is sometimes injured in hyper-extension of the 
head. Morris says: "The suspensory ligament is tightened by exten- 
sion and relaxed by flexion or nodding; the lateral odontoid not only 
limit the rotatory movements of the head and atlas upon the axis, but 
by binding the occiput to the pivot, round which rotation occurs, they 
steady the head and prevent its undue lateral inclination upon the spine. " 

These ligaments restrict movements of the head and help to poise 
it on the spinal column. In speaking of the occipito-atlantal and the 
atlanto-axoidean joints, Morris further says: "The ligaments which 
pass over the odontoid process to the occiput are not quite tight when 
the head is erect, and only become so when the head is flexed. If this 
were not so, no flexion would be allowed; thus muscular action, and not 
ligamentous tension, is employed to steady the head in the erect posi- 
tion. It is through the combination of the joints of the atlas and axis, 
and occiput and atlas (consisting of two pairs of joints placed symmetric- 
ally on either side of the median line, while through the median line there 



56 APPLIED ANATOMY. 

passes a pivot, also with a pair of joints) that the head enjoys such free- 
dom and celerity of action, remarkable strength and almost absolute 
security against violence, which could only be obtained by a ball and 
socket joint; but the ordinary ball and socket joints are too prone to 
dislocations by even moderate twists to be reliable enough when the 
life of the individual depends on the perfection of the articulation, 
hence the importance of this combination of joints. " These twists do 
take place which impair the joint itself and some or all of the structures 
in relation. A lesion will cause tenderness in, thickening of, and some- 
times rupture or at least a stretching of these ligaments. These liga- 
ments are subject to sprains as are the ligaments of other more freely 
movable joints. Moullin, in speaking of sprains of the back and neck 
says: "One of the most singular features in connection with these 
sprains is the way in which the backbone itself and the muscular and 
ligamentous structures around it are overlooked and ignored. Even 
in the ordinary accidents of every day life there is a great tendency to 
lay everything that is serious or lasting to the spinal cord. In railway 
cases there is no hesitation at all; if any serious result ensues it must 
be the result of damage this structure has sustained, or of inflamma- 
tion following it; little or no attention is paid to anything else. Yet it 
is difficult to see why the other structures should enjoy immunity. 
The vertebral column may be strained, especially in the cervical and 
lumbar regions; the ligaments torn or stretched; the nerves bruised or 
crushed; the smaller joints between the segments twisted and wrenched; 
the muscles detached from their bed and torn across or thrown into such 
a state of cramp that they become rigid and unable to act with freedom; 
or the fibrous sheath which contains them and helps to secure the bones 
laid open and filled with blood. " Undoubtedly these ligamentous, and 
muscular disturbances as well as bony lesions are often overlooked. 
In trauma in which there are marked lesions, these ligaments are torn 
at many points and such heal with difficulty. 

The muscles in relation with and which would be affected by an 
axis lesion, are the longus colli, inferior oblique, rectus capitus 

POSTICUS MAJOR, SEMISPINALS COLLI, INTERSPINALES, MULTIFIDUS 
SPIN^E, SCALENUS MEDIUS, SPLENIUS COLLI, INTERTRANSVERSALES, 

levator anguli scapula and transversalis cervicis. The lesion 
affects the muscles in one of two ways, either by interfering with the 
nerve and blood supply or by change of position of the axis thus ap- 



APPLIED ANATOMY. 57 

proximating or separating the origin, and insertion. This effect of 
change of position will be considered here; that from nerve disturb- 
ances under effect on nerve. 

The longus colli has to do with flexion, rotation and lateral flex- 
ion of the neck. The vertical portion is attached anteriorly to the 
lateral part of the body of the axis and is the principal part directly 
involved by axis lesions. When impaired, there is difficulty in flexion of 
neck or else the neck is held in position of partial flexion, that is, exten- 
sion is incomplete, the patient not being able to look directly upward. 

The inferior oblique has its origin in the side of the spine of the axis 
and is inserted in the tip of the transverse process of the atlas. If 
irritated it approximates the origin and insertion, that is the atlas is 
tilted or the transverse process is twisted backward. The head with 
the atlas is drawn to one side and backward. This muscle seems to be 
affected in all lesions of the atlas and axis and can be palpated quite 
deeply in, as a hard, contractured band in relation with the articular 
process of the axis, its course being up and out. I believe it is more fre- 
quently affected than any other of the cervical muscles. 

The rectus capitus posticus major has to do with extension of the 
head and is involved in the various tics and choreas. In disturbances 
of the finer movements of the head this muscle is usually at fault. 

The semispinalis has to do with extension, lateral flexion and rota- 
tion to the opposite side. This muscle is also involved in most of the 
motor disturbances of the head and neck. 

The interspinales extend the neck and have to do, when irritated, 
with approximation of the vertebra?. 

The cervical portion of the multifldus spinse muscle arises from the 
articular processes of the fourth to the seventh cervical vertebrae and is 
inserted into the spines of the vertebrae above. It has to do with ex- 
tension, lateral flexion and rotation to opposite side. It is one of the 
deep muscles of the neck and its condition has to do with the circula- 
tion of the spinal cord. If it becomes contractured, there is obstruc- 
tion to venous drainage of the spinal cord in that region. It is also in- 
volved in chorea, hysteria and spinal meningitis. Curvatures of the 
spine in general, come in part from atrophy of this muscle. 

The splenius is important on account of the part it plays in many 
cases of torticollis, especially recent cases. McClellan says: "The action 
of the splenii aids that of the sterno-mastoid muscles. When the two 



58 



APPLIED ANATOMY. 



muscles on both sides contract together they assist in holding the head 
erect. The action of either of them (the two portions working together) 
is to draw the head and the upper cervical vertebra? toward its own side. 
When this contraction is permanent it may produce wry neck and may 




Fig. 16. — Showing the muscles that have to do with producing torticollis. Note 
the sterno-mastoid and splenius. 

be confounded with the action of the opposite sterno-mastoid muscle, 
which produces the same effect. " Lesions of the axis affect the splenius 
usually producing contracture of it from which results impaired move- 
ment of the head and neck. 



APPLIED ANATOMY. 59 

The interspinales, when affected and working together, produce 
impaction of the vertebrae. 

The levator anguli scapulae, when affected either draws upward 
the scapula or extends and laterally flexes the neck. Osteopathically 
it is of importance in that it is involved in most cases of "cold in the 
head" it being contractured and tender. 

The scalenus medius arises from the upper surface of the first rib 
between the subclavian groove and tuberosity and is inserted in the 
posterior tubercles of the transverse processes of the lower six cervical 
vertebras. It is the strongest of the scaleni muscles and has to with 
lifting the rib when the fixed point is above, or lateral flexion of the 
neck when the fixed point is below. Axis lesions impair its function, 
usually producing contracture of it. The most common effect is ele- 
vation of the posterior part of the first rib. (See lesion of first rib for 
effects.) 

Axis lesions impair the above named muscles by change of posi- 
tion. The effects are, disturbance of movements of neck, spasmodic 
contraction or twitching, especially involvement of the finer movements 
of the head, torticollis, secondary lesions and disturbance of circula- 
tion of the spinal cord, cervical portion. 

The arteries directly involved by an axis lesion are the vertebral 
and its branches, muscular and spinal. Those indirectly involved are 
the terminals of the vertebral and the carotid arteries and their branches. 
This involvement comes through their nerve supply, viz., vertebral 
plexus and superior cervical ganglion, which are affected by an axis 
lesion. The lesion produces pressure on the arteries in relation thereby 
lessening the amount of blood passing through them. The muscles in 
relation are improperly nourished, and the spinal cord is deprived of 
its normal arterial supply. Varied effects follow these conditions. 
(For effect on vertebral see arteries under atlas.) 

The veins that would be affected by an axis lesion are those in re- 
lation. They are the vertebral, lateral spinal and muscular, which 
latter drain the muscles in that region. The vertebral drain the cer- 
vical spinal cord, cervical vertebras and muscles. The lateral spinal 
drain the cord and empty into the vertebral. An axis lesion especially 
affects the size of the intervertebral foramina, usually lessening it. As 
a result the lateral spinal veins are compressed, venous congestion of 
the spinal cord follows which impairs its function, sometimes increas- 



60 



APPLIED ANATOMY. 



ing, sometimes decreasing activity, this depending on the degree of con- 
gestion, length of standing and function of part involved. The chronic 
effect is one of lessened activity. A certain amount of localized toxemia 
follows congestion. This may irritate the cells in the cord thus pro- 



CONNTS WITH5M/ILL OCCIPITAL N 
CONN'TS WITH IstCERVICALN 
SPLEN1US- CAPITIS 

TRACHELO- MASTOID- 



SUPERFICIAL FASCIA OF SCALP 
ABOVE SUP. CURVED LINE 

AURICULAR BR \ I 

' ,.GK. OCCIPITAL Vi 



OCCIPITAL BRA 

COM with 6R OCCIP.iGRTAURIC 
MASTOID BRA'S 
VAGUS 




Fig. 17. — The second cervical segment showing its branches and connections. 



APPLIED ANATOMY. 61 

ducing pain and muscular contracture. The lesion would also affect 
the vertebral. Since these veins drain the cord, vertebrae and muscles 
in relation, congestion of these parts follows a lesion of the axis. 

The nerves involved by axis lesions are the second and third cer- 
vical nerves, recurrent meningeal, gangliated cord or superior cervical 
ganglion and vertebral plexus and their branches and connections. 
Indirectly all branches of these nerves may be affected by an axis lesion. 
Only the nerves in relation with the atlanto-axial articulation will be 
considered here. 

The second cervical nerve, like those below it, divides immediately 
on its exit, into an anterior and posterior division. The posterior pri- 
mary division in turn divides into a small external and large internal. 
The external supplies the muscles in relation. The internal is the great 
occipital nerve which is important in osteopathic therapeutics in that 
in headache in the back part of the head this nerve is supposed to be 
involved. It pierces the complexus and trapezius muscles after which 
it divides into terminal branches which ramify in the superficial fascia 
of the scalp as far as the posterior part of the parietal bones. Morris 
says that "occasionally one branch reaches the pinna and supplies the 
skin on the upper part, of its inner aspect." It also communicates 
with the first and third cervical nerves. Pain in the area supplied by 
great occipital nerve must be in that nerve. Hilton says: "Suppose 
a patient to comjjlain of pain upon the scalp, it is essential to know 
whether that pain is expressed by the fifth nerve or by the great or 
small occipital. Thus pain in the anterior and lateral parts of the head 
which are supplied by the fifth nerve, would suggest that the cause must . 
be somewhere in the area of the distribution of the other portions of 
the fifth nerve. So, if the pain be expressed behind, the cause must 
assuredly be connected with the great or small occipital nerve, and in 
all probability depends on disease of the spine between the first and 
second cervical vertebrae." From our viewpoint this disease is a sub- 
luxation at this point and Hilton's idea bears out our practice. 

The anterior division of the second cervical nerve, unites with the 
first, third and fourth to form the cervical plexus. The branches of 
this plexus that receive their impulses from the second cervical segment- 
are the small occipital, great auricular, superficialis cervicis and mus- 
cular branches to the muscles in relation. 

The small occipital follows the posterior border of the sterno- 



62 



APPLIED ANATOMY. 



mastoid muscle and gives off twigs to the skin over the upper portion 
of the triangular space. After perforating the deep fascia it reaches 
the scalp where it terminates in cutaneous filaments. It breaks up 
into three branches, the auricular, occipital and mastoid terminal 
branches. 




Fig. 17. — Showing sensory innervation of back of head (Hilton). G. O., great 
occipital; S. O., small occipital; A. T., auriculo-temporal. Headache from cervical 
lesions are referred in general, to these areas. 

The auricular branch of the small occipital, is distributed to the 
skin of the scalp and communicates with the great occipital. The mas- 
toid, is distributed to the skin over the mastoid process. The occipital 
branches ramify over the occipitalis muscle and supply the skin of the 
scalp. They communicate with the great occipital nerve. 

In axis lesions the small occipital nerve is usually involved, hence 



APPLIED ANATOMY. 63 

a sensory effect in the above named points of distribution of the nerve. 
Headache with tenderness of the scalp is very common when this nerve 
is involved. 

The great auricular divides, in relation with the sterno-mastoid 
muscle, into three branches, — mastoid, auricular and facial. The mas- 
toid supplies the integument covering the mastoid process, communi- 
cating with the mastoid branch of the small occipital. The auricular 
supplies the back and lower part of the pinna. The facial is distributed 
to that portion of the integument of the face over the parotid gland. 
Some filaments enter the gland and communicate with the lower divi- 
sion of the facial nerve. When this nerve is involved, as it often is in 
axis lesions, pain will be referred to the area supplied by the above named 
branches. Hilton cites a case of a "kernel" or enlarged gland lying 
close to the second nerve, causing earache. Muscular contracture will 
cause a similar effect. 

The superficial or transverse cervical nerve has to do with supplying 
sensation to the integument of the lateral and anterior portions of the 
neck. It communicates peripherally with the cervical branch of the 
facial. 

The muscular branches supply the sterno-mastoid, rectus capitus 
anticus major, longus colli, genio-hyoid, the infra-hyoid muscles, ob- 
liquus inferior, complexus, splenius and trachelo-mastoid muscles. 

Axis lesions affect the muscular branches receiving impulses that 
pass out through the second cervical foramen, therefore these muscles 
would be affected, that is contracted or relaxed. The sterno-mastoid 
would thus be affected by an axis lesion. The most common effect is 
that of contracture producing torticollis. This muscle has its origin 
in the manubrium and clavicle and is directed up and back to the mas- 
toid process and adjacent portion of occipital bone. It flexes laterally 
the head and neck, rotates the face to opposite side, and when act- 
ing conjointly with its fellow, raises the manubrium and clavicle or flexes 
head or neck. In torticollis from contracture of this muscle, the face is 
drawn toward the sound side. In some cases the disease is supposed 
to be congenital, but I think most of such cases occur at childbirth, for 
in such cases much traction, or rather improper traction, is exerted on 
the neck and a lesion of the axis is produced, which in turn affects the 
second nerve, hence this muscle. The rectus capitus anticus major has 
to do with slight flexion of the neck, hence this movement would be 



64 APPLIED ANATOMY. 

abnormal in axis lesions. In some there is a fibrillary twitching as a 
result of irritation of this nerve. 

The longus colli has been considered above. The genio-hyoid 
muscle by contracting, draws the hyoid bone upwards and forwards or 
pulls the lower jaw downward. As a result of a lesion involving the 
nerve supply of this muscle, the hyoid bone would be drawn out of place, 
hence disturbances of the vocal organs. The infra-hyoid muscles, viz., 

STERNOHYOID, OMO-HYOID, STERNO-THYROID and THYRO-HYOID, are 

supplied by the second cervical nerve by way of the loop joining the 
hypoglossal nerve. They, as their names indicate, are attached to the 
hyoid bone and by their unusual contraction or relaxation the bone 
assumes an abnormal position. As suggested above, the vocal organs 
would be involved since they are in relation with this bone. Aphonia 
is the most common effect. 

The oblIquus inferior and splenitis have been considered. See 
page 57. 

The complexus is involved in axis lesions, thus interfering with 
extension and lateral flexion of the head and rotation of the face. In 
colds of the head this muscle is usually contractured. 

The second cervical nerve connects with the ninth, tenth, eleventh 
and twelfth cranial nerves and the superior cervical ganglion. The 
vagus is reached by filaments to the lower' ganglion or ganglion of the 
trunk, which is placed below the base of the skull. 

The impulses passing over this nerve go from the superior cervical 
ganglion to the pneumogastric. On this account they are supposed 
to be vaso-motor and secretory in function. From a clinic point of view, 
it appears that motor impulses pass from the ganglion to the vagus 
since vomiting occasionally occurs from a lesion of the axis. In other 
cases seen by the author, asthma and violent attacks of coughing re- 
sulted from the lesion. This nerve filament is in relation with the atlanto- 
axoidean articulation and is affected in some lesions of this joint. 

The eleventh unites in the sterno-mastoid muscle with the mus- 
cular branches of the second cervical supplying the sterno-mastoid. 

This nerve is affected by an axis lesion both along its course and at 
its spinal origin. Contracture of the sterno-mastoid muscle will cause 
it to be impinged on. The spinal portion arises as low in the spinal 
.cord as the fifth cervical segment. The filaments pass out or the lateral 
column of the white matter of the spinal cord and forming a few strands, 



APPLIED ANATOMY. 65 

pass upwards through the foramen magnum into the cranial cavity. 
As soon as it leaves the skull, it communicates with the vagus, and its 
accessory fibers continue into the recurrent laryngeal, cardiac, pharyn- 
geal and superior laryngeal branches. 

The axis lesion interferes with the nutrition of the spinal seg- 
ments in which are located the cells of origin of the spinal portion of 
this nerve, hence the effects on its function. This interference is the 
result of circulatoiy derangements of the supply and drainage of this 
segment. 

The hypoglossal nerve receives fibers from the first and second 
cervical nerves that supply the infra-hyoid muscles. The spinal origin 
of the nerves of these muscles has been proven by experiments on animals. 

The superior cervical ganglion communicates with the second cervical 
nerve by means of a grey ramus uniting with the anterior division. 

The ninth cranial, connects with the superior cervical ganglion by 
a fine communicating filament. This nerve filament is supposed to 
carry vaso-motor impulses from the ganglion to the nerve, hence to 
parts supplied by the nerve viz., the pharynx, tonsils and tongue. 

To summarize -the effects on the second cervical nerve, there would 
be pain in the back of the head, ear, parotid gland and part of face, 
that is headache, earache and neuralgia; torticollis, chorea and various 
other disturbances of the cervical muscles; aphonia, and other impair- 
ments of the voice; various secondary effects on the tenth, eleventh and 
twelfth cranial nerves and structures supplied by them; also some effect 
on the superior cervical ganglion. 

The recurrent meningeal would be affected in a way similar to that 
in atlas lesions. 

The second cervical segment would probably be directly af- 
fected by this lesion. Vascular disturbances of the cord, meninges, 
ligaments and column are the important effects of disturbance of the re- 
current nerve. The effects and diseases caused by the superior cervical 
ganglion have been considered (see p. 31.) This ganglion being in relation 
with the axis is more easily and more commonly affected by an axis 
than by an atlas lesion. 

The vertebral plexus surrounds the vertebral artery and is more 
or less affected by the lesion. This plexus sends filaments over the 
lateral spinal arteries into the cord. The blood supply of the cord, 
perhaps the second segment more than any other, would be affected by 



66 APPLIED ANATOMY. 

disturbance here of the vertebral plexus. The meninges are affected 
in all marked lesions. A part of the coverings of the cord passes out 
with each nerve and is attached to the vertebra, hence would be affected 
by every abnormal change of position. These coverings are also affected 
through the blood and nerve supply. Meningitis and other disturbances 
follow such lesions. The spinal cord is affected through its blood sup- 
ply or by direct pressure, in which case there is usually paralysis of the 
parts below, resulting in death. Arterial supply to and drainage of the 
cord are impaired and, as mentioned above, the cells in the various 
centers fail to properly perform their function. 

Summary. The axis is the most frequently subluxated of all the 
vertebrae, at least the atlanto-axoidean articulation is oftenest affected. 
This comes from the free mobility of this joint and lever action of parts 
above. The articular processes of the axis can be more readily palpated 
than those of the other cervical vertebrae, they being best felt at a point 
about midway between the spinous and transverse processes. A strain of 
the ligaments will cause a thickening, which irregularity may be mis- 
taken for a bony lesion. A unilateral thickening or lump over the artic- 
ular process is indicative, if not diagnostic, of a strain of the ligaments. 
This is quite often but not always accompanied by a subluxation. This 
explains why in many cases in which faithful and persistent work has 
been given the irregularity, the lump or thickening, remains and the 
articulation continues to be tender. Strained ligaments heal slowly. 

An axis lesion may produce almost any form of disease in organs 
and tissues above it. The diseases most commonly associated with 
axis lesions are eye affections, headaches and vascular disturbances of 
the head. 

The vaso-motor effects of this lesion are similar to those of an atlas 
lesion and are explained in a similar way. In addition it might be 
stated here that some of the vaso-motor effects in parts supplied by the 
ninth, tenth and twelfth cranial nerves, are the results of this lesion 
affecting the superior cervical ganglion and its branches of communica- 
tion to these nerves over which the impulses pass. 

The motor effects are most marked in the cervical muscles, the 
throat and hyoid muscles and the involuntary muscle fibers of the eye. 
The secretory, are the same as for an atlas lesion. The sensory and 
trophic effects are best explained through the vaso-motor connections. 



APPLIED ANATOMY. 67 



THIRD CERVICAL. 



The third cervical vertebra is the smallest of the vertebrae. The 
laminae are especially light, thus permitting of fracture which occurs 
oftenest in this vertebra. It is located farther anterior than the other 
cervical vertebrae, partly on which account this region is weak. Mc- 
Clellan says: "The weakest point, not only in the neck but also in the 
entire spirxal column, is between the second and third cervical verte- 
brae." The Superior Facets of the third cervical face upward and 
backward, are slightly concave and somewhat smaller than the cor- 
responding ones of the atlas and axis. The shape of the superior facets 
would permit of almost any form of movement, but antero-posterior 
motion as in nodding the head, is most pronounced. The spinous 
process is shortest of all the vertebral spinous processes and can, in the 
the normal neck, be felt with difficulty unless flexion is used. If il 
cannot be palpated when the neck is flexed, or if it can be palpated with- 
out flexion of the neck, it is ordinarily regarded as abnormal, especially 
so if tenderness is present over the spine or articular process. This 
shortness permits of freer movements. The transverse processes 
are perforated for passage of the vertebral arteries as are those of the axis, 
but are not so well developed as those below, yet are usually longer 
than those of the axis. 

This bone and its articulations are subject to displacement and 
injury as are all vertebrae and their articulations. The most common 
lesions are an anterior or posterior subluxation, or torsion. This ver- 
tebra is possibly dislocated as an individual bone, more often than any 
other cervical vertebra. Usually, in a "lesion" one part of the spinal 
column is moved on another, hence only two articular facets are in- 
volved and it is not so common for both the superior and inferior facets 
to be involved as would be the case in a subluxation of a single vertebra. 
The exception seems to be in the third cervical vertebra, since its most 
common subluxation is one in which it is forced either forward or 
backward, that is, both superior and inferior facets are involved. The 
diagnosis is based on irregularity, tenderness and disturbance of motion. 
In making tests for weak places or lesions in the spine in general, Dr. 
G. D. Hulett advised extreme flexion. In this test there will be pain 
at the weakest points. This can with advantage be used in cases of 
suspected lesions of the neck. 



68 APPLIED ANATOMY. 

The intervertebral discs in the cervical region are not very thick 
but are thicker anteriorly than they are posteriorly. The curve of the 
neck depends on this rather than on the size of the bodies of the vertebrae. 
Curvatures in the cervical as well as in other regions, are partly the re- 
sult of changes in thickness in the intervertebral discs. These discs are 
elastic, have blood-vessels and nerves, and their function is impaired by 
bony lesions of the corresponding vertebrae, and as they become thinned, 
the foramina become smaller. 

The effect of a lesion of the third cervical on the ligaments is sim- 
ilar to that of an axis lesion, that is they become as a rule thicker, and 
tender, which conditions can best be ascertained by palpation over the 
articular facets. The ligaments attaching the third cervical vertebra to 
the axis and fourth, are the regular spinal ligaments while the atlas and 
axis have, on account of the extra strain, special ligaments to reinforce 
the common spinal. The ligaments common to all the vertebrae 
are the intervertebral discs, anterior common, posterior common, 
ligamenta subfiava, capsular, supraspinous, interspinous, and inter- 
transverse. These ligaments quite securely bind the vertebrae together, 
limit the movements of the individual vertebrae, and assist in the pro- 
tection of the spinal' cord and its nerves branching from it. They are 
to a certain extent elastic and are subject to contraction and relaxation 
since they have both blood-vessels and nerves. No detailed description 
of the ligaments common to the spinal column is deemed necessary, 
but attention is called to the intervertebral discs, the capsular and 
supraspinous ligaments. The supraspinous ligament, or ligamentum 
nuchae, in chronic lesions is usually so much thickened that it can be 
readily palpated by pressure directed against the spinous process. The 
best sign of chronic lesions, especially in the thoracic and lumbar regions, 
is a softening and thickening of the supraspinous ligament. In most 
cases these changes are followed or accompanied by a shortening, hence 
approximation of the vertebrae. This in turn thins the discs, lessens 
the size of the foramina and changes the contour of that part of the 
spinal column. 

The principal muscles of importance attached to the third are the 
anterior and middle scaleni, rectus capitus anticus major, longus colli, 
levator anguli scapulae, splenitis, transversalis colli and multifidus spinae. 
All but the scalenus anticus and transversalis colli muscles have been 
discussed. (See page 57.) The scalenus anticus arises, from the an- 



APPLIED ANATOMY. 69 

terior portion of the transverse processes of the third, fourth, fifth and 
sixth cervical vertebrae and is inserted into the tubercle on the upper 
border of the first rib anterior to the groove for the subclavian artery. 
It is of interest in that the first rib is drawn upward against the clavicle 
when this muscle is in a contractured condition, which is often the case 
when the vertebrae to which it is attached are displaced or its nerve sup- 
ply affected. As a result there is trouble from pressure on structures 
by the displaced rib and from disturbance of the sympathetic gangliated 
cord, since the first dorsal and last cervical ganglia are located on the 
head of the rib. 

The arteries involved in lesion of the third cervical vertebra are the 
vertebral and its lateral spinal and muscular branches. The effect here 
is similar to, if not identical with, that outlined under the axis. 

The third cervical segment would probably suffer more than other 
segments, if the lateral spinal branch passing through the third cervical 
foramen were disturbed. This artery, like those from below, passes up 
the sheath of dura mater which envelops the roots of the spinal nerves. 
A lesion of the third cervical vertebra would cause contraction of many 
of the muscles supplied with blood by the muscular branches of the 
vertebral. As a result, circulation through the vertebral and its other 
branches would be impaired. This means a vascular disturbance of 
the cervical spinal cord and perhaps medulla and brain with many pos- 
sible effects ranging from a "cold in the head" to meningitis. 

The veins involved are the vertebral and its spinal and muscular 
tributaries. From this involvement comes congestion of the spinal 
cord and the neck muscles in relation, which is accompanied by various 
symptoms, they depending on the centers involved. 

The nerves involved by a lesion of the third are the third and fourth 
cervical nerves (only the third will be considered here) and their branches 
and communications the superior cervical ganglion, vertebral plexus, 
and the recurrent meningeal. 

The third cervical segment gives origin to the following nerves, all 
of which pass out of the foramen in relation with the articulation of the 
axis and the third; small occipital, great auricular, superficial 
cervical, supra-clavicular, branch of communication to the hypo- 
glossal, third, or smallest occipital, muscular branches, and usually 
a root of the phrenic. 

The small occipital has been considered along with the great auricu- 



70 



APPLIED ANATOMY. 



INTEC'MT OVER BACK OF NECK AMD SCALP. 



trachelO-mastoid 

SPLE.NIUS COMPLEXUS 
POST N ROOTS 

\SPINAL GANG. , 




LEVATOR ANGUL1 SCAPULAL" 
CERVlCALISDESCENDtNSANDDESCHYPOGLOSd! 



PHRENIC N. - " (STERNO-HYOID 

ANSA-CERVICALIS WITH 3RAJS STERNOTHYROID 

OMO-HYOID 
INTEG'MT OVER SHOULDER ANDZ/JDsDELTOID - 
SKIN OF LOWER NECK AND CHESTTO 
LOWER BORDER OF MANUBRIUM 

I PLEURA PERiTOneuM 
PERICARDIUM 
RT.AURICLE 

( LIVER -01 ATHM 
DIAPHRAGMATIC SUPRARENAL CAPSULE 
PLEXUS ( 1M(r VEIMA CAVA 

EbOPHASVJS 



OMIO 



INTEG'l 
BREAST AS LOWAS 
NIPPLE 



FlG . 19.— The third cervical segment showing its branches and connections. 



APPLIED ANATOMY. 71 

lar, and superficial cervical as well as some of the muscular branches. 
The effect on the above named nerves from a lesion of the third cervi- 
cal is very similar to, if not identical with, that from an axis lesion. An 
additional point regarding the superficialis colli nerve might be indi- 
cated here. Deaver says that the ascending branch "sends filaments 
to the external jugular vein, communicates with the inframaxillary 
branch of the facial nerve, and supplies the platysma myoides muscle 
and the skin of the front of the neck as far as the chin. " This is of value 
since certain forms of jerking of the head or chorea are due to spasmodic 
contraction of the platysma myoides. Such spasmodic contractions 
result from an interference with the nerves supplying it, this interfer- 
ence in many cases resulting from a subluxation of the axis or third 
cervical. 

The supraclavicular or descending branch of the cervical plexus 
come almost entirely from the third cervical segment. This nerve 
divides into an internal, middle and external or posterior branch. The 
internal or suprasternal ramifies over and below the inner third of the 
clavicle and terminates over the upper part of the sternum. Some 
filaments are furnished to the sterno-clavicular articulation (Rudinger). 

The middle or supra-clavicular, supplies the integument over the 
forepart of the deltoid and the pectoral muscles as low as the third rib 
and over the upper part of the mammary gland as low as the nipple. 
These filaments communicate with the small lateral cutaneous branches 
of the upper intercostal nerves. 

The external branches innervate the integument over the acromion 
and outer and back part of the shoulder, and above the spine of the 
scapula. In conditions of pain, if cutaneous, in the above areas, this 
nerve is usually involved. Contractures in the neck, and lesions of the 
axis or third, readily affect this nerve which is manifest by sensory dis- 
turbances in the above mentioned areas. 

Deaver says: "Herpetic eruptions in the area of distribution of 
the superficial branches of the cervical plexus (herpes cervico-occipi- 
talis) are occasionally seen. In caries of the cervical vertebra, pain 
may be referred to the areas of the skin supplied by these nerves. It 
is through the descending branches of the cervical plexus that pain is 
referred to the neck in carcinoma of the mammary gland. " Lesions 
of the third cervical vertebra cause pain in the area of distribution of 
the supra-clavicular nerve because it is in relation with the articulation 



72 APPLIED ANATOMY. 

f 

and is irritated or otherwise affected by the subluxation. 

The third or smallest occipital nerve, the inner branch of the pos- 
terior division of the third cervical nerve, supplies the skin of the upper 
part of the back of the neck, and part of the scalp in the region of the 
external occipital protuberance. This nerve is involved in pain in the 
back of the neck, coldness of the part and in boils and carbuncles which 
so frequently attack the back of the neck on account of the great thick- 
ness of the integument. If a lesion of the axis or third cervical vertebra 
exists, the back of the neck is cold a great deal of the time. Coldness 
of this part of the neck is accompanied or followed by nasal catarrh or 
"sore throat. " If the back of the neck is always kept warm, I seriously 
doubt the possibility of one "catching cold" in the head and throat. 
Lesions of the third affect the third occipital, and since it is distributed 
to the back of the neck, this region is in all probability affected, with 
the above predisposition to nasal catarrh. 

The muscular branches coming from the third cervical segment 
supply, at least in part, the following muscles: Rectus capitus anticus 
major, longus colli, trapezius, levator anguli scapulae, sterno-mastoid, 
diaphragm, intertransversales, multifidus spina?, complexus, splenius 
and the infra-hyoid muscles. All of the above named muscles except 
the trapezius and diaphragm have been considered. The usual effect 
on these muscles is that of producing a contractured condition which, 
if unilateral, produces a muscular curvature, but if symmetrical, draws 
the vertebra? more closely together thus lessening the size of the inter- 
vertebral foramina. 

The trapezius, one of the superficial muscles of the back, is of osteo- 
pathic interest in that it is always tender in cases of cold in the head; 
the more severe the attack the more tender the muscle. This area of 
tenderness in colds corresponds to the distribution of the two trapezii 
muscles. By contraction, it draws the head back, flexes the neck to- 
ward the same side and turns the face to the opposite side. If the mus- 
cle is in a contractured state, these movements are impaired, the cir- 
culation through the muscle impeded, the circulation to the spinal cord 
affected and the sympathetic gangliated cord deranged, as is evidenced 
by the vaso-motor changes accompanying and following its contracture. 
The diaphragm will be considered in the discussion of lesions of the fourth 
cervical vertebra (see page 78). 

The nerve communicating with the hypoglossal nerve is frequently 



APPLIED ANATOMY. 73 

involved by a lesion of the third as a result of which the hyoid muscles 
are affected and from this, disturbances of the voice box. The phrenic 
is also involved by this lesion, the effects of which are discussed with 
that of effects on nerves in lesions of the fourth cervical vertebra. 

The superior cervical ganglion is sometimes affected by this lesion 
but not so frequently as by lesions of vertebrae above. For effects see 
page 29. 

The recurrent meningeal, which enters the spinal canal, is nearly 
always affected by the lesion as a result of which, various pathological 
changes take place in the structures innervated by it, viz., the spinal 
cord, meninges, vertebra and ligaments. The vertebral plexus is also 
involved, the effect being similar to that from an atlas or axis lesion. 
The most important effect is that on the eye. According to Deaver, 
contraction of the pupil on the same side follows ligation of the vertebral 
artery. Probably the effect is through the vertebral plexus of nerves 
rather than through the artery. If a ligature will produce an effect, 
lesions of the cervical vertebral articulations will also in some way affect 
the eye. At least the connection between the neck and the eye is proven. 

Lesions of the axis and third affect the vertebral artery and its 
accompanying nervous plexus, hence an effect on the eye. 

The third cervical segment contains several centers of importance. 
Motor centers are located here which control the amount of nerve force 
to and nutrition of the muscles supplied by the third cervical nerve. 
These have been named above. Sensation to the back of the head and 
possibly the face or areas supplied by the fifth cranial are influenced by 
this segment. The explanation is that one of the sensory roots, the 
descending or long root, has been traced to the floor of the fourth ventri- 
cle and to the grey matter in the lower part of the medulla oblongata 
and as low in the spinal cord as the third cervical segment. 

The spinal accessory nerve which is supposed to take the place of 
the white rami in the cervical region, is affected by this lesion on ac- 
count of its spinal origin. Most of the vaso-motor, motor, and viscero- 
motor impulses passing out over the spinal accessory reach the pneu- 
mogastric and are distributed with its branches. The spinal origin of 
the eleventh cranial nerve is as low in the spinal cord as the seventh 
cervical segment. On this account, its cells of origin are affected by 
cervical lesions through interference with nutrition. 

A lesion of the third cervical vertebra will affect the various nerve 



74 APPLIED ANATOMY. 

filaments connecting the superior cervical ganglion, ninth, tenth, eleventh 
and twelfth cranial, and the upper cervical nerves. 

A small filament connects the superior cervical ganglion with the 
ninth. It is supposed to be vaso-motor in function, that is, the vaso- 
motor impulses passing over the ninth are derived, at least in part, from 
the superior cervical ganglion by way of this communicating branch. 
As a result of the lesion there •will be vaso-motor disturbances in the 
parts supplied by the glosso-pharyngeal nerve viz., the tonsils, tongue, 
and throat. 

There are several nerve strands that connect the tenth cranial and 
the superior cervical ganglion. They pass to both ganglia of the nerve, 
the ganglion of the trunk and the ganglion of the root. They are vaso- 
motor in function and furnish the vagus with some if not a majority of 
its vaso-motor impulses. 

The hypoglossal receives vaso-motor impulses from the superior 
cervical ganglion by way of a filament directly connecting the two. 
Langley says in connection with this nerve: "The peripheral part of 
the hypoglossal nerve has a slight vaso-constrictor action on the arteries 
of the tongue. The vaso-constrictor fibres come in part, at any rate, 
from the superior cervical ganglion. It has been supposed that some 
issue with the roots of the hypoglossal nerve but the evidence is not sat- 
isfactory. " 

Clinically it seems without doubt that the vaso-motor impulses of 
the hypoglossal nerve are derived by way of the superior cervical gang- 
lion judging from the vaso-motor effects of a cervical lesion on the parts 
supplied by the twelfth nerve. 

Grey rami communicantes connect the superior cervical ganglion 
and the upper four spinal nerves. Those branches to the third and 
fourth, according to Quain, often pierce the rectus capitis posticus major 
muscle. Contracture of this muscle from a lesion of the third cervical, 
would interrupt this connection and lead to disturbances of function. 
"Some of these fibres pass peripherally, some centrally." Of those 
passing centrally "some follow the posterior primary division of the 
nerve, others enter the sheath of the nerve, the surrounding tissue in 
the intervertebral foramen, and the dura mater, running up the latter 
in the posterior- root. " Quain further says: "The fibres passing dis- 
tally in the anterior and posterior primary divisions of the nerves have 
been shown by experiments on animals, to supply vaso-motor nerves 



APPLIED ANATOMY. 75 

to the arteries of the body wall and limbs, pilo-motor fibres to the mus- 
cles of the hairs and secretory fibres to the sweat glands. " A lesion of 
the third cervical vertebra will interfere with this connection, because 
the grey rami are in relation with the articulations of this vertebra. 

The external branch of the spinal accessory, according to Landois, 
"anastomoses with sensory filaments from the posterior root of the 
first, less commonly also of the second cervical nerve, which supply 
muscle-sense fibers to it." It then supplies the sterno-mastoid and 
trapezius muscles. Landois says further that the external branch anas- 
tomoses also with several cers'ical nerves. "Either these fibres take 
part in the innervation of the muscles named, or the accessory returns 
to them, in part, the sensory filaments received from the posterior roots 
of the two uppermost cervical nerves, which then constitute the cutan- 
eous branches of these cervical nerves." 

The filament connecting the upper cervical nerves with the hypo- 
glossal nerve, carries motor and vaso-motor impulses to it, thus supply- 
ing the hyoid muscles, and tongue. 

The function of the fibres connecting the vagus and the upper cer- 
vical nerves is unknown. Judging from clinical indications, it is proba- 
bly sensory. The writer has known of cases in which pressure exerted 
at the second cervical vertebra would produce nausea and vomiting. 
Possibly the impulses were transmitted by these connecting filaments. 

The ninth nerve is directry connected with the jugular ganglion 
of the vagus but according to Landois, the function of this branch is 
unknown. 

He says in connection with the branches uniting the pneumogastric 
and spinal accessory nerves that the "entire inner half of the accessory 
nerve enters the trunk of the vagus. This transmits to the latter, 
motor fibers for the larynx (through the recurrent branch of the vagus), 
for the pharynx and the cervical portion of the esophagus and the 
stomach (?), as well as the cardiac inhibitory fibres." 

Some of these functions seem to be doubtful, since he marks them 
as inconstant or uncertain. 

The function of the filament connecting the vagus and the hypo- 
glossal nerve is unknown. 

The above statements concerning the effects on these communicat- 
ing branches will apply equally well to lesions of the atlas and axis. 

Some writers attribute vaso-motor functions to the third cervical 
nerve that are independent of the superior cervical ganglion but Lang- 
ley seems to doubt such statements. 



76 APPLIED ANATOMY. 

Summary of the third cervical vertebra. It is the most fragile 
vertebra hence most easily broken; its articulations are quite freely 
movable, thus lesions are common. As a result of a lesion of this bone, 
certain disturbances fairly constant, are found, such as eye troubles, 
especially weakness and impairment of vision. I have reference in the 
above, to tendency to formation of tears on exposure to wind and pho- 
tophobia if light is strong. In addition, there results headache (occipital), 
roaring in the ear, and what some call a "beefy" neck which is charac- 
terized by increase in amount of connective tissue which gives it a soft, 
bulky feeling. There may be disease of any part of the head and face 
as a result of lesion of this vertebra, but the eye is most frequently af- 
fected of all parts. 

THE FOURTH CERVICAL. 

The fourth cervical vertebra has few if any peculiarities, it being 
a typical vertebra. In size it is slightly larger than the third, the spinous 
process is longer, the transverse processes slightly larger, while in most 
cases it is not located so far anteriorly as the third. The superior facets 
face upwards, backwards and inwards, are slightly concave and permit 
of slight movement in all directions, perhaps the antero-posterior move- 
ment being the most marked. 

This vertebra is subject to lesions similar in character to those of 
other vertebra, a torsion or lateral deviation being most common. 

These lesions are characterized principally by a thickening of the 
ligaments in relation with the articular processes. The ligamenta sub- 
flava and the capsular are usually the ligaments most affected. By 
careful and deep palpation over the articularprocesses,thatis at a point 
about midway between the spinous and articular processes, these thick- 
ened and tender ligaments can be distinctly felt thus furnishing one of 
the most reliable of signs of a cervical vertebral lesion. In cases in which 
the lesion was produced by trauma, these ligamentous changes are par- 
ticularly noticeable. 

In lesions of this bone the movements of the neck are impaired, 
since its articulations are involved in the various movements of the 
head and neck. As a result of a traumatic lesion the ligaments attaching this 
bone to the adjacent vertebras are stretched, torn or otherwise affected, 
this depending on the degree of lesion. This change in the ligaments 
makes free movement of the head difficult, lessens the size of the for- 
amina and weakens this portion of the spinal column. In other cases 



APPLIED ANATOMY. 77 

relaxation of the ligaments takes place, thus permitting too free mobil- 
ity, and in marked cases the patient is unable to hold the head erect. 
The discs are also stretched, torn or abnormally compressed, which 
changes affect the normal curvature of the neck, thus laying the founda- 
tion for spinal curvature of the cervical region. 

The principal muscles attached to the fourth cervical vertebra and 
which would necessarily be affected in some way in lesions of it, are the 
following: Scalenus anticus, scalenus medius, rectus capitis anticus 
major, longus colli, multifidus spinse, semispinalis colli,- complexus, 
cervicalis ascendens and splenitis. The effect on these muscles is most 
frequently that of contracture. The other attachments of these mus- 
cles are drawn nearer the fourth or else it is drawn closer to them, that 
is the cervical spinal column is drawn out of line. In either case there 
would be a warping of the framework of the body, for muscles are gen- 
erally attached to bones and are always shortened when contractured. 

The arteries and veins correspond to those of the third and would 
be affected similarly, the effects being about the same. The spinal cord 
suffers most when these vessels are impinged. 

The nerves having their origin in the fourth cervical segment and 
passing out through the fourth cervical foramina are the posterior 
division of the fourth, the supra-clavicular, muscular and phrenic. 

There are various other nerves and connecting filaments in rela- 
tion with this vertebra, and would, in all probability, be affected by the 
lesion. They are, the recurrent meningeal, vertebral plexus, sympa- 
thetic gangliated cord, and the filaments connecting the superior cer- 
vical ganglion with the upper cervical and the cranial nerves. On ac- 
count of the relation of the parts thus connected, these filaments are in 
relation with the articulations of the fourth, and would be impaired by 
the lesion. As to the functions of these nerve fibers see effects on nerves 
of a lesion of third cervical. 

The supraclavicular nerve and its distribution have been discussed 
(see third cervical). The muscular branches supply the following: 
Rectus capitus anticus major, longus colli, scalenus medius, 
scalenus anticus, diaphragm, levator anguli scapulae, trapezius, 
complexus, splenius, multifidus spin.'e, semi-spinalis colli and 
interspinales. All of these have been considered with the exception 
of the diaphragm which will be considered here, since its innervation 
is almost entirely from the fourth cervical segment. 



78 APPLIED ANATOMY. 

The diaphragm is a dome-shaped, thin muscular sheet which sep- 
arates the thoracic and abdominal cavities, forming the floor of the 
former and roof of the latter. Its construction is peculiar in that it con- 
sists of "muscular and tendinous portions which arise by numerous 
digitations and, arching upward and inward, converge to be inserted 
into a common central tendon. " It is attached above to the pericardium 
which serves to maintain its arched position during respiration. It 
arises from the lower six or seven ribs, the internal surface of the ensi- 
form cartilage, the bodies of the lumbar vertebrae and the tendinous 
arches over the quadratus lumborum and psoas muscles which are called, 
from their shape and ligamentous character, the ligamentaarcuata externa 
and interna. The external extends from the twelfth rib to the transverse 
process of the first lumbar vertebra. The attachments to the bodies 
of the lumbar vertebrae are known as the crura of the diaphragm. Their 
fibers in passing upwards are so placed that they cross each other in 
such a way that they form a figure-of-eight arrangement around the 
various openings of the diaphragm. The fibers converge for insertion 
into the central tendon. 

In applying this knowledge of origin and insertion it can be seen 
that displacement of the lower ribs or lumbar vertebrae will affect the 
muscle and change the size of the openings in it. From its position and 
relations, enlargement of the viscera in relation embarasses its action, 
as is evidenced by shortness of breath after a full meal. 

There are various openings through which pass important struc- 
tures. The aortic is between the crura and gives passage to the aorta, 
thoracic duct and the vena azygos major. The esophageal opening 
transmits the esophagus and the pneumogastric nerves and esophageal 
branches of the thoracic aorta. The opening for the inferior vena cava 
gives passage to the inferior vena cava, a branch of the right phrenic 
nerve and to some ascending lymphatic vessels from the liver. The 
sympathetic chain and the greater and lesser splanchnics of the right 
side pass through the right crus. The openings in the left crus transmit 
the greater and lesser splanchnics of the left side and- the vena azygos 
minor. These openings are affected in displacement of the muscle. 
Lesions of the lower ribs displace the diaphragm. The aorta is obstructed 
thus throwing more work on the heart, possibly causing regurgitation. 
The veins are obstructed which causes congestion of parts drained by 



APPLIED ANATOMY. 79 

them. The nerves are involved, hence disturbances in viscera inner- 
vated by them. 

The nerve supply of the diaphragm comes principally from the 
phrenic and the lower five or six intercostals. The diaphragmatic 
plexus, which is formed by offsets from the upper part of the solar plexus 
which ramify with the phrenic, reinforce the above named nerves to 
the muscle. At the point where this plexus joins the phrenic nerve is 
a small ganglion called the ganglion diaphragmaticum, which sends 
filaments to the liver, inferior vena cava and the suprarenal capsule. 
Lesions of the fourth cervical, lower ribs and lower thoracic vertebrae 
will affect the innervation of the diaphragm, hence impair its action. 

The action of the diaphragm is to deepen the chest. It is a power- 
ful muscle of inspiration. It acts in conjunction with the abdominal 
muscles in acts requiring an increase in the intra-abdominal pressure, 
such as defecation, micturition, parturition, coughing, sneezing, vomit- 
ing, etc. Its most important function is that of assisting in respiration. 
Hilton calls attention to the action of the diaphragm on the liver. By 
its contraction the liver is compressed, thereby assisting the circulation 
of the blood through it. Exercise causes an increase in the frequency 
and intensity of contraction of the diaphragm, hence is good for a tor- 
pid liver. Enforced rest often causes jaundice. 

The distribution of the phrenic to the diaphragm is an unusual 
one. It pierces the muscle and is distributed to the under surface, 
probably for the sake of protection since in respiration, pressure is 
strongest against the upper surface of the muscle. In abnormal disten- 
sion of the stomach, the nerves to the diaphragm are compressed or 
otherwise affected and hiccough results. Gravity tends to prevent 
pressure of viscera on this muscle by drawing the liver and stomach 
down. 

The phrenic has other functions than that of supplying motion to 
the diaphragm. It supplies in addition, the pericardium, pleura, sends 
a few filaments to the peritoneum and on the right side, the inferior 
vena cava and the right auricle of the heart. It helps to form the 
ganglion diaphragmaticum which sends branches to the supra-renal 
capsule, hepatic plexus and the inferior vena cava. Lesions of the 
middle cervical vertebras affect this nerve, hence would affect the above 
named structures and organs which it directly or indirectly supplies. 
The diaphragm is its most important distribution. 



80 APPLIED ANATOMY. 

The most common effect of a lesion of the fourth cervical on this 
muscle is a spasmodic contraction, or hiccough. In some cases paralysis 
of this muscle follows a neck lesion. The writer has examined cases in 
which respiration was carried on apparently by the thoracic muscles, 
the phrenic being partly or wholly paralyzed as a result of a cervical 
lesion. The respiration in such cases is usually sighing and irregular. 
In asthma the opposite condition exists, that is, the thoracic muscles 
perform a very small part in respiration, it being carried on almost ex- 
clusively by the diaphragm and abdominal muscles. 

Experimentally, section of both these nerves, is followed by par- 
alysis of the diaphragm. Death soon follows because of the inability of 
the thoracic muscles to carry on respiration since the diaphragm becomes 
so relaxed that it no longer furnishes a fixed point or fulcrum from which 
the other muscles of respiration can act. On account of this, the air 
already in the lung cannot be expelled neither can a partial vacuum be 
formed by which air is drawn into the lungs. Section of only one phrenic, 
is often followed by pneumonia according to McLachlin. A lesion may 
so impair the action of this nerve that it will have a tendency to the 
production of pneumonia. A lesion of the fourth may have either an 
inhibitor, or a irritative effect. On this account, the lesion can be sub- 
stituted for the means commonly used in experiments and the results 
will compare favorably if the difference in amount of stimulation or in- 
hibition used, is considered. 

Usually in neck lesions some form of respiratory disorder compli- 
cates on account of the effect on the phrenic nerve. This disturbance 
may be a labored respiration, Cheyne-Stokes respiration, sighing, spas- 
modic or irregular breathing. In treating such effects it does little good 
to press on, or otherwise affect the trunk of this nerve, except in cases 
in which only a palliative or temporary effect is wanted or a curative 
one can not be obtained. In hiccough, this nerve should be examined 
from origin to destination and especially at its spinal origin and exit and 
the points of its distribution. The first has been considered. The sec- 
ond part is as important since fatal attacks result from a diseased liver 
pressing on the nerve on the under surface of the diaphragm, from dis- 
placement of the lower ribs and the lumbar vertebrae and from enlarge- 
ment or displacement of the viscera in relation with the under surface 
of the muscle. 

The more obscure effects of a lesion involving the phrenic nerve are 



APPLIED ANATOMY. 



81 



ANT. PRIM.OIV.OF FOURTH - 
CERVICAL N. 



PHfXNIC- 

BRACHIAL PLEXUS c : 

RECURRENT LARYNGEAL^ 

VAGUS ■ 
PERICARDIUM 



1 ~ 



-PHRENIC N. 



INF. CERVICAL GANGLION 
^RECURRENT LARYNtZAu 



COMMC.BRAN.FR0M BRACHIAL 
PLEXUS TO PHRZNIG N. 



PERICARDIAL 
BRANCH 



RECURRENT LARVAL 



ANT. PULMONASV 



amt. pulmchvst 

If' PLEXUS 




a* * 



Fig. 20. — Showing course and distribution of the phrenic nerve. 



82 APPLIED ANATOMY. 

those on the pericardium, pleura, heart and supra-renal capsule. It is 
supposed to be a sensory nerve to these parts, in which case pain in these 
structures supplied is at least partly the result of disturbance of this 
nerve. As to the effects on the abdominal viscera and structures to 
which it is distributed, one can only conjecture. Since it indirectly 
supplies the supra-renal capsule, peritoneum, liver and the inferior vena 
cava, it is fair to assume that disturbances in these organs and struc- 
tures come in part or wholly from an impairment of the phrenic nerve, 
and since a lesion of the fourth cervical will affect this nerve the conclu- 
sion is evident. The phrenic receives a direct twig of communication 
from the inferior cervical ganglion and in most cases a branch from the 
plexus subclavius. This explains the relation of a lesion of the first rib 
and its effect on the phrenic. A dry hacking cough is sometimes the 
result of disturbance of the phrenic. I would suggest a lesion of the 
first rib as the cause in most cases. 

The posterior division of the fourth cervical nerve, dividing into the 
usual internal and external branches, supplies sensation to the integu- 
ment over the lower part of the neck. The recurrent meningeal, verte- 
bral plexus and superior cervical ganglion are affected in typical cases. 
These effects are similar to those from an axis lesion, which see. The 
fourth cervical segment is also involved, the lesion disturbing the cir- 
culation to it, especially interfering with its drainage. 

This segment contains very important centers, those for the phrenic 
being the most important. The predominate respiratory center is sup- 
posed to be in the bulb, with subsidiary centers in the spinal cord. In 
either case impulses pass through the fourth cervical segment to the 
phrenic. 

Summary of fourth cervical. Lesions of this bone are most fre- 
quently an antero-posterior displacement or a torsion. 

The motor effects of this lesion are contracture or relaxation of the 
muscles supplied by the fourth cervical segment. In the case of the 
diaphragm, there would be, on stimulation, a clonic contraction or 
hiccough. If the lesion is inhibitory, relaxation would be the result. 
The sensory effects are characterized by pain, or anesthesia or numbness 
of the integument over the lower part of the back of the neck, the upper 
part of chest and over top of shoulder, and possibly in the parts supplied 
by the phrenic nerve. 

The vaso-motor effects depend on effect on the superior cervical 



APPLIED ANATOMY. 



83 



(NTEG'MT.OvEHSHNpuS PROC anc TRAPEZIUS 
COMPLEXUS 

INTERSPINAL ES 




BRA to LIVER 
IMF VENA CAVA 
SUPRA RENS&CA, 
DIAPHRAGM— <5^T-S: 
E50PHAGUS J^ 
BYWAY OF DIAPHRAGMATIC 
PLEXUS 



SENSATION 
ovrR PECT MJ 
BratoPERICAROIUM t p 30 Rig 
PERiTOHEUM 
RI AURICLEAND PLEURA 

Fig. 21.— Showing the fourth cervical segment of the spinal cord and its 
nerves with their distribution. 



84 APPLIED ANATOMY. 

ganglion, the grey rami and the recurrent meningeal nerves. Any 
structure supplied by the above nerves is apt to be affected by a lesion of 
the fourth cervical vertebra, since the nerves are in relation. 

The secretion of sweat of parts above may be disturbed by this 
lesion since the secretory nerves to the sweat glands of the neck, head 
and face pass by way of the sympathetic nerves in relation with the 
fourth. 

With lesions of the fourth are associated hiccough, Cheyne-Stokes 
respiration, and in fact any or all respiratory affections. Almost any 
form of disease of any part above this vertebra may result from a lesion 
of the fourth, but it is not so important a factor in the etiology of dis- 
eases of the head and face as are lesions of the axis or third. 

THE FIFTH CERVICAL. 

The fifth cervical vertebra being a typical vertebra needs little separate 
description. It is slightly larger than the fourth in every respect, and 
the body more hooked, which prolongation fits in a corresponding depres- 
sion in the body of the vertebra below. This is true of all the cervical, ex- 
cept the atlas and axis. The obliquity of the spinous process is quite 
marked, its tip being on a level with the disc between the bodies of the 
fifth and sixth cervical vertebrae. Movement in this region is quite free. 
Flexion and extension, though free, are not so marked as in the lum- 
bar spine. 

The effects on the ligaments of a lesion of the fifth cervical vertebra, 
that is of the articulation between it and the fourth, are similar to those 
from a lesion of the fourth. They become tender, thickened and thus 
hinder normal movement. The size of the intervertebral foramina is 
lessened, thus producing pressure on the structures passing through. 
The discs are stretched, or abnormally compressed and soon their elas- 
ticity is lessened. 

The muscles attached to this vertebra are affected in some way by ■ 
a- lesion of its articulations. The principal muscles directly or indirectly 
involved are the scalene muscles, splenitis, complextjs, multifidus, 

SPIN^B, CERVICALIS ASCENDENS, TRACHELO-MASTOID and DIAPHRAGM. 

The scalenus posticus is attached to the second rib and in irritative 
lesions of the fifth cervical, the posterior part of the rib would be drawn 
upward. This condition is often responsible for diseases of the thyroid 
gland such as goitre, and for coughs, lung and bronchial disorders. These 
effects are explained by the fact that the inferior cervical ganglion is 



APPLIED ANATOMY. 85 

affected by a lesion of the first rib. This ganglion sends a branch di- 
rectly to the thyroid gland, and connects with the phrenic and recurrent 
or inferior laryngeal nerve. The inferior cervical and stellate ganglia 
are situated on the head of the first rib and are affected whenever it is 
drawn up b)' contracture of the scalene muscles or from other causes. 

The cervicalis ascendens is also attached to ribs; the vertebral 
ends of four or five upper ribs. By its contracture, these ribs are drawn 
upward at the vertebral end, this condition affecting structures, organs 
and viscera in relation; lung and mammary disorders being most com- 
mon. The trachelo-mastoid on account of its attachment to the 
head, by its contraction draws the head securely against the spinal 
column. Many a cervical condition attributed to an atlas lesion is in 
reality the effect of a lesion lower in the spinal column with an effect in 
the upper part of the neck through this and other muscles attached to 
the head and upper thoracic spine. 

The arteries directly involved by a fifth cervical lesion are the 
vertebral, lateral spinal, muscular and spinal branches of the ascending 
cervical. As a result of this lesion the parts supplied with blood by these 
arteries would be affected, viz., brain, cervical spinal cord, medulla and 
muscles of neck. 

The corresponding veins would be involved, hence some disorder of 
the spinal cord, column and cervical muscles and nerves. 

The nerves involved by a neck lesion are the vertebral plexus, 
fifth and sixth cervical nerves, recurrent meningeal, ramus com- 
municans, middle cervical ganglion and the branches of the above 
named nerves in relation. 

The recurrent nerve is affected in a way similar to that in other 
cervical lesions. 

The fifth cervical nerve divides into the usual anterior and posterior 
divisions. From this nerve is derived in part or in whole, the phrenic, 
posterior thoracic or nerve of Bell, suprascapular, circumflex, 
musculo-cutaneous, external anterior thoracic, subscapular, 
muscular and sometimes the musculo-spiral. There is considerable 
variation in the points of origin of these nerves, hence the variations in 
the different texts. The phrenic nerve has been described (see fourth 
cervical nerves.) 

The posterior thoracic or expiratory nerve of Bell is of interest in 
that it supplies with motor and trophic impulses, the serratus magnus 
muscle. It arises by three roots from the fifth, sixth and seventh cer- 



86 



APPLIED AXAT0M1". 



SCALENUS ANT. 
SCALENUS MED. 




SCAPULA 
TURNED BACK 



Fig. 22.— Showing attachments of the serratus magnus muscle. The relation it 
bears to the ribs is clearly brought out. 



APPLIED ANATOMY. 87 

vical nerves, of which the upper two pierce the scalenus medius mus- 
cle. On account of this, contracture of the scalenus would interfere 
with this nerve. The serratus magnus muscle is of importance in that 
its function is often disturbed by this lesion, which is followed by marked 
weakening of the shoulder and scapula. It is occasionally made use of 
by osteopaths in raising the ribs, this being practical on account of its 
attachments. This muscle arises by nine digitations from the upper 
eight ribs, the second getting two of the digitations. The fibers con- 
verge to be inserted into the anterior surface of the vertebral border of 
the scapula. Its action is to draw the scapula and shoulder forward, 
or if the scapula becomes the fixed point its contraction will evert and 
raise the ribs and push the sternum forward. It supports the shoulder, 
as in carrying a weight on it, assists the deltoid in raising the arm by 
fixing the scapula and holds the scapula closely against the chest wall as 
is demonstrated in pushing. 

The effects on this nerve of a disturbance of the articulations of the 
fifth cervical vertebra are evident. If the nerve is partly or completely 
paralyzed, as it is in some cases of cervical lesion, the arm cannot be 
raised to any marked extent, the shoulder is depressed, the ribs get 
"down" and the scapula becomes "winged." In complete paralysis of 
this nerve, the arm cannot be raised above a horizontal plane, except 
with great effort, and the other movements of the shoulder and arm are 
markedly weakened. 

In tuberculosis of the lungs, this muscle is involved in that it be- 
comes atonic with other muscles in relation, thus permitting the scapula 
to become winged. If this muscle retains its normal tone and func- 
tion, respiration is usually normal so far as the action of the thoracic 
walls is concerned; also the ribs remain in a fairly normal position. If 
a lesion affects its innervation, respiration soon becomes shallow and 
the ribs become more oblique, closer together and descend or get down. 
These rib lesions are not always the direct result of an atrophy of the 
serratus magnus but of atrophy of other muscles as well, the condition 
of the serratus magnus being a fairly true indication of the condition of 
the muscles that hold the ribs in normal position. 

The suprascapular nerve is of importance in that it supplies im- 
portant structures, the shoulder joint and the supra-and infra-spinati 
muscles; and clinically is important on account of the frequency of its 
disturbance. The branch to the shoulder joint has to do with the con- 



88 APPLIED ANATOMY. 

dition of the structures concerned, that is the synovial membrane, the 
ligaments and vessels.. 

In lesions of the fifth cervical, the function of the shoulder-joint is 
often impaired in that motion is limited and painful and the joint weak- 
ened. If the joint is stiff or if movement of the arm produces pain, the 
condition is popularly called rheumatism. "Rheumatism" of the 
shoulder is in most cases due to a cervical lesion that in some way af- 
fects the suprascapular or circumflex nerve or to a subluxated clavicle. 
Contracture of the lower cervical muscles will impinge on the circumflex 
nerve and cause pain to be referred to the shoulder joint because it is 
one of the sensory nerves to it. Pain in, or rather irritation of, other nerves 
coming fromthefifthcervicalsegment, will often be accompanied by pain 
or ache in the shoulder. The effects of a shoulder lesion on this nerve 
will be considered under the discussion of the circumflex nerve. 

The nerve to the spinati muscles is involved in most cases of "cold" 
in the head. In such cases the supra-spinati are invariably contrac- 
tured and tender. In la grippe, rheumatism and in an ordinary cold 
the joints ache, especially the shoulders. An involvement of these 
muscles is probably the cause. The lesion here acts as a predisposing 
cause, thus making it possible for the thermic and other influences to act. 

The circumflex is quite often involved by a lesion of the fifth 
cervical vertebra. As a result of a disturbance of this nerve several 
important effects are noted. The shoulder- joint is affected in a way 
similar to that resulting from a disturbance of the suprascapular. That 
is, there may be motor, sensory, trophic, secretory and vaso-motor dis- 
turbances since this nerve, as is best ascertained by clinical observa- 
tions, contains filaments for all these functions. On account of this, 
a lesion affecting the nerve will cause contraction or relaxation of the 
ligaments, pain or numbness, atrophy, lessened or increased secretion 
and congestion or anemia of the joint. Dislocations and sprains of 
this joint produce pain in the integument -over the joint, back of shoulder, 
and at insertion of deltoid muscle. Hilton says that in inflammation 
of the shoulder-joint the skin over the joint becomes very sensitive. 
"You will recollect that the same trunks of nerves which form the cir- 
cumflex nerve transmit some posterior filaments to the skin over the 
shoulder and the lower part of the neck; hence the pain is experienced 
in this region, by patients suffering from disease in the shoulder joint." 
A dislocation of the long head of the biceps which is decidedly unusual, 



APPLIED ANATOMY. 



89 



has a similar effect, that is. the pain is most severe at the insertion of 
the deltoid. Quite a common mistake is made by referring all such 
pains to the dislocation of the biceps or injury to the shoulder-joint, 
when in reality a lesion of the acromio-clavicular articulation is most 
often the cause. This articulation, that is, the acromio-clavicular, 

SUPRASCAPULAR M- 
SUPRASPINATUS 



P.BRANCH OF 
IRCUMFLEX 



}, \\V- DELTOID 



8RA.0F 
CIRCUMFLEX 




TERES- MINOR 



"■•ilK CUTANEOUS 
BRANCHES 



TRICEPS 



TERES MAJOR 



Fig. 23. — Showing relation of circumflex and suprascapular nerves to the shoul- 
der-joint. Painful affections of and around the shoulder-joint are explained by the 
above illustration. 



is often affected by the carrying of weights on the shoulder and by un- 
usual or sudden movements of the arm, and on account of its nerve sup- 
ply, the effect is usually referred to the upper part of the arm. A typical 
case may be cited here. The patient is unable to raise the arm above 



90 APPLIED ANATOMY. 

the level of the shoulder or is unable to draw the arm back as in putting 
on an overcoat. In other words, any movement wherein the muscles 
of the shoulder-girdle are used, produces a change of position of the 
clavicular-acromial joint, hence the referred pain. 

In sprains of the shoulder- joint the circumflex nerve is injured since 
the capsular ligament is bruised or torn and thus the nerve is affected 
since it pierces this ligament. Another filament supplies the deltoid 
muscle. This muscle has to do with protecting the shoulder-joint, re- 
inforcing its ligaments, rounding off the shoulder and with the move- 
ments of the arm. This muscle is affected by lesions of the fifth cer- 
vical, shoulder and acromio-clavicular articulations. As a result of 
these lesions, the muscle does not properly perform its various func- 
tions named above. In short, the shoulder is weakened, hence increased 
tendency to displacement, it loses its round-like appearance and the 
movements of the arm are impaired. These movements are forward, 
backward, with outward rotation and especially elevation. The le- 
sions of the acromio-clavicular and shoulder- joints most frequently im- 
pair its function as is pointed out above. This muscle atrophies from 
non-use, as in dislocations or fracture of the humerus, thus injuring the 
nerve, in anchylosis, or in other diseases of the joint. In ascending 
neuritis of the circumflex and in anterior polio-myelitis in this region 
of the spinal cord it is usually atrophied. In atrophy of the muscle, the 
acromion process appears to be prominent and sometimes, unless care 
is used, atrophy may be mistaken for dislocation of the shoulder. The 
writer has seen cases of atrophy of the deltoid follow lesions of the upper 
thoracic vertebrae in some cases as low as the sixth thoracic. 

The circumflex gives off cutaneous branches which supply sensa- 
tion to integument which covers the middle and lower portions of the 
deltoid muscle, also a small area of skin below the muscle. 

Another filament of this nerve is distributed to the teres minor. 
This is of importance in that this muscle adducts and rotates externally 
the humerus, also assists in backward rotation and protects the back 
part of the shoulder- joint. By a lesion of the fifth cervical, the teres 
minor muscle may be affected, thus producing an interference with the 
movements of the arm and a weakening of the shoulder-joint. 

The motor effects on the circumflex nerve of a lesion of the fifth 
cervical vertebra are paralysis or weakening of the deltoid and teres 
minor, which impairs the movements of the arm. This results in almost 



APPLIED ANATOMY. 91 

complete loss of power to raise the arm, a very trifling degree of abduc- 
tion by the supraspinatus alone remaining. 

The sensory effects are characterized by pain, numbness or 
anesthesia in the skin over the deltoid muscle and in the shoulder-joint. 
In paralytic lesions, there is loss of sensation in these areas. It is most 
marked in the skin over the lower part of the deltoid. Gowers says: 
"Hitzig pointed out many years ago that the anesthetic area is often 
the seat of vaso-motor paralysis. In some cases there is no anesthesia, 
even when the muscle is wholly paralyzed; we have seen that this is 
often the case in nerve lesions. " The vaso-motor effects are conges- 
tion or anemia of the shoulder-joint and the deltoid muscle. The secre- 
tory and trophic effects are characterized by dryness of the joint, the 
forming of adhesions, atrophy of the ligaments and muscles and weak- 
ness of the parts. 

The musculo-cutaneous and musculo-spiral nerves come in part 
from the fifth cervical. They will be discussed later on (see sixth cer- 
vical). The upper or short subscapular nerve comes principally from 
the fifth cervical. It supplies the subscapular muscle. This muscle is 
of interest in that it has to do with internal rotation of the humerus, 
with strengthening of the shoulder-joint and with holding the humerus 
in place. 

The external anterior thoracic nerve, a branch of the fifth cervical, 
supplies the pectoralis major muscle. This muscle by its contraction 
draws the shoulder and arm forward and downward. Deaver calls 
it a hugging muscle. He also says, "It would be a powerful aid in dif- 
ficult respiration if the arms are fixed. On account of its attachment 
to the anterior portions of the upper ribs and to the arm, it is used to 
elevate the chest or raise the ribs, " which is accomplished best by mak- 
ing a fixed point at the vertebral end of the rib and extending the arm 
above the head. A disturbance of its function results in impaired move- 
ments of the shoulder and arm, a weakening of the attachment holding 
the tendon of the biceps in its groove and a dropping of the anterior 
ends of the ribs. Its degree of development is an indication of the 
general strength of the patient. 

The distinctly muscular branches supply the rhomboidei and sub- 
clavius muscles. In colds of the head and bronchial tubes these muscles, 
that is the rhomboidei, are markedly contractured. This contractured 
condition interferes with the circulation to the spinal cord in that area and 



92 APPLIED ANATOMY. 

the position of the vertebrae to which they are attached. This condi- 
tion finally leads to weakening of the bronchial tubes and lungs, and 
predisposes to tuberculosis of the lungs. Repeated colds cause repeated 
contractures of these muscles. After the lungs begin to waste these 
muscles degenerate. In some cases they can be seen as fibrous cords. 
In most chronic cases they are relaxed and the scapula becomes so loosely 
attached to the thoracic wall and spinal column that the hand can easily 
be inserted beneath it. In acute cases the scapulae are drawn together. 
The muscles supplied by the fifth segment of the spinal cord are: the 
longus colli, scalene, levator anguli scapulae, serratus magnus, sub- 
clavius, supra-spinatus, infra-spinatus, teres minor, subscapularis, deltoid, 
pectoralis major, biceps, brachialis anticus and multifidus spina?. 

The fifth cervical nerve also furnishes filaments which supply the 
humerus and its periosteum. This is of importance not because dis- 
ease of the bone is not unusual, but because its nerve supply is seldom taken 
into consideration. Nearly all cases of caries are attributed to tuber- 
culosis, but back of all these so-called tubercular conditions are lesions 
of some sort that impair the vitality of the bone. A lesion of the fifth 
cervical will affect the nutrient nerve to the humerus and in some cases 
this disturbance is sufficient to produce a change, possibly caries. An- 
other branch passes to the brachial artery which appears to carry vaso- 
motor impulses to it. 

The size of the artery is partly controlled by this nerve. In vascu- 
lar disturbance of the arm the trouble may be in this branch to the artery. 

The fifth cervical segment supplies in whole or in part the shoulder- 
joint, elbow and wrist. In many cases of "rheumatism" of the joints 
of the arm the trouble is a lesion impairing the nerve supply. This 
lesion may be in the articulation itself or at the fifth cervical, at which 
point the nerve is in relation, that is, the cause may be in the spine but 
the effect is in the joints of the arm. This may work in just the 
opposite way, that is, the wrist, elbow, or shoulder-joint may be impaired 
and the pain be felt in the cutaneous areas supplied with sensation by the 
fifth cervical. A sprain of the wrist may cause pain to be felt the en- 
tire length of the arm or between the shoulders. In most cases there 
is a reflex contracture of the muscles supplied by the same segment. 

The fifth cervical nerve supplies sensation to the integument over 
the deltoid, middle and lower portions, radial aspect of forearm and in 
most cases the ball of the thumb. It communicates with the fourth 



APPLIED ANATOMY. 



93 



CERVICALCS ASCENDENS TRACHE|_0 MASTOID, 

TRANSVERSALIS CERVICIS 

COMPLExus 

splenius CApmstT.c 



INTEGUMENT over 



'I NOUS PROCESS 
SAPEZIUS 




INTERTRANSVERSAUS 
MULTIFTOUS SPINA! 

SEMISPINALS 

CONNECTS WITH 4ISCERV. N. 
LEVATOR ANGULI SCAPULA1. 
RHOMBOID NERVE 
POST. THORACIC 
NERVETO SUBCLAVIUS 
SUPRASCAPULAR 
OUTER CORD 

POSTERIOR CORD 
IMNER CORD 

EXT. ANT. THORACIC 
INT ANTTHQRACIC 
CIRCUMFLEX 



CADIAC PLEXUS 



NERVEorWRISSERG- 

Fig. 24 — Showing the fifth cervical segment with its nerves and their distribution. 



94 APPLIED ANATOMY. 

and sixth cervical and the middle cervical ganglion. The recurrent 
meningeal is formed from the fifth cervical and the corresponding grey 
ramus and is affected by the lesion. The vertebral plexus would be 
involved similarly to that from a lesion of the vertebra above. The 
posterior division of the fifth cervical nerve divides into the usual in- 
ternal and external branches. The internal branch supplies the semi- 
spinalis and complexus muscles, pierces the trapezius and supplies in 
part the integument over the back part of the neck. The external 
branch is small and helps to supply the muscles in relation, viz., splenius, 
transversalis colli, complexus, trachelo-mastoid and the cervicalis as- 
cendens. The posterior division of this nerve is often the seat of pain 
referred from diseased conditions in which the anterior branches are 
involved. In colds from exposure of the neck this nerve is the one 
first affected. Lesions of the fifth cervical weaken the tissues supplied 
by this division, hence the power to resist the effects of thermic changes 
is lessened. 

The middle cervical ganglion is located opposite the sixth cervical 
vertebra in front of the bend in the inferior thyroid artery, hence it is 
often called the thyroid ganglion. It seems to be formed by the coal- 
escence of the fifth and sixth cervical ganglia and is sometimes wanting. 
It gives off several efferent branches: the thyroid, which follow the 
artery to the thyroid gland, the middle cardiac, branches to the common 
carotid artery, and the external branches or grey rami that join the 
fifth and sixth cervical nerves. From the loop, or ansa subclavia, con- 
necting the middle and inferior cervical ganglia, spring branches which 
supply the subclavian artery by way of the plexus subclavius, the 
internal mammary artery and in some cases, communicate with the 
phrenic nerve. Branches to the thyroid gland arise from the inner 
side of the ganglion. These fibers communicate with the superior cardiac, 
the recurrent and external laryngeal nerves. This explains, in a measure, 
the throat and heart complications of exophthalmic goitre. Most of 
these branches follow the terminal divisions of the inferior thyroid artery. 

The middle cardiac (nervus cardiacus magnus) also comes from this 
ganglion. It terminates in the deep cardiac plexus after communicat- 
ing with the upper cardiac and the recurrent laryngeal. Clinically and 
experimentally, this nerve has little or nothing to do with the action of 
the heart. On account of the scarcity of cases of heart disorders from 
this lesion, it proves one of two things; that either few if any impulses 



APPLIED ANATOMY. 95 

for the heart pass through the upper cervical sympathetic nerves or 
else, a vertebral lesion will not, under ordinary circumstances, affect 
the gangliated cord in relation unless impulses pass from the spinal cord 
to the sympathetic chain at that point. The cardiac impulses arise in 
the upper thoracic portion of the spinal cord and pass out of the spinal 
canal through the intervertebral foramina in relation and at this place 
they are interrupted. 

The function of the middle cervical ganglion seems to be that of 
transmission and distribution of impulses that arise in the upper thoracic 
spinal cord. They are motor, secretory and vaso-motor in function, 
and pass to the neck, head and face. Most of these impulses pass on 
through the ganglion to parts above while a few are distributed by means 
of the efferent branches of this ganglion, viz., vaso-motor to the thyroid 
gland, and to the neck, shoulder, arm, cervical spinal cord and meninges. 
Secretory impulses for the cervical sweat glands pass through this 
ganglion and out over its efferent fibers to their destinations. 

The conclusions we draw from this knowledge of the middle cervical 
ganglion are: exophthalmic goitre may follow a lesion affecting this 
ganglion because the vaso-motor nerves to the thyroid gland come in 
part from this ganglion. Goitre seems to be a vascular disturbance, 
and a lesion of the fifth cervical vertebra will affect the middle cervical 
ganglion from which arise branches that supply the gland. The heart 
may be involved on account of relation to, and connection with the 
great cardiac nerve. The heart may be affected independently of the 
disturbance of the thyroid gland but clinically it is rare for a lesion of the 
fifth cervical to cause heart disturbances, although it does happen. 
Throat disturbances, vaso-motor, motor and sensory, result from an 
impairment of the middle cervical ganglion, which are explained by the 
above named nerve connections. Arm troubles, especially such as 
arise from a vascular disturbance, will in some cases result from a le- 
sion affecting the middle cervical ganglion because the subclavian plexus 
is derived in part from it. The parts supplied by the internal mammary 
artery may likewise be involved because of a similar reason. 

The fifth cervical segment contains nerve cells or centers that give 
origin to motor impulses that result in movement of that part of the 
spine, shoulder and arm, hence a lesion affecting this segment, and a 
subluxation of the fifth cervical will in all probability do it, will impair 
the movements of the head, neck, shoulder and arm. 



96 APPLIED ANATOMY. 

Sensation to the integument over the lower part of neck and over 
deltoid muscle, the shoulder and acromio-clavicular articulations, also 
the elbow and wrist and the ligaments of that part of the spine, is con- 
trolled by the condition of the sensory cells in the ganglion on the pos- 
terior root of the fifth cervical. The vaso-motor fibers supplying the vessels 
of the shoulder, arm, fifth cervical vertebra, fifth cervical segment of 
the spinal cord, meninges and muscles in relation, are more or less af- 
fected by a lesion involving the fifth cervical vertebra because they are 
in relation. The diseases to be associated with a lesion of the fifth cer- 
vical are: disturbances of circulation to the brain, producing in some 
cases epilepsy; eye diseases; goitre and shoulder disturbances, especially 
the so-called "rheumatism of the shoulder." Goitre comes directly 
as a result of the lesion by which the nerves and vessels to the gland are 
involved, or indirectly through displacement of the first rib as a result 
of muscular contractures. 

The lesions in this part of the spinal column, that is the middle 
cervical region, are not so important in the production of visceral and 
vaso-motor disturbances in the parts above, as are those of the upper 
part of the neck and the upper thoracic region. Clinically, it is the ex- 
ception to find the cause of any cranial disorder in the middle or lower 
cervical region, compared with the frequency of locating it in the upper 
cervical and thoracic areas. There are, however, some cases in which 
the visceral and vaso-motor disorders of the head and face are caused by 
a lesion of the middle cervical vertebrae. The explanation, as it ap- 
pears to me, is, that few if any vaso-motor impulses destined for the 
head, pass through the intervertebral foramina in this region. Prac- 
tically all, if not all of them, pass out of the spinal canal at a point below, 
and reach their destinations by way of the gangliated cord and the 
superior cervical ganglion, and its ascending branches. In ordinary 
vertebral lesions, little if any pressure is exerted on the gangliated cord 
in relation. Vertebral lesions produce most of their effects by lessening 
the size of the intervertebral foramina. Therefore, a lesion of the fifth 
cervical vertebra will not produce such a marked visceral or vaso-motor 
effect, as would a lesion of the second thoracic or the axis,because but 
few vaso-motor impulses for parts above pass through the fifth or sixth 
intervertebral foramen, at which point they might be affected by the 
lesion, but pass over the gangliated cord which is fairly secure from 
pressure by the average subluxation. 



APPLIED ANATOMY. 97 



THE SIXTH CERVICAL. 

The sixth cervical vertebra is also a typical vertebra, hence needs 
little separate description. All its parts are slightly larger than those 
of the fifth. The spine is longer and larger, the body more hooked or 
beaked. The transverse processes are not always perforated for the 
passage of the vertebral vessels. Immediately above the transverse 
process of the seventh cervical the anterior tubercle or the front of the 
transverse process of the sixth, can be palpated quite readily if the 
head is moved from side to side. On account of its relation to the carotid 
artery it has received the name of carotid tubercle. This bony enlarge- 
ment or apparent irregularity, should not be mistaken for a lesion of 
the sixth, even though it be quite prominent. The facets are directed 
upward, inward and backward. The movement of its articulations 
is less than that of the various articulations above, and the spinous pro- 
cess is often very near the spine of the seventh. It approaches the 
thoracic type of vertebrae. 

It is subject to lesions very similar in character to lesions of the 
vertebras above; perhaps as in the fifth, the most common lesion being 
an anterior one. The effect on the ligaments is that of rupturing fibers 
in them, this, as stated before, producing swelling and tenderness in the 
ligament. The muscles involved, that are important, are the cervicalis 
ascendens, trachelo-mastoid, multifidus spinas, complexus and splenius 
colli. All of these muscles have been considered above. 

The arteries are the vertebral and its lateral spinal branch and the 
lateral spinal from the ascending cervical. A disturbance of them would 
follow a lesion of the sixth, hence vascular disorders of the cervical 
spinal cord and part of the brain. The corresponding veins would be 
disturbed by this lesion in a way similar to that from a lesion of the 
cervical vertebras above. 

The nerves that have their center in the sixth cervical segment or 
that would in some way be affected by a lesion of the sixth cervical are 
the suprascapular, long or posterior thoracic, external anterior thoracic, 
subscapular, circumflex, median, musculo-cutaneous, musculo-spiral, 
muscular, recurrent meningeal, vertebral plexus, and the middle cervical 
ganglion and its branches and connections. 

By affecting the supra-scapular, there would be a pathological 
change in the spinati muscles and the shoulder-joint. 



98 APPLIED ANATOMY. 

The long or posterior thoracic supplies the serratus magnus, hence 
in lesions affecting it there is difficulty in raising the arm above the 
horizontal position, the contour of that part of the spine is altered, and 
the position and movement of the ribs changed. 

A disturbance of the external anterior thoracic would affect the 
pectoral muscles. 

The subscapular nerve supplies the latissimus dorsi, subscapularis 
and teres major. There are three of these nerves, the upper or short, 
the middle or long and the lower subscapular. The upper is distributed 
exclusively to the subscapularis muscle. The long supplies the latissi- 
mus dorsi muscle, and the lower is distributed to the teres major. These 
muscles strengthen and support the shoulder-joint, the bicipital tendon, 
and help to fix the scapula. In affections of the nerve supplying the 
subscapularis muscle, , inward rotation of the humerus is lessened. If 
the long subscapular nerve is paralyzed, "forcible backward depression 
of [the raised arm is lost, and the shoulder cannot be put back without 
being also raised (by the trapezius). The teres major muscle has to 
do with drawing the humerus backward and inward as in climbing. 
In paralysis, the elevation of the shoulder, with the arm against the side, 
is lost" (Gowers). In lesions of the sixth, the movements of the scap- 
ula and humerus would be affected and the shoulder-joint weakened. 

In lesions of the sixth cervical and shoulder-joint, the circum- 
flex is involved hence impaired movements of the arm, pain in joint and 
over shoulder, and sometimes atrophy and anesthesia. The deltoid is 
also involved. 

The musculo-cutaneous nerve is of importance in that it supplies 
the coraco-brachialis, biceps and brachialis anticus muscles, the humerus, 
its nutrient artery, the elbow and wrist-joints and sensation to the thenar 
eminence and skin of the forearm, outer side, as far as the wrist. Le- 
sions involving it would result in an impairment of the muscles inner- 
vated, malnutrition of the humerus, stiffness of the elbow- and wrist- 
joints and sensory disturbances of the posterior and outer aspect of the 
forearm and thenar eminence of the hand. 

The median nerve is of importance from a pathological standpoint 
on account of the character of effects from involvment of it. This nerve 
supplies sensation to the palm of the hand, palmar surface of three and 
one-half fingers, and pulp under nails on first three and one-half fingers. 
It supplies the muscles of the thumb, flexors of the wrist and long flexors 



APPLIED ANATOMY. 99 

of the fingers. The elbow, wrist, metacarpal and phalangeal joints 
are supplied by it. ProgTessive muscular atrophy is manifest first by 
atrophy or wasting of the muscles composing the thenar eminence. 
The thenar eminence is composed of four muscles, viz., the adductor 
pollicis, opponens pollicis, abductor pollicis and the flexor brevis pollicis. 
All of these muscles with the exception of the adductor pollicis, are sup- 
plied by the median nerve. Progressive muscular atrophy is due to pro- 
gressive impairment of the motor and trophic cells in the lower cervical seg- 
ments of the spinal cord, which is determined by the fact that the effect 
of the disease is first manifested by atrophy or wasting of the thenar 
eminence which is supplied by the median and ulnar nerves, they having 
their origin in the lower cervical and upper dorsal segments of the spinal 
cord. A lesion of the sixth cervical vertebra will affect the median 
nerve either at its origin or exit and cause a paralysis, partial or com- 
plete, with symptoms identical with, or very similar to the disease rec- 
ognized as progressive muscular atrophy. There seems to be, judging 
from clinic cases, trophic centers for the arm in the upper thoracic spinal 
segments, (upper four), hence lesions in that area may cause this dis- 
ease. From an osteopathic viewpoint, the lesions of the lower cervical 
and upper thoracic vertebra? are the most important causes of this dis- 
ease, these lesions causing the disease by disturbing the circulation 
through the motor and trophic areas in which are located the cells gov- 
erning the arm. These cells are in the anterior horns of the grey matter 
of the spinal cord. These lesions alter the size of the intervertebral 
foramina, thus producing pressure on the blood-vessels passing through 
them; this interfering with the nutrition of these nerve cells. The causes 
usually mentioned as responsible for progressive muscular atrophy are 
recognized as exciting ones, but probably of themselves are not suf- 
ficient to produce the disease. 

The musculo-spiral nerve would be more or less affected by a le- 
sion of the sixth cervical vertebra. It supplies the extensor muscles of 
the elbow-joint and wrist, sensation to the posterior and outer aspect 
of the upper arm, forearm and hand and sends articular branches to the 
elbow, wrist, metacarpo-phalangeal and phalangeal articulations. This 
nerve on account of its course, is more frequently injured than the other 
nerves of the brachial plexus. Fractures of the humerus, pressure 
from the use of a crutch, lead and alcoholic poisoning are important 
causes of disturbance aside from the above mentioned lesions. Wrist- 



100 



APPLIED ANATOMY. 



I Tl 



IT.211 



k 



S E.C 



I.ECS 



p. \J 



Fig. 25. — The musculo-spiral nerve and its branches. Note relation to humerus. 

0. I. nerve to outer head of biceps; S. E. C. superior ex. cut; B. R., N. to brachio- 
radialis; E. C. R. L., N. to extensor carpi radialis longior; I. E. C, Inf. ex. cut.; R., 
radial; P. I., post, interossous; An. N. to anconeus; I. T. 1 & I T. 2, nerves to triceps; 

1. C, Internal cutaneous. 



APPLIED ANATOMY. 101 

drop follows a paralysis of the extensor muscles of the wrist, also wasting 
of other muscles in relation. Other effects may follow lesions affecting 
it since many movements of the forearm, wrist and fingers, depend on 
this nerve. Dana says: "Its function is to extend and supinate 
the forearm, to extend the wrist and fingers, and to adduct and abduct 
the fingers slightly." These varied movements would of necessity be 
impaired if the nerve were affected, which is the case in lesions of the 
lower cervical vertebrae. 

The important muscles supplied by the sixth cervical nerve are the 
scalene, serratus magnus, subseapularis, teres major, deltoid, pectoralis 
major, biceps, multifidus spinas, the extensors of the wrist and flexors 
of the thumb. All of these have been considered except the biceps. 
This muscle is of interest in that its long head is supposed to be subject 
to "displacement. This head "arises by a long tendon from the top of 
the glenoid cavity and the glenoid ligament and, arching over the head 
of the 'humerus within the capsule of the shoulder-joint, pierces the 
latter between the two tuberosities and descends in the bicipital groove 
between them covered with a reflection of the synovial membrane of the 
joint, which serves to lubricate it and facilitate its movements." It 
is held fairly well in place by the attachments of the pectoralis major 
muscle. Occasionally this tendon becomes torn loose from its mooring 
and gets out of the groove, but I believe this to be an exceptional accident. 
In most of the cases diagnosed as a dislocation or "slip "of this tendon, 
the acromio-clavicular articulation was found impaired, in other words 
a subluxated clavicle, acromial end, was found. If the tendon is dis- 
placed, all the movements wherein the biceps muscle is used, are pain- 
ful. 

Pain in and over the muscle often comes from neck, shoulder and 
clavicle lesions. 

The extensor muscles of the wrist were considered with the mus- 
culo-spiral nerve. 

In spinal cord diseases,groups of muscles are affected since the seg- 
ments of the cord are involved and, usually, all the muscles innervated 
by the diseased segment are affected. This is especially true in an- 
terior polio-myelitis. 

The posterior division of the sixth is also involved by a lesion of 
the corresponding vertebra. As a result, the muscles supplied are af- 
fected and the integument over the lower part of the neck is disturbed 
as to sensation. 



102 



APPLIED ANATOMY. 



TRACHELO MASTOID TRANSVERSAL!! OERVICIS 

CERVICALIS ASCENOENS 
SPLENIUS CAP ET COLLI 




INTEG-UMEUITOVER 
SPINOUS PROCESS 
AND TRAPEZIUS 

INTERTRANSVERSALIS 
MULTIFIDUS SPlNAi 
SEMISPINALS 
C0NTSWITH4TS CERV N 
POST THORACIC N 
CONTSWrTw 3? CERV N. 
ANSA VIEUSSENS 
TO SUBCLAVIAN ARTERV 
RHOMBOID NERVE 
SUBCLAVIUS 
SUPRASCAPULAR 
UTER CORD 

POSTERIOR CORD 
INNER CORD 

EXT. ANT. THORACIC 
INT.ANT.THORACIC 
.CIRCUMFLEX 



S4TERNALCUTANEOUS- 

liERVEOT UBR1S8ERG- 



Fig. 26. — Showing the sixth cervical segment with its nerves and their distribution. 



APPLIED ANATOMY. 103 

The recurrent meningeal which supplies in particular the sixth 
cervical segment of the spinal cord, is usually involved by a lesion of 
the sixth. 

The vertebral plexus is in relation, usually entering the transverse 
process of the sixth, and would be disturbed in some way by a lesion of 
this bone. This furnishes an explanation of eye disturbances from le- 
sions so low in the neck. 

The grey ramus connecting the middle cervical ganglion with the 
sixth nerve is very liable to injury in lesions of the sixth. 

The middle cervical ganglion is in relation with the transverse pro- 
cess of the sixth and is frequently affected in lesions of this vertebra. 
This ganglion gives off branches that supply the heart, thyroid gland, 
common carotid artery, ami, and indirectly sends filaments to the 
phrenic and occasionally the mammary artery. It communicates with 
the recurrent laryngeal, external laryngeal, superior cardiac, superior 
and inferior cervical ganglia, on which account many disturbances of 
the parts innervated by these nerves come from lesions of the lower 
cervical vertebrae, those of the fifth and sixth, affecting this ganglion. 

The parts affected by a lesion of the sixth cervical are: the first 
rib, it being pulled out of place by the contractured scalene muscles, 
this lesion affecting their innervation; the wrist-joint, the shoulder and 
hand; the scapulae on account of the disturbance of the nerve of Bell; 
the chest wall; the brain, such a lesion sometimes producing epilepsy 
since the vaso-motor tracts are involved; and the eyes through the 
cervical sympathetic and the vertebral plexus. There may be pain or 
numbness of the arm and hand and between the upper parts of the scap- 
ulae. The thyroid gland is often affected, exophthalmic goitre being 
common. The heart is sometimes involved. The throat is affected, a 
dry hacking cough being the most common condition. The eye, arm 
and throat are most frequently affected by a lesion of the sixth cervical 
vertebra. ■ 

These effects are not the results of pressure of the displaced bone 
on the nerves as commonly as they are the results of a disturbance of 
the nutrition of the nerve cells. Pressure of the displaced vertebra on 
a cerebro-spinal nerve would produce some sensory disturbance, as is 
demonstrated by pressure on the ulnar. These nerves are mixed, and 
pressure on them will affect the sensory element in preference to the 
motor. If the irritation is severe, there will be both a sensory and a 



104 



APPLIED ANATOMY. 



motor effect. In lesions characterized by painful effects, the nerve is 
affected external to the spinal cord. In spinal lesions in which there 
is only a motor effect, the cells of the spinal cord are affected, as in an- 
terior polio-myelitis. In short, if the disorder is in the cells of the spinal 
cord, the effect is a motor one, but if it is external to the cord it may be 
sensory or both sensory and motor, seldom is it a purely motor effect. 
In a general way, use can be made of this in the diagnosis of the cause 
of the particular pain or motor disorder, that is, in determining whether 
the trouble is in, or external to, the spinal cord. 

THE SEVENTH CERVICAE. 

The seventh cervical vertebra is called a transitional vertebra in 
that it has characteristics of both the cervical and thoracic. Its most 
marked peculiarity is the very long, non-bifurcated spinous process 
on which account, it is called the vertebra prominens. The transverse 
process is quite large, especially the vertebral or posterior part, it ap- 



SEVENTH 
ERTEBRA 




Fig. 27. — Showing cervical ribs. Drawn from a dissection made at the A. S. O. 
On one side the rib was anchvlosed, on the other, the articulation was freelv movable. 



proaching in appearance the transverse processes of the thoracic verte- 
brae. It is seldom pierced by a foramen like those above, but in some 
cases a small foramen is present which transmits a vein. 



APPLIED ANATOMY. 105 

The superior facets face almost directly backward and present a 
flat* surface. The principal motion here is a gliding one although nearly 
all the ordinary neck movements are present but considerably limited. 
It is somewhat more posterior than the sixth, it taking part in the nor- 
mal posterior swerve of the upper thoracic spine. The movements at 
the articulation between the sixth and seventh cervical are very limited, 
on account of which is the possible explanation of this articulation being 
involved less frequently than those above in which movement is more 
marked. Its most common lesion is a forward rotation by which the 
spines of the seventh and sixth are approximated. As a result of this 
there is a separation of the spines of the seventh and first thoracic ver- 
tebra or what is ordinarily called a "break." As a rule in these breaks 
or separations, the vertebra above the break is the one involved. 

In this part of the spine the usual bony lesion consists of an altera- 
tion in position of the articular facets caused by one part or section of 
the spinal column being forcibly moved, to a pathological extent, on the 
other. As a result of a lesion of the articulation between the sixth and 
seventh cervical vertebra?, its ligaments, muscles and foramina; would 
be disturbed in some way. The effect on the ligaments is usually one 
of undue traction quite often to a pathological degree. 

The ligamentum nuchae is attached to the spine of the seventh and 
extends to the crest of the occipital bone, it being attached to the spines of 
all the cervical vertebrae. Although it is more or less affected in any cer- 
vical lesion it will be discussed here. In man it is rudimentary; in the 
horse, ox, etc., it is well developed and constitutes an elastic support 
of the head. In man it occasionallj r becomes contractured and tender, 
which conditions are associated with occipital headache and a drawing 
sensation in the back of the neck. Flexion of the head on the chest 
causes pain if the ligament is shortened, as it is in most pathological 
conditions, but such treatment is often helpful in relieving pain in the 
neck. Care should be used in stretching this ligament lest too much 
force be exerted on account of the leverage, the ligament be injured or 
a vertebra pulled out of line. In palpating in the median furrow of the 
neck, pressure should be made to one side of this ligament since by so 
doing the condition of the deeper structures can the better be ascertained. 

The important muscles attached to this vertebra and which would 
therefore be affected by a lesion of it, are the trapezius, rhomboideus 
major, serratus posticus superior, splenius, multifldus spina?, levator 



106 



APPLIED ANATOMY. 



costse, scalenus posticus and medius, complexus and trachclo-mastoid. 

Since the posterior part of the vertebra is usually rotated upwards and 
forwards, the muscles attached to points below would be put on a ten- 
sion. The serratus posticus superior in such a case, would pull up on 



INTERSPINAL 
MUSCLE 




FORAMINA FOR 
VERTEBRAL ARTERY 



Fig. 28. — Showing ligamentum nucha?. This ligament often becomes contractured 
and tender, which condition tends to produce headache accompanied by a drawing 
sensation in the back of the neck. 



APPLIED ANATOMY. 107 

the angles of the upper ribs, this condition in turn affecting the thoracic 
viscera by altering the position of these ribs. The disturbance of the 
levatores costarum muscles would have a similar effect, that is the verte- 
bral end of the ribs would be displaced or at least drawn slightly up- 
ward. This is the usual form of rib displacement and probably is ac- 
counted for by the above arrangement of the muscles. The scalene 
help to produce this form of rib lesion in the upper two ribs. 

It is not unusual for such a lesion to produce a painful contracture 
of the above named muscles. In such cases there is a constant ache in 
the lower part of the neck and the upper thoracic region and marked 
flexion produces an acute pain. The patient complains of a dull, chronic 
ache in the region of the seventh, catches cold quite easily and any ex- 
ercise wherein these muscles are used, produces fatigue of this part. 

The arteries involved by a lesion of the seventh, are the vertebral 
and its lateral spinal branch (not constant), the lateral spinal branch 
of the ascending cervical and the lateral spinal branch of the superior 
intercostal artery. The corresponding veins are affected, thus producing 
disturbance with the drainage of the muscles of this region and espec- 
ially of the spinal cord and its coverings. The effects vary with the de- 
gree of congestion and the function of the part involved. As a rule 
passive congestion lessens activity, or at least the function of the part 
congested is perverted. 

The nerves involved by a lesion of the seventh cervical vertebra, 
are those passing out through the foramina above and below it, these 
being directly involved, while their communications and connections 
are indirectly affected. On account of the extra cervical segment, both 
sets of nerves will be considered in connection with the seventh, instead 
of pnly the nerves passing through the seventh cervical intervertebral 
foramen, that is the nerves above the corresponding vertebra as we 
have done in the other cervical nerves. 

The nerves in relation with the seventh are the posterior thoracic, 
subscapular, ulnar, median, musculo-spiral, internal anterior thoracic, 
internal cutaneous, muscular, recurrent meningeal, possibly the verte- 
bral plexus and the inferior cervical ganglion and its branches and com- 
munications. 

The posterior thoracic is involved in winged scapulae, that is in re- 
laxed conditions of the serratus magnus muscle, and has been considered. 

The subscapular supplies the subscapular and latissimus dorsi mus- 



108 



APPLIED ANATOMY. 



transversalis cervicis 
cervical1s ascendens- — 
splenius capitis et colli 
cqmplevus trachelo-mast i; 
post n. roots 

>;;t eXTbranch 

./jSsJ '^^\5PIN«LGAN(^-^ 




INTEGUMENT over 

CERVICAL SPINOUS 

PROCESSES 

INTERTRANSVERSALIS 

MULTIFIDU5 SPINA 

SEMI SPINALIS 

ANSA VIEUSSENII 

TO SUBCLAVIAN ART. 

To INT MAMMARV ART. 

RHOMBOID 

PHRENIC N 

TO 5I» CERVICAL N 

POST.THOHACIC N. 

TOSUBCLAVIUS MUS. 

SUPRASCAPULAR. 

OUTER CORD 

STERIOR CORO. 
ER CORD 

XT ANT THORACIC N. 
INT ANT. THORACIC K. 
1RCUMFLEX N. 
MUSCULO SPIRAL 

MUSCULO 
CUTANEOUS 



Fig. 29. — Showing the seventh cervical segment with its 

tribution. 



ULNAR NL 



N.OFWRISBERG 

nerves and their dis- 



APPLIED ANATOMY. 109 

cles and is principally motor, controlling the position of the scapula 
and backward movements of the arm. 

The ulnar, the "crazy bone" nerve is of interest to us. Pain or 
other sensory disturbance in the hypothenar eminence, little finger, 
ulnar side of ring finger, or back of hand (ulnar aspect) is the result of 
direct or indirect disturbance of this nerve. Numbness in the little 
finger, the left being more frequently involved than the right, is quite 
a common condition in the aged and in patients subject to heart dis- 
ease, particularly angina pectoris. Pain in the lower part of the fore- 
arm is, to a certain extent, due to an interference with the ulnar nerve. 
Many of these sensory disturbances are reflex from lesions of the elbow, 
shoulder and lower cervical and upper thoracic vertebra?. The seg- 
ments of the spinal cord that give rise to impulses that pass to the ulnar 
nerve also give origin to impulses that supply the heart and lungs. Ap- 
plying Head's law we then have an explanation of angina pectoris and 
valvular disease producing numbness or pain in the little finger. Eckley 
offers an explanation that is slightly different: *" (1) The heart is sup- 
plied by sympathetic nerves by the cardiac plexus; (2) the sympathetic 
nerves forming the cardiac plexus communicate with the somatic nerves 
in the area where are given off the nerves forming the brachial plexus; 
(3) as sensory nerves report pain peripherally, we may logically account 
for the digital pain in valvular lesions in the distribution of the brachial 
plexus in general, or in the specific distribution of the ulnar nerve in 
particular. " 

Since this nerve supplies the majority of the intrinsic muscles of the 
hand, muscular disturbance of the hand, that is atrophy and contracture, 
result from lesions involving the ulnar nerve, a lesion of the seventh 
cervical not being unusual. In progressive muscular atrophy this nerve 
with the median is primarily involved, at least the effects of this disease 
are first evident in the parts supplied by them, viz., the muscles of the 
thumb that form the thenar eminence. In eversion of the hand, as in 
rheumatoid arthritis, this nerve is in all probability the first to be in- 
volved. If the grip is weakened this nerve is affected, since it supplies 
the deep flexors of the fingers. 

The median nerve has been considered with the sixth cervical seg- 
ment. The principal point to be remembered concerning it is its con- 
nection with progressive muscular atrophy. 

*Fractical Anatomy, p. 265. 



110 APPLIED ANATOMY. 

The musculo-spiral is at fault in wrist-drop and is often injured in 
fractures of the humerus or by an improperly worn crutch. 

The internal anterior thoracic nerve supplies the pectoral muscles, 
hence in disturbance of them this nerve is usually at fault. 

The internal cutaneous nerve is sensory, supplying the integu- 
ment of the upper and inner aspect of the arm, and the posterior 
and internal part of the forearm as low as the wrist. It communicates 
with the musculo-spiral and ulnar nerves. Pain in these regions is 
usually the result of disturbance of this nerve. The cause of the dis- 
turbance may be at the seventh cervical vertebra or it may be reflex 
from disease of viscera supplied by the same segment in which are the 
cells that give rise to this nerve. 

In addition to the muscles described as innervated by the above 
nerves the posterior division gives off muscular branches that supply 
the multifidus spina? and other muscles. 

The articulations of the elbow, wrist and hand are also supplied by 
the seventh and would be involved by a lesion of the seventh cervical 
vertebra. Thus dryness of these joints, pain and rheumatic affections 
are directly attributed to a lower cervical lesion. In some instances 
the brachial plexus receives filaments from the left vagus. McClellan 
states that in "two dissections made within the last year, the author 
has found distinct branches passing from the pneumogastric on the left 
side to the brachial plexus. " This is of value in associating pain in the 
arm with cardiac disease, such as angina pectoris and valvular disease 
or endocarditis. 

The posterior divisions of the seventh and eighth cervical, do not 
supply sensation to the integument in relation as do those above and 
below. The cutaneous nerves of this region come from the posterior 
divisions of the sixth and first thoracic nerves. 

The interior eervical ganglion is in relation with the seventh cer- 
vical vertebra, connects with the seventh and eighth cervical nerves, 
and is involved in lesions of this vertebra. The branches of this gang- 
lion are: grey rami communicantes which pass to the anterior division 
of the seventh and eighth cervical nerves; the subclavian loop connect- 
ing the inferior and middle cervical ganglia; a small branch, sometimes 
wanting, which communicates with the recurrent laryngeal; inferior 
cardiac; and branches that form the vertebral, inferior thyroid, and in- 
ternal mammary plexuses of nerves. 



APPLIED ANATOMY. 



Ill 



TRACHELO- MASTOID CER VI CAL1S ASCENOEN 

THANSVERSALIS-CERVICIS 
SPLENIUS-CAPITIS ET COLLI 
POST.N ROOTS COMPLEXUS 

\AN3A 

SPINAL GANG 




INTEGUMENT OVER 
CERVICAL SPIHOUS 
PROCESSES) 

INTERTRANSVERSALES 
MUlTIFIOUS SPIN*. 
COMPLEXUS 
SEMiSPINALiS 
5IH CERVICAL N 
6IB CERVICAL N 
TO S'JBCLAVIUS MUS 
SUPRASCAPULAR N 
SCALENI ANO LONGUS COLLI 
POSTERIOR THORACIC 
EXTANT. THOR N. 
IMT.ANT THORACIC N. 
OUTER CORD 
POST CORD 
INNER CORD 

MUSCULO 
CUTANEOUS 

CIRCUMFLEX 



INF CARDIAC N 

CAROIAC //' 

PLEXUS J 



INTER COSTO-HUMERALN><^ 
LATERAL CUTANEOUS N . 
LESSER. INTERNAL CUTANEOUS N 

Fig. 30. — Showing the eighth cervical segment with its nerves and their distribution' 



112 APPLIED ANATOMY. 

Not definitely knowing the kind and character of all the impulses 
carried by the grey rami, it would be impossible to describe accurately 
the effect of injury to them. Most all of the authors state that both 
afferent and efferent impulses are transmitted by the grey rami, but the 
efferent preponderate. 

These efferent fibres carry vaso-motor impulses to the blood-vessels 
of the skin supplied by the nerves derived from the seventh cervical 
segment ; secretory and pilomotor impulses to the same area. Perhaps 
a few sensory impulses from this area reach the cord by way of these 
grey rami. 

The ansa subclavia supplies the subclavian artery, internal mam- 
mary artery and sends a communicating branch to the phrenic nerve. 
Some authors have described a branch from this ganglion that goes 
directly to the phrenic and clinically this seems to be the case. A le- 
sion of the first rib will affect the phrenic and produce hiccough, and 
this branch seems to be the best explanation of the clinical fact in that 
the phrenic is affected through the inferior cervical ganglion. In dis- 
sections made and seen by the author, this communicating branch to 
the phrenic was quite often found. 

As a result of a lesion affecting the ansa subclavia there would 
follow: (1) vascular disturbances in the parts supplied by these arteries, 
viz., arm, mammary gland and a part of the chest wall, and (2) derange- 
ment of function of all or a part of the structures supplied by the phrenic, 
viz., diaphragm, pleura, pericardium, peritoneum, heart and the dia- 
phragmatic plexus. 

The recurrent laryngeal nerve supplies motion to the larynx, hence 
the relation between lower cervical and upper rib lesions and throat 
affections, especially coughing. A better explanation of why lower 
cervical and upper rib lesions produce throat disorders is that these 
lesions affect the inferior thyroid artery by way of its nerve supply. 
This artery supplies to a great extent, the esophagus, trachea, larynx, 
the deep muscles of the neck and the phrenic nerve. If this artery is 
affected, congestion or anemia of these parts follows. Congestion leads 
to disordered secretions and other disturbances. Congestion in this 
case is due to vaso-motor inhibition which causes the vessels to dilate. 
This inhibition comes from a lesion that disturbs the middle or inferior 
cervical ganglion, since the vaso-motor impulses to this artery come by 
way of these ganglia, and especially the inferior. On account of this, 



APPLIED ANATOMY. 113 

a lower cervical or upper thoracic lesion will produce vascular changes 
in the throat, hence the hacking cough, catarrh, dryness and disturbances 
of the voice. 

The heart may be, and often is, affected by lesions affecting the 
inferior cervical ganglion and its cardiac branches. The impulses reach- 
ing the heart via the inferior cardiac do not, according to the best author- 
ities, arise in the inferior cervical ganglion, but at a point in the spinal 
cord somewhat lower; the ganglion demudullating and otherwise chang- 
ing the fibers. This cardiac nerve connects with the middle cardiac 
and inferior laryngeal nerves. This explains some cases of hacking 
cough accompanying and resulting from many forms of heart and lung 
diseases. 

The vertebral plexus would also be affected by a lesion of the seventh 
cervical. This plexus sends vaso-motor filaments to the vertebral artery 
and all its branches, which control their size, hence the amount of blood 
passing through them. Thus the amount of arterial blood in the cer- 
vical spinal cord and vertebral column, medulla, pons, cerebellum and 
the posterior part of the cerebrum is governed to a marked extent by 
the condition of the vertebral plexus of nerves. As a result of this le- 
sion almost any disease or disturbance of function of the parts supplied 
would arise, the principal one being eye affections. This is best ex- 
plained by the fact that the centers for the eye, located in the floor of 
the fourth ventricle and the occipital lobes, are dependent to a great ex- 
tent for their nutrition on the vertebral artery and its branches, while 
it in turn, is dependent on the healthy action of the vertebral plexus 
of nerves. 

Not only the artery and its branches are supplied but the vertebral 
veins receive their vaso-motor impulses from this source. 

The writer has seen cases of epilepsy, chorea and various circula- 
tory disturbances of parts above result from a lesion of the seventh. 
A great majority of nerve fibers located in the inferior cervical ganglion 
have their origin lower, and transmit various sorts of impulses to parts 
above. Since nearly, if not all impulses reaching the head from parts 
below pass through this ganglion, it follows that any disturbance of it 
would in some way interfere with the transmission of these impulses, 
hence an effect in the points of destination. The inferior cervical gang- 
lion, according to Quain, transmits pupillo-dilator fibers, motor fibers 
to the involuntary muscles of the eyelids and orbit, vaso-motor fibers 



114 APPLIED ANATOMY. 

to the head and face, secretory fibers to the submaxillary gland, and 
accelerator fibers to the heart. All of the above fibers are supposed to 
originate in the upper thoracic portion of the spinal cord. The seventh 
and eighth cervical segments of the spinal cord contain pupillo-dilator 
fibers according to some observers. 

Transverse myelitis often results from falls which dislocate or frac- 
ture this part of the spinal column. The thoracic vertebrae are fairly 
well fixed, hence the articulation between the seventh cervical and first 
thoracic vertebra suffers most because of the change of mobility which 
takes place at this joint. The writer has treated many cases of para- 
plegia caused by a lesion at this articulation which in most of them set 
up a myelitis. 

Summary of seventh cervical. Lesions of this vertebra are asso- 
ciated with affections of the upper extremity, such as pain, numbness, 
swelling, paralysis, sensory and motor, and in short almost every form 
of disturbance of the upper extremity; neck affections, eye diseases, 
headache, heart disturbances, throat disorders, and especially vascular 
disturbances of any or all parts above this vertebra. Eye diseases are 
very often the result of a lesion in the lower cervical region. Progres- 
sive muscular atrophy, Erb's palsy, Duchenne's paralysis, clawed hand, 
wrist drop, "rheumatism" of the arm, neuritis and occupation neuroses 
result in many cases from a lesion of the seventh cervical vertebra. 

In all neck lesions there is tenderness. This tenderness is most 
commonly deep, that is, in the ligaments and deep muscles. Occasion- 
ally it is superficial, that is, in the integument. It is most pronounced 
in the structures around the articular processes and is exaggerated by 
pressure. The nerves involved are the posterior divisions of the cer- 
vical nerves that supply the ligaments and deep muscles around the 
cervical vertebrae. The tenderness is due to contracture of the deep 
muscles attached to the vertebrae, pressure of the displaced bone directly 
on the nerve, sprain of the ligaments which takes place to a greater or 
lesser extent in all vertebral lesions or the tenderness is due to some in- 
terference with the nutrition of the cells located on the posterior nerve 
root. In most cases I believe that the tenderness is due to the injury 
to the ligaments, that is, the ligament is partly or completely torn, be- 
comes congested and swollen and is affected in a way similar to that 
of a sprained wrist or ankle only to a lesser degree. The tenderness 
in a contractured muscle is clue to mechanical pressure from the conges- 



APPLIED ANATOMY. 115 

tion and to the chemical irritation from the toxic material which has 
formed in the muscle but has never been eliminated. 

In the neck lesions the tenderness is found most frequently to be 
over the spinous and articular processes or at least in relation with these 
processes. It is present in many cases in which there is no bony dis- 
placement, the lesion in such cases being a ligamentous one. Manip- 
ulation of the joint will lessen it or even entirely remove it. This manip- 
ulation consists of passive movement of the joint, that is, the function 
of the joint is artificially restored. 

THE REGION OF THE NECK. 

The region of the neck. Anterior aspect. The sterno-mastoid 

muscle is the great muscular landmark of the side and front of the 
neck. Its degree of development and contraction determines to a 
great extent the contour and size of the neck. It is affected in lesions 
of the second and third cervical vertebra? and subluxations of the head 
on the spinal column. The angle of the chin, and the way the head is 
carried are determined by this muscle. It furnishes a reliable landmark 
for the vagus and phrenic nerves and the carotid artery and jugular 
veins, these structures being located immediately anterior to the middle 
portion of the muscle. Deaver says: "Its anterior border is the sur- 
geon's guide in the ligation of the common, external and internal carotid 
arteries, the superior thyroid, lingual, facial and occipital arteries at 
their origin, and the inferior thyroid artery as it enters the thyroid 
gland; in exposing the spinal accessory nerve; upon the left side in the 
operation of esophagotomy, and in all other operations upon the front 
or the side of the neck." Torticollis is the principal disturbance of this 
muscle. 

The contour of the central part of the anterior part of the neck is 
made irregular by the thyroid and cricoid cartilages. They are very 
movable, their position being altered in swallowing and in -forced respira- 
tion. The thyroid cartilage is the more prominent and forms in many 
people, especially males with thin necks, a noticeable, angular promi- 
nence. It is of importance on account of its relation to the vocal cords. 

The cricoid cartilage is immediately below and can readily be out- 
lined. Aphonia follows displacement of, or injury to this cartilage. - 

The hyoid bone is located directly below the chin and its cornua 
■can be distinctly outlined by pressure directed inward beneath the 



116 APPLIED ANATOMY. 

angles of the jaw. Its position is determined by the condition of the 
various muscles attached to it. The vocal cords are in relation, or at 
least would be affected by malpositions of this bone. Aphonia is very 
commonly due to a displacement of it. It becomes displaced by colds, 
which cause the muscles to contract, or by direct trauma as in choking 
or other injury to the front of the neck. Its displacement may, in ad- 
dition to that of producing aphonia and hoarseness, cause a chronic 
hacking cough, sore throat and dysphagia. In whooping-cough it is 
said to be displaced and that by drawing it forward away from the 
laryngeal nerves, the spasm of coughing can be prevented or at least 
lessened. 

The supra-sternal fossa depends for its depth on the amount of 
adipose tissue in the lower part of the neck and the position of the 
clavicles. It is pathologically deepened in dyspnea as in asthma and 
tuberculosis of the lungs. In laryngitis, pressure in this fossa produces 
pain but gentle manipulation is beneficial. 

The supra-clavicular fossa is the depression above the clavicle. 
When increased in depth it is symptomatic of tuberculosis of the lungs. 
It is also deepened in the emaciated and in the aged. When obliterated, 
it is indicative of a depressed clavicle unless the patient is obese. In 
tubercular patients this fossa and the adjacent tissues should be ex- 
amined very closely by percussion and auscultation, since the apex of 
the lung, which is in relation, is the first part to be affected. 

The infra-clavicular fossa is the depression immediately below the 
clavicle. It is of interest in that it is deepened in tubercular condi- 
tions of the lung. 

The platysma myoides muscle is a superficial one which has to do 
with drawing down the lower lip and the raising of the skin and super- 
ficial fascia of the neck lying between the lower jaw and pectoral muscles. 
In some this muscle is remarkably developed, in others it cannot be out- 
lined. It is of especial interest in that it is frequently the seat of a tic, 
the muscle undergoing spasmodic contraction every few minutes. The 
jaw is usually depressed and the shoulder raised and the face suddenly 
drawn into a peculiar expression. These movements are spasmodic. 
In such cases the cervical nerves instead of the seventh cranial, are most 
frequently involved. 

The skin on the front of the neck is very thin in contrast to that on 
the back of the neck. Probably on this account, it is ■quite free from 



APPLIED ANATOMY. 



117 



eruptions. It is highly sensitive, being supplied in the main by nerves 
from the cervical plexus. The superficial vessels covered by it can or- 
dinarily be outlined quite readily and the pulsations of the deep vessels 
can be seen if the pulsation is abnormally hard. 

The thyroid body is a very vascular gland which is situated over 
the front and sides of the trachea and extending upward to the larynx. 




Fig. 31. — Showing the platysma myoides muscle. Xote the direction of its fibers and 
their insertion on the face. 



118 



APPLIED ANATOMY. 







Fig 32. — Showing the platysma myoides muscle. (From photo). 



APPLIED ANATOMY. 119 

It is composed of two lobes with an isthmus connecting them. It is of 
special interest because of enlargements or goitre occurring in it. Ordi- 
narily the gland does not affect the contour of this part of the neck but 
when enlarged the gland can be plainly seen, this of course depending 
on the degree of enlargement. The gland varies in size in different in- 
dividuals and at different periods in life. ' ' It is relatively larger in the 
child than in the adult, and in the female than in the male." Exoph- 
thalmic goitre is rare in the male, common in the female. The causes 
of this disease seem most frequently to be lesions of the lower cervical 
vertebra? and upper ribs, such lesions affecting the circulation of the 
blood through and from the thyroid gland. The arteries are remark- 
able for their size, number and free anastomosis. They are the superior 
thyroid from the external carotid, the inferior thyroid from the thyroid 
axis of the subclavian, and the thyroidia-ima which comes from the 
aorta or innominate. From the above arteries it is ascertained that 
the sympathetic nerves to this gland are derived from the cervical sym- 
pathetic, the superior, middle and inferior ganglia. The inferior cervical 
ganglion clinically seems to be most frequently involved. Since the 
nerves to the thyroid are derived from the lowest part of the cervical 
and upper thoracic region, lesions of the lower cervical vertebrae and 
upper ribs, the first in particular, would affect it. The impulses reach 
the gland by way of the branches that surround the thyroid arteries. 

The veins of this gland are also large and very numerous, forming 
a plexus which is drained by the superior and middle thyroid, which 
empty into the internal jugular, and the inferior thyroid which empties 
into the innominate vein. A displacement of the first rib, it usually 
being backward and downward at the sternal end, upward and back- 
ward at the vertebral, will directly or indirectly produce pressure on 
these veins. A subluxated clavicle will in a similar way interfere with 
drainage. 

Atrophy or lack of development of the gland will produce myxede- 
ma; in children, cretinism or idiocy. 

Aneurism of the arch of the aorta or carotid arteries may change 
the contour of the anterior part of the neck. 

The trachea is located immediately below the cricoid cartilage, it 
being about one and a half inches above the sternum, ft can only be 
seen when the neck is in extreme extension. The trachea is sometimes 
opened to relieve dyspnea, as in croup. 



120 APPLIED ANATOMY. 

The vessels that can be seen in the anterior part of the neck art! 
the superficial veins that stand out so very boldly in many patients 
during exertion, especially if the breath is held. The posterior and 
external jugular are the most important. Experiments have been per- 
formed in which oil was injected into the pericardial sac. In such 
cases it was found that the superficial veins of the neck became dis- 
tended. Clinically in cases in which there is a pericarditis or pleural 
effusion by which the right auricle is compressed, the superficial veins 
of the neck become distended. The explanation is that the venous re- 
turn is obstructed, to a certain extent, by the pressure on the heart, and 
the blood is forced back along the veins and the effect is most marked 
in the superficial because they are not supported by muscles as are the 
deep veins. In some types of organic disease of the heart, pulsation of 
the superficial veins of the neck is quite noticeable. I have noticed that 
children suffering with sore throat or tonsillitis often have enlargement 
and distension of the veins of the neck. 

The carotid arteries can be palpated and the pulsation, if unusually 
hard, can be seen. Such latter pulsations of the carotid arteries are 
very suggestive if not diagnostic of some form of heart disease. 

The lymphatic glands of the neck' are often very much enlarged, so 
that the contour is decidedly changed. Scrofula, tonsillitis or disease 
of any part drained by the anterior cervical lymphatic glands will cause 
their enlargement. In ordinary sore throat "kernels" form under the 
angle of the jaw. Lesions of the neck sometimes produce these enlarge- 
ments. Tuberculosis is the common cause of chronic enlargement of 
these lymphatic glands, especially if the enlargement is marked. Ton- 
sillitis produces an enlargement or swelling immediately anterior to 
and below the angle of the jaw. This swelling or rather fullness, is 
always present in chronic tonsillitis, therefore a fullness under the angle 
of the jaw is almost diagnostic of disease of the tonsils or of adenoid 
growths in the throat. Chronic tonsillitis predisposes to tuberculosis 
of the lymphatic glands of the neck in that the tubercle bacilli enter the 
crypts of the tonsils, thence into the lymphatic glands that drain the 
tonsil. The lowered vitality of these glands permits the micro-organisms 
to gain a footing in the body, and soon the patient has scrofula. The 
kernels increase in size and finally an abscess forms. On this account, 
children suffering with chronic sore throat or especially tonsillitis, should 
be treated early and thus prevent infection through the tonsils. 



APPLIED ANATOMY. 



121 



APONEUROSIS COMPLEXUS OCCIPITALIS 




SPLENIUS 
CAPITIS 



TRAPEZIUS 



L1CAMENTUM 
NUCHA 



SPLENIUS COLLI 



Fig. 32. — Showing the relation of the superficial muscles of the upper part of the 
back of the neck. These are first to be affected by thermic influences as in the catch- 
ing of cold in the head. 



122 APPLIED ANATOMY. 

Tuberculosis may be the cause as stated above of these lymphatic 
enlargements, but in all probability it is the result of the infection 
that reached the glands through the throat and tonsils. 

The nerves that are in relation with the superficial structures of 
the front of the neck are the vagus, and phrenic. These nerves are 
sometimes treated for a palliative effect by pressure directed over their 
course. In hiccough the phrenic is inhibited; in disturbance of struc- 
tures supplied by the vagus, this nerve is either stimulated or inhibited 
by manipulation of it along its course. Such treatments are not cura- 
tive and not always palliative, and are only advised when no better treat- 
ment can be given. Pain near the angle of the jaw is usually in the 
inferior division of the fifth cranial. Pain in the median line or near 
by is suggestive of laryngitis. Pain in this region is seldom a referred 
one in the sense that it is the result of disorder elsewhere, it being 
due to direct, involvement by some local disturbance. The cause of 
greatest pain in the front and side of the neck is some form of tonsillitis. 
Acute laryngitis and diphtheria also produce marked pain in this region. 

The contour of the back of the neck is governed more by the condi- 
tion of the trapezii than by any other one factor. These muscles form 
a furrow, the median furrow of the neck, along which the spines of the 
cervical vertebra?, with the exception of that of the atlas, can be readily 
palpated. The trapezius is contracted in colds in the head, uterine 
headache, spinal meningitis and headache from weakness or other dis- 
turbance of the eyes and is quite tender when contractured. This ten- 
derness is possibly due in part to the fact that the muscle is markedly 
congested when contractured. To the other or outer side of the inser- 
tion of this muscle is a fossa, the sub-occipital fossa, which is a very im- 
portant place from an osteopathic viewpoint, because the articular pro- 
cesses of the cervical vertebras can be palpated along the furrow lead- 
ing down the neck from it. Tenderness in the sub-occipital fossa is 
almost diagnostic of an upper cervical lesion. In such cases deep pal- 
pation reveals muscular contractures and a general tightness in the 
upper cervical region. Pressure at this point-, applied by means of the 
fingers, is the usual palliative treatment for headache. Headaches 
caused by an upper cervical lesion can be relieved by such a treatment. 
By deep pressure applied to this point is secured adjustment of the 
vertebral articulations and relaxation of the contractured tissues. 

The best place to apply this pressure in the treatment -of headaches 



APPLIED ANATOMY. 123 

is in the median line immediately below the occiput. By applying it 
here the occiput is pried slightly off the atlas and the circulation to and 
from the head freed, to a certain extent. This is an especially effective 
treatment in cases in which the headache is due to a tightening of the 
cervical tissues, that is in cases of congestive headache, especially the 
form due to disorders of the eye, such as eye-strain. 

In lesions of the cervical vertebra?, the irregularity can best be de- 
termined by palpation along the above mentioned furrow. The artic- 
ular processes are changed in position in lesions affecting the bones; 
the articular processes are in relation with this furrow, hence in suspected 
lesions of the neck, carefully palpate over the articular facets. 

The bony landmarks of the neck are the transverse processes ot 
the atlas and the spinous processes of the second and seventh. The 
third may be regarded as a landmark since its spine is furthest anterior. 
The greatest movement exists at the atlanto-axial articulation. Mo- 
bility is also quite marked at the third cervical, it being subject to dis- 
locations. It is also subject to fracture, at least it is most frequently 
fractured of the cervical vertebrae. Always test for mobility of the var- 
ious cervical articulations. This is best done by grasping and holding 
the neck at points corresponding to the different articulations and then 
with the other hand move the head in various directions. 

The skin of the back of the neck is very thick and the circulation 
through it more sluggish than through the vessels of the skin of the 
front of the neck. On account of this fact and that it is subject to fric- 
tion from the clothing, this part of the neck is subject to boils and car- 
buncles. This is also true of the integument covering the upp-er part 
of the back and shoulders, also that of the gluteal region. 

The temperature of the back of the neck is indicative of the condi- 
tion of the tissues beneath the skin. The condition of these tissues de- 
termines the condition of many of the organs and structures above, 
especially the mucous membrane lining the nasal fossa. If the back 
of the neck is cold, it indicates a condition of low vitality of the part 
which is most frequently the result of cervical lesions. Such conditions 
are followed or accompanied by catarrh. The catarrhal effect will 
come in a few minutes after sitting with the back of the neck exposed 
to a draught. Coryza is the result. The explanation is that the thermic 
stimulation readily affects the neck if the part is weakened by cervical 
lesions, thereby setting up muscular contractures. These contractures 



124 APPLIED ANATOMY. 

affect the centers controlling the amount of blood to the head, espec- 
ially the nasal mucous membrane. The impulses are so interfered 
with that congestion follows in a very short time, which congestion is 
manifest first by a sense of tightness followed by a "running of the 
nose." If the patient can sneeze, often the cold will be aborted. These 
vaso-motor centers are located in the upper thoracic segments and the 
impulses pass through the superior cervical ganglion, from which they 
pass up through the ascending branches to the fifth cranial nerve, thence 
to the vessels of the nasal mucous membrane. The contractured cer- 
vical muscles prevent, or rather interfere with, the normal amount of 
impulses. The conclusion is, keep the back of the neck warm all the 
time and the probabilities are that colds in the head can be prevented. 
To do this, correct all cervical lesions that so weaken the neck that a 
slight draught will affect the muscles thus made abnormal. If this is 
done, every little change of weather and exposure to draughts will not 
cause coryza or make the catarrh worse. Also be careful about need- 
lessly exposing the back of the neck to a draught. Nature attempts 
to prevent this by causing the hair to grow long. We destroy nature's 
fortifications by wearing the hair closely cropped, as in the male, or 
knotted or rolled up on top of the head as does the female. 

The back of the neck is subject to many changes from atrophy or 
enlargement of the parts composing it, or from deposits or new growths. 
The muscles, as mentioned above, are subject to contracture. The 
trapezius is affected in curvatures of the spine, hip dislocations; in short, 
from limping from any cause, if chronic. In torticollis the sides are 
not symmetrical. In hemiplegia the neck muscles are involved. Thick- 
ening of the muscles may take place without affecting the contour of 
the neck. In all head and throat affections, some of the posterior mus- 
cles of the neck are always thickened, the obliqui, splenii, trachelo- 
mastoid and multifidus spina? being most frequently contractured. 

The ligaments become thickened from lesions of the articulations. 
The thickening is most marked on the convex side. A thickening on 
the left side over the articular process would indicate that the ligaments 
had been partly torn by extreme flexion to the right side. The tender- 
ness will be on the left. This explains unilateral tenderness from ver- 
tebral lesions. If tenderness is about equal on each side, it indicates 
stretching of both sides, that is, the lesion resulted from extreme flexion 
or extension of the neck. The unilateral thickening or enlargement is 
by far the more common. 



APPLIED ANATOMY. 125 

The lymphatic glands along the sides of the neck become enlarged 
from causes similar to those producing enlargement of any lymphatic 
gland : scrofulous conditions or formation of toxic material in area drained 
by the gland. 

The neck is the seat of many kinds of aches and pains. In most 
cases the patient is not aware of possessing so many tender places in 
the neck until an examination is made by palpation. Tenderness under 
the occiput in the median line is indicative of eye affection. Tender- 
ness over the articular processes is almost diagnostic of subluxation of 
the vertebra or injury of the ligaments. Superficial tenderness or hyper- 
esthesia is an accompaniment of recent injuries, meningeal affections 
and lesions affecting the sensory innervation. Tenderness and pain 
are increased by pressure, tightening of the muscles from the catching 
of repeated colds, improper treatment of the neck, such as a sudden 
and unexpected twist or pull, and disturbances of the spinal cord. 

The neck as a region is more subject to injury than any other part 
of the body. This is on account of its free mobility, exposed position 
and its size. Childbirth, improperly handled, is responsible for many 
cases of idiocy, paralysis usually of the spastic type or Little's disease, 
monstrosities and various deformities of the head and body. Too much 
or improper traction is used. Forceps are unnecessarily applied. Force 
is used in a wrong direction, the neck twisted and traction exerted dur- 
ing rotation of the head, and the neck is injured. The child's mental 
and physical development are retarded and the trouble is attributed to 
heredity. There are cases of hydrocephalus, microcephalus, spastic 
paraplegia; retraction of the head, inability to talk, Little's disease, 
non-control of movements of limbs, diseased gums with crumbling teeth 
and many other forms of disease that, in the author's practice, were 
found to be the result of injury at delivery. 

Dr. Still has called my attention to the improper extraction of 
teeth, in many cases, as a cause of neck lesions. The strain, the posi- 
tion, the force, the sudden jerk that accompanies or follows extraction, 
all tend to injure the neck, for it bears the brunt of the strain. 

There are many other causes, such as colds, a sudden turn of the 
head, improper treatment, occupation and the various injuries to which 
the neck is subjected. The parts of the neck most frequently affected 
are the atlanto-axial articulation and the articulations of the third 
cervical, the points of greatest mobility and weakness. 



126 APPLIED ANATOMY. 

Many disorders of the cervical region are the result of lesions lower 
in the spinal column. A lesion in the upper thoracic region will cause 
contracture of the cervical muscles which in turn, interferes with move- 
ment of the head and neck. In some cases seen by the writer, there 
was a constant pain in the cervical region as a result of a lesion of the 
fourth dorsal vertebra. The pain started from the point of lesion but 
was greatest in the upper part of the neck. Perhaps most of these 
secondary cervical disorders are the result of muscular contracture, while 
some are due to direct interference with the innervation of the neck. 
The point to be remembered in this connection is, that the lesion is not 
always at the point of pain or where the effect is, but often at a place 
somewhat distant from the manifest effect. 

The effects of these lesions are manifold. The special senses, brain, 
face, throat, arms and the neck itself are involved. The kidneys may 
be affected, 0¥ a spinal curvature may result from a neck lesion as was 
the case in a patient seen by the writer. Most of the diseases of the head, 
face and throat have been considered with the discussion of effects of 
lesions affecting the superior cervical ganglion. Some of the arm af- 
fections have been described. In addition to those mentioned there might 
be named the occupation neuroses, Erb's paralysis, wrist drop, pro- 
gressive muscular atrophy, contractures and deformities of the forearm, 
wrist and fingers, and the painful disturbance usually, called neuralgia. 
In all occupation neuroses seen by the author in which the upper ex- 
tremity was involved, a neck or thoracic lesion was found. These le- 
sions weaken the arm and act as predisposing causes; the occupation is 
the exciting cause. If the occupation were the only cause there would 
be many more cases of telegrapher's cramp. As it is, only a very small 
per cent of telegraphers are attacked. The same is true of the other 
occupation neuroses. To cure such cases, remove both the predisposing 
and exciting causes; that is, correct the neck lesion and advise the pa- 
tient to rest. 

Erb's paralysis involves the upper arm and shoulder, at least the 
effect is there. Neck and upper thoracic bony lesions disturb the origin, 
exit and nutrition of the nerves which supply these parts, hence the 
effect. These lesions change the size of the intervertebral foramina, 
which must of necessity affect the vessels and nerves that pass through 
them. This effect may be motor, sensory, secretory, vaso-motor or 
trophic. The conclusion is that in any or all effects in the upper ex- 



APPLIED ANATOMY. 127 

tremity the cause lies in the spinal column, especially the cervical and 
upper thoracic portions, unless the trouble is due to trauma whereby 
the nerve trunk is directly injured. Occasionally, the nerve is affected 
by a dislocation of the shoulder, elbow or wrist, so it is well to begin at 
the point of disturbance and follow the course of the nerve back to its 
exit from the spinal canal since in this way it is easier to locate the lesion. 

THE THORACIC VERTEBRA. 

The dorsal or thoracic vertebrae being typical vertebrae, consist of 
two parts, a body and an arch. The body is not quite circular but some- 
what heart-shaped, it being wider transversely than antero-posteriorly. 
It is concave above and below, in which concavities fit the interverte- 
bral discs.- The bodies are somewhat concave from above downward 
and are slightly beaked. The front surfaces are perforated for the 
passing in and out of the various blood-vessels, the smaller transmitting 
the nutrient arteries, the larger the veins (the venae basis vertebrarum) . 

The arches give rise to seven processes. The spinous project 
backward and downward and can be seen in most patients. The two 
transverse processes project outwardly, are quite thick and terminate 
in a clubbed extremity. Each articulates with the corresponding rib. 
They give attachment to many muscles and furnish a powerful leverage 
to them. 

The two superior articular processes project upwards and bear 
facets which project or rather face backwards, slightly upward and 
outward. 

The inferior facets face directly opposite to the superior. The 
laminae are continuous with the spinous processes and complete the arch 
posteriorly. 

THE FIRST THORACIC. 

The first thoracic is a transitional vertebra, in that it resembles 
the cervical and thoracic types. Its spine is usually more prominent 
than that of the vertebra prominens. It is thick, very strong and in 
position is almost horizontal, projecting slightly downward. The 
superior facets are almost flat and face backward, slightly outward 
and upward. 

The articular processes help to form the foramina, on which account 
the least change in their position would affect the size of the foramina 
formed by them. 



128 APPLIED ANATOMY. 

The transverse processes are typical of those of the other thoracic 
vertebra and have facets for articulation with the first ribs. The facets 
on the transverse processes face slightly upward, thus giving a better 
support to the upper ribs. The body has two facets on a side for artic- 
ulation with the heads of the ribs; the upper one is entire, the lower a 
demifacet. 

The movements of this vertebra are slight, rotation being, perhaps 
the most pronounced. Flexion and extension are present but to a very 
slight degree. 

Lesions of various types are found affecting the articulations of 
this vertebra. The vertebra is subject to anterior, posterior and twisted 
conditions, this being determined by the character of the lesion. The 
effects of lesions involving this vertebra, that is, the articulation with 
the seventh cervical or with the second thoracic, depend on the degree 
of disturbance of structures attached to it and the amount of change 
in size of the intervertebral foramina. 

The indications of a lesion of the articulations of the first thoracic 
vertebra are tenderness over and around the spine, irregularity of the 
spine, it being out of line or approximated to one above or below, and 
disturbance of function of that part of the spinal column or of the vis- 
cera innervated by the upper thoracic spinal cord. 

The effects of a lesion on the articulations are similar to effects 
from other vertebral lesions, that is, a thickening of the tissues attached, 
the ligaments being congested or inflamed, hence tender. The supra- 
spinous ligament is always affected in chronic cases, it becoming soft- 
ened and thickened and quite smooth, sometimes entirely filling the 
space between the adjacent spinous processes. 

The important muscles attached to the first thoracic vertebra, hence 
necessarily involved by a displacement of this bone, are the levator 
costae, serratus posticus superior, multifldus spina?, rotatores spina?, 
spinalis dorsi, transversalis colli, trachelo-mastoid and complexus. All 
of these have been considered with the exception of the rotatores spins 
and levator costae. 

The levator costae muscle arise from the transverse processes of the 
vertebrae and is inserted into the rib below at a point between the 
angle and tubercle. The lower ribs receive two slips. The function 
of the muscle is, as its name indicates, to elevate the rib, that is to assist 
the external intercostals. The blood-supply is derived from the inter- 



APPLIED ANATOMY. 129 

costal arteries in relation. The nerve supply is from the intercostal 
nerves that are in relation. Contracture of this muscle causes a dis- 
placement of the ribs. In the upper thoracic region this is most fre- 
quent, and thus there is a predisposition to lung affections. In all 
cases of acute lung disease, these muscles are in a contractured state, 
while in the lung affections characterized by wasting and atrophy these 
muscles are atrophied as in tuberculosis of the lung. 

The rotatores spinae muscles, as their name indicates, have to do 
with rotation of the spine, a rather important movement of this region. 
A disturbance of their function would result in impaired movement, 
that is painful or otherwise disturbed rotation, of this part of the spinal 
column. Their fibers run from above downward and outward and 
can be palpated when contractured. As a result of a lesion of the first 
thoracic vertebra the position and movement of the ribs would become 
pathological, and flexion, extension, lateral flexion and rotation of this 
part of the spine would be interfered with, the movements being re- 
stricted or painful. 

The spinal column would be weakened at the point of lesion. Fa- 
tigue would be first and most marked at the first thoracic, if it were sub- 
luxated. Colds would settle at this place and the patient would be 
conscious of a weakness in this region. This weakness has a tendency 
to produce change in contour of this part of the spine, flattening being 
the common change. 

The lower articulations of the thoracic vertebra; will be considered 
instead of the upper as was the case in the cervical vertebra;; this is 
done in order to make the nerve correspond in number with the verte- 
bra. Only one articulation will be considered with each vertebra. 

The first thoracic vertebra articulates with the second by two facets 
and the body. Two foramina are formed through which pass vessels 
and nerves. I believe that nearly all diseases caused by vertebral 
lesions are the result of a lessening in size of the intervertebral foramina. 
Every vertebral lesion causes a lessening in size of either the foramina 
above, or below the affected vertebra. This affects the structures trans- 
mitted by the foramen. 

The veins passing through the intervertebral foramen between the 
first and second thoracic vertebrae, are the lateral spinal. They drain 
the vertebra, meninges and especially the first thoracic segment of the 
spinal cord. This vein follows the sheath of dura mater that surrounds 



130 



APPLIED ANATOMY. 



the first thoracic nerve. It is joined by the vein draining the muscles 
in relation. The vein thus formed empties into the upper superior in- 
tercostal vein, which in turn empties into the vertebral or innominate. 
An obstruction to the intercostal or spinal veins would produce passive 
congestion of the parts drained, viz., muscles, vertebra, ligaments, men- 
inges and spinal cord. 



SURINTE.RCOSTAI ART 
1st THORACIC N 
1st INTERCOSTAL N 
2dlNT'C N 



■ ANT.INTC, 
ART'S. 



INF.CERV.GANG. 




INT. MAMMARY j/^ '/"" 'HI! 
^3rf 4th.lNT'C A.VN. Ist^d.AORTIClNT'C A 



Fig. 34. — Showing the upper intercostal arteries and their anastomoses and 
branches. Note their relation to ribs. 



The lateral spinal artery passing through the foramen below the 
first, is derived from the superior intercostal which is a branch of the 
subclavian. The nerve supply of it is derived mostly from the sub- 
clavian plexus. The lateral spinal branch divides into three branches, 
one going in front of the body of the vertebra, called preneural; one going 
to the back of the spinal canal, or retro-neural; and a, middle branch 



APPLIED ANATOMY. 131 

which supplies the spinal cord and anastomoses with the anterior and 
posterior spinal arteries from the vertebral. The nutrition to these 
parts to which the artery is distributed will suffer to some extent, if the 
arteries are compressed even though there is a fairly free anastomosis. 
This would be the case in a subluxation of the first thoracic vertebra. 

The nerves passing through the first thoracic intervertebral foramen 
are the first thoracic nerve and the recurrent meningeal. The first 
thoracic carries many impulses to and from the spinal cord. 

They are composed of filaments that carry vaso-motor impulses to 
the head, neck, arm and shoulders and integument; secretory to many 
of the glands above; motor to the muscles supplied by this segment 
and the -involuntary muscles of the orbit and to the heart; sensory to 
to the viscera and integument supplied by this segment; and trophic to 
the various structures named above. The impulses distributed by the_ 
cervical sympathetic ganglia come from the upper thoracic spinal cord, 
hence a part of them pass over the first thoracic nerve, that is, through 
the first thoracic intervertebral foramen. On account of this peculiarity 
Hulett, in his Principles of Osteopath}' says: "The general statement 
is not far wrong that any disorder produced by a cervical lesion may 
be duplicated b_y an upper thoracic disturbance." 

The first thoracic nerve divides into an anterior and posterior di- 
vision. The anterior, gives rise to the internal anterior thoracic, inter- 
nal cutaneous, lesser internal cutaneous or nerve of Wrisberg, ulnar, 
median and first intercostal. The posterior divides into the internal 
and external branches. 

The internal anterior thoracic is of importance on account of sup- 
plying the pectoral muscles. A disturbance of this nerve would cause 
atrophy or other effects in these muscles, hence impairment of move- 
ment of the arms and chest. 

If the internal cutaneous nerve is involved by a lesion of the first 
thoracic, there will be sensory disturbances along the inner and anterior 
part of the forearm as low as the wrist and also along the inner and upper 
part of the arm. It is a sensory nerve. 

If the nerve of Wrisberg is involved there will be pain or other 
sensory disturbances over the olecranon process and a part of the inner 
aspect of the lower part of the arm. On account of this nerve communi- 
cating with the intercosto-humeral nerve, the sensory disturbance may 
be referred to the upper two or three intercostal spaces, or a lesion af- 



132 APPLIED ANATOMY. 

fecting the intercosto-humeral may cause the sensory disturbance to be 
referred to the lower part of the arm and elbow. The ulnar and median 
nerves have been discussed above. 

The smaller division of the first thoracic nerve continues along the 
first intercostal space as the first intercostal nerve, and supplies the in- 
tercostal muscles and pleura in relation. It seldom supplies the integu- 
ment over the first intercostal space, the lateral cutaneous branch being 
absent. It occasionally communicates with the lesser internal cutaneous 
and the intercosto-humeral. 

The internal branches of the posterior division of the first dorsal 
nerve supply the integument in relation; the external supply the muscles 
in relation. These nerves are reflexly affected in bronchial, throat and 
lung affections as is evidenced by the sensory and muscular disturbances. 
Pain over the parts supplied by the posterior division of the first thoracic 
nerve is indicative of (1), lesion of the first thoracic vertebra or first rib, or 
(2), disease of the upper part of respiratory tract as in colds, bronchitis 
and la grippe. 

The first thoracic nerve controls, in part at least, flexion of the 
fingers, pronation of hand, forward movement of the arm and shoulder, 
movements of the upper ribs through action of the levatores costaruni, 
serratus posticus superior and intercostal muscles, extension and lateral 
flexion of the upper part of spine. The motor effect of impairment of 
this segment from a lesion or from hemorrhage or inflammation (mye- 
litis), would be most marked in the muscles of the hand, back and upper 
part of chest. The rib muscles acting symmetrically would be little 
if any affected unless both sides of the cord were involved. These mus- 
cles are rarely jjaralyzed either by hemorrhage in the brain, as in hemi- 
plegia, or in the spinal cord as in anterior polio-myelitis. 

The first thoracic controls the sensory condition of the ulnar aspect 
of the forearm, inner side of the upper arm, the integument of the back 
in relation with the first thoracic vertebra, and the first intercostal space. 

The recurrent nerve, which is vaso-motor to the arteries in relation 
supplying the vertebra?, ligaments, meninges and spinal cord, would be 
involved by a lesion of the first thoracic. 

The stellate ganglion, which is in relation with the first thoracic 
vertebra, will be affected in some way by a lesion of this vertebra. This 
ganglion is irregular in form, slightly larger than the other thoracic 
ganglia and often coalesced with the inferior cervical ganglion. It is 



APPLIED ANATOMY. 



133 



PUPILO-DILATORS ORBITAND EYE-LID- 
VASO-MOTOR TO HEAD AND FACE ANDARM '. 
SECR'YTO SUBMAX'Y ANO SWE AT GLANDS \ 
VASO-GONSTfi'S PILO- MOTORS. \ 
CARDIAC ACCELERATORS --.. 
ERECTOR SPINAv 

ROTATORES 



INTEGUMENT OVERNtCKAS FAR AS MIDnLE orSCAPULA. 

longlss i mos dorsi semispinals 
/-accessorius multifious-spins. 
/ intertransversalis 
/^Interspinalis. \\ 



POSTTHORACIC 
POST CORD 




INF. CARDIAC N. 
PULMONARY PLEXUS 
AORTIC ,. 
CARDIAC „■£?-' 
CORONARY,,-^ 



MEDIAN 



Fig. 35. — Showing the first thoracic segment of the spinal cord with its nerves and 

their distribution. 



134 APPLIED ANATOMY. 

situated immediately in front of the head of the first rib and is in rela- 
tion with the pleura and the superior intercostal artery. It is connected 
with the ganglion above and below by the sympathetic chain and gives 
off the following branches: Filaments to the first dorsal vertebra and its 
ligaments, the thoracic aortic plexus and to the lungs and the grey 
ramus communicans. This ganglion transmits all vaso-motor, secre- 
tory, trophic, and possibly motor impulses destined for the parts above, 
or at least all impulses arising in the thoracic spinal cord pass through 
this ganglion on their way to the head and face. Some cells are located 
in the ganglion but its function seems to be that of transmission of im- 
pulses rather than that of originating them. Brubaker says that, in 
the cat, cutaneous nerves for the fore-limbs have their origin from cells 
in the stellate ganglion (first dorsal). 

The white ramus communicans, which is usually present, passes 
from the anterior division of the first thoracic nerve to the stellate gang- 
lion, thus carrying impulses from the spinal cord to the gangliated cord. 
Some of the fibers come from the posterior root. The gangliated cord 
generates some impulses, at least motor impulses, but the cells are mostly 
in the grey matter of the spinal cord. Quain says: "Some of the medul- 
lated fibers are continued over the ganglia of the cord to enter the ef- 
ferent branches; others end in the ganglia, often ascending or descending 
for a considerable distance in the cord to reach ganglia at a higher or 
lower level than that of the communicating branch by which they pass 
to the sympathetic." These fibers are not confined to one ganglion, 
sometimes passing to several ganglia above or below. The white rami 
therefore transmit to the gangliated cord, impulses generated in the 
spinal cord, some of which pass up, some down the gangliated cord, 
others passing directly through, thus forming the rami efferentes. The 
white ramus passing from the first thoracic nerve to the stellate ganglion 
carriespupilIo-dilatorimpulses,and impulses to the involuntary muscles of 
the eyelids and orbit, vaso-motor impulses to the head and face, accelerator 
impulses to the heart and secretory to some. of the salivary glands. 

The pupillo-dilator fibers originate in the upper thoracic segments 
of the spinal cord and pass out over the white rami into the gangliated 
cord, thence up the cord to the superior cervical ganglion, thence over 
the ascending branches to the third and fifth nerves. These impulses 
may arise as high as the seventh cervical and as low as the fourth thoracic. 
Lesions affecting these segments or the white rami, will interfere with 



APPLIED ANATOMY. 135 

the origination or transmission of these impulses, hence an effect in the 
parts supplied, that is the pupil. Contraction of the pupil may follow 
injuries to the first thoracic vertebra when these nerves are affected. 

The centers for the involuntary muscles of the orbit and eyelids are 
also located in these segments and the impulses reach their destination 
in a similar way. Strabismus often results from a lesion of the first 
thoracic vertebra. The vaso-motor, or the above nerve connection will 
explain it. Some claim that the voluntary muscles of the eye receive 
impulses from this part. 

Disturbance of the ciliary nerves is a common effect of this lesion. 
Blepharospasm, pain in the eyeball, weakness of the eyes, photophobia, 
conjunctivitis, and in fact almost any vascular disturbance of the orbit 
and eyelids results from a lesion of the upper thoracic vertebrae, the first 
in particular. The explanation is that the various impulses for the eye, 
especially motor and vaso-motor, originate in the upper thoracic 
spinal cord or there are subsidiary centers there and these impulses pass 
over the white rami to the gangliated cord, thence through the cervical 
ganglia to the nerves supplying the eye. Lesions of the first thoracic 
affect both the segments and rami, and hence interfere with the centers 
and the nerve tracts conveying the impulses. This has been practically 
proven in three ways: (1) by physiological experiments on lower ani- 
mals; (2) by dissection and (3), most important of all, clinically by taking 
cases with the diseases, correcting the upper thoracic lesions and curing 
the diseases. 

The vaso-motor centers for the head and face are also located in 
this region. It is possible and quite common for upper thoracic lesions 
to produce vascular effects in the head, congestion being most common. 
The writer has relieved many cases of headache by correcting a lesion 
of the first thoracic vertebra. The explanation of such lesions affect- 
ing the head is that they interfere or alter in some way, the passing of 
these impulses; they, originating in the upper thoracic segments of the 
spinal cord, pass out over the white rami to the gangliated cord thence 
up the cord to the vessels of the head and face. 

The accelerator impulses to the heart are transmitted in part by 
the white ramus of the first thoracic nerve to the sympathetic gangliated 
cord in relation, thence directly across to the cardiac plexus or up the 
gangliated cord to the cervical ganglia, thence out over the cardiac 
branches. Clinically most of these fibers emerge from a point lower in 



136 APPLIED ANATOMY. 

the spine, the fourth dorsal foramina being the most important. Con- 
gestive headaches are often the result of cardiac disturbances. A le- 
sion of the first thoracic vertebra may affect the heart, hence an effect 
is in the head. Congestive headaches may thus result from a disturb- 
ance of the vaso-motor nerves to the head or from heart affections. The 
upper thoracic lesions will affect both. 

The grey rami communieantes, as in the cervical region, arise from 
cells located in the sympathetic ganglia and pass to the anterior pri- 
mary division of the corresponding cerebro-spinal nerve. After reach- 
ing the nerve Quain says that "the fibers are directed both peripherally 
and centrally. Of those passing centrally some go off in the posterior 
primary division of the nerve, others enter the sheath of the nerve, the 
surrounding tissue in the intervertebral foramen, and the dura mater, 
running up to the latter in the posterior root." The fibers passing 
distally in the anterior and posterior primary divisions of the spinal 
nerves have been shown, by experiments oh animals, to supply "vaso- 
motor nerves to the arteries of the body-wall and limbs, pilo-motor 
fibers to the muscles of the hairs, and secretory fibers to the sweat glands. " 
Lesions of the vertebrae and ribs affect the grey rami. 

A lesion of the articulations of the first thoracic vertebra will affect 
the first dorsal ramus. As a result of this there are vaso-motor effects 
in the body-wall in relation, vertebras, ligaments, meninges and spinal 
cord, and secretory effects in the sweat glands. The predominating 
sweat centers seem to be located in the upper thoracic region, thus a 
lesion there will lessen or increase the amount of perspiration. 

It seems that the spinal nerves, through filaments that pass through 
the sympathetic gangliated cord, control or supply the viscera with 
sensation. Quain says: "There is strong reason for believing that the 
thoracic and abdominal viscera are supplied with sensory fibers derived 
from the spinal nerves, and passing through the sympathetic." These 
fibers pass from the posterior root to and through the sympathetic gang- 
liated cord without interruption, to the viscera. This then offers an 
explanation for referred pain. Head, after experimenting on animals 
and from inferences drawn from clinical observation in man, formulated 
a law, the substance of which is that a stimulus applied to an area of 
low sensibility in close central connection with an area of high sensibil- 
ity may result in pain being felt in the area of high sensibility. As an 
illustration, an irritation of the heart will produce pain in the chest wall 



APPLIED ANATOMY. 137 

over the heart. Sympathetic nerves supply areas of low sensibility, 
cerebro-spinal, areas of high sensibility. According to Head, the heart 
and lungs are supplied in part with sensation by nerves that come through 
the first thoracic foramen of the spinal column, that is by the first thoracic 
nerve. The impulses pass over the sympathetic to the white ramus, 
thence over the posterior nerve root to the spinal cord. Diseases of 
the heart and lungs affecting these sensory nerves would cause pain to 
be felt that is referred to the areas supplied with sensation by the upper 
thoracic nerves, in this case, the first. The impulses from the heart 
and lungs, and those from the areas supplied with sensation by the 
upper thoracic nerves pass through the upper thoracic segments of the 
spinal cord thence over a common tract to the sensorium. According 
to Head's law, the sensorium is often mistaken as to the source of the 
impulses and refers them to the areas of greater sensibility. This seems 
very plausible since all of the. sensory impulses from the above region 
pass through the upper thoracic segments of the spinal cord. As a 
result of this confusion of impulses, the pain in heart affections is re- 
ferred to the chest-wall and left arm, especially the ulnar aspect. In 
lung affections, it is referred to the intercostal nerves that are derived 
from the same segments of the spinal cord that supply the lung. The 
conclusion that we are forced to draw, is that the segmental innervation 
of viscera can be accurately determined by noting the points of pain in 
disease of the viscus, that is by rioting the cerebro-spinal nerve that is 
the supposed seat of the pain. To illustrate, if the heart is affected and 
the pain is referred to the fifth intercostal nerve, the fifth thoracic seg- 
ment of the spinal cord is the one that gives origin to the nerves of the 
heart, especially do the sensory impulses pass through this segment on 
their way to the sensorium. 

In quite a large per cent of all cases of angina pectoris, there is pain 
or numbness of the little and ring fingers of the left hand. The explana- 
tion as stated above is that that the sensory impulses from both the hand 
and heart pass through the same segment and there arises a confusion 
as to the source since normally, such impulses come entirely from the 
arm and chest wall. 

Summary. Lesions of the articulations of the first thoracic vertebra 
produce eye, brain, arm, bronchial, lung and throat disturbances. In 
colds, the articulations of this vertebra are invariably involved either 
primarily or secondarily through muscular contractures. Lesions of 



138 APPLIED ANATOMY. 

this bone produce pain in arm, chest and upper part of spine, muscular 
contractures in the interscapular region, impaired movement of the fingers, 
arm and spine and disturbances of sweat secretion in this area. The 
thoracic aorta, coronary and bronchial vessels and the splanchnic nerves 
may also be involved. 

THE SECOND THORACIC. 

The second thoracic vertebra is very similar to the first except that 
it has two demi-facets for articulation with the ribs, instead of an entire 
facet and a demi-facet. It is a typical thoracic vertebra. The spinous 
process is a little more oblique than that of the first. The movements 
of its articulations are very slight. Rotation is said to be the most 
marked of these movements, although flexion and extension are also 
represented. The superior facets face backward, slightly outward 
and upward'the surfaces being nearly flat. The inferior, face the op- 
posite way. The most common lesion is a lateral deviation if the sec- 
ond alone is affected, but if several of the upper thoracic vertebrae are 
involved, the most common lesion is an anterior deviation. Extreme 
flexion of the head and neck is productive of pain at the articulations of 
the second thoracic, if it is displaced. The other indications of a lesion 
are the usual pain, tenderness, softening and thickening of the ligaments 
and irregularity, or at least some change of contour. 

Lesions of this vertebra, and by lesion I mean a subluxation, affect, 
the ligaments attached to it, the muscles in relation, and the contour of 
that part of the spine. These are affected in a way similar to that re- 
sulting from a lesion of the first thoracic vertebra, which has been de- 
scribed. The intervertebral foramina are lessened in size thereby com- 
pressing a part or all of the structures passing through them. 

The veins are the lateral spinal which drain the spinal cord, the sec- 
ond thoracic segment in particular. They empty on the right side into 
the right superior intercostal, which empties into the vena azygos 
major; on the left they empty into the left superior intercostal vein 
which empties into the innominate. A lesion of the second thoracic 
vertebra or corresponding ribs will cause pressure on these veins, hence 
passive congestion of the parts drained by them. 

The arteries come from the superior intercostal. The spinal branch 
as stated above, divides into branches which supply the vertebra and 
the spinal cord with its coverings. Vascular changes in the cord would 



APPLIED ANATOMY. 



139 



pup:lo-dilators ORBITANDEYE-LIO. 
VASOMOT0RI0HEAD FACEANDARM , 
SECR"VTO 5UBMAXTAN0 5WEAI 6LASCS '. 
VASO-CONSTR'S PILOMOTORS 
CARDIAC ACCELERATORS -- 
ERECTOR SPINiE 
ROTATORES 



INT E&UMENT OVER BACK AT SPINE OF 2dTH0RACIG 

INTERTRANSVERSALIS 

SEMISPINALS DORSI 

MULTIFIDUS SPINS. 

-ACCESSORIUS 

SERRATUS-POST1CUS 

LEV. COSTARUM 

LONGISS1MUS- 
DORSI 

8lh CERVICAL 




Fig. 36. — The second thoracic segment of the spinal cord, with its nerves and 

their distribution. 



14(1 APPLIED ANATOMY. 

follow change in size of the intervertebral foramen, and muscular disturb- 
ances in that region. 

The anterior and posterior nerve roots unite at the inner edge of 
the foramen, while the trunk thus formed divides at the outer part, 
into the usual anterior and posterior divisions. This nerve trunk formed 
by the uniting of the two roots, carries many and varied impulses which 
will be considered separately. They are motor, sensory, vaso-motor, 
secretory and trophic. The size of the foramen through which these 
nerve filaments pass, is determined by the position of the vertebra. In 
flexion of the body, the foramina are increased in size while extension 
lessens their size. An anterior lesion that is a subluxation, has a greater 
effect on the size of the intervertebral foramen than does a posterior. 
These lesions by thus affecting, that is, lessening the foramina, interfere 
with the passing of nerve impulses through, and over the nerve involved, 
and the effect varies with the degree of pressure and the nerves involved. 

A motor effect is fairly constant in all lesions of the second thoracic 
vertebra. The muscles most frequently affected are the erector spina?, 
multifldus spina?, intercostal, levatores costarum and serratus posticus 
superior, the common effect being a relaxation or contracture. If the 
lesion is inhibitive, it will produce descent of the ribs, weakness of the 
spine, and a flattening or lessening of the normal posterior condition of 
this part of the spinal column. There are other causes of such effects 
since chronic disease of the heart and lungs will cause atrophy of these 
muscles and an increase in the width of the interscapular space. This 
is particularly true of tuberculosis of the lungs. 

Contracture of the above named muscles, and this is the result of 
an irritative lesion, would displace upward the vertebral end of the upper 
ribs, extend or laterally flex the spine, approximate the vertebra? if the 
contracture is bilateral, thereby thinning the intervertebral discs and 
lessening the lumina of the intervertebral foramina. Movements of this 
part are painful and the muscles are tender on pressure. The circulation 
through them is altered and the spinal cord fails to be properly supplied 
with blood, hence disturbance of function of the various centers located 
in this part of it. The dorsal branch of the intercostal artery divides 
into a lateral spinal and a muscular branch, or rather a spinal branch is 
given off and the main trunk of the artery passes out to the muscles. 
By noting the relation of these branches it can be readily seen that a con- 
tractured condition of the muscles supplied by the muscular branches would 



APPLIED ANATOMY. 141 

produce increased pressure in, and congestion of, the proximal branch, the 
spinal. The contractured muscle is congested and offers an obstruction 
ot the transmission of arterial blood. Thus the spinal cord suffers. 

The sensory effect resulting from pressure on the spinal nerve, would 
be anesthesia or pain or some perversion of sensation as in formication. 
These disturbances would be marked in the second intercostal space, 
between the scapula; and along the inner side of the arm. The last named 
part is affected because of the connection of the second thoracic nerve 
with the nerve of Wrisberg, by way of the intercosto-humeral. Dis- 
turbed sensation in the above mentioned places is due to some disturb- 
ance of the second thoracic nerve, this most frequently being the result 
of a lesion of the second thoracic vertebra or the corresponding rib. 
These sensory disturbances are explained in several ways. In some cases 
they are the result of direct pressure on the nerve trunk. This produces 
numbness, or a tingling sensation, and possibly a distinct pain in excep- 
tional cases. The lesion may interfere with the blood supply of the nerve 
trunk and in this way, that is, by producing a congestion, interfere with 
its function. The subluxated vertebra may obstruct the circulation to 
the second dorsal segment of the spinal cord in which are located the 
cells that control the efferent impulses. Again, this lesion by causing 
contracture of the muscles of the spine, causes sensory disturbances. 
This effect is characterized by an ache or else the part becomes easily 
fatigued on exertion. The sharp, lancinating pain is due to irritation 
of the nerve ; the ache, to contractured muscles ; the numbness, to pressure 
on the nerve trunk. These effects are in the main due to the direct result 
of the lesion, but in some cases, they are due to heart and lung disorders 
in which cases they are reflex. 

The second intercostal nerve also supplies the pleura, the rib and 
its periosteum. In the female it supplies the mammary gland. Thus 
there may be pleurisy, caries of the rib and mammary affections. 

The white rami join the anterior division of the nerve with the cor- 
responding ganglion on the sympathetic cord. The fibers come from the 
spinal cord, hence pass through, and form a part of, the cerebro-spinal 
nerve as it lies in the intervertebral foramen. A lesion of the second 
thoracic, by lessening the size of the foramen, would produce pressure 
on at least some of these fibers, hence some disturbance of the parts 
supplied by the impulses traveling over these fibers. These fibers con- 
vey vaso-motor impulses to the head and face, hence eruptions on the 



142 APPLIED ANATOMY. 

face, headaches and any vascular disturbance of these parts may follow 
a lesion affecting these fibers contained in this nerve trunk. Pupillo- 
dilator fibers also pass out through the second nerve and reach their 
destination by way of the cervical sympathetic nerves and their branches 
as described in the discussion of the first dorsal vertebra. The invol- 
untary muscles of the eyelids and orbit have a center in the second thoracic 
segment of the spinal cord, the impulses from which, reach their destina- 
nation by way of the white ramus and the cervical sympathetic and the 
Gasserian ganglion. The submaxillary gland receives its secretory im- 
pulses from this segment, they reaching it in a way similar to those 
above described. A lesion of the second thoracic vertebra would affect 
the passing of these impulses hence an altered secretion of the saliva. 
The writer has treated cases of dryness of the mouth resulting from a 
lesion of the second thoracic. The opposite condition may result. 

Some of.the sweat centers controlling the secretion of sweat in the 
arm are located in this segment. The impulses reach the arm by way 
of the roots and trunk of the second thoracic nerve, white ramus, gang- 
liated cord and brachial plexus. or subclavian plexus. 

The vaso-motor centers for the arm are also located in this segment 
and reach their destination in a similar way. Therefore, excessive or 
lessened perspiration of the arm, congestion or coldness of the arm. in 
fact any vascular change in it may follow a lesion of the second thoracic. 

The vaso-motor centers for the retinal vessels and the blood-vessels 
of the ear are located in this segment, the impulses from which pass out 
over the white ramus to the gangliated cord thence to their destinations. 
"Stimulation of the cervical sympathetic nerves produces contraction 
of the retinal vessels. Stimulation of the upper thoracic sympathetic 
nerves produces dilatation." 

The vaso-constrictor nerves to the pulmonary vessels pass in part 
through the second thoracic foramen. The size of the pulmonary ves- 
sels is controlled by these nerves. If these nerves are inhibited the pul- 
monary vessels dilate. As a result the circulation of the blood through 
the lung for. aeration is lessened, the blood is not properly oxygenated 
and the entire body suffers. The patient is tired because of impure blood. 
Fatigue is due to impure blood. The better the circulation through the 
lung the better the blood is oxygenated and the more rapid the recovery • 
from fatigue. Again, the lung and body are predisposed to disease when 
the pulmonary or bronchial vessels are dilated because (l).of the con- 



APPLIED ANATOMY. 



143 




Fig. 37. — Showing the innervation of the heart. 



144 APPLIED ANATOMY. 

gestion of the lung and (2), because of the interference with oxygenation 
of the blood and nutrition of the lung substance. Germs or toxic ma- 
terial inhaled, are not readily destroyed. 

The centers which give rise to accelerator impulses to the heart are 
also located, in part, in this segment. These impulses pass over the an- 
terior nerve root into the mixed nerve, out over the white ramus to the 
second dorsal sympathetic ganglion, then either up the cord to the 
stellate ganglion thence over the cervical cardiac branches, or else direct- 
ly across to the cardiac plexus, as McClellan states. In several dissec- 
tions the author has found quite a large branch connecting the vagus 
with one or more of the upper thoracic sympathetic ganglia. The im- 
pulses pass over the different filaments in the nerves in the foramen. 
This nerve is subject to pressure from lesions, hence the heart trouble. 
Not only is the cardiac plexus affected but the coronary plexus as well. 
This plexus controls the nutrition of the heart. 

The bronchi will be involved because of the disturbance of their 
nerve supply. This conies principally from the pulmonary plexus. 
This plexus is formed by nerves from the upper thoracic segments. 
They pass out of the spinal canal through the intervertebral foramina. 
A lesion of the second dorsal will affect, the passing of the impulses over 
these filaments. Congestion of the respiratory tubes may follow. Na- 
ture tries to expel the foreign body by coughing. The foreign body is 
most frequently a thickened mucous membrane or exudate. 

The vaso-motor innervation of the nasal tract comes from, at least 
in part, the second thoracic segment. On this account, a lesion at this 
point will affect the vascular supply of this part, hence any disease in 
which the circulation is involved. Clinically, the lesion producing hay 
fever, especially complicating asthma, is found at the second thoracic 
vertebra. The explanation is that the subluxation intercepts the pass- 
ing of the vaso-motor impulses, hence the congestion and hyper-secre- 
tion of the nasal mucous membrane. These impulses pass through the 
second thoracic intervertebral foramen and it is at this point that the 
disturbance takes place. 

The splanchnic nerve may arise as high as the second dorsal seg- 
ment but this is to be doubted. In such cases the impulses pass out 
over the cerebro-spinal nerve and the white ramus, thence down the 
gangiiated cord to the fifth dorsal ganglion, from which they pass over 
the ramus efferens. From this it theoretically follows that a lesion of 



APPLIED ANATOMY. 145 

the second dorsal will produce disorders in viscera supplied by this por- 
tion of the splanchnic, if the transmission of the impulses is interfered 
with by the lesion. Clinically it is unusual for a lesion so high to affect 
the viscera supplied by the great splanchnic. 

The impulses passing over the grey ramus enter the corresponding 
cerebro-spinal nerve, thence to parts supplied by this nerve. As stated 
above, the nerve fibers are, in all probability, medullated, and connect the 
viscera with the spinal cord, they passing through without interruption to 
the posterior nerve roots. In this way the heart and lungs are supplied 
with sensation by the upper thoracic branches of the spinal cord. The pain 
is usually referred to the intercostal nerves when these viscera are in- 
volved. Note the "grip-like" pain over the heart in angina pectoris 
and the stabbing pain of pneumonia. The pain in these cases being 
in the intercostal, that is cerebro-spinal nerves. 

The fibers that pass distalty in the somatic nerves "supply vaso- 
motor nerves to the arteries of the body-wall and limbs, pilo-motor fibers 
to the muscles of the hairs and secretory fibers to the sweat glands. " 
Every nerve fiber passing through the second thoracic foramen is sub- 
ject to pressure or other disturbance, from a lesion of the second dorsal. 
All of these may be involved, or only a few may be affected; in every 
case some of these fibers are disturbed. Disorder of the parts supplied 
necessarily follows, hence the above named affections. 

This lesion will affect the gangliated cord since it is in relation. 
Although the main function of this cord seems to be that of demedullat- 
ing fibers and transmitting impulses, yet some impulses arise in the 
ganglia. A lesion of the vertebra? will thus produce disease by affect- 
ing these ganglia, by interfering with their blood supply, rather than by 
direct pressure on them. 

The various centers located in this segment of the cord are subject 
to impairment through a derangement of the circulation to the segment. 
Again a diseased or simply a weakened condition of the viscera supplied 
by the segment will reflexly affect the centers in it. A lesion of the sec- 
ond dorsal vertebra will weaken the lungs and heart, thus the segment 
will reflexly be affected. An error in diet will cause congestion of the 
spinal cord and contracture of the muscles of the back. Excessive 
coitus will congest the spinal cord, usually the lower thoracic segments. 
Cold on the lungs will affect the second dorsal segment and produce con- 
tracture of muscles in relation. In this segment are located the various 



146 APPLIED ANATOMY. 

centers named above, such as vaso-motor to head, face, arm, lung and 
heart; motor to the muscles in relation, heart and eye; sensory, which 
are really in the ganglion on the posterior nerve root, to the heart, lungs, 
pleura and the integument over the second intercostal space and a por- 
tion of the interscapular region; secretory to sweat glands of arm, and 
to the submaxillary glands; trophic to the arm, rib, periosteum, liga- 
ments and vertebra. Each of these centers may be involved, or only 
one may be affected. From this can be ascertained the variety of struc- 
tures that may become diseased from this lesion, also the kind of dis- 
ease. Lesions of the second dorsal are clinically most commonly looked 
for in diseases of the head, such as congestion, and vertigo; and inarm 
and lung diseases. 

THE THIRD THORACIC. 

The third thoracic vertebra differs slightly from the second in that 
its spine is slightly longer and more beaked or knobbed than the spine 
of the second. The transverse processes point upward and outward for 
articulation with the rib. This the better supports the ribs. The 
facets on the transverse processes in many skeletons examined by the 
author, face slightly upward, this also helping to support the ribs. The 
superior articular facets face backward, slightly outward and upward 
and their surfaces are plane. The mobility of the articulations varies 
little from those of the second. The lesions are also similar, that is 
any form of deviation may take place, a lateral rotation being most 
common. As a result of a lesion of it the muscles and ligaments attached 
to it, are always involved. The foramina are lessened and some or all 
the structures passing through are involved. 

The veins and arteries are analogous to those of the second. 

The nerves passing through the foramen between the third and 
fourth thoracic vertebrae, carry motor impulses to the heart, possibly 
the lungs, pupil, and muscles in relation. The impulses to the heart 
travel by way of the anterior root, common nerve, white ramus, gang- 
lion and rami efferentes. Those to the pupil pass up the gangliated 
cord and out over the fifth cranial. 

Although it has not been demonstrated that motor impulses pass 
from the upper part of the thoracic spinal cord to the bronchi and bron- 
chioles, yet, judging from the effects of treatments applied in this region 
in patients suffering with motor disorders of these parts/ one is almost 



3 




148 APPLIED ANATOMY. 

forced to the conclusion that they do. In the paroxysm of asthma, the 
attack can either be entirely stopped or at least lessened in severity by 
treatment applied to this area. Sometimes pressure alone will relieve. 
Although it is possible to explain these effects in a way, by means of the 
vaso-motor connection, yet we do not believe this the true explanation. 
Experimentally, stimulation of the anterior roots of these nerves in ani- 
mals has no noticeable effect on the size of the bronchi, but clinically 
in man, the correction of a rib lesion in the upper thoracic region will 
almost instantly relieve an attack of asthma unless the case is a very 
chronic or severe one. 

The muscles supplied are the intercostals, levatores costarum, ser- 
ratus posticus superior, multifidus spina; and erector spince. These 
muscles will be either relaxed or contractured by a lesion affecting their 
nerves. 

Sensory impulses from the integument of the axilla and arm, third 
intercostal space and upper part of back pass through this foramen. 
Sensation of the heart and lungs is controlled by nerve filaments that pass 
through this segment, the impulses therefore passing through this foramen. 
The impulses from the integument pass up the anterior and posterior 
divisions of the nerve, thence over the posterior root into the spinal cord, 
usually directly across to the opposite side. The sensory impulses from 
the heart and lungs are probably carried by special nerves that pass 
through the sympathetic ganglia with little or no alteration, as Quain 
points out. Some pass through the white rami, the third posterior root 
and finally into the spinal cord. On account of these sensory connec- 
tions, a disease of the heart or lung will give rise to impulses that travel 
into the spinal cord, and the sensorium refers them to the areas of distribu- 
tion of the upper thoracic nerves, principally the intercostals. To illustrate, 
the pain in heart disease is described by the patient as in the precordial 
region. It is referred to this point. 

The pleura is supplied with sensation by the third intercostal, hence 
pleurisy often follows a lesion of the third thoracic vertebra. The im- 
pulses pass over the intercostal to the spinal cord thence to the sensorium. 
False pleurisy results from some forms of vertebral lesions. The pressure 
is exerted on the nerve while in the foramen, the impulses thus generated 
pass to the sensorium over the usual route but are referred to the peri- 
phery of the nerve, hence the "stitch'' in the side from a rib or vertebral 
lesion. 



APPLIED ANATOMY. 149 

In the female, the mammae are supplied by the third intercostal 
nerve. This nerve is principally sensory hence in painful conditions of 
the breast the intercostal nerves are involved. 

Again, lesions, such as that of the third dorsal, cause painful con- 
ditions to be referred to the breast. In all cases of pain in the mammary 
region ascertain if there is a local, organic disturbance, or if it is purely 
reflex. The vertebral or rib lesion is responsible, in either case, for a 
vast majority of diseases of the breast. 

Vaso-motor impulses to the arm, head and face, lungs, heart, muscles 
of back, spinal cord and its coverings pass in part through this foramen. 
The different pathways are described above under the second dorsal. 

The arteries involved by this lesion are those in relation and those 
innervated by the vaso-motor nerves that pass through the foramina 
in relation with the third dorsal vertebra. The intercostal arteries are 
supplied with vaso-motor impulses derived from the third thoracic seg- 
ment. These pass by way of the thoracic aortic plexus. On this ac- 
count the lesion will affect this artery, either causing its constriction or 
dilatation. This artery supplies the part of the chest wall in relation, 
the pleura, the rib and its periosteum, the muscles of the back and the • 
spinal cord. As a result of the lesion there are vaso-motor effects in 
these parts. The lateral spinal arteries which are branches of the inter- 
costal, are in relation with the vertebra and would be affected partly 
on this account, and, partly on account of the relation of their vaso-motor 
nerves to the third thoracic vertebra. This artery supplies the spinal 
cord and its coverings, hence vascular disturbances of the part when 
the vessel is increased or decreased in size. 

The carotid arteries are affected since they receive their vaso-motor 
impulses from the thoracic area. Some of these impulses pass out 
through the foramina in relation with the third thoracic vertebra. As a 
result of such a disturbance, the amount of blood in the parts supplied by 
these arteries and their branches becomes pathologically changed. 
Usually the artery is dilated and congestion of the parts is the sequel. 

The vertebral artery receives its nerve supply from this part of the 
spinal cord and thus would be affected by lesions of the second and third. 
Its function and distribution have been considered before. 

The pulmonary vessels receive their vaso-motor impulses partly by 
way of the nerve passing through the third intervertebral foramen. 
Consequently, there will be congestion or anemia of the lungs. This 
predisposes to pneumonia. 



150 APPLIED ANATOMY. 

The bronchial vessels also receive their innervation in a similar way. 
An upper thoracic lesion will thus affect the nutrition of the lung, this 
predisposing to diseases of the lung tissue, such as tuberculosis. 

The coronary arteries which control the nutrition of the heart's 
muscle, receive their vaso-motor impulses from the upper thoracic spinal 
cord. They pass out over the anterior nerve roots, the common trunk, 
the anterior division and thence by the white ramus into the gangliated 
cord and cardiac plexus. As a result of a lesion at the third thoracic 
vertebra, the nutrition of the heart may be interferred with. Angina 
pectoris is perhaps the best example of this form of disease. 

The axillary artery and its branches are also innervated in part 
from this segment, thus diseases of the arm often result from lesions 
as low as the third thoracic vertebra. 

A lesion of the third dorsal will interfere with the passing of these 
impulses and the blood-vessels of the above named parts are affected. 
The usual effect on the vessel is that of dilatation. The effect of a le- 
sion pressing equally on all the fibers composing the nerve trunk is man- 
ifest first in the weakest part. Although each may be affected, the 
strongest resist longest and the weakest are affected first. A lesion of 
the articulations of the third dorsal vertebra, may, in one case, produce 
a vaso-motor effect in the eyelids, in another case, in the throat. The 
explanation is, the weakest part is affected most if a lesion disturbs all 
of these fibers alike, but ordinarily the lesion affects some fibers more than 
others. A lesion of the third thoracic vertebra produces vaso-motor 
disturbances in the above mentioned structures by producing pressure 
on the nerve fibers as they pass through the foramen, by producing pres- 
sure on the blood-vessels supplying or draining the spinal cord, or by 
pressure on the gangliated cord or rami which are in close relation. 

The sweat glands of the arm and back (upper part) and the sub- 
maxillary glands receive impulses which are carried by nerve fibers 
passing through the third thoracic intervertebral foramen. The effect 
on these glands is variable; sometimes there is increased activity, some- 
times lessened activity. 

If there is a dry condition of the skin, or if there are night sweats, 
the lesion is found most frequently to be in this region, the articulations 
of the third thoracic being most commonly affected. Perhaps these 
effects are the result of the direct disturbance of the sweat glands or per- 
haps the result of general nutritive disturbances. The latter seems to 



APPLIED ANATOMY. 151 

be the better explanation since in practically all such cases, there js mal- 
nutrition. If the sweat disorders are not accompanied by nutritive 
changes, the sweat glands are directly affected, but this is the exception 
rather than the rule. 

Trophic fibers are derived from the third dorsal segment that supply 
the arm, periosteum of the third rib, the third rib itself and all other 
parts supplied by the third thoracic nerve. A general nutrition center 
is supposed to be located here which will be considered later. The 
writer has seen cases of caries of the ribs result from a spinal lesion. 

Atrophy of the arm is not unusual by any means, as a sequel to a 
lesion of the third dorsal vertebra. Several cases have come under my 
notice in which the arm was completely paralyzed, both sensory and 
motor, as a result of a hard lift or injury by which the third thoracic 
vertebra was dislocated, or rather subluxated, thus producing a mono- 
plegia. In many of such cases there is a dislocation of the acromial end 
of the clavicle. 

The third thoracic nerve connects with the third dorsal sympathetic 
ganglion and occasionally sends a filament to the nerve of Wrisberg and 
other filaments which communicate peripherally with the supra-clavic- 
ular branches of the cervical plexus. Through the third ganglion com- 
munication is established with the second and fourth sympathetic thor- 
acic ganglia, pulmonary, cardiac, coronary and solar plexuses, and in 
some cases the pneumogastric. The author has made and seen dissec- 
tions in which was found quite a large branch directly connecting the 
third and fourth sympathetic ganglia with the vagus. 

The function of this connecting branch can only be surmised. It, 
in all probability, carries impulses from the spinal cord to the thoracic 
viscera or perhaps to other viscera and structures supplied by the pneu- 
mogastric nerve. If the branch were constant, the various effects of 
an upper dorsal lesion on the lungs and heart, could the more easily be 
explained, especially asthma and motor disorders of the heart. So 
far as I know, no experiments have been performed by which the func- 
tion of this connecting branch could be definitely ascertained since it is 
not recognized as a constant branch. 

In marked dislocations of the third thoracic, as in other vertebrse, 
transverse myelitis may develop, from pressure on the cord exerted by 
the displaced vertebra. At the third thoracic vertebra, paralysis, both 
motor and sensory, of all parts below would follow. The line of demarka- 
tion can be definitely outlined, it following the intercostal nerve. 



152 



APPLIED ANATOMY. 



PUPILO- DILATORS ORBITAND EYELIDS 

VASO MOTORTO HEADANDFACE. TOARM \ 

JECRETORYTO SUBMAXILLARY 
AND SWEAT GLANDS 

CARDIAC ACCELERATOR 

PILO-MOTOR 

VASO-CONSTRICTOR 



INTEGUMFNTOVEft BACKATSPINE 
SEMISPINALS DORSI 
MULTIFIOUS SPINA1 
ERECTOR SPIWff. 
LEV COSTARUM 



RATU5 POSTICUS 
CESSORIUS 
LONGISSIMUS DORSI 




Vertebra 
aortic pi 

CARDIAC 

PULMONARY 

CORONARY 



Fig. 39. — Showing the third thoracic segment with its nerves and their dis- 
tribution. 



APPLIED ANATOMY. 153 

The spinal cord is affected in ways other than by pressure directly 
on it. Pressure on the posterior nerve root or ganglion will cause as- 
cending degeneration thus involving some or all the sensory columns of 
the spinal cord. Locomotor ataxia probably has its origin in pressure 
or other disturbance of these posterior nerve roots. Pressure of the dis- 
located vertebra on the blood-vessels affects the drainage, also the nutri- 
tion, hence activity of the cord and its centers. 

Clinically, there seems to be various centers in the spinal cord which 
are affected by a lesion of the articulation of the third and fourth thor- 
acic vertebra. The author has had patients complain of a weight rest- 
ing, as it were, on their back and shoulders and in nearly all such cases 
some disturbance of the third or fourth thoracic vertebra, was found, 
upon the correction of which, the symptoms were relieved. Others are 
hysterical and want to cry; some have hysterical fits of laughter. On 
account of the effects of a subluxation of the third on the emotions it 
has been given as an emotional center. Why it exerts such an influence 
on the emotions no anatomical explanation will be attempted, only these 
clinical phenomena above mentioned. 

Subluxations of the third and fourth thoracic vertebrae, seem to 
produce malnutrition »~>f the entire body, and from the frequency of dis- 
ordered nutrition following such lesions, it is reasoned that there is a 
center at or near this region, which controls the nutrition of the body. 
This center is in all probability, in the grey matter of the third and fourth 
segments of the thoracic spinal cord. The explanation that 1 would 
offer is the fact that these segments have to do with supplying the vital 
organs of the bod)', viz., the heart, lungs and stomach. Thus a lesion 
affecting these segments would interfere (1) with the circulation of the 
blood, the heart being weakened, (2) with the oxygenation of the blood 
and (3) the process of absorption or power to take nourishment from the 
ingested food. • Circulation of the blood is necessary to nutrition, ox- 
genation of the tissues is indispensable, thus the general result, malnutri- 
tion. The kind of lesion found, is a flattening of this area of the spine. 

The cilio-spinal center is located, in part at least, in this segment. 
Headache from eye disturbances can ofttimes be cured by correcting 
a lesion of the second or third thoracic vertebral articulations which 
affects the cilio-spinal center. This center is either irritated or inhibited 
by the lesion. There is a vascular effect in the eye, the parts most 
frequently becoming congested and headache follows. As stated above, 



154 



APPLIED ANATOMY. 




Fig. 40. — Diagrammatic representation of the roots and ganglia of the spinal 
nerves, showing their position in relation to spinal column (after Cunningham). 
The ganglia are in the intervertebral foramina and are subject to pressure in sub- 
luxations of the vertebrae on account of change in size of these foramina. 



APPLIED ANATOMY. 155 

the impulses pass out from this center over the anterior root into the 
common trunk, white ramus, gangliated cord, thence up and out over 
the third and fifth cranial nerves. 

The center for the accelerator impulses of the heart is located in 
part, in this segment. Palpitation, arrhythmia and other effects are 
manifest when this center is disturbed. 

The center for the lungs is also located in part, in this segment of the 
spinal cord. A lesion of the articulations of the third dorsal will weaken 
the lungs. Repeated contractures of the muscles of the upper part of 
the back will also weaken the lungs thus predisposing the patient to 
tuberculosis of the lungs. Repeated colds on the chest is an example. 
Congestion of the lung will produce contracture of the muscles supplied 
by this segment, also pain in the areas supplied with sensation by the 
nerves of this segment. The sharp intercostal pain in pneumonia, and 
the tenderness of the intercostal muscles in pulmonary tuberculosis, 
are examples. The well known and much used counter-irritant, is an- 
other illustration of how a stimulation of one part causes an effect in 
another, through the spinal cord. The explanation is that the spinal 
center, located in part in the third thoracic segment, controls the lung 
and the sensory and motor nerves supplying the part of the chest wall 
in relation, and the irritation of the peripheral nerve, will cause an effect 
in this segment, hence in branches coming from the segment. 

The arm has a special nutritional center in these upper spinal seg- 
ments, as is evidenced by cases in which there is monoplegia resulting 
from lesions of the articulations of the third thoracic vertebra. Per- 
haps the vaso-motor centers and nerves have a great deal to do with the 
nourishment of the arm, these centers being in this segment. If the 
trophic center and nerves are separate from, and independent of the 
vaso-motor nerves, we can offer no explanation as to the pathway of 
these impulses which are supposed to pass from this segment to the 
arm. Clinically, it is well known that a lesion of the upper thoracic 
vertebral articulations, is often followed by an atrophic change in one 
or both arms. 

Sweat centers are also located here which control the amount of 
perspiration of the upper part of the spine and arms. Localized sweat- 
ing of a lateral half of the face most commonly results from a neck lesion, 
but may come from lesions lower in the spinal column. Localized sweat- 
ing along the median furrow comes from a lesion of an upper thoracic 



156 APPLIED ANATOMY. 

vertebra. Sweating along the course of a rib is suggestive of a rib 
lesion (the one in relation). This produces a lowering of the tempera- 
ture of the part. Abnormal dryness of the skn of the upper part of the 
back and chest may follow a lesion of the third thoracic vertebra, which 
in turn, disturbs the normal activity of the sweat centers for these areas. 

Some forms of chorea result from lesions in this part of the spinal 
column, judging from clinical observations. In some of the cases 
treated by the writer, in which the arms were especially affected, the 
lesion was found to be in the upper thoracic area and upon its correction 
the choreic symptoms disappeared. I have no explanation to offer 
for this unusual effect of the lesion unless it would be possible for the 
subluxation so to interfere with the passing of motor and vaso-motor 
impulses to the arm that they pass intermittently instead of constantly. 
The obstruction to the passing of impulses over the nerve to the arm 
produces a damming up of the impulses which after a time, when the 
pressure gets to be quite strong, break over and thus the spasm or rather 
the uncontrollable contraction of the muscles supplied. Clinically, 
pressure applied near, or at the exit of the nerve from the spinal column, 
will lessen or completely stop the choreic spasm. From this we con- 
clude that the trouble is at the exit of the nerve, that is in the foramen. 

Summary. A lesion of the third thoracic vertebra may produce 
disease of the bronchi, lungs, heart, stomach, arm, vertebral column, spin- 
al cord, upper part of chest and back, neck, pleura, mammary glands, and 
structures in the cranial cavity, especially the eye, salivary glands, ear 
and nose. The most common diseases following a lesion of this verte- 
bra are pneumonia; pulmonary tuberculosis, the lesion in these diseases 
so weakening the lungs that the different pathogenic micro-organisms 
gaining access to the lung set up pathologic processes; arrhythmia, pal- 
pitation, angina pectoris, chronic cough (dry or hacking); disturbances 
of vision; mammary diseases; pleurisy; paralysis of arm; chorea; writer's 
cramp; pain between shoulders; stiffness of neck and headache. 

THE FOURTH THORACIC. 

The fourth thoracic vertebra is one of marked importance on ac- 
count of frequency of subluxation and the profound effects from lesions 
of it. It is located in a rather weak part of the spinal column, is sub- 
ject to great strain when the arms and shoulders are used as in strong 
muscular exertion, and is the seat of trauma of different kinds, especially 



APPLIED ANATOMY. 157 

that resulting from a sudden' push or blow between the shoulders as in 
the case of school children, one suddenly and forcibly pushing another 
at an unexpected moment. This produces an anterior condition and 
often is the starting place of Pott's disease of the spine and spinal curva- 
ture. 

The fourth, seems to be the point of division between the upper 
and lower parts of the spinal column. Dr. Still has often told me that 
in disorders of parts above, that is of the head and face, look as low in 
the spine for the lesion as the fourth, while in affections of parts below, 
look as high as the fourth. The explanation of this is that the heart is 
at this level, that is all parts above the fourth are supplied with blood 
by the ascending branches, while all parts below this vertebra, are sup- 
plied by the descending branches. This is true in the main. In a gen- 
eral way, expect the lesion to be between the part affected and the heart. 

The superior facets of the vertebra in this region are so placed that 
a directly anterior displacement without separation, is practically im- 
possible, but they may rotate in various directions. The anterior rota- 
tion causes an approximation of the spines of the third and fourth ver- 
tebrae and a separation of the spines of the fourth and fifth dorsal. The 
break is below the lesion, and is a point of increased mobility. At the 
point of approximation of the spinous processes, mobility is lessened 
and is the place that most needs treatment. The object in the treat- 
ment of such a condition, as in all vertebral subluxations, is the restora- 
tion of normal mobility. Lateral rotation of a single vertebra, results in 
a lessening of the size of the intervertebral foramen on the side to which 
the vertebra is turned. The opposite intervertebral foramen is either 
not affected or is increased in size. In such cases there is a unilateral 
effect as in monoplegia, an upper extremity being involved. Usually in 
such a lesion, there is a palpable irregularity although this does not hold 
true in every instance. The author has seen dissections in which no 
bony lesion could be palpated by external examination, so far as con- 
tour was concerned the spines being very regular, but on dissecting the 
articular processes, quite an irregularity or subluxation was found. 

These lesions of the fourth dorsal, affect structures attached to it, 
blood-vessels and nerves in relation, and centers and viscera depending 
for their activity upon normal position of the bone; an abnormal posi- 
tion interfering with their nutrition and motor, vaso-motor or sensory 
supply. 



15S APPLIED ANATOMY. 

The principal muscular effect of a lesion of the fourth thoracic ver- 
tebra, is manifest in the erector spinas muscle. At first it becomes con- 
tractured but after a while, atrophies or becomes degenerated and hard- 
ened. The median furrow, which is formed principally by the two 
erector spinas muscles, is widened in chronic cases, at the point of lesion 
and especially so, if several adjacent vertebrae are involved. The other 
muscles involved by this lesion are the levatores costarum, rotatores 
spinae, multificlus spinae, intercostals and serratus posticus superior. 
As a result of these muscular disturbances flexion, extension and rota- 
tion of this part of the spine are painful and difficult or weakened. The 
rib movements are impaired or in some cases, the ribs are subluxated 
by the continued contracture. In other cases relaxation, instead of 
contracture, follows the lesion. This permits of descent of the ribs and 
causes the spine to be imperfectly supported. The patient drops the 
shoulders and sits with the spine very much arched posteriorly, that is 
the. patient is "piled up" instead of sitting erect and supporting the 
weight of the trunk on the tuber ischii. 

The blood-vessels affected are the veins and arteries passing through 
the fourth thoracic foramen, those of the muscles in relation and some 
or all of the branches of these vessels. 

In addition to these, the thoracic aorta in relation, with its branches 
will be affected. The branches involved are, the pericardiac, bronchial, 
esophageal, and the fourth intercostal. These arteries are innervated 
by branches of the thoracic aortic plexus, which is derived from the 
nervi efferentes of the upper thoracic sympathetic ganglia. On this 
account, a lesion of the fourth dorsal vertebra will disturb the function 
of this plexus and thus affect the amount of blood passing to the above 
named parts. The effect on the vessels is one of obstruction, or vaso- 
motor inhibition, therefore congestion occurs in most instances; how- 
ever, anemia may result. 

The parts congested are the spinal muscles, pleura, spinal cord; in 
fact all structures in relation are subject to congestion by this lesion. 
The spinal vessels are supplied with nerves by the recurrent nerve and 
by filaments from the thoracic aortic plexus, which gives rise to fibers 
that accompany the intercostal arteries and their branches. 

The following nerves are affected, most of them directly, by a lesion 
of the fourth thoracic vertebra: Fourth thoracic with its intercostal 
or anterior, and posterior divisions, muscular branches .of the above, 



APPLIED ANATOMY. 



159 



PUPILO DILATORS EYE-LIDS 
VASO-MOTOR TO HEAD, FACE ARM 
SECRETORY TO SWEAT &LANDS ■, ' 
ACCELERATOR TO HEART 
ROTATOFES M 

ACCESSORIUS M 



1NTE&UMENT OVER BACK ATSPINE0F4-lhT. 
ERECTOR SPIN*. 

MULTIFIDUS SPIN/S. 
LEVATOR COSTARUM 




CARDIAC , 
CORONARY , 
PULMONARY, 



VASO-MOTOR, ABDOMINAL 
VISCERA ANOTOLUN& 



Fig. 41 — Showing the fourth thoracic segment with its nerves and their dis- 
tribution. 



160 APPLIED ANATOMY. 

recurrent meningeal, grey and white rami, the fourth thoracic sympa- 
thetic ganglion and its branches and the gangliated cord. 

As a result of an impairment of the fourth intercostal nerve, the 
intercostal muscles, pleura, mamma, fourth rib and its periosteum are 
disturbed in some way as to function. The intercostal muscles are most 
frequently relaxed, thus respiration is impaired. If the lesion is an 
irritative one, the muscles become tender and contractured to a slight 
degree, at least they become swollen. The pleura is affected, there 
being pain on inspiration or what is more frequently described as a 
"catch" or "stitch" in the side. 

These painful affections follow such a lesion because (1) the parietal 
layer of the pleura receives its sensory innervation from the intercostal 
nerve in relation, the nerve being affected by the lesion, and (2) because 
the pleural surfaces move on each other in respiration. These surfaces 
are swollen, •sometimes inflamed, and the least movement is productive 
of excruciating pain. 

The mammary gland is involved by this lesion. The character 
of the disturbance may vary between a slight pain and a cancerous con- 
dition. This nerve, i. e., the fourth intercostal, seems to be sensory, 
trophic and possibly secretory to the gland. The effect of the disturb- 
ance of the nerve may be pain, lack of development or atrophy and 
lessened secretion of milk. 

It has not been definitely demonstrated that the mammary gland 
has any secretory nerves at all. Clinically, it would appear that secre- 
tory nerves supplied the gland and that they came by way of the inter- 
costals in relation. This is based on observations of the results of rib 
lesions and the effects of their correction. As in other glands, the secre- 
tion depends to a large degree on the blood-supply. 

Howell says, in discussing the mammary gland: *" Regard- 
ing the question of the existence of a secretory nerve, Basch re- 
ports that the extirpation of the celiac ganglion or section of the sper- 
matic nerve does not prevent the secretion, but causes the appearance 
of colostrum corpuscles. Experiments, therefore, as far as they have 
been carried, indicate that the gland is under the regulating control of 
the central nervous system, either through secretory or vaso-motor 
fibers, but that it is essentially an automatic organ. " 

*Text-book of Physiology, page 857, 1905. 



APPLIED ANATOMY. 161 

The trophic effects may often result in ulceration, which simulates 
cancer, and in tumefactions of the breast. 

The fourth rib is also supplied with trophic impulses by the fourth 
intercostal, hence often suffers as a result of lesions involving this nerve. 
The writer has seen cases of caries of the rib result from a vertebral le- 
sion, the disease being diagnosed as tuberculosis of the rib. The perios- 
teum of the rib is of course also supplied by this nerve, this probably 
explaining the caries in such cases in which this nerve filament is in- 
volved. 

Sensation of the fourth interspaces is affected by a lesion involving 
the fourth dorsal vertebra. Pain is the most common effect, although 
numbness, burning sensation or some other form of perverted sensation 
may occur. Complete sensory paralysis is uncommon but is occasionally 
met with in cases of marked vertebral lesions. 

The posterior division supplies a part of the integument over the 
middle part of the thoracic region and the muscles in relation, the in- 
ternal branch supplying sensation, while the external branch is princi- 
pally motor. This nerve is frequently involved in uterine or other 
pelvic disease. Aching between the shoulders is a very common symp- 
tom in these cases. I believe that in such cases the muscles of the upper 
thoracic region are reflexly put in a contractured state and, like other 
muscles, they soon become fatigued and begin to ache. The pathway 
of the reflex arc is not well understood. The author presumes that 
there is a center in the fourth thoracic segment that controls the activity 
of the mammary glands. These glands are parts of the generative 
system, hence closely connected in every way with the rest of the genera- 
tive organs. On this account, they are subject to reflexes as a result of 
pelvic derangement. The muscles ache the more when used. If the 
patient should attempt to use the shoulders and arms as in sweeping, 
the shoulders ache for some time afterward^. This reflex ache seldom 
occurs independently of a lesion of the vertebra or ribs in relation, the 
lesion acting as the predisposing cause. If this were not the case every 
woman suffering with a congested uterus would have a pain or ache be- 
tween the shoulders. 

The grey ramus is subject to pressure from a subluxation of the 
fourth dorsal vertebra. This pressure is most frequently indirect, that 
is through adjacent tissue which is deranged. Sensory and vaso-motor 
impulses are carried by this nerve, hence an affect on the spinal cord and 



162 APPLIED ANATOMY. 

the part of the thoracic wall that is in relation, to which this nerve carries 
impulses. 

The white rami are also subject to impairment in the above lesion. 
The fourth white ramus carries from the fourth dorsal segment to the 
fourth thoracic sympathetic ganglion, impulses for the eyes, head and 
face, heart, lungs, bronchi and arms; thus disease or weakening of any 
or all of these organs and structures may result from a lesion impairing 
this white ramus. It also carries afferent impulses from certain of the 
viscera, to the spinal cord. 

The gangliated cord and the fourth thoracic sympathetic ganglion 
are sometimes affected directly by a lesion of the articulations of the 
fourth. This ganglion gives rise to the following branches: Filaments 
that pass to the thoracic aortic, cardiac, pulmonary and coronary plex- 
uses and small branches to the vertebrse and their ligaments. Most of 
the impulses passing over these branches originate in the spinal cord, 
a few perhaps being formed in the sympathetic ganglia. In either case, 
the effect of the lesion would practically be the same; that is, an inter- 
ference with the transmission of the impulses to the lungs, heart, vessels 
.and vertebra?. 

The nerves connecting with the fourth dorsal nerve are the fourth 
thoracic ganglion and, through this ganglion, the third and fifth gang- 
lia and the solar, pulmonary, cardiac and coronary plexuses. 

The parts that are most frequently affected or actually diseased by 
this lesion are, the eyelids, optic nerve, retina, ocular muscles, the head, 
face, heart, lungs, arm, pleura, chest wall, mamma?, spine, back, spinal 
cord, everything in the fourth intervertebral foramen, the. abdominal 
vessels and stomach. The eye and its appendages are not often affected 
by a lesion so low. In the dog it has been shown experimentally, that 
vaso-motor impulses arise in the cord as low as the fourth but clinically 
in man this is to be doubted. The fourth thoracic segment contains 
clinically, centers for nutrition, sweat, emotions, arm, heart, lungs, 
mammae, cilio-spinal, and some describe a center here which when affected, 
produces chills. These centers consist of groups of nerve cells that con- 
trol the motor, vaso-motor, secretory, trophic and possibly the sensory 
impulses to the above named parts of the body. For these centers to 
be effective they must be well nourished and in close connection with 
the parts supplied, that is the reflex arc must be intact. The activity 
of the nerve cells is controlled by the efferent as well as afferent impulses 



APPLIED ANATOMY. 163 

reaching them and the degree of nourishment furnished them. The 
lesion affects these centers by disturbing the nutrition of the cells by 
exerting pressure on the vessels that supply and drain this part of the 
spinal cord. This disturbs nutrition hence is productive of disorders 
of one or more of these centers. 

Osteopathically, a lesion of the fourth dorsal is associated with cer- 
tain effects that are fairly constant. Named in order of their importance 
and frequency we have: malnutrition, functional heart affections and 
lung disturbances; other diseases such as pleurisy, spinal cord affections 
in which the fourth segment is involved, mastitis and other mammary 
diseases, weakness of the muscles in relation and disturbances of the 
spinal column such as Pott's disease and curvature sometimes result. 

Malnutrition is the most constant effect of a lesion of the fourth 
dorsal. The form of lesion most frequent is an anterior condition 
characterized by softness, tenderness and a smooth rounded condition 
of the tip of the spinous process. The most significant change and sign 
is the anterior position. The explanation of the general effect lies in the 
fact that the lungs which purify the blood, the heart which propels the 
blood, and the stomach and liver which furnish nutrition to the blood, 
are all innervated, at least in jaart, by the fourth thoracic segment of the 
spinal cord. Malnutrition is usually mostly due to lack of, that is im- 
perfect, oxygenation of the blood. Blood to be health}' must have 
oxygen. This is furnished the blood b^y the lungs. If the lungs are not 
active, the amount of oxygen furnished the lungs is decreased in propor- 
tion to the weakening of the lung. On account of this, intercurrent dis- 
eases are more fatal. The lungs can not meet the requirements. A per- 
son with weak lungs is anemic and malnourished. If such a person con- 
tracts disease, the chances of recovery are lessened in proportion to the 
weakness of the lungs. The lesion of the fourth thoracic vertebra weak- 
ens the lungs by interfering with (1) the circulation to and through the 
fourth thoracic segment of the spinal cord in which are located some of 
the vaso-motor and trophic centers, and (2) by interfering with the 
transmission of these impulses since the intervertebral foramen is less- 
ened either directly by change in position of bone, or by ligamentous 
thickening. The inrpulses pass over the anterior nerve root into the 
common trunk, thence over the white ramus into the ganglion, then out 
over the rami efferentes to the pulmonary plexus. Malnutrition is 
most marked in the young. There are, of course, other causes such as 




r T,A. 



Fig. 42.— Showing the deep, short muscles of the back, (after Spalteholz). 
Note the direction of the fibers and effect of contracture on position of vertebra) 
end of rib. 



APPLIED ANATOMY. 165 

imperfect respiration and bad air. One writer has stated, and I think 
truthfully, that tuberculosis of the lung was "a disease of the lazy," 
meaning that the lungs were not used properly, deep breathing being 
too much of an effort. 

If the heart is weakened it does not properly propel the blood around 
the vascular circuit and the circulation is lessened in rapidity. This 
causes impure blood because of imperfect elimination and increased 
formation of toxic material. One's vitality is measured by the condi- 
tion of the blood. A sluggish circulation implies poor blood, hence a 
lowered vitality. 

The other cause of malnutrition, that is an interference with ab- 
sorption of food, is perhaps not so important as the two named above. 
This may occur independently of a lesion of the vertebrae, viz., from 
dietetic errors, yet such lesions make it possible for slight indiscretions 
of diet to produce marked effects. In all cases of anemia, defects in 
development of this part of the vertebral column, and back, shortness 
of breath on exertion, in fact in any form of malnutrition, examine care- 
fully for a lesion of the fourth dorsal. 

The cardiac disturbances are most commonly functional, occasion- 
ally organic diseases follow. Arrhythmia is the most frequent of these 
effects. The heart beats regularly for a few moments then apparently, 
if not in reality, loses a beat. The explanation is that the nerve feed 
to the heart that is, the motor impulses do not regularly reach the heart. 
A muscle responds to the various changes in the nerve impulses. These 
impulses supplying the heart arise in part from centers located in the 
fourth thoracic segment. They pass to the heart via the anterior root, 
common nerve, white ramus, gangliated cord, thence up to the stellate 
and cervical sympathetic nerves, then over the cardiac branches or 
directly across by way of the rami efferentes. This lesion affects the 
origin of the impulses or the nerve transmitting them. The former is 
affected by way of the blood supply to the segment; the latter in the 
intervertebral foramen which is lessened in size by the lesion and through 
which the nerve fibers pass that carry impulses to the heart. The pres- 
sure on the nerves carrying the impulses to the heart is the better ex- 
planation. 

Palpitation is explained in a similar way. The lesion obstructs the 
transmitting of cardiac impulses. The nerve force seems to accumulate 
back of the obstruction and finally overcomes it. The heart then re- 



166 APPLIED ANATOMY. 

sponds to the accumulated impulses. This is soon exhausted and the 
heart lessens in rapidity in proportion. Again the cardiac centers may 
be unstable from lesions involving them or from impure blood on ac- 
count of which the nerve cells are improperly nourished. In exercise, 
the heart beats rapidly in order to force blood to the lung for oxygena- 
tion as rapidly as it becomes deteriorated from katabolism. Fright 
may cause palpitation, if the heart is irritable, as is often the case when 
it is weak. Its tone and strength depend on the condition of the centers 
and the line of communication reaching from these centers to the heart. 
If they are weakened from any cause, and a lesion of the fourth dorsal 
is the most common, any exciting cause such as a displaced uterus, dis- 
tended stomach, exercise or fright will have the greatest effect on the 
weakest organ; in this case, the heart. 

Bradycardia is the result of an impairment of the cardiac centers. 
This impairment may be from a lesion or from some disease as the pro- 
found toxemia from diphtheria. Tachycardia is indicative of a weak, 
irritable heart. It seems to be in such a nervous condition that any 
exciting cause may markedly increase the pulse rate. The lesion of 
the fourth dorsal predisposes the heart to such diseases by interfering 
with its nerve mechanism described above, thus leaving it in a weak, 
irritable and nervous condition. In cases of Bright's disease the heart 
may become very rapid. 

The "smothered feeling" is sometimes due to a lesion of the fourth 
dorsal but more commonly due to a displacement of the fourth rib on 
the left side. Angina pectoris, of which the above is a symptom, is the 
result of a similar lesion. Hypertrophy sometimes follows a lesion of 
the fourth dorsal which has an irritative effect on the cardiac centers 
or nerves. Organic heart troubles in most cases, follow lesions of the 
upper thoracic vertebra? or ribs on the left side. Rheumatic fever is 
given the credit of producing most cases. It is the exciting cause. 
The writer has carried many patients through attacks of acute rheu- 
matism without cardiac complications. In these cases care was used 
to correct and keep corrected, all lesions that would affect the heart. I 
believe that organic heart disease, that is endocarditis, can be prevented 
by such treatments, that is by correcting all lesions that would affect 
the innervation of the heart. The explanation is that these lesions so 
weaken the heart that the fever, with its toxic products, the more readily 
affect the valves and thus interfere with the nutrition of the heart muscle. 



APPLIED ANATOMY. 167 

Some diseases of the heart result from a vaso-motor disturbance of 
the nerves of its blood-vessels. The coronary artery and its ramifica- 
tions supply the heart. This artery is controlled presumably, by the 
coronary plexus, which in turn is governed by centers in the thoracic 
spinal cord. The impulses reach the coronary plexus by way of the 
cardiac plexus. The vaso-motor supply of the heart has not been definite- 
ly demonstrated. A lesion of the fourth dorsal impairs the transmission 
of these impulses by lessening the size of the intervertebral foramina. 

Remember that the heart is a muscle. Muscle fibers contract when 
their nerves are stimulated and relax when inhibited. There must be a 
center for control, and there must be a line over which impulses pass 
from the center to the muscle. A lesion of the fourth dorsal affects 
both. There may be a stimulation or inhibition, at least there will be 
a pathological effect from such disturbances of the cardiac nerves and 
centers. • 

The lungs are weakened by a lesion of the fourth dorsal because 
the nerves supplying them pass through the intervertebral foramina. 
After the lung is thus weakened any disease to which it is subject, the 
more readily sets in; in fact, microbic diseases of the lung would not 
occur if the viscus were not first weakened. 

Summary. Lesions of the fourth dorsal should be suspected in 
malnutrition, heart diseases, lung diseases, mammary affections, atrophy 
of one arm, in some cases of stomach disorder, localized pain over this 
region; in short, disease of any part innervated by the fourth thoracic 
spinal segment. 

THE FIFTH THORACIC. 

The fifth thoracic vertebra differs slightly from the fourth in that 
the spinous process is a little longer, more oblique and more distinctly 
hooked or clubbed. The superior facets face almost directly backwards 
and are as a rule, plane surfaces. The foramina are partly formed by 
these articular processes and the least deviation in position of these 
processes would cause a change in size of the foramina; either the lower 
or upper foramina are lessened in size. The same remarks that were 
made concerning the frequency and cause of lesion of the fourth will 
apply to the fifth. Mobility of this part of the spinal column is very 
slight. This part acts as a sort of pivot, the movements above, that is 
in the upper thoracic and cervical regions, being marked, as are the 
movements of the lumbar spine. 



168 APPLIED ANATOMY. 

Contractured muscles in this area, can scarcely be relieved by physi- 
cal exercises on the part of the patient. Such contractures are less 
common in the more movable parts of the spinal column. Movement 
of the parts tends to relieve such conditions, hence when such occur in 
the region of the fifth thoracic, they are not much affected by ordinary 
exercises since movement of the spine at this point, is slight. 

Lesions of the fifth result ordinarily from one of two causes: Con- 
tractured muscles from, thermic or other influences; or from trauma. 
The most common form of trauma is a sudden, unexpected bend in this 
part of the spine. This sort of injury produces a sprain of the ligaments, 
some serous exudation, disturbance of the intervertebral discs, espec- 
ially those connecting the articular processes, contracture of muscles 
attached and a lessening in size of the intervertebral foramina. This 
form is characterized by pain on movement or what is often called, a 
stitch in the'back, which in favorable cases gradually disappears. In a 
vast majority of cases it furnishes the starting point for diseases of the 
spinal cord in this region, the spinal column and the stomach. The supra- 
spinous ligament, on account of its position, seems to be affected more 
than the other vertebral ligaments. It thickens, softens and remains 
tender and compressable for quite a while. After awhile it shortens, 
this helping to produce approximation of the vertebra? as in a stiff or 
rigid spine. 

The commonest lesion of the fifth is an anterior subluxation caused 
by a forward rotation of the upper part of the vertebra. This would 
cause an approximation of the spines of the fourth and fifth dorsal. From 
this it may be inferred that in a case of a break in the spine, the vertebra 
immediately above the break is the one at fault unless one part of the 
spinal column is turned, twisted or otherwise displaced on the part be- 
low. The latter is, in my opinion, by far the most common form of 
spinal lesion in which there is irregularity. In treating such conditions, 
the part below should be grasped and held firmly while the part above 
is used as a lever, thereby restoring normal relation between the two 
portions. 

The muscles directly involved are the erector and multifidus spina?, 
rotatores spina? and the levatores costarum. These muscles in the 
typical lesion, become contractured and as a result, their origins and in- 
sertions are approximated to a pathological degree. The bony frame- 
work becomes warped, as it were; that is, secondary bony lesions form. 



APPLIED ANATOMY. 169 

These muscles remain tender and can be readily palpated, remaining 
cord-like. These contractures interfere with the circulation of blood 
through them and through the intervertebral foramina. Congestion or 
arterial anemia of the spinal cord follows the latter. In some forms of 
lesions the muscles undergo atrophy. 

The veins passing out through the fifth intervertebral thoracic 
foramen, empty into the intercostal after uniting with the veins that 
drain the muscles in relation. The blood then on the left side, usually 
passes into the left upper az_ygos veins thence to the heart by way of 
the vena azygos major and superior vena cava. The blood from the 
right intercostal, passes direciiy into the vena azygos major. These 
veins are subject to pressure from enlargement of the lungs, stomach, 
intestines and liver. Congestion of the lungs interferes with the pass- 
ing of blood through these veins, by exerting pressure directly on them, 
especially the left azygi veins, because they cross the bodies of the verte- 
brae. In all diseases of the above named viscera in which the size of 
the viscus is increased, the patient should lie as much as possible in the 
ventral or lateral position. If the ventral position is not assumed at 
least daily, congestion of the spinal muscles and particularly the spinal 
cord, follows. This in turn coupled with the toxemia resulting from 
the disease, often produces a form of paralysis. Post-typhoid paralysis 
is a good illustration of paralysis, from in part at least, faulty posture. 

The arterial circulation through the parts in relation with the fifth 
dorsal is affected by a lesion of this bone. The arteries in relation are 
the intercostal and their branches, the principal one being the dorsal, 
which divides into the muscular and spinal. The spinal branch is given 
off first, hence in muscular contractures, which obstruct the muscular 
branch, the blood backs up into the spinal branch, thus congesting the 
spinal cord and especially the fifth segment. 

The nerves that would be involved by a lesion of the fifth dorsal 
are the fifth thoracic, its anterior or intercostal and its posterior branches, 
the recurrent meningeal, the grey and white rami communicantes, the 
fifth thoracic sympathetic ganglion and its branches and the gangliated 
cord. 

The nerves that pass through the fifth thoracic intervertebral 
foramen are the fifth dorsal and the recurrent meningeal. The trunk of 
the fifth dorsal contains fibers that transmit all of the kinds of impulses 
peculiar to this region. Motor impulses pass out over this nerve to the 



170 APPLIED ANATOMY. 

following muscles: Intercostals, levatores costarum, obliquus externus, 
rectus abdominis, erector spinae, rotatores spinas and multifidus spinse. 
These impulses may be augmented or decreased by the lesion of the fifth 
dorsal vertebra. As a result of increase in intensity of impulses, the 
movements of the chest, back and abdomen are impaired. The ribs 
are pulled upward at the vertebral end, the spinal column curved later- 
ally since these muscular contractures are seldom equal on both sides, 
and the abdominal wall is made tense. These changes are common but 
result oftener as reflexes from visceral disease than directly from the 
fifth dorsal lesion. If the impulses are inhibited or interrupted the 
above named muscles atrophy to a certain extent, but not very markedly 
since this nerve, that is the fifth dorsal, furnishes only a part of the in- 
nervation of them. There seems to be in typical cases, a contracture 
of a portion of the erector spinae and a relaxation of the rectus abdomi- 
nis and oblique muscles. 

The common trunk of the fifth dorsal contains fibers over which 
pass the accelerator impulses, the nerves being called the cardiac accelera- 
tors. Their course is similar to those described under the other upper tho- 
racic cardiac accelerators, (which see) . Clinically, these fibers are often in- 
volved by a lesion of the fifth dorsal, and a lesion of this vertebra is ex- 
pected in most cases of cardiac disturbance. 

The pulmonary vessels receive vaso-motor impulses from the fifth 
thoracic segment of the spinal cord. These impulses pass out over 
fibers contained in the ventral root of the fifth dorsal, the common trunk, 
white ramus, ganglion, and the efferent pulmonary. It seems that 
these impulses leave the gangliated cord at points above the fifth. If 
the lesion interrupts the impulses passing over these fibers, the pul- 
monary vessels will dilate. This causes congestion. The circulation 
of blood is lessened in rapidity, oxygenation interfered with and sys- 
temic as well as local disorder, is the result. If these impulses are aug- 
mented there will be constriction of the pulmonary blood-vessels, the 
blood pressure is increased and the lung becomes pathologically anemic. 
The first is the usual effect, that is congestion, with its tendency to 
pneumonia and tuberculosis. 

By experiments on the dog, it has been determined that vaso-motor 
impulses to the blood-vessels of the arm arise in the fifth dorsal segment 
and reach the arm by way of the ventral root, common trunk, anterior 
division, white ramus, gangliated cord and the brachial,' or the sub- 



APPLIED ANATOMY. 171 

clavian plexus. In man we find clinical evidence that proves that the 
nerve centers and conducting tracts are similar to, if not identical with, the 
above. A lesion of the fifth dorsal will in many cases, cause monoplegia 
of the arm. The explanation is that the lesion lessens the size of the 
intervertebral foramen through which pass impulses from the center in 
the spinal cord to the arm. These impulses are supposed to be trophic 
and vaso-motor. 

Vaso-motor impulses to the abdominal blood-vessels, arise in the 
fifth dorsal segment and reach the blood-vessels by way of the great 
splanchnic. The thoracic blood-vessels are also supplied by way of the 
thoracic aortic plexus which receives efferent fibers from the upper 
thoracic ganglia. 

Many sensory impulses are carried by the fibers contained in the 
nerve trunk which passes through the fifth dorsal intervertebral foramen. 
The integument over the fifth interspace and a portion somewhat below 
the spine of the fifth, are supplied with sensation by the fifth dorsal 
nerve. The impulses pass to the common trunk by way of the anterior 
and posterior divisions, thence over the posterior nerve root into the 
spinal cord, most of the impulses passing across to the opposite side of 
the cord, thence to the sensorium. Sensory impulses from the pleura, 
periosteum, peritoneum, and mammary glands, pass to the sensorium in a 
similar way. The sensorium then refers the pain to the seat of the irri- 
tation or the supposed source. For example, stimulation of the nerve 
trunk or any of the fibers, will cause a pain which is referred to the per- 
iphery of the nerve. In lesions of the fifth dorsal or corresponding rib, 
the fibers conveying sensory impulses, as mentioned above, are pressed 
on but the painful effect is in the periphery instead of at the point of 
pressure. From this, it follows that painful affections of the areas de- 
scribed above are, in many cases, due to the vertebral and rib lesions. 
Anesthesia results if the sensory fibers are inhibited while parasthesia 
results if the nerve is stimulated by the lesion. These lesions lessen the 
size of th.e intervertebral foramina and the effect is determined by the 
amount of pressure from this change in size, and the kinds of fibers in- 
volved. 

The lungs have a sensory center in the fifth dorsal segment, or rather 
sensory impulses from the lungs pass through it on their way to the 
sensorium. The impulses pass by the afferent sympathetic fibers to 
the gangliated cord thence over the white ramus, posterior root, spinal 
cord, etc., to the sensorium. 



172 APPLIED ANATOMY. 

Clinically it seems to be demonstrated, that sensory impulses pass 
from the stomach to this segment. They are in all probability carried 
by the great splanchnic nerve. In gastralgia, inhibition at or near the 
spine of the fifth dorsal, is often sufficient to relieve temporarily. 

The recurrent, is distributed in a way similar to that of the recurrent 
nerves described above. 

The grey filaments carry impulses from the fifth thoracic ganglion 
to the anterior and posterior divisions of the fifth dorsal nerve. The 
impulses are mostly efferent in character, the vaso-motor being the most 
inrportant. 

Sensory impulses from the stomach pass over the white ramus. 
Lesions affecting the ramus may cause pain to be referred to the stomach 
and other viscera supplied by this segment. 

The white ramus of the fifth, carries impulses from the spinal cord 
to the fifth thoracic ganglion. The impulses then go up or down in the 
gangliated cord or out over the efferent nerve. The impulses carried 
by the fifth thoracic white ramus, supply the heart, lungs, arms, stomach, 
and abdominal blood-vessels. They vary in character, some being motor, 
vaso-motor, secretory, trophic and viscero-inhibitory. The motor sup- 
ply, the heart; the vaso-motor the pulmonary and abdominal blood- 
vessels; the secretory the gastric glands; the trophic the muscles in re- 
lation and those of the arm; the viscero-inhibitory, the stomach. 

A lesion of the fifth dorsal, that is a slight displacement or sublux- 
ation, will affect the white ramus in most instances. Perversion of 
function follows, the particular effect being determined by the fibers 
affected and the degree of pressure or other disturbance of them. Pres- 
sure on these filaments is the usual cause of disturbance of their function. 
The filaments composing the white ramus pass on uninterruptedly from 
the spinal cord to the sympathetic ganglion, forming a part of the ven- 
tral nerve root, common trunk and anterior division. The foramen 
through which these filaments pass is lessened in size by certain forms 
of lesions of the fifth thoracic vertebra, therefore the impulses passing 
over these filaments would be affected in some way. 

The fifth thoracic sympathetic ganglion is adjacent to the fifth dor- 
sal vertebra and would be involved in most cases. The effects of dis- 
turbance of this ganglion are similar to that from disturbances of the 
white ramus, since all the impulses carried by the white ramus pass into, 
and most of them through, the corresponding ganglion. Some cells 



APPLIED ANATOMY. 



173 



are located in this ganglion which generate impulses, viz., those carried 
by the grey rami. These would be disturbed. 

The great splanchnic nerve is the principal branch of this ganglion. 
It is formed by the union of roots that branch from the thoracic ganglia 
from the fifth to the ninth. Quain says: "The trunk thus constituted, 



VASO-MOTOR TOARMANDTOLUN&. 

VASOCONSTRICTOR TO PULMON- 
ARY VESSELS ANO ARM 

SECRETCXYTO SWEAT GLANDS-, \ 

ACCELERATORS HEART 



INTEGUMENT OVER BACK AT SPINE or 51h. 

ERECTOR SPINS. 

MULTIFIOUS SPINA 

LEVATOR 
COSTARUM 




CORONARY , , 

PULMONARY , ) 

ESOPHAGEAL. 

VASO-MOTOR TO 
ABDOMINAL VISCERA 

SENSORY. SECRETORY 
AND VISCERO-INHIBITOB 
TO STOMACH 



Fig. 43. — The fifth thoracic segment, with its nerves and their distribution. 



174 APPLIED ANATOMY. 

descends obliquel}" forward over the bodies of the dorsal vertebra?, and 
after perforating the crus of the diaphragm terminates in the upper 
part of the semilunar ganglion; some of the fibers may occasionally be 
followed to the supra-renal body and the renal plexus. This nerve is 
remarkable from its white color and firmness due to it consisting in large 
part (four-fifths according to Rudinger) of medullated fibers, which are 
continued directly from the spinal nerves; from the highest root they 
may be traced upward along the sympathetic cord as far as the third 
thoracic ganglion and nerve, or even higher." This nerve gives off 
filaments that supply the esophagus, aorta and terminates in the solar 
plexus. The impulses passing from the fifth dorsal ganglion over the 
upper root forming this nerve go principally to the stomach supplying 
it with motor, secretory, vaso-motor, trophic and viscero-inhibitory 
impulses. A lesion of the articulations of the fifth dorsal will affect 
this nerve-in nearly every instance. In one case there may be a motor 
disturbance, in another a secretory or vaso-motor derangement. The 
explanation is that in the one case only the part of the nerve carrying 
the motor impulses was involved, in the other case the secretory or vaso- 
motor fibers were affected. 

The great splanchnic nerve has a variety of functions. It conveys 
motor impulses to the stomach, therefore stimulation of it increases 
peristalsis. It carries vaso-motor impulses to the blood-vessels of the 
stomach, liver and intestines and especially the portal vein. Lesions 
involving this nerve usually cause a dilatation of these blood-vessels in 
that the impulses are inhibited. Congestion of the stomach and liver 
is a very constant effect of a lesion of the fifth dorsal. These conditions 
lead to many forms of disease. This congestion may at first be arterial 
but later on becomes venous. Venous congestion of the stomach causes 
an increase in the amount of gastric juice but its quality is impaired. 
A catarrhal condition exists. This increased mucous secretion counter- 
acts the hydrochloric acid of the stomach and the gastric juice becomes 
alkaline. Pepsin acts with difficulty, if at all, in an alkaline medium. 
Therefore, the food when ingested is not readily digested and it ferments 
in the stomach. This gives rise to lactic acid. The gas, being acid, 
gives rise to a burning sensation which is called "heart-burn" since it is 
referred to the region of the heart. Dyspepsia in all its varying forms, 
results from some lesion interfering with the transmission of impulses 
from the spinal cord to the stomach. Errors in diet aggravate the con- 



APPLIED ANATOMY. 



175 



dition and in many cases are alone responsible for the dyspepsia. 

A lesion of the fifth dorsal, lessens the size of the foramen through 
which pass vaso-motor impulses to the stomach by way of the great 
splanchnic nerve. 

Some vascular disturbances of the stomach result from abuse of 




Fig. 44. — Showing the great splanchnic nerve, left side, with its roots of origin, 
the gangliated cord, rami and pulmonary branches. (From photo). The nerves were 
colored before taking the photo, r, ramus; p. pulmonary branches; 1, 2, 3, 4, 5, 
roots of the great splanchnic nerve, 1. s. lesser splanchnic. 



176 APPLIED ANATOMY. 

the organ. Errors in diet often cause pathological vascular changes 
in the walls of the stomach. 

*Landois says: The great splanchnic is the inhibitory nerve for 
the intestinal movements, but only so long as the blood in the capillaries 
has not become venous and the circulation in the intestine remains un- 
disturbed. If the latter condition has arisen, irritation of the splanch- 
nic causes increased peristalsis. If arterial blood be introduced, the in- 
hibitory action is prolonged." Applying this to effects of lesions dis- 
turbing the great splanchnic, a disturbed circulation will necessarily 
result , with either a lessened or increased peristalsis. This nerve is also sen- 
sory to the stomach and intestines, that is, it is partly afferent and sen- 
sory impulses are carried to the spinal cord by it. It is probably a great 
deal less sensitive than the cerebro-spinal nerves in relation, hence the 
pain is quite frequently referred to the abdominal or thoracic wall, that 
is 3 areas supplied by the fifth intercostal nerve. 

A portion of the peritoneum is supplied by the great splanchnic. 
There is a marked sympathy existing between the abdominal wall and 
the viscera covered by it. A blow on the abdomen will cause vaso- 
motor paralysis. A painful stimulus applied to the viscus will cause 
contracture of the abdominal wall. 

A few other branches come from the fifth thoracic ganglion: The 
branches to the thoracic aortic plexus and the vertebra; and ligaments. 
The gangliated cord is often involved by a lesion of the fifth dorsal. 
The passing of impulses in such cases along the sympathetic chain 
would be interfered with. This is not indicated by any definite dis- 
eased condition but by a general effect on the viscera receiving impulses 
that pass along the sympathetic cord. 

The fifth dorsal segment of the spinal cord contains certain centers 
that have been fairly well determined clinically and experimentally. 
The level of the segment is considerably above that of the spine of the 
fifth dorsal, but the local effects are most marked at and around the 
spinous process, so when reference is made to a center, the external point 
or landmark is the spine of the corresponding vertebra. The center for 
the nutrition of the body is partly located in this segment. This is ex- 
plained above. The motor, vaso-motor and secretory centers for the 
stomach are in part located here. This the most important viscus 
having almost all its centers in this segment. The liver also has a center 

(Text-book of Human Physiology, p. 288). 



APPLIED ANATOMY. 177 

in this segment but the important centers for it are further down the 
spinal cord. The spleen possibly derives some of its innervation from 
the fifth dorsal segment. The centers for the accelerator impulses to 
the heart are partly located in this segment. The fourth dorsal segment 
is the most important, so far as the innervation of the heart is concerned. 
Sweat centers for the middle thoracic area are in this segment; motor 
and trophic centers for the muscles innervated by the fifth thoracic 
nerve are of course, located in this segment. 

The structures and viscera most frequently involved by a lesion of 
the fifth dorsal are the stomach, liver, pleura, mammary gland, heart, arm, 
spinal cord and the muscles of the back in relation. The effect on the 
stomach varies with the character of the lesion and the kind of fibers 
involved. Dyspepsia is the most common effect on the stomach, of a 
lesion of the fifth dorsal vertebra. This is partly explained above under 
the head of vaso-motor function of the great splanchnic nerve. Lessen- 
ed activity of the muscular fibers, that is dilatation with lessened peri- 
stalsis, is also common, especially in the chronic types of dyspepsia. The 
various types of dyspepsia, ulceration, heart-burn, gastralgia, gastrop- 
tosis, dilatation, nausea and vomiting, boulimia and in fact any stomach 
disorder, may follow a lesion of the fifth dorsal. The explanation is, the 
lesion lessens the size of the foramen through which pass blood and 
lymph vessels to and from the spinal cord (fifth dorsal segment) also 
the various nerve filaments over which pass impulses to the stomach 
by way of the great splanchnic nerve. These impulses are named under 
the function of this nerve. 

Vomiting may be due to several causes. The various muscles of 
respiration are called into service and the peristalsis of the stomach and 
duodenum seems to be reversed. The contraction of the abdominal 
muscles, according to Howell* is believed to be the principal factor in 
vomiting. 

"It was long debated whether the force producing this ejection 
comes from a strong contraction of the walls of the stomach itself or 
whether it is due mainly to the action of the walls of the abdomen. A 
forcible spasmodic contraction of the abdominal muscles takes place, 
as may easily be observed by any one upon himself, and it is now believed 
that the contraction of these muscles is the principal factor in vomiting. 
Magendie found that if the stomach was extirpated and a bladder con- 
text-book of Physiology, p. 651, 1905. 



178 APPLIED ANATOMY. 

taining water was substituted in its place and connected with the esopha- 
gus, injection of an emetic caused a typical vomiting movement with 
ejection of the contents of the bladder. Gianuzzi showed, on the other 
hand, that upon a curarized animal vomiting could not be produced 
by an emetic — because, apparently, the muscles of the abdomen were 
paralyzed by the curare. " 

If the cause lies in the stomach, the vagus furnishes the afferent 
path. "The efferent paths of the reflex are found in the motor nerves 
innervating the muscles concerned in the vomiting, namely the vagus, 
the phrenics and the spinal nerves supplying the abdominal muscles." 
Clinically, lesions involving the spinal nerves, the fifth and sixth dorsal, 
being the most important, at least predispose to nausea and vomiting. 
Morning sickness in pregnancy is made worse by such lesions. 

The liver is sometimes affected by a lesion of the fifth dorsal. Ordi- 
narily, liver-disorders are associated with lesions of the sixth and seventh 
thoracic vertebrae, under the discussion of which its diseases will be con- 
sidered. The explanation of why a lesion so high as the fifth would 
affect the liver is, that the portal vein as well as the other vessels, are sup- 
plied by the splanchnic, and this nerve would be involved by a lesion of 
the fifth dorsal, because of its relation to the articulations of the vertebra. 

Disorders of the pleura result, in some cases, from some form of 
lesion of the fifth dorsal. The explanation is that the fifth intercostal 
nerve which supplies in part, the parietal layer of the pleura, is usually 
involved by a lesion of the fifth dorsal. 

Mammary affections are explained in a similar way, that is, by the 
effect of the lesion on the fifth intercostal. 

A few of the cardiac accelerator fibers pass out of the fifth dorsal 
foramen and many pass through the foramen between the fourth and 
fifth dorsal, therefore heart disease follows lesions of the fifth dorsal, if 
these fibers are affected by the lesion. Heart and stomach disorders 
are often found in the same patient. The common lesion explains this 
peculiarity as well as the proximity of the organs. 

The upper extremities are often affected by a lesion of the fifth dor- 
sal. The important effect is weakness or atrophy. In some cases 
complete paralysis follows. The spinal cord is directly involved by 
pressure if the subluxation or displacement is marked. Paraplegia is 
the sequel to this, it being the result of the transverse myelitis produced 
by the subluxation. 



APPLIED ANATOMY. 179 

Other spinal cord diseases, not depending on direct pressure, come 
indirectly from these vertebral lesions. The contour of this portion of 
the spine is changed and the median furrow is often widened from atrophy 
of this portion of the erector spinas muscle. 

Chorea in which the arms are mostly involved, comes in some cases 
as a sequel to a lesion at the fifth dorsal. Cutaneous diseases, neuralgia, 
"shingles" and in fact any disease of this part of the body, may be the 
result directly or indirectly, of a lesion of this vertebra. 

Summary. The stomach is the principal viscus supplied by nerves 
■coming out of the spinal canal in relation with the fifth dorsal, hence 
the most common visceral effect from a lesion of this bone is stomach 
disorder. Dietetic errors produce pain and muscular contractures in 
this region. Some effect on the stomach can be obtained by palliative 
treatment applied to the spine at this point. This effect is measured 
by the effect obtained on the medium treated. To get a stimulating 
effect on the stomach remove the lesion causing the unnatural inhibi- 
tion. To secure an inhibitory effect on the stomach, remove the lesion 
causing the increased peristalsis. In either case the lesion produces 
the effect through stimulating or otherwise affecting the great splanchnics. 
Sometimes, external treatment will cause a direct effect on the stomach, 
that is pressure on the spine at the fifth dorsal will lessen peristalsis and 
stimulation will increase peristalsis. This effect, if obtained at all, is 
at best only temporary, as stated above. If this pressure or stimula- 
tion relaxes the muscles or adjusts the spine or ribs, the stomach will be 
affected proportionately. 

THE SIXTH THORACIC. 

The sixth thoracic vertebra is similar in most respects, to the verte- 
bras described above. The spinous process is very long and oblique, 
reaching to the body of the eighth dorsal. The superior foramina like 
those of other thoracic vertebras, are bounded posteriorly by the an- 
terior portion of the articular processes, hence any movement of it would 
cause some change in size in the foramen. The articular facets are almost 
plane surfaces. The transverse processes are directed upward, outward 
and backward and bear facets that are quite deep and concave. The 
movements of this vertebra are very limited and the remarks applied 
to the fifth dorsal, will apply to the sixth. 

Lesions of the articulations of this bone are usually very chronic, con- 



ISO APPLIED ANATOMY. 

sequently, chronic diseases of the stomach and liver follow lesions of this 
vertebra. This is because the lesion has been overlooked at or soon 
after its occurrence. The usual signs and symptoms of vertebral le- 
sions are present. Softening and thickening of the supra-spinous lig- 
ament are the most important signs. Tenderness over the spine and 
some irregularity are usually present. As is the case of lesions of most 
single vertebrae, the bone is anterior more commonly than all other dis- 
placements combined. 

The ligaments and muscles attached to it are affected if only one 
side is involved. A scoliosis quite commonly develops. If anterior, 
a lordosis may follow. 

The azygi veins are subject to injury from subluxations of the ver- 
tebra and from enlargements of adjacent viscera. The lateral spinal 
vein is affected in a way similar to that of other lateral spinal veins. Pres- 
sure on it c'auses congestion of the areas drained by it: the meninges, 
vertebra? and especially the sixth dorsal segment of the spinal cord. 

The arteries involved by this lesion are the sixth intercostal and 
its branches, and through their nerve supply, the thoracic aorta and 
its branches. The intercostal arteries are obstructed, the muscles of 
the back contractured and the spinal cord congested. 

The intercostal lymphatic vessels are also affected by a vertebral 
lesion. The vessels draining the spinal cord pass from it by way of 
the intervertebral foramina. From this it can be determined why they 
are disturbed in function. Their function is not well understood. Edema 
of the part drained seems to be the most constant effect of a disturbance 
of the lymph vessel. 

The nerves are affected in a way similar to that from other vertebral 
lesions. The muscular branches supplying the intercostal, levatores 
costarum, obliquus externus, rectus abdominis, and the erector, multi- 
fidus and rotatores spinse muscles are at least affected in part. The 
most constant effect is on the erector spina? and levatores costarum mus- 
cles. The erector spins mass at first contracts but later on undergoes 
atrophy; this producing a local widening of the median furrow of the 
spine. The levatores costarum, by their contracture, displace the angle 
of the ribs upward, this prying or rotating the anterior or sternal end 
downward. 

The obliquus externus is either relaxed or contractured. In irrita- 
tive diseases of the stomach, this muscle becomes contractured and thus 



APPLIED. ANATOMY. 181 

the abdominal wall becomes tense. The patient yields to this contracture 
and consequently, a stooped posture. In non-irritative disorders of the 
abdominal organs the muscle becomes relaxed and the viscera descend 
from lack of support. The same might be said of the rectus abdominis. 

The effects on these muscles are so fairly constant that they are 
diagnostic. They are reflex effects and are explained by the proximity 
of the cells in the spinal cord that give rise to impulses that supply both 
the viscera and the muscles. An irritation of the afferent nerves of the 
stomach causes an increased activity of the cells in the sixth dorsal seg- 
ment possibly on account of the overflow of impulses, hence congestion. 
This soon becomes pathological and the motor cells are affected that 
supply the muscles in relation and contracture is the result of the pro- 
• longed and unnatural stimulation. In case of relaxation, the disorder 
is a chronic one and the nerve cells are in a sense, paralyzed. In the 
case of the abdominal muscles, often there are degenerative changes in 
the muscle itself that are so marked and extensive, that the fibers are 
permanently shortened or lengthened. The lesion may directly affect 
both sets of nerves, those innervating the muscles and the viscera, and 
thus produce pathological effects in both. 

The abdominal muscles protect the delicate structures covered by 
them, contracting firmly and quickly from any expected blow directed 
against them. 

The sensory branches of the sixth thoracic nerve, supply sensation 
to the integument over the pit of the stomach, the sixth interspace and 
a portion of the integument and tissues at and around the sixth dorsal 
spine. In subluxations of the sixth dorsal or other disturbance of it, 
such as fracture or Pott's disease involving it, the pain is often referred 
to the pit of the stomach. In gastralgia.the greater part of the pain is 
in the walls of the stomach while some of it is in the abdominal wall. 

This is proven by the fact that the pain is intermittent. The pain 
in colic is due directly to the contraction of the viscus. The contrac- 
tion is a reflex one and dependent to a great extent on the amount and 
character of the contents of, in this case, the stomach. The afferent 
nerves are the great splanchnic and the vagus while the efferent, are the 
splanchnic and the intercostal. The pain seems to be in the walls of the 
stomach and is the result of spasm or contracture of the muscle fibers 
composing the wall, this compressing the nerves in the walls. In some 
cases possibly the pain is the direct result of a stimulation of the sensory 



182 APPLIED ANATOMY. 

nerves but I believe this to be the exception especially in gastralgia, or 
else the pain would be constant. It is possible to get contraction of the 
muscles of the stomach by direct stimulation after all nerve connections 
with the spinal cord are severed. This is explained by the presence of 
intrinsic ganglia in the walls. 

In inflammatory diseases of the stomach, this part of the abdominal 
wall, that is the pit of the stomach, is tender. Tenderness on pressure 
at the pit of the stomach is almost diagnostic of inflammatory or other 
organic disease of the stomach. The explanation is that the same seg- 
ment that supplies the stomach, supplies the pit of the stomach and the 
pain is referred to the part supplied by the more highly sensory nerves, 
the cerebro-spinal. While in other cases, it is due to the inflammation 
of the pyloric end. 

Sensation to the pleura and peritoneum is also directly furnished 
by this sixth dorsal nerve. The cardiac end of the stomach is supplied 
with sensation by the sixth nerve, it carrying the impulses to the corre- 
sponding segment. The impulses pass from the stomach to the sixth dor- 
sal nerve by way of the great splanchnic. 

The liver and gall-bladder are also supplied with sensation by this 
nerve and the impulses reach it in a similar way. In acute, painful 
disturbances of these viscera, the muscles supplied by the same segment 
become markedly contractured, particularly the spinal muscles, while 
the abdominal wall, as a rule becomes tender and in acute cases, con- 
tracted and tense. Hepatic colic is a good illustration of this point. 

Pressure over or at the place of emergence from the spinal canal of 
the sixth dorsal nerve, may lessen or completely stop the passing of the 
sensory impulses from the viscus to the spinal cord, thereby relieving 
the pain. Gastralgia and hepatic colic (mild form) can in most cases, be 
controlled by such treatment. This treatment is only palliative and 
relieves temporarily, if at all. By relaxing the contractured muscles of 
the spine, marked effect can be obtained on the affected viscus. Relax- 
ation is better secured by adjusting the bony lesion rather than by in- 
hibiting the muscle by pressure directly applied to it. The muscular 
.contracture is the effect and by relaxing it, although the effect is thus 
counteracted yet the cause remains. The subluxation of the sixth dor- 
sal, is, in most cases the primary cause of both the visceral and muscular 
trouble and by correcting it the effects, unless too chronic, will be and 
remain relieved. If a muscle when contractured undergoes structural 



APPLIED ANATOMY. 



183 



SPINAL LIGAMENTS 

SEMISPINALS DORS 

INTERSPINALS 

ROTATOR ES 



INTEGUMENT OVER SPINE OF 6th T 
MULTIFIDU SPINA 
TRANSVERSUS ERECTOR SPINA. 

S LEV.COSTARUM 







R f£t§< 



PLEXUSES ETC. (SprSEE8thSEG'T 7 
S SOLAR A. AORTIC C CELIAC 



cli ^tW '' Sp SPLENIC TOSPLEEN PANCREASE AND STOMACH 



KS, 



'&&, % R RENAL TO KIDNEY S R SUPRARENALTO SUP CAPSULE 
lfi£, c GGASTRIGTOSTOMAGHANDESOPHAGUS E ESOPHAGLALTOESOPH'S. 




H.HEPATICTO LIVER GALL BLDB STOMACH. DUODENUM ANDPANCREAS- 
DIAPHRAGMATIGTODIAPHRAGN,VENACAVA(RSiDE)ESOPHA&uS(LEFTSIDE) 

S.M SUP MESENTERIC TO SMALL INTESTINES CA1CUM 
APPENDIX ASCENDINGANDTRANSVE.RSE COLON 

I M INF.MESENTERICTODESCENDING ILIAC AND 
PELVIC COLON and UPPER PART OF RECTUM 

S.G SEMILUNAR GANGLION AG AORTIC-RENAL GANGLION 

GRT S.ano=>MS. SPLANCHNICS 

TRIANGULARIS-STERNI M 



r TO. 45. — The sixth thoracic segment with its nerves and their distribution. 



184 APPLIED ANATOMY. 

changes that prevent relaxation, stretching of the muscle is to be advised 
in such cases. 

Vaso-motor impulses to the abdominal blood-vessels pass out over 
the sixth dorsal nerve, the white ramus, sixth thoracic ganglion, and 
thence to the various vessels by way of the great splanchnic and the 
solar plexus. The spinal cord, liver, stomach and small intestines are 
especially supplied with vaso-motor impulses by the sixth dorsal seg- 
ment. The sixth dorsal ganglion gives origin to one of the roots of the 
great splanchnic nerve. This nerve has been discussed in part under 
the fifth dorsal segment. It gives off branches to the thoracic aorta and 
the oesophagus, before it reaches the solar plexus. 

A lesion of the sixth dorsal will affect the spinal cord. The various 
centers in the cord may be involved, such as the center for the tone of 
muscle, vaso-motor, secretory, viscero-inhibitory, sweat and trophic. 
These centers may be involved from direct pressure on the cord or from 
changes in size of the foramina which interfere with the nutrition of the 
cells. The grey matter in particular, is often affected by lesions occuring 
in the young. Anterior polio-myelitis can often be traced to a fall or 
other injury in which the spine is involved. These injuries result in a 
disturbance of the cells in the anterior horn and the disease known as 
infantile paralysis, develops. The explanation of the lesion of the thor- 
acic vertebra producing the disease is (l),the nutrition of the cells is eut 
off, or (2), the nerve tract connecting the cell with the muscle fibre is 
destroyed. The first explanation is the better since in most cases there 
are marked vaso-motor changes in the spinal cord. If this congestion 
does not result in destruction of nerve cells, a cure is possible, but if the 
cells are destroyed whether by congestion or hemorrhage, a cure is scarce- 
ly possible. There are in addition to the bony lesions, exciting causes 
which act in proportion to the impairment caused by the lesion. 

The various columns as well as the cells of the spinal cord, are af- 
fected by some forms of lesions of the sixth dorsal. The effect may be 
from pressure on the cord itself or from pressure on the vessels that 
nourish and supply these columns. Locomotor ataxia and the paraple- 
gias are examples. Perhaps not all patients suffering with these forms 
of spinal cord disease have lesions of the vertebrae that can be distinctly pal- 
pated, but the vast majority of cases result from vertebral lesions, the 
sixth dorsal being a common location of the lesion. 

In locomotor ataxia, the pressure is exerted directly on the gang- 



APPLIED ANATOMY. 1S5 

lion on the posterior nerve root or on the blood-vessels that supply it and 
the spinal cord. The ganglion is in close relation with the processes that 
form the intervertebral foramina and are thus subject to pressure if there 
is the slightest deviation. Although this would of itself produce loco- 
motor ataxia, yet I believe the better explanation is that the spinal cord 
and its nerves are affected through the disturbance of nutrition caused 
by these spinal deviations affecting the circulation of the spinal cord and 
its branches. Syphilis may have something to do with the production 
of the disease but this as yet has not been demonstrated, only surmised. 
The toxemia of any disease will make the effect of a spinal lesion on the 
spinal cord the more marked. The treatment of syphilis by the internal 
administration of the anti-syphilitic remedies such as mercury and the 
iodide of potassium is perhaps responsible for the production of the 
locomotor ataxia in many cases. Excessive coitus is a very important 
cause of locomotor ataxia. * " When sexual impulses force the con- 
cerned ganglionic cells too often, and for too long periods of time, they 
lose power; and if the state of exhaustion continues without time for 
physiological recuperation, degeneration is the final result.'' 

This condition plus the spinal lesions are responsible for most if 
not all cases of tabes dorsalis notwithstanding the statements in the 
various texts that syphilis is the only cause. 

*von Raitz so well expresses my ideas in regard to the cause of tabes, 
that I quote the following: "Injury to the cord, as an etiological fac- 
tor of tabes, has of late arrested the attention of unbiased observers, 
and there is sufficient evidence to force serious consideration of those 
cases whose history points to accidents after which tabetic symptoms 
appeared. Injury to the cord may occur without any external evidence, and, 
as a matter of fact, seemingly trivial accidents are. at times, followed by 
tabes. Severe traumatism to the spine may cause instantaneous partial 
or total, transient or permanent paralysis below the level of the injury, 
but no symptoms of locomotor ataxia, while a simple fall or sharp twist 
of the spinal column, leaving no external evidence of injury to the spine, 
and no immediate symptoms referred to the cord, may induce locomotor 
ataxia. When, after a fall, symptoms appear gradually, they are not 
understood until locomotor disturbances set in; and even then serious 
attention is not paid to them, but liniments and antirheumatic remedies 
are employed until a competent man makes a diagnosis of tabes. If 

*Medical Record, p. 650, 1905. 



186 APPLIED ANATOMY. 

this physician holds to the syphilis theory, he will, under all circumstances 
find that the patient has had syphilis some time ago, no matter whether 
he has had symptoms of the disease or not, for, if all evidence fails, the 
"benefit of the doubt" covers every lack of information. The fall is 
thrown out as an etiological factor as soon as mentioned, because no ex- 
planation of how a fall can cause tabes, has as yet, been offered. Some, 
however, admit that a fall, while not the cause of the condition, might have 
hastened the progress of the disease, which was present before the fall. 
How a simple fall can cause injury to the cord and subsequently 
tabes is, however, not difficult to understand. We know, when a blood- 
vessel is subjected to tension and torsion, it loses its elasticity by over- 
stretching or rupture of the muscular fibers of its walls. When a per- 
son falls, he will, before the body reaches the ground, try to save him- 
self by throwing his weight in the opposite direction. This motion is 
carried out with great suddenness and with as much power as the per- 
son has at his command. The spine is then bent and twisted at the point 
of greatest flexibility. The anatomical relations of the spinal column 
allow the greatest freedom of motion in the lumbar spine, and there 
the center of gravity of the lower part of the body, in its downward 
course is suddenly met by the weight of the upper part of the body in 
its opposing direction, thus mitigating the impact of the body with the 
ground. To oppose the falling of the body still more forcibly, the arms 
are suddenly thrown out in the opposite direction, and according to the 
degree of pronation of the upper body, necessary to oppose the fall, a 
corresponding bending and twisting of the spinal column takes place, 
during which the blood-vessels are stretched and twisted. If the degree 
of tension and torsion is greater than the elasticity of the implicated 
arterial walls can endure the muscular fibers are damaged and the walls 
may, at one or more points, collapse and obliterate. The portion of the cord 
concerned will now, sooner or later, suffer for want of nutrition, in propor- 
tion to the number or importance of the nutrient arteries involved, and 
corresponding symptoms of degeneration become, more or less ap- 
parent. The progress of degeneration once started, has a tendency to 
progress, unless checked by forced nutrition, which, no doubt, often 
enough, takes place in strong individuals. After such injury the spinal 
nerve fibers or ganglionic cells, or both, may be affected, as this depends 
on where nutrition ceases, and the first symptoms which present them- 



APPLIED ANATOMY. 1.S7 

selves are disturbances of locomotion. This class furnishes the motor 
type of tabes." 

This sprain or as we would term it, lesion, may occur in the thor- 
acic as well as in the lumbar region. If the disease were due to syphilis 
and not dependent on other causes, why is it that only a small per cent, 
of syphilitic patients contract the disease? In those that do, we believe 
that the antisyphilitie drugs are as much to be blamed for the produc- 
tion of the disease as the syphilis itself. 

A marked lesion or fracture of the sixth dorsal will cause transverse 
myelitis if there is pressure on the spinal cord. 

The contour of the spinal column is affected in ninety per cent, of 
cases if the lesion occurs before the growth of the spinal column is com- 
pleted. These curvatures usually start from a subluxation or strain of a 
single articulation and get well under way, before they are noticed. The 
articulations of the sixth dorsal furnish a very common starting point 
of the trouble. Deviations or sprains of these articulations cause atro- 
phy of the muscles on one side and the opposite side proceeds to draw 
the spine toward that side and in a year or so a well defined scoliosis is 
developed. 

Pott's disease may set in as a result of a lesion of the sixth dorsal. 
The explanation is that the lesion lessens the resistance, that is, lowers 
the vitality of the part, which condition permits of the entrance and 
propagation of the micro-organisms peculiar to this disease. Care should 
be exercised in the treatment of such a spine not to use much force since 
the vertebra? may be badly injured on account of the honey-combed 
condition of the body of the bone. 

A lesion of the sixth dorsal will cause a disturbance of the ribs artic- 
ulating with the transverse processes. The character of the effect is de- 
termined by the kind and degree of the vertebral lesion. This is true of 
all the thoracic vertebra?. In scoliosis with rotation, a marked bulging 
takes place on the convex side with concavity on the opposite side of the 
thorax. At first the change in position of the rib produces pain along 
the intercostal nerve if the subluxation is a sudden one. If it comes on 
gradually, nature adapts herself to the changes and little or no pain is 
felt as the rib changes its position. 

If the sixth thoracic vertebra is turned toward the right side, the 
sixth rib on that side will be forced forward while the corresponding one 
on the left will be carried backward. If the vertebra in displaced di- 



1S8 APPLIED ANATOMY. 

rectly forward, both ribs are carried with it and there in a corresponding 
depression of the shafts of the ribs. In this way a differential diagnosis 
between a forward displacement of the vertebra and an apparent one, 
can be made. If the vertebra is displaced backward, the ribs are carried 
with it and the shafts become more prominent. When the part of the 




Fig. 46. — Showing effects on disc in lateral subluxation of 5th and 6th thoracic 
vertebra. This unequal pressure on the discs is responsible for lateral curvature of 
the spinal column. Compare with Figs. 48 and 49. 

rib in relation with the transverse process of the vertebra is displaced, 
the shaft, hence the anterior part, is changed as to position. Therefore 
examine the position of the ribs in making up a diagnosis of the particular 
form of vertebral lesion if it is in the thoracic area and remember that the 



APPLIED ANATOMY. 189 

rib lesion, that is displacement, may be secondary. A lesion of a thor- 
acic vertebra will always produce some form of rib lesion but the con- 
verse is not necessarily true, that is a rib lesion does not as a rule, pro- 
duce a perceptible vertebral lesion. 

A lesion of the sixth dorsal, if chronic, invariably affects the stomach 
and liver. It may also affect the peritoneum, pleura, diaphragm, pan- 
creas, gall-bladder and small intestines. Only the effect on the liver 
will be considered at this place. The effect on this organ is primarily 
that of congestion. This follows because the innervation of its blood- 
vessels comes from the sixth dorsal segment, the impulses reaching the 
blood-vessels by way of the splanchnic nerves, solar plexus and hepatic 
plexus, and these vaso-motor impulses are obstructed by the lesion. 
Almost all liver disturbances start as a congestion. The functions of 
the liver are perverted, it becomes heavy and tender, indigestion soon 
sets in, followed by many and varied discomforts. Congestion of the 
liver increases the amount of formation of bile and seems to lessen ex- 
cretion and the patient soon becomes bilious. In passive congestion, 
and this is the most common type of pathological congestion, the qualit}' 
is impaired with a tendency to a formation of gall stones. 

In active congestion of any gland, the quantity of secretion is in- 
creased, while the quality is not necessarily affected. In passive con- 
gestion there is usually an increased quantity secreted as well as a change 
in quality. The secretion after awhile becomes thickened, nasal catarrh 
and leucorrhea being the best examples. It is a well known fact that in 
colds of the head, there is first a coryza, but afterward the secretion be- 
comes thicker as the disease becomes more chronic. In all probability 
this is the condition in the liver. That is, in chronic passive conges- 
tion the bile is not only increased in amount, but becomes thickened. 
The thicker the secretion, the greater the tendency to the formation of 
a sediment, which is usually preliminary to the formation of gall stones. 

A torpid or sluggish liver seems to be the predisposing cause of gall- 
stones, hence the connection between a lesion of the sixth thoracic ver- 
tebra and gall-stones. The bile pigment which is increased in amount 
by this congestion, is absorbed by the lymphatics, and an attempted 
elimination produces jaundice. The other functions are more or less 
affected by a lesion of the sixth dorsal because this lesion affects all the 
nerves going to the liver, particularly the vaso-motor, trophic, secretory 
and sensory. From these effects come jaundice, gall-stones, indiges- 



190 



APPLIED ANATOMY. 



tion, biliousness, malaria, diabetes mellitus, kidney disease and dis- 
orders of the bowels and blood. 

In jaundice there is excessive secretion of bile, imperfect excretion, 
absorption by the lymphatic vessels and an attempt orl the part of the 
skin to eliminate the bile pigment. Gall stones result from change in 
the character of the bile. An alteration in the composition of the choles- 




£■:. 




Fig. 47. — Showing spine of boy suffering with Pott's disease, 
like enlargement of the 6th dorsal spine. (From photo). 



Note the knuckle- 



APPLIED ANATOMY. 191 

terin, which is supposed to prevent deposit, that is, keep the bile in solu- 
tion, and imperfect elimination either from a sluggish condition of the 
liver or from obstruction to the bile ducts, acting together, produce gall 
stones. 

Indigestion may be of two forms as a result of liver disorder, gastric 
and intestinal. The former results because of the congestion of the 
stomach, which always follows congestion of the liver because all the 
blood in the walls of the stomach must pass through the liver before it 
reaches the heart. Intestinal indigestion comes from (1) the change 
in amount and quality of the bile, this hindering intestinal digestion 
since the bile has a great deal to do with this form of digestion, and (2) 
from the obstruction to the venous drainage of the small intestine. 

Biliousness results from congestion of the liver, as a result of in- 
creased secretion of the bile and absorption of it. Nausea and vomiting 
occur when the bile reaches the stomach. 

Malaria results from an impairment of the quality of the blood 
which commonly follows liver disorders, since the liver has to do with 
formation of and changes in the blood.' This condition permits the ma- 
larial toxines to thrive, or at least prevents destruction, by the blood. 

Diabetes mellitus follows a disturbance of the glycogenic function 
of the liver. The sugar is thrown directly into the blood and is excreted 
by the kidneys. Landois says in speaking of sugar in the blood: "It 
occurs a few hours after injury to a particular spot (center for the vaso- 
motor nerves for the liver) on the floor of the lower portion of the fourth 
ventricle; further after division of the vaso-motor paths in the spinal 
cord from above downward to the exit of the nerves for the liver, that is 
to the lumbar portion; in the frog, to the fourth vertebra. Division or 
paralysis of the vaso-motor conducting paths from the center to the 
liver results in glycosuria. According to recent researches by Francois 
Franck and Hallion, the vaso-motor nerves of the liver (for the hepatic 
artery and the portal vein) arise between the sixth dorsal and second 
lumbar nerves, and pass through the communicating branches into the 
splanchnic nerves."* 

Clinically, the above has been demonstrated and I quote this since 
it offers an anatomical explanation of diabetes mellitus. 

Lesions affect these nerves, although the effect may not be so marked 
as that from section of the nerves as in the experiments from which the 

*Landois Human Physiology, p. 313, 1904. 



192 APPLIED ANATOMY. 

above was determined; nevertheless there is an effect as a result of these 
lesions characterized by dryness of the skin, progressive emaciation, 
boulimia, thirst, increased secretion of urine which responds to the 
sugar tests, sweetish breath and taste in mouth, all of which increase in 
intensity until the patient literally starves to death. We recognize 
other causes than the one mentioned, that is lesions with the lower thoracic 
vertebra?, but they are unimportant when compared with the spinal le- 
sions. The vertebrae seem to undergo a change. They become more 
prominent and the spinous processes seem clubbed, that is enlarged, 
and the change produces a condition in the spinal column that is almost 
pathognomonic of the disease. 

Kidney diseases follow or complicate liver disorders because of the 
change in the urea, it being nature's diuretic, and an increase of waste 
matter, thus throwing more work on the kidneys. 

Bowel disorders result from the bile changes, there being a change 
in amount or quality. Marked odor to the stool is usually due to some 
abnormality of the bile, since one of its functions is to prevent putre- 
faction. 

The blood diseases result because, as stated above, the liver has a 
great deal to do with elaboration of the blood. 

Lesions of the sixth dorsal, produce these effects, as explained above, 
because the various impulses to the liver arise in part in the sixth 
dorsal segment, pass over the roots of the sixth dorsal nerves, thence 
over the great splanchnic to the liver, and these lesions interfere either 
with the center, or the nerves connecting center and liver. These inter- 
ferences result mostly from a lessening in size of the intervertebral fora- 
men through which nutrition in part, is carried to the spinal centers and 
through which all impulses that go from the spinal cord to the liver must 
pass. Indirectly the liver may be affected by a lesion impairing the 
action of the diaphragm, stomach and small intestines. 

Summary. Lesions of the sixth dorsal may produce dyspepsia, 
gall-stones, jaundice, pleurisy, peritonitis, gastralgia, intercostal neuralgia, 
spinal cord diseases, spinal affections and diaphragmatic disturbances. 

THE SEVENTH THORACIC. 

The seventh thoracic, differs so little from those described above that 
it does not merit separate description. Its spine is on a level with the 
inferior angle of the scapula. Motion at this point of the spinal column 



APPLIED ANATOMY. 



193 



is very limited although more marked than that of the upper thoracic 
articulations. The movement is mostly restricted by the ribs. As in 
the vertebral articulations above, the most frequent movement is an 
anterior and posterior one as in respiration. Use is made of this to cor- 
rect anterior deviations. The lungs act as a fulcrum, and then when the 




Fig. 48. — Showing a swerving of the spine of the sixth to the right and the spine 
of the seventh to the left. Compare with Figs. 46 and 49. 



194 APPLIED ANATOMY. 

spine is flexed and the chest securely braced when the lungs are filled 
with air, powerful backward pressure is exerted, and after repeated 
attempts, the anterior condition can, in some cases, be overcome. This 
anterior condition is common and constitutes a condition hard to re- 
lieve. The opposite condition may be present and especially in certain 
forms of disease, principally diabetes mellitus. 

Sprains of the back take place quite commonly at the articulation 
between the seventh and eighth dorsal. This condition is very painful, 
movement being almost impossible. The ligaments are partly torn, 
congested and thickened. If apparent recovery does take place, an 
irregularity will remain, the foramen is lessened in size and a lessening or 
complete destruction of mobility results. Many spinal lesions, I refer 
to chronic displacements of vertebrae, have a sprain as a starting point. 
Several vertebrae are usually involved and a change in contour is the 
result. 

The blood-vessels passing through the foramina are affected in le- 
sions of the seventh. The vein starts in the seventh dorsal segment 
and after being reinforced, passes downward and outward through the 
corresponding foramen, thence into the intercostal vein. 

The arteries branch from the intercostal. The main trunk con- 
tinues into the muscles. A branch is given off which passes into the 
foramen and being inclosed by the sheath of dura mater that surrounds 
the roots of the seventh dorsal nerve, passes obliquely upward to the 
corresponding segment, hence carries nutrition to this part of the spinal 
cord. 

Lesions of the seventh dorsal ordinarily produce pressure on these 
vessels. The segment becomes in a measure, congested because the anas- 
tomosis is not complete enough to carry blood to and from the cord 
without there being any effect. After a while the collateral circulation 
may be established, but in the meantime the functions of this segment 
are perverted in proportion to the degree of vascular disturbance. 

The nerves passing through the intervertebral foramina, with their 
branches, are directly affected and the various nerves with which these 
connect, are more or less affected indirectly. 

The seventh intercostal, supplies the intercostal and abdominal mus- 
cles, diaphragm, pleura, peritoneum, the seventh rib and its periosteum, 
and. sensation to the pit of the stomach and the seventh interspace. If 
the lesion irritates this nerve, in acute cases there will be a, contraction of 



APPLIED ANATOMY. 



195 



the intercostal muscles, or rather an interference with the normal action 
of these muscles, since contracture is scarcely possible. The diaphragm 
may be affected. Hiccough may develop, which form often ends fa- 
tally, or at least runs a course of several days unless stopped by reliev- 
ing the irritation to this or other intercostal nerves. The abdominal 
muscles contract and cause the patient to assume a stooped posture. 
There will be pleurisy and intercostal neuralgia, or there may be neuritis 




Fig. 49. — Showing effects on the foramina, between the 6th and 7th, and 7th and 
8th thoracic vertebra? in an anterior rotation of the 7th. The articular process is 
rotated forward into the lumen of the foramen. Inflammatory deposits fill in the 
foramina and fix the vertebrae in their abnormal position. Compare with Figs. 
46 and 48. 



196 APPLIED ANATOMY. 

or shingles. Peritonitis, or pain simulating it, will develop, it being 
most intense on the affected side and in the pit of the stomach. Pain 
along the course of the nerve is the most common effect, it being the 
result of congestion of the nerve although it may be a purely referred 
pain. If the lesion inhibits, that is partly paralyzes the nerve, 
there will be relaxation in the muscles and numbness in the sen- 
sory areas. Contracture of the abdominal muscles, upper part, may 
result reflexly from stomach, pancreatic or liver disorder, or a diseased 
condition of the small intestines. 

Pain in the seventh intercostal nerve may be a referred one from a dis- 
ordered condition of viscera innervated by the seventh dorsal segment. 
Therefore, liver complaints, stomach disorders and intestinal affections 
cause pain, some of which is referred to the seventh intercostal nerve. 
The lesion of the seventh dorsal may be responsible for the visceral dis- 
order and the referred pain, since the segment may be directly involved 
by the lesion. 

The posterior division of the seventh dorsal nerve may be irritated 
by the lesion. If such is the case the muscles of the back supplied by 
this nerve become contractured and pain is present in the region of the 
spine of the seventh. Disease of the liver or stomach will also produce 
a contracture of these same muscles. Clinically, if the muscles of the 
back innervated by the seventh dorsal are contractured, there is in all 
probability, liver or stomach disorder. If the lesion inhibits this nerve, 
there will be perversion of sensation in this region of the back with re- 
laxation of the muscles supplied. Visceral disease, if chronic, will cause 
atrophy of some of the spinal muscles. Liver and stomach disorders, 
if chronic, cause atrophy of a portion of the erector spina? muscles in re- 
lation with the seventh thoracic spine with widening of the median 
furrow at that point. Clinically, widening of the median furrow at the 
seventh dorsal is diagnostic of chronic liver and stomach disease.. The 
converse is not always true since there may be disease of the stomach 
without a widening of the median furrow, but this the exception. 

It is stated that the anterior and posterior divisions of the spinal 
nerve carry vaso-motor, secretory and trophic impulses in addition to 
motor and sensory. Thermic impulses are also carried by these nerves. 
Coldness of the integument corresponding to the distribution of an inter- 
costal nerve is quite common in lesions of the corresponding rib or ver- 
tebra, and in certain visceral disorders. Stomach disorders are often 



APPLIED AXATOMY. 



197 



SPINAL LIGAMENTS 

SEMISPINALS DORSI 
INTERSPINALIS 

ROTATORES 



INTEGUMENT OVER SPINE OF 71hT. 
MULTIHDUS SPINS. 
ERECTOR SPINS 
LEVATOR COSTARUM 







PLEXUSES 
A AORTIC C CELIAC 



&m, 



^o^ SR SUPRARENAL TO CAPSULE R.REN ALTO KIDNEY 
SpSPLENICTOSPLEEN PANCREAS ANBSTOMACH/ 
G GASTRIC-TO STOMACH AND ESOPHAGUS E.ESOPHAGIAL 



SM SUP MESENTERIC™ SM. INTESTINES CftCUM 
APPENDIX ASCENDINGAND TRANSVERSE COLON 

I.M. INr MESENTERIC TOOESCENOING ILIACANO 
PELVIC COLON AND UPPER PARTorRECTUM 

D. DIAPHRAGMATICTO DIAPHRAGM VENACAVA R SIDE ESOPHAGUS L.S., 

H.HEPATICTO LIVER GALLBLADDER.STOMACH, DUODENUM. PANCREAS'^ 

SG. SEMILUNAR GANGLIOM A.C. AORTICO-RENAL GANGUOHT, 

Gfi S amdSM.S SPLANCHNICS 

TRIANGULARIS STERNI M.. 




Fig. 50. — Showing the seventh thoracic segment of the spinal cord with its 
nerves and their distribution. 



198 APPLIED ANATOMY. 

characterized by a lowered temperature of the integument supplied by 
the sixth and seventh intercostal nerves. 

Perhaps the explanation is that the vitality of this part of the abdom- 
inal or thoracic wall is lowered directly by the lesion or reflexly, by the 
gastric disorder. When the nutrition of a part is below par, the blood 
stream is slowed and metabolism lessened. In disorders of the stomach, 
there is a lowering of the vitality of the parts supplied by the same spinal 
segment and the activity of the parts is lessened, hence the lowered 
temperature. After all it is a matter of circulation and, in this par- 
ticular sort of case, the vitality of the wall is lowered on account of (1), 
a central lesion directly involving the part, and (2), a visceral one that 
impairs the circulation to that part of the spinal cord that controls the 
nutrition of, hence circulation of blood through, the affected area. 

Vaso-motor changes in the area supplied by the seventh intercostal, 
are not unusual when a lesion of the vertebra or rib, exists. Herpes 
zoster, is a type of these disorders. If both intercostal nerves are af- 
fected, the patient complains of a constriction around the body corre- 
sponding in position to the seventh intercostal nerves. Locomotor 
ataxia is a cause, in which case the lesion is a central one. Lesions of the 
lower dorsal vertebrae arid ribs are more common and important in the 
production of this peculiar constricting pain. 

Practically it may be stated that nearly, if not all diseases of the 
viscera innervated by the seventh dorsal segment, produce some effect 
in the areas supplied by the anterior and posterior divisions of the seventh 
dorsal nerve. The explanation is that the impulses set up by the dis- 
order, pass to the spinal cord which in turn, in most instances, becomes 
congested. This congestion affects the cerebro-spinal nerves derived 
from the same segment. 

The rami communicantes are more or less affected by a lesion of the 
seventh dorsal. If pressed on, the impulses may be lessened or entirely 
shut off; and if irritated, they may be increased. The grey rami are 
principally efferent and convey as is the case of those above, vaso-motor, 
secretory and pilomotor impulses. Undoubtedly, some sensory im- 
pulses are transmitted by the giey ramus, consequently irritation of the 
seventh grey ramus would cause pain to be referred to the parts sup- 
supplied by the great splanchnic and seventh nerves. Inhibition of it 
would cause vaso-motor disturbances in the cord and abdominal and 
thoracic walls and lessening of sensation in parts supplied by the seventh 
thoracic nerves. 



APPLIED ANATOMY. 199 

If the white rami are affected the various efferent impulses that 
normally pass over the great splanchnic nerve will be disturbed in some 
way. It is then possible for there to be perverted peristalsis, secretion, 
nutrition and blood supply of parts innervated by the nerve filaments 
in and composing in part, these white rami. The recurrent meningeal 
is in most lesions, affected by direct pressure, hence dilatation of the 
spinal blood-vessels takes place if the pressure inhibits instead of stim- 
ulates the nerve. 

The seventh thoracic sympathetic ganglion is involved directly or 
indirectly in all typical lesions of the seventh dorsal. The ganglion lies 
in relation with the head of the seventh rib. The rib is partly displaced 
in all lesions of the vertebra. The impulses passing to the seventh gang- 
lion are carried by filaments that pass through the corresponding inter- 
vertebral foramen. This foramen is lessened or otherwise affected by a 
lesion of the seventh dorsal. The branches of this ganglion then would 
be more or less affected by a lesion of the seventh dorsal. Its branches 
are the third root of the great splanchnic and branches to the vertebra 
and ligaments. The great splanchnic gives off branches to the thoracic 
aortic plexus and the oesophagus before it reaches the solar plexus. If 
the nerve is irritated by the lesion the oesophagus and aorta may be con- 
stricted since it is at least vaso-motor and possibly motor to the esopha- 
gus and vaso-motor to the aorta. 

Dysphagia sometimes results from a lesion at the seventh dorsal. 
The other functions of the nerve are more or less affected by the lesion. 

The bile duct and gall-bladder are relaxed in the chronic lesion hence 
tendency to the formation of gall stones because of the incomplete evacua- 
tion of the gall-bladder as a result of lessening of the peristalsis. The 
sediment may form a concretion, which, on account of its character 
and location, is called a gall stone. 

The spinal column and cord are affected by this lesion in a way 
similar to that from a lesion of the sixth dorsal, which see. Also the 
ribs are affected as are other ribs; that is, either a subluxation takes 
place or else a strain of theirligaments results from the vertebral lesion. 

The liver, stomach, pancreas and the small intestines are the viscera 
most frequently diseased by a lesion of the seventh dorsal. They are 
affected because (1) a part of their spinal cord centers is located in the 
seventh dorsal segment and this segment is invariably disturbed by the 
lesion; and (2) the line of communication between these centers and the 
viscus is broken or impaired by the lesion. 



200 APPLIED ANATOMY. 

The structures involved by a lesion of the seventh dorsal are the 
peritoneum, pleura, periosteum of the seventh rib and all tissues at- 
tached. The explanation is that the nerve supply to these structures 
is directly affected by the lesion or else they are affected by contiguity. 

The functions of the liver are disturbed by this lesion in a way sim- 
ilar to that from the lesion of the sixth dorsal. If the lesion is irritative, 
there is increased activity up to a certain point after which fatigue sets 
in and the lesion has the opposite effect. There is disturbance of ex- 
cretion of bile. It is then retained in the liver, is absorbed by the lym- 
phatics and partly excreted by the skin. This gives rise to biliousness, 
jaundice, change in character and odor of stool, intestinal indigestion 
and constipation, because of the change in character of the bile, the 
abnormal place it occupies and the lessening in amount at the nor- 
mal place, that is in the intestines. Biliousness follows because of the 
toxemia; jaundice, from attempted excretion of the pigment by the skin; 
the odor of putrefaction, since the feces undergo a certain amount of de- 
composition when the bile is absent; indigestion because bile assists in 
the digestion of the fats; and constipation because a lack of bile causes 
a lack of secretion of mucous and because the parts are not sufficiently 
lubricated. 

The glycogenic function is disturbed, this usually resulting in gly- 
cosuria. The secretion of urea is altered and kidney diseases develop 
in a short time if the disturbance is marked. Metabolism is interfered 
with and the food products carried to the liver by the portal vein are 
not properly acted on. Most of these effects depend on the vascular 
changes in the liver. Sensory disorders of the liver also seem to depend 
on the vascular changes since if it is congested, it is tender on pressure. 

Any one or all of the these factors are affected by the lesion, hence 
the disturbance in function. 

Summary. Lesions of the seventh dorsal, cause stomach disorders 
such as gastritis, gastroptosis, acidity with eructation of gas, gastralgia, 
or even ulcer and cancer, because the nerves controlling the movement, 
secretion, nutrition, sensation and the amount of blood, are affected by 
the lesion, because they pass through the foramina between the seventh 
and eighth dorsal vertebrae. Diseases of the liver follow a lesion of the 
seventh dorsal because the amount of blood in it is controlled by the 
nerves that are impaired by the lesion, viz., the great splanchnic. These 
diseases vary with the character of the lesion and the function affected. 



APPLIED ANATOMY. 



201 



There may be malaria, kidney disease, cirrhosis, gall stones, glyco- 
suria, and biliousness with periodic headache. A "sluggish" liver with 
its retention and absorption of bile, is the most common effect. Vomiting 
is nature's .method of relieving bilious headache. In nearly all chronic 
cases of biliousness seen by the writer, a marked anterior condition of 
the sixth, seventh or eighth dorsal vertebra was found. The explanation 
is that the lesion causes congestion of the liver by dilating the blood- 
vessels. There is in all probability, increased secretion of bile and ob- 




Fig. 51. — Showing a posterior subluxation of the 7th and Sth thoracic vertebrae 
and an anterior condition of the 9th. (From photo). The patient had congestion 
of liver. 



structed elimination. It then is absorbed and acts as a toxemia. In 
hepatic colic the sensory nerves involved are the great splanchnic and 
the sixth, seventh and eighth intercostal nerves. Inhibition, in which 
marked pressure is exerted against these vertebra; (6, 7 and 8) and the 

body is bent backward, will usually relieve the attack. This sort of 
treatment lessens the size of the intervertebral foramina thereby inter- 
feres with the transmission of the sensory impulses to the sensorium. 



202 APPLIED ANATOMY. 

Perhaps the effect of this treatment is due in part to the effect on 
the vaso-motor nerves that also pass through these foramina. By 
moving the vertebra, it may adjust it so that the normal impulses will 
again pass through, in which case the treatment is a curative one. Since 
most pain is due to pressure from congestion, another explanation of 
why such a treatment relieves even in many cases of colic, is that the 
circulation through the viscus is bettered, hence the irritation resulting 
from pressure and chemical stimulation is lessened. 

The pancreas is also involved by a lesion of the seventh dorsal on 
account of the resulting disturbance to the great splanchnic nerve, solar 
and coeliac plexuses. Glycosuria is one effect of a disturbance of the 
pancreas. The small intestine is often involved by this lesion but not 
so frequently as by a lesion of the lower thoracic vertebra;. The various 
lesions of the seventh dorsal, most frequently produce disease of viscera 
by obstructing the foramen through which impulses pass from the spinal 
cord centers to the viscera, and through which the corresponding parts 
of the spinal cord are nourished and drained. 

THE EIGHTH THORACIC. 

The eighth dorsal vertebra does not differ materially from the seventh. 
The mobility of its articulations is slightly more marked because of the 
change in character of the ribs articulating with it. This is demon- 
strated best by causing the patient to bend in various directions with 
the fixed point at the eighth dorsal. 

The most common lesion is the anterior subluxation. Many of 
these come from falls backwards against some object, striking at the 
eighth dorsal. Extreme flexion may also cause a lesion. Torsion 
is the most common condition of all the lesions of the eighth. The effect 
is most marked on the side to which the vertebra is turned. Such le- 
sions result from a twisting of the body while in extreme flexion or ex- 
tension. 

The effects vary with the degree, length of standing, cause, condi- 
tion of patient and parts affected. The cutaneous sensory effect is man- 
ifested by sensory disturbances along the eighth interspace, especially 
in that portion of the abdomen supplied by the seventh and eighth dor- 
sal nerves, and a portion of the integument in relation with and imme- 
diately below the spines of the seventh and eighth dorsal vertebra;. The 
usual effect is pain, although there may be anesthesia, coldness of part 



APPLIED ANATOMY. 203 

or perverted sensation such as formication. These sensory effects vary 
with the kinds of lesions. If the lesion is an irritative one, pain will be 
the result; if paralytic, anesthesia follows. Not all pains or other sen- 
sory disturbances in those areas are due to a lesion of the eight dorsal. 
A rib lesion of the same side will cause it. Irritative disease of the eighth 
dorsal segment or of viscera supplied by it, will cause sensory disturb- 
ances in the areas supplied by the eighth dorsal nerve. Hepatic colic, 
intestinal indigestion, liver diseases such as abscess, and occasionally 
gastric disturbances will cause pain to be referred to the integument 
supplied by the eighth dorsal nerve. The explanation is that the im- 
pulses set up by the diseased viscus are carried to the spinal cord (8 d. 
segment) over the great splanchnic nerve, thence over the same nerve 
tracts that carry impulses from the integument supplied with sensation 
by nerve filaments that pass through this segment. The sensorium, in 
such cases of referred pain, is mistaken, as to the real source, and ordinarily 
refers the impulses to the areas of higher sensibility; or if both visceral 
and cutaneous impulses travel over the same column or tract of the 
spinal cord, the pain would also be referred to areas that had the greatest 
sensory innervation. On this account, lesions of the articulations of the 
eighth dorsal may produce sensory disorders that simulate the various 
painful affections of viscera supplied by the eighth dorsal segment. 

The direct cutaneous sensory effects are due to impingement on or 
other disturbance of the common trunk of the eighth dorsal nerve or its 
branches. The subluxated bone ordinarily produces direct pressure 
on the nerve filaments as they pass through the foramen, at which place 
they are in relation with the articular processes of the vertebra. If the 
pressure is marked, there will anesthesia; if intermittent, pain or per- 
version of sensation. In many cases, especially in mild ones, the pres- 
sure is exerted indirectly on the nerve. 

Certain structures supplied with sensation by nerves that pass 
through the eighth dorsal segment, are affected by a lesion of the eighth 
dorsal vertebra. These structures are the peritoneum, pleura, eighth 
rib and periosteum, certain muscles, that is muscles supplied by the 
eighth dorsal segment, esophagus, and the gall-bladder and ducts. The 
explanation is that the sensory impulses, in part if not entirely, from 
these structures must pass through the seventh and eighth interverte- 
bral foramina which are changed in size by the lesion. Even though 
the impulses safely reach the spinal cord, the columns of the cord that 



204 APPLIED ANATOMY. 

have to do with transmitting sensory impulses, may be affected by the 
lesion and consequently there will be some sensory effect in parts sup- 
plied. The kind of effect varies, as does any sensory effect, with the kind 
and number of impulses and the condition of the cells receiving them. 
In the above, pain or hyperesthesia is the rule, hence a lesion of the 
eighth dorsal may and often does simulate peritonitis, muscular rheu- 
matism and hepatic colic. The explanation of cause and effect is that 
the above named structures are innervated in part by the eighth dorsal 
segment which controls sensation to them through the eighth intercostal 
nerve, posterior division of the eighth dorsal and the great splanchnic 
nerve. In such cases it is the rule for the nerve to be congested or in- 
flamed. Certain viscera manifest sensory disturbances when the eighth 
dorsal vertebra is subluxated, viz., the liver, stomach, small intestines 
and possibly the spleen and pancreas. They are affected because their 
sensory nerves, that is the branches of the great splanchnic, are in rela- 
tion with the eighth dorsal or rather, the filaments that cany impulses 
to and from it are in relation and are always affected in typical lesions. 
This disturbance in the viscera gives rise to colic, hence in such affect- 
ions examine for a vertebral lesion. 

The motor effects of a lesion of the eighth dorsal, are manifested in 
the structures and viscera supplied by the seventh and eighth dorsal 
segments. There may be increased or lessened motion, this depending 
on the character and degree of the lesion. In acute cases, the muscles 
are contractured; in chronic ones, the opposite condition is the more 
common or else there are structural changes in the muscles from which they 
become shortened and hardened. The muscles involved are the inter- 
costals, levatores costarum, obliqui abdominales, recti and transversales 
abdominales, erector, multifidus and rotatores spinsB and the diaphragm. 

The intercostal muscles do not become contractured although they 
may become quite tender from congestion. This makes respiration 
painful, hence difficult. These muscles often atrophy as a result of 
the lesion, in which case the respiration is carried on almost entirely 
by means of the diaphragm. 

The levator costa; muscle, if contractured, will draw up the angle of 
the rib; if weakened, Mali permit the angle of the rib to descend. The 
muscle will be affected one way or other if the lesion affects its nerve 
supply or attachments. 

The abdominal muscles are usually symmetrically affected, that is, 



APPLIED ANATOMY. 205 

there is either a general relaxation or contraction. If the lesion is irrita- 
tive, the muscles contract, but if inhibitive, they relax. The condition 
of these muscles is a good index to the condition of the viscera covered 
by them. In chronic intestinal indigestion, they are usually contrac- 
tured; in gastroptosis, enteroptosis and especially in chronic constipa- 
tion, they are relaxed. Vertebral lesions are in most cases, responsible 
for both the contiactured or relaxed condition and the visceral disorder. 

The erector, multindus and rotatores spinae muscles are usually 
contractured by a lesion of the eighth dorsal. In cases of malnutrition 
they will be relaxed. Their contracture, especially that of the erector 
and rotatores spina? muscles, lead to spinal curvatures. If only one side 
is involved, a scoliosis with rotation. But on the other hand it must 
not be forgotten that curvature comes most frequently from relaxation, 
hence these apparently contractured muscles, pull the spine to the op- 
posite or convex side. 

The function of the diaphragm may be seriously interfered with by 
a lesion of the eighth dorsal, because such a lesion often affects the eighth 
intercostal which assists in the innervation of the diaphragm. Re- 
spiratory disturbances, and the supposed "liver cough" follow. 

These muscles named above are supplied by the anterior and posterior 
divisions of the eighth dorsal nerve. This nerve is affected by lesions of 
the eighth dorsal, because the foramen through which it passes is lessened 
in size, or at least, either the seventh or eighth intervertebral foramen 
is always affected by a lesion of the eighth dorsal vertebra. This le- 
sion also affects the spinal cord, the eighth dorsal segment, especially 
the cells that give rise to the filaments that form the nerves supplying 
the muscles named above. 

The motor and viscero-inliibitor nerves to the stomach are in part, 
in relation with the eighth dorsal vertebra and are affected by a sub- 
luxation of the vertebra. As a result of this impairment, the peristalsis 
of the stomach is perverted. If excessive, ulcers are likely to form since 
the stomach attempts to digest itself. There is a sense of hunger usuallv 
described as a "gnawing" sensation. If the peristalsis is lessened, diges- 
tion is retarded, and fermentation of the food follows. If reversed, vomit- 
ing occurs. In ordinary cases of catarrh of the stomach, there is lessened 
peristalsis. As to whether this is due to an inhibition of the motor or 
stimulation of the inhibitor nerves, there seems to be considerable doubt. 
The splanchnic nerve acts as a motor and viscero-inhibitor nerve, hence 



206 APPLIED ANATOMY. 

the lesion may affect either or both. The effects on the stomach are ex- 
plained by the fact that the great splanchnic nerve, which after com- 
municating with the vagus supplies the stomach, is disturbed by a le- 
sion of the eighth dorsal vertebra. Nearly all the motor impulses pass- 
ing over this nerve arise in the spinal cord, pass out over the ventral loot 
into the common nerve thence over the white ramus into the gangliated 
cord, thence over the efferent or splanchnic nerve to the semi-lunar 
ganglion. This line of communication is often broken, or at least crippled, 
by the lesion, hence the effect mentioned above. 

The motor effect on the small intestines is similar to that on the 
stomach, that is, there is increased, perverted or lessened peristalsis, 
characterized by diarrhea or griping, vomiting and constipation. The 
explanation offered in regard to the motor effects on the stomach will 
apply to the small intestines. 

A lesion *of the eighth dorsal will also have a motor effect on the 
esophagus. Constriction with dysphagia is the common result. The 
explanation is that the great splanchnic, sends filaments to the oesophagus 
and this nerve is involved in subluxations of the eighth dorsal. Most 
disturbances of the esophagus come from lesions affecting the fifth and 
sixth roots of the great splanchnic, although a lesion of the eighth dor- 
sal may affect it. This connection explains the correlation of forces 
in vomiting. 

Landois says: "The splanchnic nerve is the motor nerve of the 
bile ducts and the gall bladder." Osteopathically, lesions involving 
this nerve cause accumulation of bile and gall stones. Inhibition of this 
nerve causes relaxation, hence dilatation of the bile ducts Hepatic 
colic unless due to an attempted passage of a large calculus, is relieved in 
this way, that is by applying pressure at the eighth, extreme extension 
of the spine with fixed point at the eighth or by correcting the lesion at 
the eighth. 

The vaso-motor effect of a lesion of the eighth dorsal is quite marked 
on account of the large area innervated and the importance of the blood- 
vessels that are supplied by this part of the spinal and gangliated cords. 
The abdominal blood-vessels as a whole, are more or less affected. The 
vessels of the alimentary tract are innervated by the middle thoracic 
area. The superficial blood-vessels in this part of the body are nearly 
always involved and special mention should be made of the portal, renal 
and splenic vessels. The blood-vessels innervated may be increased 



APPLIED ANATOMY. 207 

or decreased in size, this being determined by the character of the le- 
sion. If it irritates, the blood-vessels will remain small so long as the 
stimulation keeps up, but if the lesion inhibits the blood-vessels will 
become larger. The first condition is followed by anemia, the second 
by congestion. If the constriction is localized there will be no general 
rise in blood pressure, but if general, the arterial tension or pressure is 
increased. 

Dilatation of the superficial arteries occurs in the erythematous 
conditions, red neuralgia being a type. Dilatation of the portal vein 
causes congestion of the liver, which condition is characterized by a 
plethoric, bilious condition. There is a Irypersecretion of bile with ab- 
sorption. Constriction of the vein has the opposite effect. 

Dilatation of the renal veins is characterized by increase in secre- 
tion of urine and later on, by organic disturbances. In interstitial neph- 
ritis the opposite condition probably exists. The functions of the spleen 
are likewise increased or decreased in a similar way. The abdominal 
vessels are affected through the great splanchnic nerve. Landois says: 
"Stimulation of the splanchnic nerve causes contraction; its division, 
dilatation, of all of the intestinal blood-vessels possessing muscle fibers. 
In the latter event enormous accumulation of blood takes place in the 
intestinal vessels, so that anemia of other parts of the body results, and 
in consequence even death may take place from anemia of the medulla 
oblongata." The superficial blood-vessels are affected because their 
vaso-motor impulses pass over the grey ramus from the gangliated cord 
to the cerebro-spinal nerve, thence to the vessels by way of the inter- 
costal nerve and posterior division of the nerve. The nerve tract is 
broken or otherwise affected by a subluxation of the eighth dorsal, be- 
cause it is in direct relation. 

The portal vein is supplied directly by the great splanchnic nerve 
which is the vaso-motor nerve to the liver. P'xperimentally, "division 
or paralysis of the vaso-motor conducting paths from the center to the 
liver, results in glycosuria." A lesion will have a similar effect, if it in- 
hibits these impulses. 

"The passage as rapidly as possible of large amounts of blood 
through the liver acts most favorably upon the secretion." This is 
controlled by nerves that are affected by lesions of the eighth dorsal 
vertebra. If these nerves are affected, faulty secretion of bile follows, 
hence jaundice or other changes. 



208 APPLIED ANATOMY. 

The renal vessels are affected by a lesion of the eighth dorsal, be- 
cause it affects the great splanchnic nerve "which contains the vaso- 
motor fibers for the kidney. " If the impulses are inhibited the vessels 
dilate. If it is a localized condition, increased secretion of urine follows; 
if the rest of the abdominal vaso-motor nerves are paralyzed at the same 
time, "the secretion of urine diminishes even to the point of complete 
cessation. " The splenic vessels are innervated by the splenic plexus 
which ultimately receives its impulses from the great splanchnic nerve, 
hence the explanation of effect of the lesion on it has been given above. 

The secretory effects of a lesion of the eighth dorsal are manifest 
in the amount and quality of sweat, urea, glycogen, gastric juice, succus 
entericus, pancreatic juice and the secretions of the spleen. The secre- 
tion of the peritoneum should also be considered in the secretory effects 
of this lesion. 

The amount of sweat secreted seems to depend on things other than 
secretory nerves. Landois says: "As in the secretion of saliva, vascu- 
lar nerves are principally active in the secretion of sweat in addition to 
the true secretory nerves, and most frequently the dilators, as indicated 
by the sweating when the skin is reddened." However, the sweat 
fibers may be active even though there is anemia. The lesion produces 
a disturbance of the sweat glands (1) by affecting the sweat center in 
the spinal cord, and (2) by affecting the nerve tracts over which these 
impulses travel from the spinal cord to their destination and (3), by 
changing the amount and character of the blood supplying the sweat 
glands. The center is affected through its blood supply, a venous con- 
dition stimulating it to greater activity. The nerve tracts are in the 
cerebro-spinal nerve and its branches. This nerve is always more or 
less affected by a lesion of the vertebra in relation. The amount of bile 
secreted may be increased or decreased as a result of the lesion of the 
eighth dorsal. As in the production of sweat, the amount of blood must 
be considered. Landois, in speaking of bile secretion, says: "All pro- 
cedures that cause contraction of the arteries of the abdomen, such as 
irritation of the valve of Vieussens, of the inferior cervical ganglion, 
the hepatic nerves, the splanchnic nerve, the spinal cord, whether di- 
rectly as by strychnin, or reflexly by irritation of the sensory nerves, 
diminish the secretion. " Osteopathically, a lesion of the eighth dorsal 
vertebra would have a similar effect because it would irritate the hepatic 
nerves, splanchnic nerve and spinal cord, hence the secretory effect. 



APPLIED ANATOMY. 209 

He further says, "All procedures that produce stagnation of blood in 
the hepatic vessels, such as division of the splanchnic nerves, diabetic 
puncture, division of the cervical cord, have a like effect." 

"Acceleration of the excretion of bile experimentally, follows stimu- 
lation of the region of the spinal cord from which the motor nerves (the 
splanchnic) are derived that supply the bile ducts and gall-bladder." 
The glycogenic function also depends to a large degree, on the vascular 
conditions, hence the explanations offered under the head of vaso-motor 
effects of the lesion, will apply to the secretory effects on the liver, of a 
lesion of the eighth dorsal. 

The great splanchnic controls to a large degree the secretions of 
the stomach and small intestines. Lesions of the middle thoracic ver- 
tebras affect this nerve hence the disturbance in secretion. Catarrh is 
the most common effect. Other causes such as thermic changes and 
dietetic errors are important. The pancreatic juice is affected in quan- 
tity by a lesion of the eighth dorsal, because the great splanchnic is af- 
fected by it. Landois says in speaking of the secretion of the pancreatic 
juice: "The nerves are derived from the hepatic, splenic and mesen- 
teric plexuses, to which the pneumogastric and splanchnic nerves send 
branches. The secretion of the gland is excited by stimulation of the 
medulla oblongata, of the splenic nerve (feebly) and of the peripheral 
stump of the pneumogastric." The pancreas is supposed to secrete a 
ferment that destroys or counteracts the sugar in the blood, thus gtycosu- 
ria would follow if this ferment were not secreted. This lesion may also 
affect the secretion of urine but clinically, the lesion that affects urinary 
secretion is lower in the spine and will be considered later. 

Nearly, if not all nerves are supposed to exert trophic influences, 
thus the trophic effects of a lesion of the eighth dorsal, would be determin- 
ed by the nerves involved and the areas innervated. The effect may be 
a general one on account of effect on the liver, stomach and pancreas, 
but is usually localized in a group of muscles. Some forms of skin 
diseases characterized by desquamation, are due to an interference with 
the trophic nerve supplying that portion of the integument. 

A lesion of the eighth dorsal, affects the spinal column and often is 
the starting place of a spinal curvature. As stated above, some of the 
spinal muscles are weakened and the opposing muscles draw the spine 
toward the sound side. The contour of the ribs is also changed since 
they articulate with the vertebrae. 



210 



APPLIED ANATOMY. 



R0TAT0RES SPIN* 
SEMISPINALS DOR SI 

INTERTRANSVERSAJJ 

INTERSPINALS 



INTEGUMENT CTMER SPINE OF 8lhT. 
MULTIFIDUS 6WNA1 
ERECTOR SPINA 

LEV. COSTA RUM 




PLEXUSES ETC. 

S SOLAR C. CELIAC A. AORTIC 

W H.HEPATItTO LIVER GALL-BLDR.STOMACH DUODENUM PANCREAS 

fe °k G. GASTRIC TO STOMACH ANO ESOPHAGUS E-ESOPHAGIAL 

~%% *%* SpSPLENICTO SPLEEN PANCREAS ANO STOMACH 
I.M?4 



0. DIAPHRAGMATIC TO DIAPHRAGM VENA CAVA R.SIDE ESOPHAGUS L SIDE/ 

S.M.-SURMESENTERICTO SM.INTESTINES.CfcCUM. APPENDIX, A5C'AWDTRANS.C0L0N^ 

|,M." INF. MESENTERIC TO DESC. ILIAC ANO PELVIC COLON AND UPPER RECTUM. 

Spr.SPERMATIC TO SPERMATIC CORD TESTICLE IN FEMALE THE OVARIAN 
TO OVARY BROAD LIGAMENTAND FALLOPIAN TUBE 

S.R; SUPRARENALTO SUP CAPSULE R RENALTO KIDNEY 

GR. S ANOSM.S. SPLANCHNICS 

S.& SEMILUNAR GANGLION 





Fig. 52. — Showing the eighth thoracic segment of the spinal cord with its nerves 
and their distribution. 



APPLIED ANATOMY. 211 

The effect on the spinal cord depends on (1) pressure on the blood- 
vessels supplying and draining it; (2) pressure on the nerve roots, par- 
ticularly the posterior, and (3), pressure directly on the spinal cord. 
The first comes as a result of a lessening in size of the intervertebral 
foramina, thus directly obstructing the vessels that pass through. The 
corresponding segment is affected most, since the blood-vessels pass up 
the sheath of dura mater that encloses the corresponding nerves. Pres- 
sure on the posterior nerve roots causes ascending degeneration, loco- 
motor ataxia possibly being the best illustration of the effects. The 
ganglion is most subject to pressure on account of its location. Pressure 
on the cord causes transverse myelitis with partial, if not complete par- 
alysis of the body below the level of pressure. 

Summary. The eighth dorsal is the clinical center for splenic dis- 
eases, pancreatic disturbances, gall-stones and intestinal indigestion 
that is, lesions of it most constantly produce these effects. Biliary and 
intestinal colic, can ordinarily be relieved by inhibition at this point, 
the treatment being most effectual if the spine is extended as far as pos- 
sible with pressure at this point, that is at the eighth dorsal spine. This 
movement lessens the size of the foramina through which the afferent 
impulses pass. Backache is common in this region in lesions of the 
articulations of the eighth and in kidney, ovarian and intestinal dis- 
orders. The prolonged contracture of the spinal muscles in the above 
conditions gives rise to backache or in acute cases, to lumbago. 

THE NINTH THORACIC. 

The ninth thoracic vertebra is slightly larger than the eighth dorsal, 
the spine is not as oblique or so hooked. It is classed with the peculiar 
vertebrae because it has no demi-facets for articulation with the ribs. 
The mobility of its articulations is greater than that of the eighth dorsal, 
because of change in character of the ribs. The intervertebral foramina 
are formed like those above, by the articular processes and are subject 
to change in size by subluxations of the vertebra. The most common 
subluxations are torsions and anterior ones. Slight separations such as 
"breaks" often occur at one of its articulations, that is between the 
eighth and ninth dorsal or between the ninth and tenth dorsal. Such le- 
sions ordinarily come from hyperflexion of the spine, especially if force 
is exerted while in the stooped position. The lifting of a heavy weight 
is often responsible for the separation. The torsion results from an un- 



212 APPLIED ANATOMY. 

expected twist or turn of the spine. It may at first be diagnosed as 
a "crick in the back." 

The anterior subluxation is the most important from a pathological 
standpoint because of the effect on the foramina, it lessening their 
size and compressing the structures that pass through them. In all 
acute or recent cases, the ligaments are either stretched or torn in 
every pathological case. If torn, they heal slowly and often are 
markedly thickened. After a while they contract and approximate the 
vertebrae, thus producing a smooth or stiff spine. In most cases they 
remain tender and softened, thus indicating by these conditions the 
affected vertebra. A separation'or break is not so important as an ap- 
proximation. On testing the mobility of the spine, note that it is 
greatest at the widened area and lessened or entirely lost at the points 
of approximation. As a rule, a separation needs little or no treatment. 

All subluxations of the ninth dorsal affect the tissues attached to it. 
Some are stretched and irritated, others are relaxed and inhibited. The 
connective tissue is affected and the circulation through it obstructed. 
The muscles are irritated and soon a contractured condition results. 
The muscles then begin to ache or act with difficulty. If the patient 
were to assume a stooped posture for a few minutes, it would be difficult 
to straighten the spine, the patient complaining of stiffness and an achy 
feeling. The principal muscles involved are the erector and multifidus 
spinas. 

The arteries affected by a subluxation, are the ninth intercostal and 
its spinal and muscular branches, the abdominal aorta and its branches 
that supply the liver, spleen, stomach, small intestines, pancreas, supra- 
renal capsule, ovary and testicle and the kidney. 

The intercostal and its branches are affected directly by pressure 
either by the displaced vertebra, or by traction on, or contraction of, the 
tissues through which the vessels pass. The abdominal aorta and its 
branches are affected through their nerve supply, that is, by disturbance 
of the splanchnic nerves which cany vaso-motor impulses to these ves- 
sels. Direct pressure on an artery lessens the flow of blood through it 
by obstructing the lumen. Anastomosis will take place if the arteries 
are not of the terminal variety. When its nerve supply is disturbed, 
the artery usually becomes larger, hence the rapidity of the flow of blood 
is lessened and congestion results. It may become smaller if the lesion 
is an irritative one, which is occasionally the condition, especially in 
recent cases, 



APPLIED ANATOMY. 213 

The veins in relation are affected by direct pressure. The veins 
correspond to the arteries. The inferior vena cava and its branches 
draining, by way of the portal system, the principal abdominal viscera, 
are affected through their nerve supply. The most common effect 
on the vein is dilatation, this producing congestion. In the case of the 
portal vein, congestion of the abdominal viscera results with its disturb- 
ances of function. 

The nerves affected by this lesion are (1) cerebro-spinal and (2) 
sympathetic. The cerebro-spinal affected are the ninth thoracic and 
its branches, the ninth intercostal and the posterior division. The sym- 
pathetic nerves affected are the gangliated cord, the ninth thoracic gang- 
lion and its branches, the great and lesser splanchnic, the rami and the 
branches that supply the ligaments, vertebrae, meninges and spinal cord. 
Those affected secondarily are the solar plexus and its branches, the 
semi-lunar ganglia, and the aortic and renal plexuses with their branches. 

The impulses that are carried by these nerves pass through the in- 
tervertebral foramina in relation with the ninth dorsal vertebra. At 
least two of these foramina are lessened in size by any form of lesion of 
the ninth dorsal, therefore the impulses would be impaired. The nerve 
cells giving rise to these impulses are nourished and drained by blood that 
passes through these foramina, hence a disturbance of these cells in cases 
in which the foramina are lessened in size. 

The principal abdominal, and some of the pelvic viscera are more 
or less disturbed by a lesion of the ninth dorsal. The viscus most fre- 
quently and constantly affected is the kidney. This is explained by the 
fact that it gets most of its nerve impulses from the ninth dorsal 
segment, while the liver, stomach, etc., are innervated mostly by seg- 
ments higher in the cord. The kidney is affected then because the le- 
sion interrupts the passing of nerve impulses from the spinal cord to it. 
These impulses are usually carried by the lesser splanchnic although the 
great splanchnic carries some. There is a direct line of communication 
between the cord and the kidney although separate names are given to 
the different parts of it. The impulses arising in the grey matter of the 
ninth dorsal segment, pass over the ventral root, common nerve trunk, 
anterior division, white ramus, ninth dorsal ganglion, lesser splanchnic 
thence into the aortico-renal ganglion. Sometimes the lesser splanch- 
nic furnishes a direct twig to the renal plexus. Pressure at any point 
on this line,will disturb the power the nerve has of transmitting impulses, 



214 



APPLIED ANATOMY. 



INTEG. OVER SPINES 9th AND lOfh." 

INTERVERTEBRAL DISG 

ROTATOR ES 

VERT. LI GTS 
AND 

MENINGES 



SEMISPINALS OORSI 

ERECTOR SPIN* 




Fig. 53. — Showing the ninth thoracic segment of the spinal cord with its^nerves 
and their distribution. 



AI'1'LIED ANATOMY. 215 

hence disturbance of function of the part innervated. In a similar way, 
the kidney may be affected by this lesion interfering with the innerva- 
tion of its blood-vessels. This nerve supply controls secretion, nutri- 
tion, sensation and vaso-motor impulses sent to the blood-vessels of the 
kidney. If the lesion is irritative, there will be increased secretion, if the 
secretory nerve is involved, pain referred to the kidney or side, and anemia, 
if the case is an acute and recent one. Secretion and excretion of urine 
seem to depend partly on the secretory nerve, blood pressure, and the 
quality and quantity of blood. If the lesion is paralytic, there will be at 
first a moderate increase in the amount of urine for a few hours, finally 
the action of the kidney becomes entirely suspended and an organic dis- 
ease follows. 

The suprarenal capsules are affected by a lesion of the ninth dorsal, 
because their nerve and blood supply are affected by the lesion. The 
nerve impulses that pass to this organ, at least a majority of them, pass 
over the lower roots of the splanchnic nerves. These nerves or their 
roots, are affected by the lesion. The blood-vessels supplying the supra- 
renal capsule are innervated by the solar, phrenic and renal plexuses 
which receive most of their impulses from the splanchnic nerves. The 
lesion may indirectly cause disease of these organs by causing disease of 
other organs, such as the kidney. As to the effect on the body of a lesion 
impairing these capsules, little is known. They have to do with the 
elaboration of the blood, there being an internal secretion. 

The ureter is, or may be affected by a lesion of the ninth dorsal, be- 
cause its nerve supply is disturbed. The nerves, motor, sensory and 
and vaso-motor, that supply the ureter are derived from the renal plexus 
which in turn is formed by the splanchnic nerves. The ninth dorsal 
segment contains nerve cells that give rise to filaments that pass directly 
to the ureter supplying it with motor, vaso-motor and trophic impulses. 
The efferent impulses pass out of the cord over the ventral root, thence 
through the intervertebral foramen over the common trunk, then to the 
ureter by way of the white ramus, gangliated cord, lesser splanchnic and 
renal plexus. The effects will be considered with the study of the tenth 
dorsal segment. 

The spleen is affected by a lesion of the ninth dorsal because the 
ninth segment sends nerve filaments to it. The principal effect of a 
lesion involving this nerve seems to be a vaso-motor one. In diseases 
characterized by splenic trouble, the lesion often is as low as the ninth 



216 APPLIED ANATOMY. 

dorsal, although the predominating- spinal center seems to be higher up 
in the spinal cord. Schsefer and Moore say that in the dog they found 
motor nerves to be present in the third thoracic to the first lumbar in- 
clusive. *"The most marked effect was obtained on stimulating the 
sixth and eighth dorsal nerves; a very distinct contraction on stimulating 
the fifth, ninth and tenth nerves; a slight contraction on stimulating the 
third, fourth, eleventh, twelfth and thirteenth thoracic and the first 
lumbar nerve." Clinically, it can be proven that a lesion will stimulate 
a nerve. A lesion of the ninth dorsal will stimulate the nerves to the 
spleen or it may inhibit them, and in most splenic disorders the ninth 
dorsal is involved. 

The testes and ovaries are involved through their innervation. 
This comes almost entirely through the renal plexus and lesser splanch- 
nic nerve. 

A lesion of the ninth dorsal will interfere with the passing of im- 
pulses from the spinal cord to the testicle or ovary since it lessens the 
size of the intervertebral foramen. The effects will be considered with 
the tenth dorsal segment. 

The small intestines are nearly always involved by a lesion of the 
ninth dorsal, on account of disturbance of the innervation. Indigestion 
is a common effect. This results from the interference with the sensory, 
secretory, vaso-motor and motor impulses. Constipation results in 
some cases, on account of interference with the peristalsis of the bowel, 
it being lessened. Diarrhea, even enteritis, follows if the lesion is an 
irritative one. Intussusception may occur. 

The liver may be involved by a lesion so low, since its blood supply 
is impaired by such a lesion. Also the stomach is sometimes affected 
but in such cases the small intestines are also involved, that is, a group 
of lesions is present, extending from the fifth to the eleventh dorsal. 
The pyloric end of the stomach is said to be most frequently affected 
by the lesion. 

The principal effect of this lesion (the ninth) is on the vaso-motor 
nerves innervating the above named viscera. That the viscus is con- 
gested or made anemic by the lesion, needs no proof since it has been so 
frequently demonstrated. As to the explanation, it must be through 
the vaso-motor nerves or else the congestion would be constant. The 
lesion alone is usually not sufficient to produce the vascular effects as 
*Note. — Schssfer's Text-book of Phj'siology, p. 643, Vol. II. 



APPLIED ANATOMY. 217 

we find them. The lesion only weakens, then the error in diet, the ex- 
posure during the menstrual period or the overwork or any exciting 
cause, will then bring on the attack. It does not necessarily follow that 
the lesion produces a pathological congestion or anemia of the viscera 
that is constant, because the symptoms are irregular; or that there are 
no lesions present during the interval between the attacks, because there 
are no apparent indications of them. This applies particularly to ovarian 
disorders and sick headaches. As stated above, the lesion plus the ex- 
citing cause will invariably bring on an attack, whereas if only one cause 
were present, it would take quite a while for the vitality to become so 
impaired that an attack would occur, as in the case of a sick headache. 

The diseases most commonly associated with a lesion of the ninth 
dorsal are Blight's disease, ovarian disease, diabetes mellitus and in- 
sipidus, renal colic and in many cases, biliary calculi. The explanation 
is that the ninth dorsal segment contains the centers for the above named 
viscera and connects with them by a series of nerve strands. 

In all cases of megrim, chronic ovarian colic, imperfect secretion 
and lessened elimination of urine, and in cases in which there is a pasty, 
muddy complexion, it is well to carefully examine the ninth thoracic 
vertebra. Usually there is an anterior condition or a marked separa- 
tion of the spinous processes of the ninth and tenth. In patients suffer- 
ing from a cystic degeneration of the ovaries, invariably lesions were 
found in this region in the cases that have come under the writer's ob- 
servation. 

The lesion either affects the nerve centers in the spinal cord by com- 
pressing the spinal vessels, or else it breaks the line of communication 
between the spinal segment and the viscus. The effects on the spinal 
cord and spinal column are similar to those of lesions of other thoracic 
vertebrae. 

THE TEXTH THORACIC. 

The tenth dorsal vertebra is classed with the peculiar vertebras be- 
cause it has an entire costal facet at its upper border and no lower demi- 
facet. It approaches the lumbar type of vertebrae in that all the facets 
are larger and the spinous process shorter and more nearly horizontal. 
The movements of its articulations are more marked than those above, 
possibly on account of the character of the ribs articulating with it. Its 
lesions are similar to those above and result from similar causes. The 
anterior and twisted conditions are most common. The lesion causes 



218 APPLIED ANATOMY. 

many and varied symptoms. It may have a sensory, motor, vaso-motor, 
secretory or trophic effect on viscera. It may cause pressure on adja- 
cent structures such as the connective tissue or spinal cord. 

A lesion of the tenth dorsal will produce a sensory disturbance in 
the small intestines. This disturbance may be hyperesthesia, pares- 
thesia or anesthesia. Hyperesthesia occurs in enteritis and colicky con- 
ditions which ordinarily come from congestion of the intestinal mucus 
membrane. This hyperesthesia is conducive to increased secretion and 
excessive peristalsis, hence in typical cases, diarrhea, as in typhoid fever. 
The seat of the irritation may be in the mucous membrane but in many 
cases the cause lies in the spinal cord, the nerve roots and trunks, or in the 
spinal column. The gastric crisis is a well known effect of locomotor 
ataxia. The intestinal colic of a baby is another example of effect on 
intestines of a lesion in the spinal cord. 

The thermic influences cause contracture of the spinal muscles, 
which in turn affect the spinal cord and its nerves, especially the nerves 
to the stomach and small intestines. The colic is not entirely due to the 
stimulation of the sensory nerves by the lesion, whether bony or muscu- 
lar, but in part is due to the peristaltic cramping of the bowel. The ex- 
planation of the cause (a lesion of the tenth dorsal) and effect (pain in 
small intestines) lies either in the fact that the sensory impulses from 
the small intestines pass over the superior mesenteric plexus, the lower 
part of the solar plexus which receives the lesser splanchnic nerve, the 
white ramus, tenth thoracic nerve, posterior root, thence by way of the 
spinal cord to the medulla and sensorium, or in the fact, that the motor 
innervation of the intestine is by the same route and that the filaments 
are also in relation with the foramina of the tenth. Since both kinds of 
impulses pass through these foramina, any lesion of the tenth thoracic, 
will thus interfere, in some way, with these nerve filaments and conse- 
quently, sensory disturbances follow. 

A lesion of the vertebra may irritate the sensory nerves in relation 
thus setting up impulses that would be referred to the small intestine or 
tenth dorsal nerve, their supposed source. Inhibition at the tenth 
dorsal, may stop the passing of impulses to the sensorium, hence relief 
would follow. Extreme extension of the spine with fulcrum or fixed 
point at the eleventh dorsal, is the best way in which to apply this treat- 
ment. The subluxated vertebra may interfere with a part of the im- 
pulses, hence a perverted sensation. Again, this lesion may entirely 



Al'PLIED ANATOMY. 



219 



EG. OVER SPINES OF ICKTi 

INTERVERTEBRAL DISC 
ROTATORES 



SEMISPINALS OORSl 

ERECTOR SPINA! 

V 




Fig. 54. — Showing the tenth thoracic segment of the spinal cord with its 
nerves and their distribution. 



220 APPLIED ANATOMY. 

cut off the sensory line of communication, hence sensory paralysis of 
the small intestines. Peristalsis of the small intestines, depends to a 
very marked extent on normal activity of the sensory nerves supplying 
them. Normally the presence of food in the small intestine stimulates 
the sensory nerves, thereby setting up impulses that are carried to the 
spinal cord which, in turn, transfers them to the efferent nerves, thereby 
causing peristalsis of the small intestine, in other words it is a reflex 
process. A lesion of the tenth dorsal will interfere with this process, 
hence lessened peristalsis. From this comes indigestion and constipa- 
tion. 

According to Head, the liver and gall-bladder are supplied with sen- 
sation, in part, by the tenth dorsal nerve. The explanation is that the 
lesser splanchnic nerve carries impulses to and from the ceeliac plexus 
which innervates the liver and gall-bladder by way of the hepatic, which 
is a branch or division of the celiac. The effects of such a disturbance 
have been considered above. 

Pain in the kidney may result from a lesion of the tenth dorsal, since 
the lesser splanchnic nerve, which conveys the sensory impulses from 
it, is involved by a subluxation of this vertebra. An irritation of this 
nerve then, would produce pain that would be referred to the kidney. 
Pain in the ureter also comes from this lesion and is explained in a sim- 
ilar way. Such pain is called renal colic and most frequently comes 
from the passing of gravel. In some cases it comes from a lesion of the 
lower thoracic vertebra? and the effect is often quite marked, in fact I 
have seen cases in which the pain from such a lesion was as marked as 
from the passing of an ordinary calculus. Inhibition at the tenth dor- 
sal in such cases, will cause dilatation of the ureter because it lessens the 
pain, hence lessens the reflex muscular contractions, or else the inhibition 
directly lessens the amount of motor impulses passing to the ureter. 
Inhibition at this point breaks the circuit or stops or lessens the number 
and intensity of the sensory impulses, hence the sensorium is not aware 
of the real condition. 

According to Head, the tenth dorsal nerve contains sensory fibers 
for the prostate gland. Clinically, this seems to be the exception, the 
sensory centers being lower in the spinal cord. Accepting the statement 
as being true, the possible route would be the lesser splanchnics, sper- 
matic plexus and prostatic plexus. 

The testicle is supplied with sensation in part by the tenth dorsal 



APPLIED ANATOMY. 221 

nerve, that is nerve filaments having their origin in the cells of the 
tenth dorsal ganglion pass directly to the testicle by way of the lesser 
splanchnic, renal plexus and spermatic plexus which are afferent as well 
as efferent in function. If these nerves are stimulated by the lesion, 
pain will be referred to the testicle. In pain or aching of the testicle, in- 
hibition at the tenth dorsal may relieve since the impulses pass by way 
of the tenth thoracic segment on their way to the sensorium. Anes- 
thesia or a loss of sensibility is more common and follows a paralytic 
lesion of the tenth dorsal, that is one that entirely obstructs the passing 
of sensory impulses beyond the point of obstruction. 

In the female the analagous organ, the ovary, is affected in a similar 
way. It is not uncommon for a lesion of the lower dorsal vertebra 
to produce ovarian colic. Contractures of muscles in relation with the 
tenth dorsal will also produce the ovarian cramp. The explanation is 
that the lesion affects, that is irritates the sensory nerves leading from 
the ovary to the spinal cord, that is the lesser splanchnic, which contains 
these sensory filaments. The point of irritation is usually in the com- 
mon nerve trunk which is in relation with the intervertebral foramen. 

The fundus of the uterus is also supplied with sensation by the 
ovarian plexus, hence some sensory disturbance would follow injury to 
this plexus. If the nerves were irritated by the lesion, there would be 
pain in the fundus which would be fairly constant but made worse by in- 
creased peristalsis. The effects of this disturbance would be painful 
menstruation. If the sensory impulses were inhibited, difficult menstrua- 
tion and parturition would follow since each is a reflex process. These 
will be discussed later on. 

The pancreas would be involved through its sensory nerve supply, 
this probably coming from the cceliac plexus. Deaver says that the 
lesser splanchnic goes directly to this plexus, hence the explanation of 
the sensory effects, is made easy. 

A lesion of the tenth dorsal will produce a cutaneous sensory effect 
in the integument supplied by the tenth dorsal nerve through its anterior 
and posterior divisions. There may be hyperesthesia, perversion of 
sensation or anesthesia. In most cases the pain from this lesion is re- 
ferred to a point external to and below the umbilicus. Disturbances 
of the viscera and structures innervated by the tenth dorsal segment, 
are often characterized by pain in the tenth intercostal nerve. This is 
especially true of intestinal, kidney, ureter, ovarian and some uterine 
diseases. 



222 APPLIED ANATOMY. 

The peritoneum in relation with the tenth nerve, the tenth rib and 
its periosteum, the fascia and muscles in relation, are supplied with sen- 
sation by the tenth dorsal ganglion, consequently would be affected in 
some way by the lesion. Backache in this region is the result of con- 
tracture of the muscles in relation, this producing irritation of the sen 
sory nerve supplying the muscles. 

A lesion of the tenth dorsal vertebra will produce a motor effect in 
the viscera and organs mentioned under the above head since nearly if 
not all nerves are mixed nerves. A lesion affecting one part of the nerve 
will in all likelihood, affect other parts; that is, if the sensory filaments are 
involved, the motor filaments will also be affected. The peristalsis of the 
small intestines may be lessened or increased by a lesion of the tenth 
dorsal since it may inhibit or stimulate the motor supply. The gall- 
bladder and bile ducts are affected by this lesion, but possibly not so 
readily as by a lesion a little higher in the cord, The ureter is also af- 
fected through its motor supply, there being a disturbance of peristalsis. 
In a similar way the motor supply of the testes and ovaries, prostate 
gland and uterus may be altered in some way by the lesion since the 
impulses pass over the lesser splanchnic, which nerve is nearly always 
affected by an ordinary lesion. The spleen is similarly involved, that 
is, its movements or rhythm are interfered with by the lesion. 

The muscles innervated by the tenth dorsal segment are affected by 
a lesion of the articulations of the tenth dorsal vertebra. The effect on 
the muscles may be one of relaxation or contracture. If the lesion is 
an irritative one, contracture will follow, if paralytic, relaxation will 
result. The muscles involved directly by a lesion of the tenth dorsal are 
the intercostales, levatores costarum, serratus posticus inferior, obliqui, 
transversales and recti abdominales, erector, multifidus and rotatores 
spins and the diaphragm. The effects of relaxation and contracture of 
these muscles have been considered above. 

A lesion of the tenth dorsal will produce a vaso-motor effect on ves- 
sels innervated by the nerves that are in relation with the vertebra. 
The blood-vessels involved are the tenth intercostal and its branches, 
renal, ovarian, and spermatic, celiac axis with its branches, the splenic, 
gastric and hepatic, superior mesenteric and the vena azygi veins. The 
effect is either one of constriction or of dilatation. In most instances 
dilatation takes place, or at least is the chronic effect of the lesion, on the 
vessel. If the intercostal vessels are dilated, the circulation through the 



APPLIED ANATOMY. 223 

muscles of the back, abdominal wall, parietal layer of the peritoneum 
and, most important of all, the circulation of the tenth dorsal segment 
is impaired. The last leads to passive congestion of the cord with mal- 
nutrition of the nerve cells of this segment. As a result, it is possible 
for every nerve derived from this segment to become diseased. The ef- 
fect on the visceral nerves seems to be most marked in those that sup- 
ply the small intestine and ovary. 

In cases of disturbances of activity of the ovary, kidney and small 
intestine, the trouble may be in the spinal center, its nutrition being in- 
volved by the lesion causing dilatation of the blood-vessels. Conges- 
tion of the spinal cord, if passive, in such cases, tends to lessen activity 
of the nerve cells in the segment involved. 

The renal vessels are involved because the lesser splanchnic nerve 
is affected by the lesion, and this nerve carries vaso-motor impulses to 
the vessels of the kidney. Inhibition will at first produce an increased 
secretion of urine on account of the congestion, but later on lessened secre- 
tion results. Stimulation of the vaso-motor nerve will lessen the size of 
the renal vessels hence will lessen secretion. Most diseases of the kidney 
are of vaso-motor origin, that is the vessels are dilated and the circula- 
tion lessened in rapidity, hence a lowering of the vitality of the blood and 
of the part, in proportion to the degree of dilatation of the vessels and 
slowing of the blood-stream. 

The ovarian blood-vessels are very often affected by a lesion of the 
tenth dorsal. If the vaso-motor impulses are inhibited, congestion of 
the ovary follows. Congestion of the ovary is attended by dysmenor- 
rhea, disturbed ovulation, pain in the iliac fossa on the same side, back- 
ache, sense of weight, and finally leads to inflammation. Mammary dis- 
orders, as well as disturbances of the sexual function, follow or ac- 
company the congestion. A constriction of the ovarian blood-vessels 
causes anemia of the ovary which, if kept up for any great length of time, 
causes atrophy with softening. The infantile ovary results most fre- 
quently from an injury to the spine from the ninth to the twelfth dorsal, 
which affects the ovary through the vaso-motor nerves; that is, the devel- 
opment is arrested or else the nourishment is disturbed. The lesion of 
the tenth dorsal, produces these effects by producing pressure, either on 
the filaments that go to form the lesser splanchnic nerve, or on the 
blood-vessels that nourish the tenth dorsal segment. 

In the male analogous conditions may arise; that is congestion and 



224 APPLIED ANATOMY. 

anemia of the testicle. The most common and important effect on the 
testicle is varicocele. In this disease the vaso-motor nerves are inhi- 
bited by the lesion, and as a result, the spermatic veins dilate. If this 
condition remains for a while it is called varicocele. There are other 
causes of dilatation of these veins which are important and classed as 
exciting ones and probably the most potent cause of all is repeated, un- 
gratified sexual desire. 

The superior mesenteric vessels are quite frequently affected by a 
lesion of the tenth dorsal, judging from the effects in the parts supplied 
by this artery in cases in which there is present this lesion. If the le- 
sion inhibits the nerves to these blood-vessels, congestion takes place 
with altered and increased secretion. Catarrh of the intestine is a com- 
mon type. Intestinal indigestion is a sequel. Typhoid fever is another 
disease which has for a predisposing cause congestion of the intestine, 
from lesions inhibiting the vaso-motor as well as other nerves supplying 
the bowel. If the lesion stimulates the vaso-motor nerves, anemia of 
the bowel results but this is only a temporary effect since prolonged stim- 
ulation leads to inhibition. In anemia, the secretions are lessened and 
peristalsis impaired. 

The pancreatic blood-vessels are affected in a similar way; that is, 
they are dilated when the lesion inhibits, and lessened in size when the 
lesion is irritative. Dilatation causes increased secretion at least for 
a while; after it becomes chronic, the quality of the blood may be so im- 
paired that secretion is altered or lessened. 

The splenic, hepatic and gastric vessels may be affected since the 
lesser splanchnic nerve passes into the celiac plexus and this plexus 
supplies the above named vessels. The lesser splanchnic as stated 
above, is affected by the lesion of the tenth dorsal, and this nerve conveys 
vaso-motor impulses to the celiac plexus. 

The azygi veins are supplied in this region by branches from the 
solar plexus. The lesser splanchnic nerves in all probability, carry im- 
pulses to the parts of the veins in relation with this segment. 

A lesion of the tenth dorsal will have a secretory effect on organs 
that secrete and are supplied by the lesser splanchnic nerve. The most 
important organs affected are the small intestines, testes, ovaries, kid- 
neys, pancreas, supra-renal capsules and probably the liver, spleen and 
stomach. Secretion does not depend entirely on the vaso-motor nerves 
but in part (I do not know how much) on the so-called secretory 



APPLIED ANATOMY. 225 

nerves. Stimulation of these secretory nerves increases the amount of 
secretion; inhibition lessens it. The lesser splanchnic is supposed to 
have in it secretory filaments. Lesions stimulate or inhibit. 

A lesion of the tenth dorsal may stimulate or inhibit tht; tenth dor- 
sal nerve. The tenth dorsal nerve supplies the integument in relation 
with secretory impulses to the sweat and sebaceous glands, hence disturb- 
ance of these glands in lesions of the tenth dorsal. 

All nerves are more or less trophic in character. A lesion of the 
tenth dorsal will produce trophic effects in parts supplied by the nerves 
having their origin in the tenth dorsal segment. The effect is most 
marked in the muscles of the back. At first marked contracture 
takes place; later on, atrophy, as is evidenced by the widening of- the 
median furrow of the spine. 

The adjacent tissues and structures are also affected by the lesion. 
We would mention in particular the spinal ligaments, fascia and spinal 
cord. The effect may come from traction or pressure on the tissues in 
relation. The effect varies with tissues involved and the amount of 
traction or pressure. Pressure on the spinal cord produces myelitis. 

Summary. A lesion of the tenth dorsal will affect the lesser splanch- 
nic and the tenth dorsal nerves. The splanchnic conveys sensory, 
motor, vaso-motor, secretory and trophic impulses to the kidney, ureter, 
ovaries and testes, fundus of uterus and prostate gland, stomach, liver, 
spleen and pancreas. The cerebro-spinal nerves supply the integument, 
muscles and fascia. Almost any disease of the above mentioned parts, 
follows a lesion of the articulations of the tenth, since the lesion interferes 
with the nerves, blood-vessels, spinal cord and all tissues in relation. 

THE ELEVENTH THORACIC. 

The eleventh dorsal vertebra is also classed as one of the peculiar 
vertebrae. Morris says: "The eleventh has a large body resembling 
a lumbar vertebra. The rib facets are on the pedicles and they are 
complete and of large size The transverse processes are short, show 
evidence of becoming broken up into three parts, and have no facets for 
the tubercles of the eleventh pair of ribs. In many mammals the spines 
of the anterior vertebras are directed backward and those of the pos- 
terior directed forward, while in the center of the column there is one 
spine vertical. The latter is called the anti-clinial vertebra and indi- 
cates the point at which the thoracic begin to assume the character of 



226 APPLIED ANATOMY. 

lumbar vertebrae. In man the eleventh thoracic is the anti-clinal ver- 
tebra. " 

The mobility of its articulations is quite marked since the ribs do 
not articulate with the transverse processes. The intervertebral discs 
are thicker and possibly more elastic, judging from the increased mo- 
bility. The vertebra is often subluxated, due, I believe, to its position, 
it being located at the junction of a movable portion, the lumbar verte- 
bras, with a comparatively immovable portion, the thoracic vertebras. 
It is subject to lesions similar in degree and character to those mentioned 
above, the approximation or separation being very common, if not the 
most frequent. If this vertebra alone is involved, the subluxation most 
frequent is an anterior rotation of the vertebra, affecting the articula- 
tions above and below. 

The integument supplied by the eleventh dorsal nerve is affected 
by a lesion.of the eleventh dorsal, because of impairment of the nerve 
supply. This nerve is supposed to carry sweat impulses to the integu- 
ment of the eleventh interspace and to that in the lower thoracic and 
upper lumbar regions. Stimulation of the nerve usually increases the 
amount of sweat since its secretion is determined by secretory rather 
than vaso-motor nerves. Localized sweating in the lower thoracic 
region is not uncommon and is suggestive of a nervous condition or 
bowel disorder such as constipation. Lessened secretion of sweat re- 
sults if the sweat centers are made less active by the lesion or if the 
eleventh thoracic is inhibited, thereby impairing the passing of secre- 
tory impulses to the skin. This condition is spoken of by Landois who 
says: "It has been observed in circumscribed areas of the skin as one 
of the phenomena of certain tropho-neuroses as, for instance, unilateral 
atrophy of the face, and in paralyzed parts. In some of these cases 
there may be paralysis of the nerves in question or of their spinal centers. " 

The trophic condition of the skin is controlled to a great extent, by 
nerves called the trophic nerves. In case of the spinal nerves the trophic 
nerve is only a part of it, not a separate distinct nerve trunk, but com- 
posed of filaments enclosed in a common sheath. Church says: "The 
significance of abnormal variations in the nutritional conditions of a 
part is at once apparent when it is recalled that the growth and nourish- 
ment of all the structures of the body are presided over by trophic cen- 
ters acting through peripheral nerves." 

For the proper nutrition of skin, muscle, nerve and bone, the integ- 
rity of the trophic center, of its peripheral nerves, and their terminals, 



APPLIED ANATOMY. 



227 



is essential. In other words, the anterior spinal cell and its polar pro- 
longation in the efferent nerve, the lower neuron, can not be injured 
or destroyed without correspondingly impairing the function of nutri- 
tion in its area of distribution. Lesions of the vertebra affect both the 
trophic center and its peripheral path, thus dystrophies of the skin fol- 




Fig. 55. — Showing an anterior condition of the 10th and 11th thoracic verte- 
brae, b; c. muscular contracture The patient had some kidney disorder. (From 
photo). 

low. These lesions affect the trophic center through its nutrition and 
the peripheral path by pressure on the nerve, usually at its exit from 
the spinal canal. 

A lesion of the eleventh dorsal will affect a localized portion of the 



228 APPLIED ANATOMY. 

skin principally on account of effect on the peripheral tract, the eleventh 
thoracic nerve and its branches. These trophic disturbances are char- 
acterized by a thickened, dry, scaly epidermis and in some cases a glossy 
condition. In other cases, pimples or even boils develop. The lesion 
may so affect the superficial nerves that an inflammation or neuritis 
may develop, herpes zoster being an example. In milder cases the le- 
sion produces a superficial or cutaneous tenderness. In many of these 
cases there are no inflammatory indications but the slightest touch 
produces intense pain. In such cases the lesion affects the spinal cord, 
its meninges, or in some cases, the trunk of the spinal nerve. In other 
cases the lesion affects the viscera supplied by the eleventh dorsal seg- 
ment, and if irritative, the pain is referred to the cerebro-spinal nerves 
and is felt in the integument of superficial tissues. Inflammatory dis- 
turbances of the ovary, small intestine, vermiform appendix, ureter, 
cecum and 'the peritoneum in relation with these structures, will cause 
pain to be referred to the areas innervated by the eleventh thoracic 
spinal nerves. 

The muscles of the back and abdomen, the intercostals and the dia- 
phragm will be affected by a lesion of the eleventh dorsal. In the case 
of the spinal and abdominal muscles, they will be. contractured or re- 
laxed; contractured if the lesion is irritative, relaxed if inhibitory. The 
intercostal muscles also, in all likelihood, become contractured but they 
are so flat and short that the condition can not be readily detected. 
Contractured conditions of the spinal muscles produce (1) backache, 
(2) vascular disturbances of the spinal cord and (3) curvature of the 
spine. Relaxation of these muscles produces weakness of the spinal 
column. Relaxation of the abdominal muscles produces enteroptosis. 
If the diaphragm is affected, and it frequently is, respiration is disturbed, 
usually becoming difficult. 

The peritoneum is affected by a lesion of the eleventh dorsal. Its 
secretion is disturbed, usually lessened. If increased, ascites develops; 
if lessened, pain on movement of parts. In some, the lesion produces 
a pain that is referred to the abdominal wall and peritoneum. Peri- 
tonitis develops if the lesion is irritative, since the blood-vessels of the 
peritoneum would be affected by the lesion. Relaxation of the vis- 
ceral layer of the peritoneum followed by enteroptosis, occurs in par- 
alytic lesions. 

The ligaments of the ribs and vertebra are affected by a lesion of 



APPLIED ANATOMY. 



229 



MULTtriDUS SPIN* 
INTERSPINALS ROTATOR ES 



INTE&.OVER PdT051h L 



ERECTOR SPIN*. 

LEVATOR 
COSTARUM 




Fig. 56. — The eleventh thoracic segment of the spinal cord, with its branches and 
their distribution. 



230 APPLIED ANATOMY. 

the eleventh dorsal, because their innervation is disturbed. This is also 
true of the periosteum. The ligaments of the vertebra are either stretch- 
ed or broken by the lesion. At any rate they always thicken and prob- 
ably always partly fill the intervertebral foramina. In acute cases the 
ligaments become very tender and remain so for quite a while if not 
properly treated. The vertebral joints are sprained in a way similar 
to that of other joints and the effects are also very similar. 

The spinal cord is affected by the lesion either directly, as by pressure, 
or indirectly through impairment of its circulation. Pressure on the 
spinal cord at this point would produce paraplegia and loss of control of 
the various centers at points lower down in the cord. If pressure pro- 
duces complete transverse myelitis, atonic paraplegia follows; but if not 
complete, spastic paraplegia results. Interference with the circulation 
to the cord- of course produces various effects which depend on cells 
affected, amount and degree of disturbance and length of standing of 
lesion. The spinal cord is also affected by ascending degeneration from 
injury of or pressure on, the posterior nerve roots. These ganglia are 
in the foramina and a very slight deviation of the vertebra would pro- 
duce pressure on them, this producing degeneration. The effect seems 
to be a sensory one, there being a loss, to a certain degree, of tactile sen- 
sation. 

The spinal column is weakened by a subluxation of any of its ver- 
tebrae. A lesion of the eleventh dorsal, causes a weakness of the small 
of the back and the patient is unable to undergo much exercise without 
marked discomfort in this area. Spinal curvatures often start from a 
subluxation of the eleventh dorsal, in fact, I doubt that pathological 
curvatures start from any other cause than a subluxation of a vertebra. 
Lumbago, often results from a lesion of the eleventh dorsal, but most 
often results from a lesion lower in the spinal column. The explanation 
is that the movement of the spinal articulations is lost or markedly 
lessened on account of the subluxation of the vertebra or a sprain of its 
ligaments. 

The viscera most commonly affected by this lesion are the small 
intestines, cecum and vermiform appendix, ovary and testicle, kidney, 
spleen, ureter, prostate, uterus, epididymus, Fallopian tubes, and supra- 
renal capsule. 

The small intestines are affected because their nerve and blood sup- 
ply are disturbed by the lesion. The lesser splanchnic carries sensory, 




Fig. 57. — Showing the nerve supply of the abdominal viscera. The liver has been 
drawn back, exposing the gall-bladder. Enteroptosis produces a 
stretching of these nerves. 



232 APPLIED ANATOMY. 

motor, secretory, vaso-motor and possibly trophic fibers to the small 
intestines. This nerve is affected because the filaments composing it 
are subject to compression by the subluxated vertebra while they are 
in the intervertebral foramen. 

Howell in speaking of the function of the sympathetic innervation 
of the small intestine says: "The fibers received from the sympathetic 
chain give mainly an inhibitory effect when stimulated, although some 
motor fibers apparently may take this path. Bechterew and Mislawski 
state that the sympathetic fibers for the small intestine emerge from the 
spinal cord as medullated fibers in the sixth dorsal to the first lumbar 
spinal nerves, (or lower-bunch) and pass to the sympathetic chain in 
the splanchnic nerves and thence to the semilunar plexus. " 

Clinically, it seems that these impulses to the small intestine pass 
to it by way'of the ninth, tenth and eleventh spinal nerves, that is. these 
segments have more to do with the innervation of the small intestine 
than any other. This has been determined, to a great extent, by ob- 
serving the effects of lesions is this region on the intestine; it being found 
that a lesion affecting this part disturbs the intestine most. 

From this lesion there would result pain, as in enteralgia; disturbed 
peristalsis, as in diarrhea; constipation and invagination; increased or 
lessened secretion, as in catarrhal enteritis and constipation; congestion, 
as in enteritis and ulceration. 

Enteralgia can be relieved by inhibition at the eleventh dorsal spine, 
It can be cured in most instances, by correction of lesion of the tenth 
or eleventh dorsal vertebra. 

The cecum is affected through disturbances of its blood and nerve 
supply. Its nerve supply is from the superior mesenteric plexus which 
is derived from the lower part of the solar plexus into which part, the 
lesser splanchnic nerve enters. This nerve controls the blood-vessels 
supplying the cecum, also its sensory, motor, secretory and trophic im- 
pulses. The cecum marks the junction of the large and small intestines. 
It is quite large and has leading from it the vermiform appendix. Its 
function is similar to that of the rest of the large bowel, that is, to serve 
as a sort of reservoir in which desiccation of the fecal matter may take 
place. A lesion of the eleventh dorsal will, through the nerve supply, 
alter and affect its peristalsis, secretion, sensation and amount of blood. 
Constipation with impaction of the cecum is the result.- From this 
develops a change of position from the increased weight, that is the cecum 



APPLIED ANATOMY. 233 

prolapses. This causes congestion and stagnation of the blood and is 
the starting point of many abdominal disorders. The impaction soon 
weakens or paralyzes the valve closing the lumen of the appendix so that 
it can neither prevent the passing of particles of fecal matter into the 
appendix, nor expel them after they enter. The contents of the ap- 
pendix then undergo fermentation, possibly putrefaction, and soon the 
patient has appendicitis. The lesion of the eleventh dorsal vertebra is 
the predisposing cause, the particles of partly digested food, the ex- 
citing cause. The lesion inhibits the passing of sensory, motor and sec- 
tory impulses, hence a deadened condition of the bowel results. These 
nerve impulses arise in the spinal cord and reach the cecum by way of 
the ventral root, common trunk, anterior division, white ramus, sympa- 
thetic ganglion, lesser splanchnic, solar plexus (lower portion) and super- 
ior mesenteric plexus. If the lesion is irritative, there may be excessive 
peristalsis, hence flux, or diarrhea in mild cases. Invagination may re- 
sult and the small intestine be partly drawn into the cecum. 

Inflammatory conditions occur if the vaso-motor nerves are inhibited 
to such a degree that the blood-vessels remain engorged. In typhoid 
fever, the predisposing cause is a lesion in the lower thoracic area, which 
weakens the part, principally through the trophic and vaso-motor dis- 
turbances, after which the bacillus, the exciting and immediate causes 
the more readily attacks the part. The lesion is often at the articula- 
tions of the eleventh dorsal, affecting the lesser splanchnic, which carries 
trophic and vaso-motor impulses to Peyer's patches of the small 
intestines. The trouble may at first be a secretory or motor one; that 
is, there is lessened peristalsis and finally constipation. A lessened secre- 
tion of succus entericus is responsible for many cases of constipation. 
Constipation is indicative of a lowering of the vitality of the parts, which 
is mainly responsible for the fever. If the intestines are normal, the 
ingestion of food or water in which there are typhoid bacilli will have 
no deleterious effect, but if the vitality of the parts is lowered by a le- 
sion which interferes with the passing of trophic, vaso-motor, motor or 
secretory impulses, the microbe peculiar to typhoid fever will find a fa- 
vorable nidus for propagation, and typhoid fever will result. 

The kidneys are affected by this lesion because the lesser splanch- 
nic nerve conveys the various nerve impulses from the spinal cord to the 
kidney. As explained above, this nerve, either the trunk or the fila- 
ments forming it, is in relation with the articulations of the vertebra and 



234 APPLIED ANATOMY. 

the slightest deviation of the vertebra will produce pressure on it. lhe 
ureter is affected for the same reason. 

According to Head, the eleventh dorsal has to do with the sensory 
innervation of the bladder, as in "overdistension and ineffectual con- 
traction. " The nerve pathway must be the lesser splanchnic and the 
aortic plexus. 

The prostate gland is also affected by this lesion; since the nerve 
impulses reach it in a way similar to those of the bladder. The lesion 
interferes with it in some way, hence the effects. 

The testes and epididymus are also involved by this lesion. The 
impulses controlling them are carried by the lesser splanchnic to the 
renal, thence over the spermatic. The nutrition, amount of blood, sen- 
sation and motion are controlled by this nerve, hence almost any patholo- 
gical condition of these parts may result from the lesion. A poorly 
developed or badly nourished small, tender, soft testicle is the most 
common effect. Varicocele is also common. Sterility is not an unusual 
effect. 

The ovaries are affected in a similar way; also the fundus of the 
uterus and the Fallopian tubes through their nerve supply, the ovarian 
plexus. Motor, sensory, vaso-motor, secretory or trophic effects re- 
sult from the lesion, hence imperfect or too marked contraction, painful 
contraction, congestion, leucorrhea or softening of the uterus, especially 
the fundus, may result. These effects on the uterus have been noted 
clinically. 

Lesions of the eleventh dorsal are most commonly associated with 
kidney, ovarian and intestinal disorders. These disorders are best rep- 
resented by albuminuria, ovarian inflammation, and intestinal indiges- 
tion and constipation. 

THE TWELFTH THORACIC. 

The twelfth dorsal vertebra is a transitional vertebra, marking the 
change from the thoracic to the lumbar type. In appearance, it very 
much resembles the lumbar vertebrae in that all the parts are large, 
the spinous process short, thick and almost horizontal. The superior 
facets face almost directly back while the inferior, instead of looking for- 
ward, are turned outward to articulate with the superior facets of the 
first lumbar which face inward. As is the case with the eleventh dorsal, 
the ribs do not articulate with the transverse processes, hence the mo- 
bility of both the vertebrae and ribs is greater on this account. 



APPLIED ANATOMY. 



235 



The transverse process is rudimentary and is usually divided into 
three parts. There is a single facet on the body for articulation with the 
head of the twelfth rib, hence the vertebra is different from those above. 
The mobility of the articulation between the twelfth dorsal and first lum- 
bar is quite marked in the normal subject but this articulation is often 
the seat of hypermobility. A "break" is the most common form of 
lesion. By this term is meant a separation of the spinous processes. 
It is sometimes pathological but in most cases is not. It occurs oftenest 



CRUS OF DIAPHRAGM 



EXT. ARCUATE LIG'T. 




LIVER 



KIDNEY 



QUADRATUS 
LUMBORUM 

Fig. 58. — Showing the relation of the kidneys to the ribs and quadratus lum- 
borum muscles. Pressure immediately below the twelfth rib near the vertebral end 
is productive of pain in most disorders of the kidney or pelvic organs. 



236 APPLIED ANATOMY. 

at this articulation on account of the change in character of the vertebrae 
and because this part of the spine bears the greatest part of the strain 
in lifting. The mobility, which is normally quite marked, is also in part, 
responsible for the separation. Unless there is approximation of the 
vertebras above or below, the break causes little trouble other than 
weakness of the spine since the foramina are increased rather than de- 
creased in size on account of the stretching of the ligaments. In many 
subjects the separation and hypermobility are only compensatory and 
in such cases it is a mistake to attempt reduction of the supposed sub- 
luxation. 

The articulations of the twelfth dorsal are subject to the usual verte- 
bral lesions such as would result from rotation, approximation, anterior 
and posterior deviations of the vertebras in relation. The effects vary 
with the degree of the lesion, length of standing, that is the extent to 
which nature has overcome the disturbance, the structures pressed on 
and also their condition. In addition, the degree of the effect is meas- 
ured in part, by the condition of the viscus or other structures depending 
on the twelfth dorsal segment for nutrition and nerve supply. For ex- 
ample, if the function of the testicle were abused, a very trivial lesion, one 
that would ordinarily have no effect, would at once affect the function of 
the organ, disturbing it the more. 

The effects of a lesion of the articulations of the twelfth dorsal ver- 
tebra may then be classified under five heads: sensory, motor, vaso- 
motor, secretory and trophic. 

The sensory effects may be conveniently divided into effect on the 
integument, on viscera and on other structures. The integument de- 
pending on the nerves in relation with the twelfth thoracic vertebra 
for sensation, is that over the crest of the ilium, the upper part of the 
gluteal region and as low as the trochanter, over the pubes and a part of 
the tip of the penis. It is rather odd that few, if. an}', sensory branches 
supplying the integument in the middle and upper lumbar regions come 
from the lumbar nerves, but from the lower thoracic, principally the 
tenth and eleventh. These areas may be anesthetic or hyperesthetic 
from the above lesion or they may be reflexly affected, that is pain may 
be referred to the skin over this area from disease of viscera supplied by 
the same spinal segment as for instance, the ovary. If the subluxation 
or lesion inhibits the passing of the sensory impulses, anesthesia or 
numbness would result. In acute or recent subluxations, an irritation 



APPLIED ANATOMY. 237 

exists producing pain in all or a part of the above described area. Con- 
versely, pain in this area is indicative of a lesion of the twelfth dorsal, or 
rib on the same side. In some forms of female disorders, especially if 
the ovaries are involved, the patient often describes a pain as passing or 
running over the crest of the ilium. This is a referred pain. The ex- 
planation is that the sensory or afferent impulses arising from the dis^ 
eased condition, are carried to the spinal cord, the twelfth dorsal segment, 
by way of the ovarian and renal plexuses, thence to the sensorium by 
the same tract that carries impulses from the integument. The sen- 
sorium mistakes the source of the impulses and wrongly refers them to 
the cutaneous nerve supplying the crest of the ilium, that is the twelfth 
dorsal or subcostal nerve. 

The renal plexus is not entirely distributed to the kidney. A part 
forms the ovarian, or rather the impulses from the spinal and gangliated 
cord pass directly through the renal to the ovarian plexus and these 
uerves carrying the impulses have little, if anything, to do with the sup- 
ply of the kidney. According to Head, the viscera supplied with sensa- 
tion by the twelfth dorsal segment or rather the viscera whose, sensory 
impulses pass through this segment on their way to the sensorium are 
the kidneys and ureter, intestines as low as the rectum, urinary bladder, 
prostate, testes and epididymus, uterus and its appendages. The im- 
pulses from the kidneys and ureter, pass to the cord by way of the least 
splanchnic. The intestines are supplied by the mesenteric plexuses 
which send to and receive impulses from, the lower dorsal and lumbar 
portions of the spinal cord. The genitalia connect with the spinal cord 
by way of the ovarian or spermatic, and uterine plexuses. 

A lesion of the twelfth dorsal articulations may produce pain in the 
various organs and viscera mentioned above, but more commonly the 
pain is referred to the areas supplied with sensation by the twelfth dor- 
sal nerve which is derived from the same source as is the sensory innerva- 
tion of the viscera. The lesion more commonly inhibits the passing of 
impulses to the spinal cord, hence the parts will not readily respond to a 
stimulation or an irritation. On account of this, the peristalsis of the 
viscera supplied by the twelfth dorsal segment is seriously interfered 
with since sensation to a great degree controls peristalsis. In the case 
of the large bowel constipation follows. How common a condition it is 
for the abdomen of a patient to feel as if it were paralyzed, and we base 
our prognosis in many cases on the degree of weakness and relaxation. 



238 



APPLIED ANATOMY. 



I NTEG. OVCR LUMBAR REGION 



INTEG. over CREST 
OF ILIUM 




OBLIQUE 
PYRAMIDALIS OVER TROCHANTER 

Fig. 59. — The twelfth segment of the thoracic spina] cord, with its nerves and 
their distribution. 



APPLIED ANATOMY. 239 

If the cecum is involved, appendicitis results in many cases. As 
stated before, if the irritability of the appendix is lessened, the particles 
of fecal matter which get into the appendix fail to stimulate the sensory 
nerves supplying it, because these nerves are partly or completely par- 
alyzed by the lesion. Peristalsis of the appendix, as well as that of the 
other parts of the intestinal tract, is governed by the irritability of the 
mucous membrane lining it, that is peristalsis is, to a great extent, a re- 
flex process. The fecal matter stimulates the sensory nerves of the 
bowels. The impulses thus generated pass to the spinal cord and are 
there transferred to the efferent nerve cells and the result is, that motor 
impulses are sent to the bowel. Any lesion breaking or crippling this 
reflex arc, will lessen peristalsis of the bowel. Anything stimulating any 
of the parts forming this arc will, in all likelihood, increase the peristalsis. 

A lesion of the twelfth dorsal vertebra will impair the passing of 
sensory impulses to the spinal cord, hence paralysis follows if the obstruc- 
tion is complete, numbness, if partial. From this arises constipation, 
appendicitis and any other disease dependent on a lessened peristalsis. 

Micturition is also a reflex process and the condition of the sensory 
nerves supplying the bladder is an important consideration. A lesion 
of the twelfth dorsal will affect the sensory innervation. It may 
stimulate it, causing frequent micturition, or it may deaden the sensi- 
bility, causing imperfect micturition or retention of urine. Although 
the center for micturition is a few segments lower in the spinal cord, 
according to Head the twelfth dorsal nerve controls the sensory in- 
nervation of the bladder. Clinically, it is found that micturition is often 
affected by a lesion of the twelfth dorsal. 

The testes and ovaries are supplied with sensation by the spermatic 
and ovarian plexuses, hence would be involved by lesions affecting these 
nerves. Nearly all the internal genitalia receive impulses from as high 
in the spinal cord as the twelfth dorsal segment, and accordingly, would 
be involved. 

The adjacent muscles and those forming the abdominal wall, also 
receive sensation from the twelfth dorsal. False or pseudo-appendicitis, 
is often due to a lesion of the articulations of the twelfth dorsal, this 
causing pain in the iliac fossa by affecting the eleventh and twelfth dor- 
sal nerves. 

The lesion at the twelfth dorsal will produce a motor effect on mus- 
cles, tissues and viscera. The muscles affected are those supplied by the 



240 APPLIED ANATOMY. 

twelfth dorsal nerve; the abdominal and back muscles, the quadratus 
lumborum and in most instances, the diaphragm. These muscles may 
be contractured or relaxed. The effects on these muscles, of a lesion 
disturbing their innervation have been considered with the exception of 
that of the quadratus lumborum. This muscle, if relaxed, will permit 
of the drawing upwards of the twelfth rib, that is it becomes displaced 
upward under the eleventh rib. If the muscle is contractured it will draw 
the twelfth rib down. In replacing or setting the twelfth rib, the con- 
dition of this muscle must be considered, because it determines to a 
great extent, the position of the rib. Contracture of these muscles pro- 
duces an ache in the region of the small of the back. This is because of 
the fatigue. 

There may be a motor effect on the small and large intestines, kid- 
ney and ureter and the internal genitalia. This is explained by the fact 
that the lesser and least splanchnic nerves carry impulses to the above 
named viscera and structures and these nerves, or the filaments going 
to form them, are always more or less affected by the lesion. These 
splanchnic nerves usually pass through plexuses but the nerve filaments 
that spring from the cells in the grey matter of the spinal cord eventually 
reach their destination, that is, the impulses originated in the cell, are 
carried directly to their destination. The lesion interrupts this connec- 
tion or else stimulates the nerves, thereby increasing the amount and 
number of its impulses. According to Qnain, the circular muscle fibers 
of the rectum are supplied by the lower thoracic segments. From this, 
rectal disorders may follow a lesion of the twelfth dorsal. 

This lesion will, through the vaso-motor nerves, affect the inter- 
costal, renal, ovarian and spermatic, mesenteric and iliac blood-vessels. 
The abdominal aorta, inferior vena cava and the agyzi veins are also 
affected by the lesion, through their nerve supply. The effects of con- 
striction and dilatation on these blood-vessels have been considered 
above. Suffice it to say that congestion of the twelfth dorsal segment, 
the muscles of the back, the intestines, ovaries and testes and the kid- 
neys are common effects. The diseases most frequently caused by these 
vasomiotor disturbances are hyperemia with hemorrhage in the spinal 
cord, catarrh of the bowels, inflammation of the ovary or testicle, var- 
icocele and nephritis. 

The secretory effects are most marked in the integument, intestines, 
kidne3*s, ovaries and testes. The first has been considered, there being 



APPLIED ANATOMY. 241 

hyperidrosis or anidrosis. The succus entericus may be lessened or in- 
creased in amount. If markedly lessened, constipation results; if in- 
creased, diarrhea. These effects, or at least some variation of them, are 
fairly common. The explanation is that the lesion affects the lesser and 
least splanchnic nerves which carry secretory impulses to the intestines. 
Experimentally, stimulation of this nerve increases secretion in the in- 
testines, inhibition lessens it. In this, the vaso-motor element must also 
be considered. The lesion at the twelfth dorsal articulation may do 
either, hence if the lesion is substituted for the electric or chemical agent 
ordinarily used, any standard work of physiology contains the explana- 
tion. Clinically, it is known that the lesion may be a paralytic or irrita- 
tive one. hence the possibility of the substitution. This lesion may 
affect the secretion of urine through the renal splanchnic nerve. 

The ovaries have an internal secretion which in all probability, is 
controlled by a secretory nerve, if it is like other glands. The secretion 
of the testicle is likewise under the control of a secretory nerve, although 
the amount and character of the blood enters largely into the process. 
The cells controlling these secretory impulses are located in the spinal 
cord, the twelfth dorsal segment containing some. They connect with 
the organs by way of the ovarian or spermatic plexus of nerves. 

The trophic effects vary in different cases. Clinically, the ovaries, 
testes and uterus are most frequently involved. The muscles are weak- 
ened, from which curvatures develop. In short, any part depending 
on the twelfth dorsal segment for its nerve supply, may be affected 
and the usual effect is that of malnutrition. 

THE FIRST LUMBAR. 

The first lumbar vertebra, is a good type of the lumbar vertebra 
which are the largest of the movable vertebra?. The body is kidney- 
shaped, that is the transverse diameter is considerably greater than the 
antero-posterior. The notches in the pedicles are deeper than those 
of the dorsal vertebra?, thus making the intervertebral foramina larger. 
The spinous process is short, large and thin, resembling a spatula in shape. 
It points in nearly a horizontal direction and its edges are slightly thick- 
ened. The transverse processes are smaller and more slender than those 
of the thoracic vertebra?. They are directed outward and slightly 
backward. The articular processes are quite large and the facets deep. 
The superior facets face backward and inward and are concave. The 



242 



APPLIED ANATOMY. 



inferior face in the opposite direction and are not so widely separated as 
the superior, since they are embraced by the superior facets of the ver- 
tebra below. The mammillary processes surmount the articular and 



TRANS. PROC 




Fig. 60. — A lumbar vertebra. 



consist of an elongated oval tubercle. They correspond to the superior 
tubercles on the transverse processes of the lower thoracic vertebrae. 
The vertebral or spinal foramina are triangular and larger than in the dor- 
sal region. 

The intervertebral disc is quite thick at this point and is slightly 
thicker in front than posteriorly, this causing the anterior curve in this 
region. The curves of the spinal column depend more on the 

THICKNESS AND ELASTICITY OF THE INTERVERTEBRAL DISCS THAN ON THE 

size of the bodies of the vertebra. The disc is particularly liable 
to compression in the lumbar region on account of the strain and super- 
imposed weight of the body. 

The mobility of the articulations of the first lumbar is very well 
marked, all movements being represented. Hypermobility is quite 
common at the articulation between the twelfth dorsal and first lumbar. 
Strains of the articulations of the first lumbar are quite common, partly 
on account of the free mobility and partly on account of the position of 
the vertebra, its articulations bearing the brunt of the muscular exer- 
tions of this area. 

The ligaments in this region are thicker and stronger than those 
above and are more subject to irritation by which they are shortened and 
still further thickened. The muscles of the back are also better developed, 
while to the body of the vertebra are attached the psoas magnus muscles. 
These muscles, when contractured, impair to a great extent; the mobility 



APPLIED ANATOMY. 



243 



CRT GANGLIATED CORD OF SYMPATHETIC 



FOURTH LUMBAR VERTEBRA 



ABDOMINAL AORTIC PLEXUS 



INF MESENTERIC PLEXUS 



LUMBAR GANGLIA 



HYPOGASTRIC 
PLEXUS 



LADDER 




f'LEXUS 
VESICAL PLEXUS 
RECTUM 

NERVES OFTHE RECTUM 
PROSTATIC PLEXUS 
UUHSALN.OrPENIS 



Fig. 61. — Showing nerves of the male pelvic organs, (after Spalteholz). 



244 APPLIED ANATOMY. 

of the part and approximate the vertebrae, thus lessening the size of the 
intervertebral foramina. These foramina transmit veins, arteries, lym- 
phatics and nerves. 

The veins drain the first lumbar segment in particular, and the spinal 
cord and its coverings in general. On removing the posterior arches 
of the lumbar and thoracic vertebras and slitting the coverings of the 
cord and nerve roots, these vessels in a well injected cadaver, can be 
readily outlined. The veins follow, or rather accompany the corres- 
ponding nerves, and are enclosed by the sheath of dura mater which 
surrounds the nerve root. A lessening of the size of the first lumbar 
intervertebral foramen, compresses the vein and some circulatory dis- 
turbance follows. Judging from clinical evidence, the effect is most 
marked in the corresponding segment. The congestion may at first 
be an irritative one, that is the nerve cells may be stimulated by this 
venous congestion, hence increased activity in parts innervated by this 
segment. The after effect, is, I believe, always that of lessening the 
activity of the cell, and diseases characterized by a lack of vitality or 
activity of the parts is the result. Constipation is a good example. 
The venous blood then passing through the first lumbar intervertebral 
foramen, comes mostly from the first lumbar segment and adjacent areas, 
and passes into the lumbar veins and then into the azygi veins. 

The arteries that pass through the first lumbar foramen are branches 
of the lumbar. Their course is similar to that of the veins, that is they 
pass up the sheath which encloses the nerve roots and into the corres- 
ponding segment of the spinal cord. A lesion of this articulation will 
cause pressure on this artery, and arterial anemia of the parts supplied 
by it will result. The degree of anemia is governed by the extent of the 
anastomosis and amount of pressure. This anemia is not the ordinary 
form, — since the same pressure or obstruction causes a retention of the 
venous blood — but an arterial form of anemia, since the arterial blood 
is obstructed. The effect is similar to, if not identical with, that de- 
scribed above since the vein is always compressed and affected more 
than the artery on account of the character of its walls. 

The nerve trunks and filaments affected by this lesion are the ilio- 
inguinal, ilio-hypogastric, genito-crural, recurrent meningeal and the 
filaments that go to form the efferent branches of the first lumbar sym- 
pathetic ganglion, viz., branches to the renal plexus, aortic plexus and 
the small branches that supply the vertebra? and ligaments. The le- 



APPLIED ANATOMY. 



245 




Fig. 62. — The lumbar portion of the sympathetic gangliated cord and lumbar 
plexus. (After Cunningham). I. M. P. inferior mesenteric plexus; A. pi. aortic 
plexus; S. M. P. superior mesenteric plexus; R. pi. renal plexus; S. R. C. suprarenal 
capsule; Va. vagus; Grt. S. great splanchnic; Sy. sympathetic gangliated cord; 11T, 
12 T, 1 L, 2 L, 3 L, 4 L, 5 L, anterior divisions of spinal nerves; Q, nerves to quadra- 
tus lumborum; I. H. ilio-hypogastric; I. I. ilio-inguinal; G. C. genito-crural; E. C. ex- 
ternal cutaneous; A. C. anterior crural; A. 0. accessory obturator; 0. obturator; 4, 
5, lumbo-sacral cord; H. pi. lrypogastric plex,us. 



246 APPLIED ANATOMY. 

sion may irritate the nerves in the foramen, hence a temporary increase 
in activity of parts supplied, but more commonly the lesion inhibits, to a 
certain extent, the passing of the nerve impulses, which is followed by a 
lessening of activity or functioning of the nerve and parts involved. 

The ilio-inguinal is one of the anterior divisions of the first lumbar 
nerve. The anterior divisions form the lumbar plexus of nerves but 
each nerve seems to retain its individuality, that is it passes through the 
lumbar plexus with few communications. This nerve sometimes re- 
ceives a filament from the last dorsal nerve and communicates with the 
ilio-hypogastric. It perforates the psoas magnus muscle, passes in re- 
lation with the quadratus lumborum and lies behind the kidney. It 
crosses the iliacus and pierces the transversalis near the crest of the ilium, 
supplying it and the internal oblique muscle. It then passes through 
the inguinal canal emerging at the external abdominal ring. It gives 
off muscular branches to the transversalis, internal oblique, rectus ab- 
dominis and the dartos. The condition of the dartos is indicative of 
the condition of the testicle. If relaxed, it shows a weakened condition 
but if the rugae are firm, it is suggestive of a healthy testicle. The con- 
dition of the dartos is controlled in a great measure by this nerve. Ac- 
cording to Cunningham, the ilio-inguinal nerve gives off cutaneous 
branches "which innervate the skin (1) of the anterior abdominal wall 
over the symphysis pubis, (2) of the thigh over the upper and inner part 
of Scarpa's triangle, and (3) of the upper part of the scrotum, and root 
and dorsum of the penis (of the mons Veneris and labium ma jus in the 
female)". A lesion of the articulations of the first lumbar, will affect 
this nerve hence there may be sensory disturbances in the above men- 
tioned areas, pain being the usual form of disturbance. Many a case 
of pruritus vulvae and pain in the external genitalia, is due to a sublux- 
ation of the first lumbar vertebra. The explanation is that the lesion 
stimulates some or all of the filaments forming this nerve and as a re- 
sult, impulses arise that are carried over the usual paths to the sensorium, 
but there is a mistake as to the source and the pain is referred to the 
periphery of the nerve, the accustomed place. This nerve may be af- 
fected by a strain of the psoas muscle or by a lesion that produces con- 
tracture of it. 

The ilio-hypogastric nerve also comes from the first lumbar segment, 
often in common with the ilio-inguinal, and its course is about the same, 
it piercing the psoas and transversalis muscles. It follows the crest 




Fig. 63. — Showing the posterior abdominal wall with its muscles and nerves 
(After Cunningham). V. O. vena caval opening; C. tend, central tendon; A. ligt. 
arcuate ligament; 12th R. twelfth rib; L. F. lumbar fascia; I. H. ilio-hypogastric n.; 
L. vis & sym. lumbar vessels and symphathetic n.; I. I. ilio-inguinal n.; O. d. b. deep 
branch of obturator n.; E. O. esophageal opening; D. lc. left crus of diaphragm; 
A. L. adductor longus; A. B. adductor brevis; G. gracilis. Note the relation of the 
lumbar nerves to the psoas muscle. 



248 APPLIED ANATOMY. 

of the ilium, running between the transversalis and internal oblique mus- 
cles and near the anterior superior spine, divides into an iliac and hypo- 
gastric branch. 

The iliac branch is supposed to correspond to the lateral cutaneous 
branch of an intercostal nerve. It pierces the internal oblique muscle 
thus becoming cutaneous, and supplies the skin over the upper and outer 
side of the buttock behind the distribution of the lateral cutaneous 
branch of the last thoracic nerve. The hypogastric branch passes for- 
ward and, piercing the internal oblique, supplies the integument over the 
hypogastrium. The ilio-hypogastric nerve supplies the internal and ex- 
ternal oblique, transversalis and rectus abdominis. 

The ilio-inguinal and ilio-hypogastric nerves are often the seat of 
referred pain. Renal colic causes pain in the areas supplied by the 
ilio-inguinal nerve. The possible explanation is that the same segment 
(first lumbar)"supplies both, and that irritation to the sensory nerves of 
the kidney and ureter will produce both a motor and sensory effect in the 
parts supplied by the cerebro-spinal nerves which comes from the same 
spinal segment. Ovarian colic will have a similar effect. vStimulation 
of the pudendum will affect the ovary possibly directly, or at least in- 
directly, through the general effect on the sexual apparatus. 

The genito-crural nerve is also affected by a lesion of the first lum- 
bar articulations. It pierces the psoas muscle, passes down in relation 
with the external iliac vessels and behind the ureter and near Poupart's 
ligament, it divides into two unequal nerves, the genital and crural 
branches. Its function and distribution will be considered under dis- 
cussion of the second lumbar segment since the greater part of the nerve 
comes from the second. 

The posterior division of the first lumbar nerve divides into the usual 
internal and external branches. The internal ends in the multifidus 
spinas muscle. The external enters the subcutaneous tissue, crosses the 
crest of the ilium, and, with the second and third, form the superior 
clunii nerves. This branch supplies the integument of the gluteal re- 
gion. 

According to Quain the first lumbar ganglion sends a nerve to the 
renal plexus. The impulses passing over this nerve originate in the 
spinal cord, the first lumbar segment. In other words, the filaments 
that go to make up this nerve are prolongations from cells located in 
spinal cord. These filaments pass through the intervertebral foramen, 



Al'PLIEl) ANATOMY. 2'1'J 

forming a part of the trunk of the common nerve, the first lumbar. 

A lesion of the first lumbar articulation will lessen the size of this 
foramen thus interfering with (1), the nerve by pressure on it, or (2) 
the blood-vessels carrying nutrition to the cells that give rise to the 
nerve filaments. This nerve (renal branch of the first lumbar ganglion) , 
carries motor, vaso-motor, and trophic impulses to the kidney and ureter 
and possibly sensory impulses from the kidney and ureter to the spinal 
cord. 

The principal efferent branches of the first lumbar ganglion go to the 
aortic and hypogastric plexuses. The aortic or intermesenteric plexus 
(plexus aorticus abdominalis) placed along the abdominal aorta, occupies 
the interval between the origins of the superior and inferior mesenteric 
arteries. It consists, for the most part, of two lateral cords which are 
connected above with the semilunar ganglia and renal plexuses and ex- 
tend downward on the sides of the aorta, meeting in several communi- 
cating branches over the front of the vessel. The cords receive branches 
from some of the lumbar ganglia and at the points where they join, there 
are often small, ganglionic enlargements which are more distinct in the 
infant. Several filaments pass to the root of the inferior mesenteric 
artery to form the plexus on that vessel, and in connection with these is 
the inferior mesenteric ganglion placed below the origin of the artery. 
"The aortic plexus furnishes the inferior mesenteric plexus and part 
of the spermatic, gives some filaments to the lower vena cava, and ends 
below in the hypogastric plexus. " (Quain.) The cells giving origin 
to these different nerve fibers are for the most part, located in the spinal 
cord and as in the case of the renal branch, the impulses pass over the 
filaments that form a part of the ventral root and common nerve trunk. 
A lesion of the first lumbar articulation will affect these filaments in a 
way similar to those forming the renal branch described above. The 
aortic plexus is motor to the intestines, this part especially supplying 
the cecum and ascending colon. It also supplies the ovary and testicle 
and, possibly, all the structures supplied by the hypogastric plexus, viz., 
the uterus, vagina, prostate and rectum. It is in -part vaso-motor to 
the abdominal aorta, inferior vena cava, mesenteric vessels, ovarian and 
spermatic vessels, vesical, hemorrhoidal, uterine and possibly the va- 
ginal vessels. The lesion usually intercepts the impulses, or at least 
lessens them, hence dilatation of the vessels is the common sequel. 
From congestion many forms of disease may arise. This plexus is also 



250 



APPLIED ANATOMY. 



MULTIFIDUS SPIN*. ERECTOR SPINK. 
TRANSVERSUS SPIN, 
SUP CLUhlJM 



CUTANEOUS FROM MIDLINE ABOVE CREST 
OF ILIUM DOWNTO BELOW (7R.TROCHANTER 



CONNECTS WITH 12th T. 

/ 

A.. LUMBAR I 




$lfe»|l^ rSU LABIA MAJUS PELVIC FLOOR 



Pr. 



CUTUS. ABOVE PUBIS, SCARPA'S 



ABO'L WALL ABOVE PUBIS 



TTtANSVERSALIS 
ABDOMINIS 

MUSCLES OF ABDOMEN 



Fig. 64. — The first lumbar segment of the spinal cord with its nerves and their 
distribution. 



APPLIED ANATOMY. 251 

secretory to the above parts, hence secretion will necessarily be impaired 
by the lesion, if it affects this plexus, and it usually does. The left strand 
of fibers almost entirely forms the inferior mesenteric plexus. Thus 
lesions affecting the foramina on the left side, are the more important so far 
as the effects on the bowel are concerned. 

The first lumbar sympathetic ganglion also furnished filaments to 
the first lumbar vertebra and its ligaments. An impairment of these 
nerves results in a weakened spinal column. In other cases, the spine 
becomes rigid from contracture of these ligaments. Caries of the ver- 
tebra? is also a sequel to a lesion affecting these nerves. 

The recurrent meningeal nerve is, like the other recurrent nerves, 
formed by filaments from the cerebro-spinal and sympathetic nerves. 
It is vaso-motor to the spinal cord, first lumbar segment, and the menin- 
ges. The nerve passes through the intervertebral foramen and thus is 
subject to pressure when the vertebrae forming this foramen are sublux- 
ated. As a result, anemia or congestion of the parts supplied, is the 
result. 

The disorders most common are lumbago, affections of the kidney, 
such as gravel, albuminuria and Bright's diseases, and bowel disorders such 
as constipation, diarrhea and flux. Bladder disturbances are also fre- 
quent when this lesion exists. Quain states that this segment furnishes 
nerves that are motor to the uterus, bladder and circular muscle fibers 
of the rectum; vaso-motor to the abdominal vessels and vessels of the 
penis and lower limbs. 

THE SECOND LUMBAR. 

The second lumbar vertebra is a typical one, so needs no separate 
description. Its size varies with the degree of muscular, and the 
general osseous development of the patient. Its articular facets 
are large and the articulations strong and apparently secure, on account 
of the depth of the facets. If this were not the case, lesions would be 
more common than they are, on account of the lumbar vertebra? not 
being reinforced by the ribs. Notwithstanding this, lesions are quite 
common. The approximation of adjacent vertebrae is one of the most 
common. A posterior condition is also common but does not cause so 
much trouble in proportion to the degree of irregularity as do other le- 
sions, as for example, an anterior condition. Whenever this bone is 
moved beyond the physiological range of motion, the tissues attached to 



252 ' APPLIED ANATOMY. 

it are either stretched or broken. The articular facets, in spines in which 
there has been a forcible and abnormal flexion or extension, are moved 
abnormally far or separated so that the function of the joint is impaired. 

The tissues involved are the periosteum, peritoneum, muscles, lig- 
aments and the fascia attached to the vertebra. The effects of the le- 
sion may be confined to those tissues attached to the vertebra and would 
be similar to those from sprain of any joint, such as edema and tender- 
ness with pain on attempt to use it. The intervertebral foramen would 
be lessened in size partly by change in position of the parts forming it 
and partly by the thickened ligaments in relation. The effects on the 
veins and arteries are very similar to those of a lesion of the first lumbar 
on the vessels in relation with it, and these have been considered above. 

The nerves that are formed from filaments passing through the sec- 
ond intervertebral foramen and would be affected by the lesion, are the 
genito-crurarj external cutaneous, anterior crural, obturator, recurrent 
meningeal, posterior division of the second lumbar nerve and the nervi 
efferentes which branch from the second lumbar ganglion, viz., branches 
to the aortic and hypogastric plexuses and to the second lumbar vertebra 
and its ligaments. 

The genito-crural nerve, soon after emerging from its foramen, 
enters the psoas muscle and after passing through it into the psoas fascia, 
divides near Poupart's ligament, into the genital and crural branches. 
The genital branch passes across the iliac vessels into the inguinal 
canal, entering it at the internal abdominal ring. It traverses this 
canal in company with the spermatic cord and supplies the iliac artery, 
cremaster muscle, integument of the scrotum and a part of the skin of 
the thigh in relation. In the female, it accompanies the round ligament to 
its destination and is also supposed to send' some motor filaments to it. 
The crural branch passes under Poupart's ligament into the thigh and 
becomes cutaneous by passing through the saphenous opening. It 
supplies the skin over Scarpa's triangle not supplied by the ilio-inguinal 
and, communicating with the middle cutaneous of the anterior crural, 
sends some filaments to the femoral artery. 

The lesion of the second lumbar articulation will stimulate or in- 
hibit the impulses that should normally pass over this nerve. If they 
are inhibited, there will be impairment or loss of sensation in the skin 
over the upper and inner part of the thigh and the skin of the scrotum. 
The scrotum will not respond to cutaneous stimulation, it becomes re- 



AVl'LIED ANATOMY. 



253 



INTEGUMENTOVER UPPER LUMBAR 







*e>/>& 



r m 






iffiajS LON&US 

wlLB/ adductors brevis 



MAGNUS QUAO. 
HIPANDKNEE- 
TO BALLOFGRTTOE 
INT'G INNER LEGANDPOOT- 



1NTEG0VER 
OUTERTHIGHTOKNEE 

SARTORIU5M. 

MID.CUTANEOUS 

PATELLA PLEXUS 



INT. CUTANEOUS 



Fig. 65. — The second lumbar segment of the spinal cord with its nerves and 
their distribution. 



254 APPLIED ANATOMY. 

laxed and the testicle is no longer held in its proper place but becomes 
pendulous. The cremasteric reflex dejDends to a great extent on the 
condition of the cutaneous nerves, and in this condition it would be 
lessened or lost. If the nerve were stimulated by the lesion, there would 
be hyperesthesia or pain in the above areas. 

This nerve is often the seat of pain referred from the ureter as in 
renal colic. The explanation is that the impulses generated by the 
calculus stimulating the sensory nerves lining the ureter, are carried to 
the second lumbar segment, thence to the sensorium over the same 
pathway as are the impulses from the genito-crural nerve and thus the 
sensorium is mistaken in part at least, as to the location of the painful 
stimulus. The pain is referred to the inner side of the thigh or scrotum, 
sometimes the penis, and retraction of the testicle is generally present.. 

This nerve supplies motor impulses to only one muscle, the cre- 
master. This muscle is named from its function, that of suspending the 
testicle. It is regarded as a detached portion of the internal oblique and 
is formed into several loops that enclose the testicle and lower part of 
the spermatic cord. It arises from the middle portion of Poupart's liga- 
ment and is inserted into the spine of the pubic bone and the fascia in 
relation. The cremaster muscle is peculiar in that its fibers are separate 
thus forming a series of loops. Its function is to draw the testicle up- 
ward and its contraction is involuntary. It can be stimulated to con- 
traction by irritation of the adjacent skin. The height of the testicle 
is ordinarily an indication of its strength. A pendulous testicle is a weak 
one, while one that is held quite closely to the pubic bone, is usually in 
a healthy condition. The cremaster muscle supports the testicle, hence 
the condition of it is a guide to the condition of the testicle. In short, 
if the cremasteric reflex is lessened or lost and if the testicle is pendulous, 
there is loss of sexual strength. 

The femoral artery may be affected by the lesion since it is inner- 
vated in part, by the genito-crural nerve which is affected by the lesion, 
because of the relation of its roots to the articulation. 

The external cutaneous nerve passes through the psoas magnus 
muscle, crosses the iliacus, passes under Poupart's ligament and becomes 
cutaneous immediately below the anterior superior spine. It divides 
into an anterior and a posterior branch. The anterior is the larger and 
supplies the integument on the outer side of the thigh almost to 
the knee. The posterior branch supplies the lower part of the buttock 



APPLIED ANATOMY. 255 

and the upper part of the outer aspect of the thigh. It is entirely sen- 
sory, hence the lesion of the second lumbar articulations will, if it affects 
this nerve, produce numbness or pain in the above areas. 

The anterior crural and obturator nerves may be affected by the le- 
sion. The effects will be considered under the discussion of the third 
and fourth lumbar. The posterior division of the second lumbar nerve 
supplies in part, the muscles of the back in relation and in conjunction 
with the first and third, supplies sensation to a part of the integument 
in the middle lumbar region. 

The branches of the second lumbar ganglion contribute to form the 
aortic plexus which in turn, helps to make up the ovarian, inferior mesen- 
teric and hypogastric plexuses. According to McClellan, the hypogastric 
plexus receives some filaments directly from the lumbar ganglia. These 
plexuses control the vaso-motor impulses to the bladder, vas deferens, 
round ligament, rectum, intestines and the uterus. They are, in all 
probability, sensory, secretory, vaso-motor and trophic to the genitalia 
and the lower intestinal tract. These plexuses are affected by the le- 
sion of the second lumbar, because the subluxated bone presses on or 
otherwise disturbs the impulses from the spinal cord that supply them. 
These impulses pass over filaments that connect the organs and struc- 
tures named above. These nerve filaments pass through the inter- 
vertebral foramen and this foramen is practically always lessened in 
size, by the lesion. As a result of the lesion, there may be congestion of 
the genitalia on account of inhibition of vaso-motor impulses. There 
may be anemia if the lesion causes prolonged stimulation. Tumefac- 
tions of the uterus result in some cases in consequence of the congestion. 
The continued congestion leads to deposits. The rigid lumbar spine is 
the most common of all bony lesions producing tumors of the uterus. 
The tumor is the result of the disordered innervation of the uterus, from 
the rigidity. The large colon may become diseased from vaso-motor 
disturbances. If the vessels are dilated, diarrhea may result, or in ex- 
treme cases, bloody flux. These conditions result from impairment of 
the lower bowel, hence the lesion is usually in the middle and lower lum- 
bar regions. 

If the nutrient nerve to the round ligament is impaired, the ligament 
relaxes and the uterus, no longer firmly held in anteversion, becomes 
retrodeviated from any exciting cause. If the ligament is stimulated the 
patient will complain of a drawing or pulling sensation along the course 
of the ligament. 



256 APPLIED ANATOMY. 

The bladder is affected because the motor supply is intercepted or 
otherwise affected by the lesion. This is because the nerve filaments 
pass through the intervertebral foramina in relation with the affected 
vertebra, the second lumbar. The muscle fibers relax if the lesion is 
paralytic, contract if it is irritative, hence the condition called vesical 
tenesmus. The uterus is also affected in a similar way. 

The rectum receives motor impulses from this segment by way of 
the aortic or hypogastric and hemorrhoidal plexuses. It also receives 
vaso-motor impulses in the same way. There may be relaxation or con- 
traction, or if the vaso-motor filaments are disturbed, hemorrhoids may 
result. 

This segment contains three centers, the functions of which have 
been quite clearly demonstrated experimentally and clinically, viz., 
defecation, micturition and parturition. A center consists of a group of 
cells that transfers afferent to efferent impulses. To do this there must 
be an afferent nerve which keeps the center informed as to the condition 
of the part, a center or group of cells to receive the afferent impulses, 
and an efferent nerve by which the center can send impulses to the part. 
Defecation is a reflex phenomenon, hence there must be a stimulus, a sen- 
sory nerve to receive and transmit the impulses, a center to receive the 
impulses and a motor nerve to transmit the impulses to the muscles in 
relation with the part stimulated. In defecation the stimulus is the 
presence of fecal matter in the rectum. Ordinarily, the rectum is empty 
except at a time just prior to defecation. When it is impacted or en- 
gorged, constipation exists. I have partly determined this in the female 
by hundreds of vaginal examinations. The sensory or afferent nerves 
are branches of the hemorrhoidal and the inferior mesenteric plexus. 
The efferent nerves are also a part of these plexuses. In order then that 
defecation be normal, the sensory nerves must be of normal irritability, 
the line of communication between the bowel and the center, and the 
center and the bowel, unbroken, and the center properly nourished. The 
afferent and efferent impulses pass through the second lumbar foramen 
over the common nerve trunk. Therefore, a lesion at this articulation 
may produce constipation by (1), pressing on the afferent nerve thus 
interfering with the impulses that arise from the pressure of accumulated 
feces; (2), by pressing on the efferent nerve, hence the motor impulses 
do not reach the bowel; and (3), by interfering with the nutrition of the 
center, thus making it less active and less susceptible to the afferent 



APPLIED ANATOMY. 257 

impulses, that is the afferent impulses reach the center but the cells do 
not respond to the stimulation, hence no efferent impulses are generated 
although the pathway is unobstructed. It must be borne in mind that 
all the afferent impulses do not reach the defecation center by waj r of the 
sensory nerves connecting directly with the second lumbar segment, but 
that some reach it by the first, third, fourth, and possibly the fifth. 
After reaching the spinal cord, the impulses may travel through several 
segments, usually from below upward, so that constipation may fee. and 
usually is produced by lesions at and below the second lumbar vertebra. 
The osteopathic treatment removes these obstructions by restoring the 
foramina to normal size, thus relieving pressure on the nerves and blood- 
vessels. A palliative effect may be obtained by artificially stimulating 
the sensory nerves lining the bowel, thus increasing the number and in- 
tensity of the impulses that are normally transmitted to the defecation 
center. These impulses may be increased to such an extent that they 
will overcome slight obstructions and awaken an inactive center, so long 
as the stimulation is applied. This may be accomplished by the use^of 
certain drugs which directly stimulate the nerves, or indirectly through 
increase of secretion of bile and succus entericus; by the introduction of 
water into the bowel, which stimulates the sensory nerves; or by mechani- 
cal stimulation, as in dilating the rectum. All these treatments are 
palliative in that they do not remove the cause. After continued use. 
they lose their power of stimulation and a change has to be made, and 
the constipation is made the worse by such treatments. 

The opposite condition (diarrhea) may result from this lesion, if it 
stimulates (l),the afferent nerve as it passes through the foramen, (2), 
the center, through increasing the amount of arterial blood, and (3), 
the efferent impulses by stimulation of the motor nerve while it is in 
relation with the vertebra. The usual palliative treatment for this con- 
dition is inhibition applied to the lumbar area of the spine. The best 
way to give this treatment is to extend" the spine over the hand or knee 
applied to the second, third or fourth lumbar spine. This lessens the 
size of the foramina, therefore shuts off (l),the amount of afferent im- 
pulses, (2), the nutrition of the center, it then becoming less active, and 
(3), by inhibiting the motor or efferent impulses. To cure this condition 
the irritation must be removed permanently, which is accomplished by 
correcting the lesion that causes the irritation. The other palliative 
measures often resorted to are (1), drugs which deaden the sensory nerves 



258 APPLIED ANATOMY. 

supplying the bowel, and (2), foods that have little residue, such as 
cheese and boiled milk. These do not remove causes, hence soon be- 
come of no value even as palliative measures. The lesion may so affect 
the bowel that the peristalsis is so increased that tenesmus, eversion of 
the bowel and discharge of blood may follow. In such cases the sen- 
sory nerves are more sensitive, the center more active and the motor 
impulses markedly increased in number and intensity. 

The micturition center, also located in this segment, may be affected 
by the lesion. Micturition is also a reflex process, the accumulation of 
urine in the bladder furnishing the stimulus, the vesical plexus the af- 
ferent and efferent nerves. When the amount of urine reaches a cer- 
tain point and the pressure a certain degree, the center is so informed 
and the bladder wall contracts, while the sphincter vesicae relaxes. The 
lesions, as in constipation, may (1), lessen the irritability of the sensory 
nerves innervating the mucous membrane of the bladder, principally the 
trigone; (2), inhibit the activity of the center; (3) , interfere with the pass- 
ing of motor impulses to the bladder or (4) , interfere with the nutrition 
of the muscle fibers of the bladder wall. In such cases the bladder be- 
comes distended with urine and finally the sphincter muscle is overcome, 
allowing the urine to dribble away. If the lesion is an irritative one, the 
nerves or center, taking part in the reflex phenomenon, are stimulated 
and frequent micturition results. In persistent and bad cases, tenes- 
mus or spasm of the bladder results. The bladder is empty but con- 
traction continues until it becomes quite painful. The sacral nerves 
may have something to do with some of these cases hence the lesion 
may be lower in the spine or pelvic bones. Inhibition at the second lum- 
bar will often relieve vesical tenesmus. This lesion may also produce 
cystitis and possibly calculi, on account of incomplete evacuation of the 
bladder from weakness. Cystitis results from retention of urine and 
from vaso-motor disturbances. Bed-wetting in children may also come 
from this lesion. The brain ordinarily exerts an inhibitory influence 
on the spinal centers but in enuresis this connection may be impaired by 
the lesion. A better explanation is that the lesion irritates the micturi- 
tion center. This center should be in a state of rest during sleep but the 
lesion keeps it irritated so that a little urine will set up impulses strong 
enough to affect and bring into activity the already irritable micturition 
center. Inhibition at the second lumbar just before retiring will, in most 
ceases, prevent the bed-wetting for that night. If only the inhibition 



APPLIED ANATOMY. 259 

is given it will have to be repeated every evening. This treatment seems 
to temporarily overcome the effect of the lesion, that is the irritation is 
in a measure counteracted. To cure the case the cause of the irritation 
must be removed or counteracted and this is accomplished by correct- 
ing the lesion. Children often outgrow the disorder because in time the 
lesion ceases to exert an irritating influence., or nature succeeds in over- 
coming or repairing the injury. 

The parturition center, so-called from the role it plays in parturi- 
tion, is also located in the second lumbar segment. It is as much of 
a menstruation center as it is a parturition center, for it controls the 
contraction of the longitudinal, and possibly the circular, muscle fibers 
of the uterus. In parturition, which is a reflex process, the stimulus 
is the fetus in utero, the afferent nerves the filaments composing a part 
of the ovarian and uterine plexuses. The efferent impulses are carried 
over other filaments of the same plexuses. If the lesion stimulates the 
center or its nerves, to any marked extent, abortion may result. If 
by a treatment the afferent or efferent nerves or the center are stimulated 
very much, contraction of the uterus to such an extent that pregnancy 
may be terminated, is possible but uncommon. During labor, stimula- 
tion of these nerves increases the intensity and frequency of the uterine 
contractions. Inhibition has the opposite effect. A lesion of the sec- 
ond lumbar may disturb parturition by (1), affecting the afferent im- 
pulses; (2), by affecting the center; (3), by impairing the activity of the 
efferent nerve or (4), by affecting the nutrition of the muscle fibers of 
the uterus. The usual effect is lessened activity, that is the lesion in- 
hibits the function of the center and inertia uteri in some form or degree, 
is the result. The explanation is that the center is on the inside of the 
spinal canal and the uterus is in the abdominal cavity and the nerve fila- 
ments connecting them must pass through the intervertebral foramina. 
In the case of a lesion, these filaments are affected hence their 
•conducting power is lessened; or else the lesion disturbs the nutrition of 
the parturition center, thus making it less susceptible to the impulses 
carried to it by the sensory nerves. In all such cases, labor can be made 
■comparatively easy by antepartum treatment. This treatment con- 
sists of correcting all lumbar lesions whether a single vertebra is affected 
•or the lesion consists of a stiffening of the articulations. These lesions 
make labor hard, as mentioned above, by interfering with the reflex 
process. Labor is made easier by osteopathic antepartum treatment 



260 APPLIED ANATOMY. 

since by it lesions of the spine are corrected, thus relieving and removing 
obstructions to (l),the afferent impulses, (2), to the blood supply and 
drainage of the parturition center, restoring it to normal activity, 
and (3), to the efferent nerve fibers. These results are accomplished to 
a great extent, if not entirely, by increasing the size of the intervertebral 
foramina, or rather by restoring them to their natural size. In some 
cases this is hard to do, in others impossible, on account of the per- 
manent or chronic changes in the thickness of the intervertebral discs 
and the thickening of the spinal ligaments in relation with the foramen. 
In the treatment of pregnant cases, precaution should be taken not to 
treat too hard, that is do not stimulate the uterus too much or too 
suddenly, or abortion may result. In cases in which abortion is likely 
to occur, the treatment is especially indicated and that in the lumbar 
area, but be careful how you give it. The writer knows from experience 
that good, thorough treatment applied to the lumbar spine for the 
purpose of restoring normal mobility to every articulation is of great 
value in making labor easy and in preventing complications and sequellse 
depending on a weakened uterus, such as postpartum hemorrhage 
and subinvolution. 

The menstrual function is also disordered by this lesion affecting the 
center or its nerves. It is the motor center for the uterus hence any 
disorder of the uterus, especially the fundus and body, may be the re- 
sult of a lesion of the second lumbar articulation. Dysmenorrhea is the 
most common. This results because the lesion affects the afferent or 
efferent nerves, hence there is imperfect contraction. In the case of 
menstruation, the menstrual flow is the stimulus; the rest of the reflex 
arc is the same as that for parturition. The lesion may stimulate the 
center or any part of its nerves, causing excessive contraction or "cramps. ' ' 
The irritation may continue for several days after the discharge ceases 
causing post-menstrual pain. It may occur at the mid-intermenstrual 
period, hence the intermenstrual pain. The lesion may inhibit the center 
or its nerves. Blood will then accumulate in the uterus and undergo 
coagulation. The afferent impulses are lessened, as are the efferent, and 
the uterus with difficulty expels the menstrual flow. The explanation 
is about the same as that given under parturition, that is the lesion 
lessens the size of the intervertebral foramina, hence interferes with the 
passing of blood and nerve impulses through them on account of which, 
the center is crippled as are the connections with the uterus disturbed. 



APPLIED ANATOMY. 261 

Almost any disorder of the lower bowel and pelvic organs may re- 
sult from a subluxation of the second lumbar vertebra because nearly, 
if not all, depend to a great extent, for their nutrition, secretion, blood, 
sensation and motion upon their nervous connection with the lumbar 
spinal cord, and the second lumbar segment is in all probability the most 
important part. This connection is partly broken by a lesion of the 
second lumbar, because a great many filaments pass through the foramina 
in relation and these are always affected by a subluxation. 

Lumbago quite often comes from subluxation of the second lumbar, 
because it affects the innervation of the spinal muscles, the sensory in- 
nervation of the joint and the mobility of the joint is either lost or mo- 
tion in it, causes pain. Like any dislocated bone, the ligaments become 
tender, and this alone will prevent movement on account of pain. In 
chronic cases, the effect depends on the degree of irritation of the sen- 
sory nerves, or on the muscular changes brought about as a result of the 
lesion, and on the changes in the articulation itself. The ordinary 
"stitch" in the back is commonly directly due to a subluxation of a ver^ 
tebra, usually a lumbar. 

This lesion will weaken the spinal column, leading to curvatures or 
in mild cases, to simply an ache or weakness of the back. The spinal 
cord or rather its prolongation, ma}' be compressed by a dislocation of 
the vertebra. A subluxation of the second, will affect the corresponding 
segment with impairment of function of every part, relying for its in- 
innervation, upon this segment or any segment below it. If a trans- 
verse myelitis takes place paralysis of the parts below would follow. 

THE THIRD LUMBAR. 

The third lumbar vertebra is quite large and all its prominences well 
developed for the attachment of muscles. It differs little from the first 
and second. Its movements are fairly well marked in the normal sub- 
ject but in the aged and in cases in which the spine is in any way dis- 
eased, the movements are impaired. The transverse processes are 
longer than those above. Lesions of two articulations may take place, 
that is the vertebra may be slipped on both its inferior and superior artic- 
ulations, but this form of lesion is not so common as the one in which 
one articulation is involved, that is one part of the spinal column is 
twisted or otherwise displaced on the lower segment. 

The ligaments in this region are thicker and stronger and the facets 



262 APPLIED ANATOMY. 

deeper than above. It takes more force to dislocate or even sprain a 
lumbar articulation than a thoracic or cervical, but the lumbar region 
is subject to many times more strain than any other part of the spinal 
column and on this account. a sprain or subluxation of a lumbar vertebra, 
occurs almost as often as that of a cervical and more frequently than that 
of a thoracic. 

A lesion of the third lumbar articulation will produce effects on the 
adjacent structures similar to that from a lesion of the second lumbar. 
The ligaments will at first be thickened, congested and tender, later on 
they contract and an approximation, with a thinning of the discs is the 
result. This always lessens the mobility hence we speak of it as a smooth 
spine. The muscles and other tissues attached to it are also affected. 

The most important of these muscles are the multifidus spina;, 
erector spina; and the psoas magnus. An irritative lesion of the third, 
will cause contracture of one or more of these muscles. If of the mul- 
tifidus spinse, the spine will be drawn to the side of contracture on ac- 
count of the way the tendinous fibers are inserted and on account of their 
length, they being very short. If of the erector spina?, extension of the 
spine becomes imperfect or difficult and the spine is swerved toward the 
affected side. If of the psoas magnus, flexion of the thighs on the ab- 
domen or of the spine become difficult and the patient walks with a 
stoop and a stiffened gait. If the lesion is a paralytic one, the effect is 
one of relaxation and weakness. The various movements of this part 
of the spine become impaired and the patient has a weak back. Par- 
alysis of one of the spinal muscles permits the unopposed muscle on the 
opposite side to draw the spine to that side and change of contour, often 
to the degree of a curvature, is the result. 

The veins and arteries passing through the formina are obstructed, 
and the parts drained by the veins and those supplied with arterial 
blood by the arteries disturbed, the spinal cord being the most im- 
portant. 

The nerves affected by this lesion are the anterior crural, obturator, 
external cutaneous, accessory obturator, posterior division of third lum- 
bar, aortic and hypogastric plexuses with their branches, the gangliated 
cord, recurrent nerve, rami communicantes, and branches to the ver- 
tebra and its ligaments. 

The anterior crural is the largest of the nerves of the lumbar plexus. 
It is formed principally from the third lumbar segment, although fila- 



APPLIED ANATOMY. 263 

ments from the fourth lumbar, and the second and sometimes the first 
lumbar, joint the root from the third, to form the nerve. It pierces the 
psoas magnus muscle. Deaver says that in psoas abscess "it is left in- 
tact, although the muscle may be entirely removed by necrosis. " Many 
a pain and ache in the lower limbs is due to disease or contracture of 
this muscle affecting this nerve which pierces it. The nerve passes out 
under Poupart's ligament, below which it becomes somewhat flattened 
out and divides into two parts, one that is principally cutaneous and 
one that is almost entirely motor. Before it emerges from the abdomen, 
it gives off muscular branches to the iliacus, some filaments to the femoral 
artery, and some anatomists claim that some fibers pass from this nerve, 
in company with the nutrient artery, to the femur. The middle cutane- 
ous supplies sensory filaments to the front of the thigh and inner side of 
the patella. The internal cutaneous supplies sensation to the integu- 
ment of the anterior and inner portion of the thigh, outer side of the 
knee, inner side of the calf of the leg and foot. It also supplies the pecti- 
neus muscle. The sartorius is supplied by the middle cutaneous; the 
rectus femoris and hip-joint by filaments from other branches of the 
anterior crural. 

These branches to the hip-joint and the femur are of importance in 
cases of malnutrition, such as tuberculosis of the joint or possibly in cases 
of arrected or improper development of the joint or bone. Lesions of 
the third lumbar articulation interfere with the nutrition of the hip- 
joint and the femur through effects on this nerve and are responsible 
for many cases of arrested development and disease of the hip-joint. In 
the treatment of tubercular disorders of the hip-joint and of the femur, 
the lumbar spinal treatment is more important than any other, since it is 
the rule for a lesion to be present there in such cases. In fact, the cure 
depends on this treatment since by it the cause of the disease is removed. 
In all cases of dislocation of the hip, treatment applied to this region is 
often very helpful in restoring strength and nutrition to the parts, through 
removing pressure on, and other disturbances of, the anterior crural 
nerve. 

The branches which supply the vastus externus and internus, also 
supply the knee-joint. The long saphenous, so named from its length 
and relation to the vein of the same name, supplies sensation to the in- 
tegument over the knee-cap and inner side of the calf of the leg and 
foot. A lesion of the third lumbar articulation would affect this nerve 



264 



APPLIED ANATOMY. 



MULTIfTOUS SPINK. ERECTOR SPINft. INTE&. OVER UP LUMBAR 
LATISSIMUS DORSI 

VERT. 




V».*«8f r REC.FEMOR1S 

>C '.ON&US^BREVIS/ VAST EXT 

gracilis/ UAST. INT. 



INTE&.INNERSIOEOFLEGTO 
BALL OF GR. TOE 



INT.CUTA'S. 

5ARTORIUS 

MID.CUTA'S. 

LOWER y4tti. 
OFFRONTOFTHI&H 
LEX. 
CRUREUS AND SUBCRUREUS 



HIPANDKNEEJT. INNERTHIGH 



Fig. 66 — The third lumbar segment of the spinal cord, with its nerves and 
their distribution. 



APPLIED ANATOMY. 265 

by producing pressure on the roots forming it, by interfering with the 
nutrition of the cells or by causing contracture of tissues pierced by the 
nerve. If the lesion stimulates the nerve, there will be pain in the parts 
supplied with sensation by it, viz., the hip-joint, knee-joint, integument 
over the anterior and inner side of the thigh, leg and foot. Pain in the 
knee may be the result of a lesion of the third lumbar articulation or 
hip. The common reflex pain in case of dislocated hip or of coxitis, is 
pain in the knee. The explanation is that the irritation applied to one 
part may, and does cause pain to be referred to another, on account of 
which errors in diagnosis have been made. 

The muscles of the front of the thigh become contractured as a 
result of an irritative lesion of the third lumbar and the condition is 
■often diagnosed as "rheumatism" of the muscles. The femoral artery 
becomes smaller in cases in which such lesions exist, and the lower 
limb is not well nourished. The branches to the hip-joint, femur and 
muscles are also nutrient. If the lesion inhibits the function of this 
nerve, there will be weakness of the limb, malnutrition of the hip-joint, 
numbness of the integument and atrophy, with a weakening of the mus- 
cles, neuralgia, rheumatism, weakness, edema, malnutrition and de- 
formities of the lower limb. In spastic paraplegia, the dragging of the 
toe is due in part, to impairment of this nerve and partly to inability to 
flex the ankle. The patient leans forward in order to be able to take a 
step on account of inability to flex the thigh. In this way, the line of 
gravity is brought anterior to the base. 

The obturator nerve also comes principally from this segment. It 
pierces the psoas muscle, and emerges from the pelvis through the thyroid 
■or obturator foramen. While in the foramen, it divides into an anterior 
and posterior branch. The anterior, supplies the hip-joint, the gracilis 
.and adductor longus muscles and the femoral artery. According to 
Hilton, this nerve passes in relation with the sacro-iliac synchondrosis 
and sends a filament to the articulation. From this it is then possible 
for a lesion of the articulations of the third lumbar vertebra to produce 
pain in the hip, synchondrosis, and spasm or contracture of the adductor 
muscles 

The posterior division supplies the remaining adductors and the 
knee-joint, and occasionally supplies the integument over the inner side 
of the thigh. In spastic paraplegia there is often spasm of the adduc- 
tors and the patient has the cross-legged progression. The lesion af- 



266 APPLIED ANATOMY. 

fects this nerve either at its origin, or at the foramen through which its 
roots make their exit. A dislocated or diseased hip, as in the case of 
the anterior crural nerve, will most commonly produce more pain at or 
in the knee-joint than in the hip-joint. In some female disorders, the 
adductors become contractured and there is also pain on inner side of 
the thigh. This is in the form of a cramp in the average case. In 
hysteria, these muscles are often involved. They are sometimes in- 
jured in parturition, falls by which the limbs are abnormally separated 
and, Deaver says, by horseback riding. They contract in dislocation of 
the hip. In congenital dislocations of the hip these muscles have to 
be stretched to a very marked extent or else forcibly broken under 
anesthesia (as practiced by Lorenz) before reduction is possible. In any 
ordinary case of dislocation of the hip, these muscles are often affected 
and, in addition to the glutei, must be considered as important factors 
in the treatment of such a disorder. In thyroid dislocations of the hip, 
the head of the femur may press directly against this nerve. The author 
saw a case of this sort in which there was constant pain, almost excru- 
ciating, in the areas supplied by the obturator. A slight change in posi- 
tion would give immediate and complete relief, while pressure in the 
opposite direction increased the pain. This nerve may be the seat of 
pain referred from organs innervated by the same segment, the uterus 
and ovaries being at fault in most cases. The real cause may be the sub- 
luxated lumbar vertebra. Hilton says, "Tracing the trunk of the nerve 
we find it associated with many internal and external parts. As- 
suming the obturator to be the seat of pain on the inner side of the knee 
and within the knee-joint, it is plain that this may depend upon disease 
within the vertebral canal or it may depend upon some diseased condi- 
tion of a vertebra near which the nerve lies. It passes over the sacro- 
iliac articulations, and when that joint is inflamed and swollen, as some- 
times happens, patients complain of pain within the knee and on the inner 
side. I have known patients to complain of pain in the inner side of the 
knee when the disease was not in the hip-joint." He also cites cases of 
psoas abscess, fecal impaction of sigmoid, and other disorders of the 
large bowel at this point, affecting this nerve. These points entirely 
agree with the osteopathic explanations, since similar cases have been 
seen. The kinds of cases seen have been those in which the diseased 
condition of the vertebra near which the nerve lay, consisted of a sprain 
or other form of lesion of the joint, subluxation being common. The 



APPLIED ANATOMY. 267 

writer had a case of synovitis of the knee-joint with marked pain and 
edema, which was the result of a subluxated innominate on the same 
side and a retrodeviated uterus. These conditions were overcome and 
the knee disturbances were entirely relieved. 

A lesion of the third lumbar articulation will produce similar effects 
by pressing on the roots of origin of the obturator nerve while they are 
in the foramina. In cases of pain in the lower limb, it is advisable to 
begin at the seat of pain and examine the articulations and parts from 
below upward with which the nerve is in relation. In most cases the 
trouble will be found to be in the spine. 

The posterior division of the third lumbar, unites with that of the 
first and second and help to form the superior clunii nerve. It supplies 
some cutaneous filaments to the gluteal region, but most of the branches 
are muscular. A lesion of the articulations of the third lumbar will 
produce contracture of the lumbar spinal muscles. These muscles are 
supplied with sensation by the same nerves that supply them with mo- 
tion and nutrition, or at least by branches of them. The same nerve 
that supplies sensation to these muscles at this level does not supply the 
integument over the muscle. Backache, when reflex from uterine or 
other pelvic disorder, is, ordinarily the result of reflex contracture of the 
the muscles. The impulses are carried to the lumbar spinal cord by the 
uterine, and hypogastric nerves; the cord becomes congested, or at least 
abnormal impulses arise that result in contracture of muscles supplied 
by this segment. If the integument over the lumbar spine is tender, 
that is, if there is cutaneous hyperesthesia, the eleventh and twelfth 
thoracic nerves are most commonly involved and the trouble is uniformly 
a disorder of the ovary or kidney. In a reflex backache in which there 
is no hyperesthesia of the skin, the trouble is most commonly in the 
uterus and the ache is due to the congestion and contracture of the spinal 
muscles in that region. In the first case the explanation is that the 
eleventh and twelfth dorsal segments are involved, and it would not be 
likely that the third lumbar segment and its sensory branches would be 
involved, unless there were other disorders, that is disorders of viscera 
supplied by this segment. The ovarian plexus gets nearly all of its im- 
pulses from the lower thoracic; the uterine from the lumbar. A lesion 
of the third lumbar articulation may produce both contracture of the 
lumbar spinal muscles and uterine disease. 

The external cutaneous nerve has been considered. 



268 APPLIED ANATOMY. 

The accessory obturator nerve is often absent but is of importance 
when present, because it sends an articular branch to the hip-joint. 

The sympathetic gangliated cord is seldom affected directly by a 
lesion of the third lumbar, but often indirectly. The nervi efferentes of 
the third lumbar ganglion consists of branches to the aortic and hypo- 
gastric plexuses. This ganglion (third lumbar) receives its motor power 
from the spinal cord but the route over which the impulses travel seems 
to be doubtful. Quain says: "White rami communicantes are not 
furnished by all the spinal nerves. According to Gaskell, by whose in- 
vestigations the fundamental constitution of the sympathetic and its 
relations to the cerebro-spinal nerves were first made clear, they are 
found in the dog from the second dorsal to the second lumbar nerves in- 
clusive; but Langley has shown that in the dog and cat, white rami com- 
municantes are given off by the spinal nerves from the first dorsal to the 
fourth lumbar, and in the rabbit from the first dorsal to the fifth lumbar 
inclusive. " In man it is most probable that they exist throughout the 
entire thoracic and lumbar regions if any reliance can be placed on clin- 
ical indications, and we will treat the subject from that viewpoint. The 
impulses then that pass into the third lumbar ganglion, come from the 
spinal cord by way of the white ramus, and in all probability, many of 
these efferent impulses pass on through the ganglion, with little or no 
interruption, into the nervi efferentes helping to form the aortic and 
hypogastric plexuses. 

The aortic plexus supplies the inferior vena cava and contains nerve 
fibers that go to form the inferior mesenteric, hypogastric and ovarian 
or spermatic plexuses. The inferior mesenteric is formed almost en- 
tirely from the left aortic plexus. The impulses, therefore, that pass to 
it from the spinal cord must pass out through the foramina on the left 
side. On this account, a lesion in which the foramina on the left 
were affected, would produce bowel disorders in preference to other dis- 
turbances, assuming the impulses come from the left side, which fact 
seems to be borne out in clinical observations. A subluxation to the 
right, would affect the uterus more than the bowel. Inhibition applied 
to the left side of the spine of the third lumbar vertebra, will have a more 
marked effect on diarrhea than a similar treatment applied to the right 
side. 

The inferior mesenteric plexus transmits, motor, vaso-motor, secre- 

*Quain's Anatomy, Vol. III. pt. II, p. 359. 



APPLIED ANATOMY. 269 

tory, sensory and trophic impulses to and from the spinal cord and the 
lower bowel. If the lesion obstructs this line of communication to such 
an extent that these impulses are checked or stopped, there would be, as 
an effect, lessened peristalsis, congestion, disturbed secretion, loss of 
irritability, and malnutrition of the rectum, and the descending and sig- 
moid colon. Constipation, hemorrhoids, ulcers and prolapsus are the 
most common sequella?. If the lesion irritated these filaments, there 
would be increased peristalsis, anemia, secretory disturbances, secretion 
usually being lessened, pain, and possibly some trophic effect if the condi- 
tion becomes chronic. It is seldom that a lesion will affect all of the fila- 
ments, hence only one or two of the above named functions of this plexus 
are usually involved by the lesion. These nerves, especially the sensory 
and motor, in all probability connect with the defecation center. I 
believe that there is a direct line of communication between the lumbar 
segments of the spinal cord and the bowel and that impulses pass over 
this line to and from the spinal cord. Also these impulses are carried 
over nerve filaments that pass through the lumbar intervertebral for- 
amina. A lesion of the third lumbar articulation produces disorders of 
the lower bowel by affecting the size of the foramen, this interfering with 
the line of communication, or disturbing the nutrition of the cells from 
which the impulses arise. 

It seems from clinical observation that few, if any, impulses pass 
from the third lumbar segment to the ovary. Although the ovarian 
plexus is derived in part from the aortic, I believe that the filaments come 
from a point higher up the cord. Clinically, we find the lesions which 
affect the ovary or testicle are several vertebrae higher, viz., the tenth, 
eleventh and twelfth dorsal, and sometimes the first lumbar. 

The hypogastric plexus may be affected through the aortic, since it 
is formed in part by the aortic, or it may be affected by the lesion directly 
interfering with the impulses that pass from the spinal cord to the plexus; 
that is, some of the nervi efferentes of the third lumbar ganglion. From 
the hypogastric plexus are derived, through the pelvic, the hemorrhoidal; 
vesical; uterine; vaginal and prostatic plexuses. This means that 
nerve cells in the grey matter of the spinal cord give rise to nerve fila- 
ments that pass, with little or no interruption in the normal case, to 
these various plexuses, or rather through them to the viscus or organ. 
The sacral nerves send branches into the above named plexuses and 
must be considered when the effects of a lesion are to be determined. 



270 APPLIED ANATOMY. 

The hemorrhoidal plexus supplies the rectum with vaso-motor, . 
motor, secretory and sensory impulses. These impulses, as mentioned 
above, are derived from the spinal cord, pass out over the ventral root 
into the common nerve trunk, thence over the white ramus into the 
third lumbar ganglion, then over the efferent branch into the hypo- 
gastric, pelvic and hemorrhoidal plexuses. The sympathetic ganglion 
perhaps alters in some way these impulses, as is the function of a gang- 
lion. A lesion of the third lumbar vertebral articulation will interfere 
with this line of communication. As a result there may be. hemorrhoids, 
diarrhea, ulceration of rectum, proctitis, prolapsus or, in fact, any dis- 
ease of the part that would result from an interference with the vaso- 
motor, motor, secretory, sensory or trophic nerve supply. 

The vesical plexus derives its impulses from the same source, in a 
similar way.. This plexus supplies the bladder, ureter, vas deferens, 
vesicle seminales and testicle. From this it is readily seen that almost 
any disorder of these parts, may result from a lesion impairing their 
innervation. If the nerves to the bladder are involved, there may be 
retention of urine, enuresis, frequent micturition, incomplete evacuation, 
dribbling of urine, cystitis, calculi, pain and tenesmus. If the ureter is 
diseased, there may be hydronephrosis, hematuria, colic or strangury. 
If the nerves to the vas deferens are affected, its function is perverted, 
that is, the secretion of the testicle is not properly transmitted to the 
seminal vesicles. If some of the nerve filaments supplying these seminal 
vesicles are disturbed, there may be retention of the semen, passing of 
semen from any strain, or emissions, usually nocturnal, although they 
may be diurnal. If the lesion is an irritative one, the nerves supplying 
the receptacles of the semen are made more irritable and involuntary 
evacuation of their contents takes place from any exciting cause, an 
erotic dream being the most potent and common. 

If the lesion is paralytic, that is if it inhibits these impulses, there 
results a condition called spermatorrhea. This disorder is characterized 
by the passing of semen in small quantities during micturition or defe- 
cation. In such cases the seminal vesicles are weak and any increase of 
abdominal or pelvic pressure, may overcome the resistance offered by the 
sphincter and a part of the contents escape. These vesicles are in rela- 
tion with the rectum, and in constipation the pressure of the impaction 
is directly against them, this tending to cause a weakening of their walls. 
The straining at stool with the downward pressure also tends to cause 



APPLIED ANATOMY. 271 

evacuation of the vesicle. If the part is weakened by the lesion inter- 
fering with its innervation, these causes act with greater effect. Abuses 
will also weaken them and should be considered in the treatment of their 
disorders. 

The testicle may be affected by a lesion of the third lumbar through 
the vesical and pelvic plexuses but clinically the lesions are higher up 
the spinal column. 

The uterine plexus is also affected by a lesion of the third lumbar. 
The reason for it is that the impulses supplying it come from the lumbar 
spinal cord and some of them pass out from the cord through the for- 
amina in relation with this vertebra. The principal functon of this 
plexus is vaso-motor and motor to the uterus. It is also secretory, 
trophic and sensory. This has been determined from clinical observations 
rather than from experiments on animals. A lesion of the third lumbar 
may produce anemia or hyperemia or congestion. Congestion is in- 
dicated by leucorrhea, backache and sense of weight, aching of limbs, 
menstrual disorders and possibly catarrh or inflammation. If the 
motor nerves are stimulated, contraction to a painful degree is the re- 
sult; if inhibited, relaxation of the muscle fibers is the sequel. On ac- 
count of these motor disturbances there may be dysmenorrhea, inertia 
uteri, subinvolution, uterine colic and superin volution. The secretory 
nerves of the uterus may be disturbed independently of the other nerve 
filaments, but this is the exception. The sensory nerves to the uterus 
may be stimulated or inhibited by the lesion, thus there may be as a con- 
sequence, pain, with increased peristalsis or numbness with lessened per- 
istalsis. The movements, that in the peristalsis, of the uterus, like other 
organs that have a rhythmical movement, are controlled to a great ex- 
tent by the condition of the sensory nerves, that is peristalsis is usually 
a reflex phenomenon. 

Fibroid tumors may follow irritation to the trophic nerves to the 
muscle fibers of the uterus, thus causing a hypertrophy of its muscle tissue, 
but this I believe is unusual. Repeated congestion of the organ is 
probably the most important cause. The vaginal plexus also receives 
a few filaments from the third lumbar segment by way of the hypogastric 
and pelvic plexuses. I believe that most of its impulses are derived 
from points lower, judging from clinical indications. 

The prostatic plexus is analogous to the uterine and is formed from 
filaments from the same source. The impulses pass out over the ventral 



272 APPLIED ANATOMY. 

root, white ramus, third lumbar ganglion, hypogastric plexus and pelvic 
plexus. They are vaso-motor, motor, sensory, secretory, and possibly 
trophic. The vaso-motor effect is that of constriction or dilatation of 
the blood-vessels. Constriction results in anemia, dilatation in conges- 
tion. Congestion increases the secretion of the prostate and often pro- 
duces prostatorrhea. This condition is often confused with spermator- 
rhea. A mucus discharge during defecation or at the completion of the 
act of micturition, is most commonly prostatorrhea. Congestion may 
produce reflex effects similar in character to those from uterine con- 
gestion, viz., backache and headache. There seems to be an increase in 
the temperature of the integument of the top of the head in such cases, 
this possibly having something to do with alopecia, the increased tem- 
perature tending to dry the roots of the hair in relation. The gland is 
more of a muscle than a gland and its function is to expel by its contrac- 
tion, what urine may in be the lower part of the bladder and urethra and 
during orgasm, the semen. If the muscle fibers are weakened, mic- 
turition is imperfect and often there is no orgasm. If weakened by a 
lesion inhibiting its motor nerve supply, this function is impaired in 
proportion to the degree of disturbance; marked weakness of this gland 
accompanies some forms of impotence. If the lesion is irritative, the 
patient experiences pain in micturition, and micturition is established 
only after several moments of straining. This is also characteristic of 
hypertrophy from any cause but is especially marked in enlargement 
from excessive venery or specific urethritis that has extended beyond 
the triangular ligament, to the prostate. The sensory effects are usually 
indicated by frequent micturition. The secretory nerves may also be 
impaired by the lesion, there being a lessened or increased amount of 
secretion. These various effects are determined more by the amount of 
venery than by any one thing else. Abuse of the organ plus a lesion, will 
in every case produce some or all of the conditions named above, hyper- 
trophy being the most important on account of its frequency. 

A lesion of the third lumbar articulation affects the prostate (1) by 
breaking or otherwise impairing the line of communication between the 
third lumbar segment and the gland ; and (2) by interfering with the nu- 
trition of the nerve cells that give rise to and control the impulses that 
pass to the gland. The lesion usually does one of the above by direct 
pressure on (1) the nerve trunk which contains the nerve filaments men- 
tioned above, or (2) by direct pressure on the blood-vessels that supply 
or drain the third lumbar segment. 



APPLIED ANATOMY. 273 

The recurrent meningeal nerve is affected in a way similar to that 
of the recurrent nerves mentioned above, and the effect of the interfer- 
ence with its function is about the same. 

The gangliated cord itself may be affected directly by the lesion 
through tightening of the tissues or enlargement of viscera, thus causing 
pressure on it. It is so located in this region that an enlarged viscus 
may produce direct pressure on it, if the patient is in the dorsal posture. 
In four footed animals, nature has so arranged that the gangliated cord 
and its branches and connections, the spinal blood-vessels and the azygi 
and -lumbar veins, are free from pressure on account of posture. This 
should serve as a hint as to the cause of certain diseases characterized 
or accompanied by disturbances of these structures, also the treatment 
for them. Pressure on the sympathetic cord will produce effects in 
viscera and structures supplied with nerve force by way of this cord. 
At the third lumbar, the pelvic viscera and the lower bowel are most in- 
volved. 

The effect on the spinal cord or cauda equina, like most other ef- 
fects, varies with the degree of the lesion and the condition of it. If the 
subluxation is so marked that pressure is exerted on the cauda equina at 
this point, degeneration with paraplegia follows. In such cases the 
paralysis affects the lower limbs, bowel, bladder and, to a certain ex- 
tent, the pelvic viscera. The limbs undergo atrophy and are cold even 
in warm weather. Deformities sometimes develop. In the case of the 
bladder, there is a dripping of urine on account of paralysis of the vesical 
sphincter. The bowels are paralyzed to such an extent that there is 
constipation in an aggravated form. The sexual organs are commonly 
involved, impotence being an effect. The circulation to this part of the 
cord is also affected. 

The spinal column is weakened at the point of lesion. In some in- 
stances it may only be a "crick" in the back, or in others the patient may 
be prostrated. Curvature develops in some, caries of the vertebra? in 
others. In every case of a true lesion of the third lumbar articulation, 
the articular facets are not in perfect apposition so that the function of 
the joint is disturbed in proportion to the degree of displacement and 
effects on the attached tissues, principally the ligaments. In some 
cases an apparent anchylosis develops and nature compensates for this 
loss of motion by increasing mobility at some other point, usually at the 
articulation between the thoracic and lumbar regions. 



274 APPLIED ANATOMT. 

A lesion of the third lumbar is most frequently associated with 
lumbago, backache, disorders of the lower bowel, pelvic organs and dis- 
turbances of the lower limb, principally motor and sensory. 

THE FOURTH LUMBAR. 

The fourth lumbar vertebra is slightly larger than the third. The 
body is distinctly reniform in shape. The transverse processes are 
frequently very much elongated while in other cases,they are rudimentary. 
They give attachment to the ilio-lumbar ligaments which are in turn 
affected in practically all subluxations of the vertebra. The spinous 
process is heavy and in old and muscular subjects, there are often found 
facets for articulation with the process above and below. The inter- 
vertebral disc is very thick and markedly elastic, yet on account of its 
position, it bearing the superimposed weight of the body, it is often 
flattened and non-elastic. There is quite pronounced movement of its 
articulations which is lessened as the patient becomes older, in sedentary 
occupations and in cases in which there are lesions in this region. The 
lesions of the articulations of this vertebra are common, most of them 
coming from sprains of the back. It is decidedly unusual for a com- 
plete dislocation to occur at the articulations of the fourth lumbar on 
account of the depth of its articular facets and the strength of the spinal 
ligaments. Sprains of the spine often occur at this point on account of 
its position, it being a point at which the_strain is very great as in lifting, 
or in any muscular effort in which the spinal column is used. An un- 
expected torsion, a mis-step, extreme flexion, rotation or extension will 
cause a rupture of some of the fibers composing the spinal ligaments. A 
sprain results if the movement of the articulation is beyond the physio- 
logical range. Every articulation has a certain definite range of move- 
ment and the ligaments of the joint limit this movement. A sudden or 
forceful twist whereby the movement is abnormal in extent, partly 
dislocates the articular surfaces and injuries the ligament. This causes 
an irritation, tenderness, a thickening, lessened movement and the usual 
symptoms and signs of a lesion or subluxation of the vertebra. Most 
of these sprains or lesions come from torsion or extreme flexion, hence 
the deviation of the vertebra which is judged, to a great extent by the 
position of the spinous process, is to one side or posterior. 

These lesions produce varied effects on adjacent and distant struc- 
tures. In acute or recent cases, the local effect is the most pronounced, 



APPLIED ANATOMY. 275 

but in chronic cases, the secondary or distant effect is most marked. 
These effects may be motor, sensory, vaso-motor, secretory, or trophic, 
depending on the degree of the lesion and the kind of nerve filaments 
and number of blood-vessels affected by the lesion. Since the fourth 
lumbar foramen is formed in part by the ilio-lumbar ligament, it follows 
that any subluxation of the fourth lumbar vertebra, would affect the size 
of this foramen if this ligament were injured, which is the condition in 
the average case. 

The motor effect may be that of a weakening or relaxation; con- 
tracture or hypertonicity. The muscles on the inner and anterior as- 
pect of the thigh may be involved by a lesion of the fourth lumbar. If 
the lesion is paralytic, relaxation with weakness of the muscles in this 
area is the result. Locomotion is interfered with since the patient with 
difficulty, if at all, is able to lift the limb, that is flex the thigh, thus the 
patient to overcome this, leans forward to carry the line of gravity be- 
yond the base. Spastic paraplegia furnishes a type of such disorder. 
If the adductors are relaxed and weakened, adduction is impaired in 
proportion to the degree of relaxation. This is not a common effect. 
If the lesion is irritative the thigh is flexed on the abdomen, and adducted. 
Straightening of the limbs and, abduction are impossible or very painful 
and hard to perform. Deformities of the lower limbs sometimes result. 
In some cases there are spasms of these groups of muscles. Continued 
contraction produces pain, sometimes a cramping of the muscles of the 
thigh. The sartorius muscle, by its contraction, interferes with the 
venous drainage of the limbs and varicosities result from the obstruc- 
tion thus caused. It crosses the thigh immediately below the saphenous 
opening and its contraction if prolonged, obstructs to a certain extent, 
the lumen of the veins in relation. These effect on the muscles result 
from inhibition or stimulation of the anterior crural and obturator nerves. 
These nerves have part of their origin in the fourth lumbar segment, and 
the roots originating in the fourth lumbar, form a part of the cauda equina 
and pass out at the fourth lumbar intervertebral foramen. This foramen 
-or the one between the third and fourth lumbar, is always lessened by 
a subluxation of the fourth lumbar, hence the effect on these nerves. 

Most contractures, I believe, result from disturbances of the vas- 
cular supply of the cells in the spinal cord. These cells are located in 
the anterior horns of the grey matter and control the tone of muscles 
innervated by the nerve filaments having their origin in these cells. A 
.stimulation of the cells would result in hypertonicity. 



276 APPLIED ANATOMY. 

The gluteus medius and minimus are innervated by this segment. 
If their nerves are inhibited, adduction of the hip-joint, rotation of the 
thigh inwards and approximation of crest of ilium and great trochanter, 
are difficult or impossible. Morris says: "In walking, if it were not 
for the powerful contraction of the gluteus medius and its associated 
muscles, the gluteus minimus and tensor vaginae femoris, the pelvis 
would not be held firmly upon the upper part of the thigh when one leg 
is upon the ground and the other is advanced in the forward step. In 
fast walking the rotatory action of the muscle comes into play, for not 
only does the gluteus medius, of the limb which is resting upon the ground 
support the pelvis by drawing downward the crest of the ilium, but, by 
drawing backward the front portion of that crest, it throws forward the 
opposite side of the pelvis and increases the length of the stride. " A 
lesion of the fpurth lumbar, will impair these movements since it dis- 
turbs the nerves innervating the above named muscles. This lesion 
will also affect the quadratus femoris muscle. This muscle is a strong 
external rotator of the femur, which function would be perverted by the 
lesion. Some of the muscles of the back of the leg are innervated by 
the fourth lumbar segment, also those of the front and outer side of the 
leg. Impairment of these muscles may be directly due to the lumbar 
lesion. Contracture, as in cramping of the muscle, is not unusual, while 
weakness is quite common. Infantile paralysis and its effects on mus- 
cles will be considered under trophic effects of this lesion. 

The muscles of the back supplied by the posterior division of the 
fourth lumbar nerve are also relaxed, or more commonly, contractured, 
as a result of the lesion. A relaxation usually means hypermobility with 
pronounced weakness of the spine at this point. A curvature results in 
approximation of the vertebra?, impairment of circulation through the 
muscle and the spinal cord, stiffness of spine, hence lessened mobility, 
tenderness in and over the muscles, and later on, deformities of the spinal 
column, that is, curvatures. These muscles, the multifidus, erector and 
rotatores spina?, are connected by filaments with nerve cells in the fourth 
lumbar segment. A lesion of the fourth lumbar articulation interferes 
with this line of communication, hence the effect. It does little, if any 
good, to treat the effect, that is to try to relax or contract the muscles 
by direct manipulation of them, unless there is structural shortening, 
since their condition is the effect. Adjust the vertebra and the effect 
will disappear. 



APPLIED ANATOMY. 277 

The uterus and Fallopian tubes, especially the former, are supplied 
with motor impulses by way of the uterine and ovarian plexuses of nerves. 
These motor impulses in all probability, come almost entirely from the 
spinal cord, although some may be derived entirely from the sympa- 
thetic gangliated cord. In the grey matter of the fourth lumbar, as 
well as in the segments above it, are located cells that control and give rise 
to motor impulses that pass to the uterus, principally by way of the ven- 
tral root of the fourth lumbar nerve, common trunk of this nerve, ramus 
communicans to the gangliated cord, then by way of thenervusefferens, 
to the hypogastric and uterine plexuses. These impulses, like others, 
may be inhibited or stimulated. If inhibited, the uterine muscle fibers 
relax. The size of the uterine blood-vessels is controlled to a great ex- 
tent, by the condition of the muscle fibers of the uterus; that is, a certain 
amount of tone or contraction is necessary to the proper functioning of 
the blood-vessels. As a result of this relaxation the blood-vessels en- 
large and congestion immediately occurs. Parturition and menstrua- 
tion are difficult on account of this muscular weakening. If the motor 
impulses of the uterus are stimulated, the uterine muscle fibers contract, 
often to a painful degree as is illustrated by some forms of dysmenorrhea 
and post-menstrual pain. Even after the menstrual flow has been en- 
tirely expelled, this irritation from the lesion continues and uterine con- 
tractions continue, hence the pain. The menstrual flow is usually 
scant, since the contraction of the uterus lessens the amount of blood in 
the uterus. 

The peristalsis of the Fallopian tube is lessened by, a lesion that in- 
hibits the impulses, while it is increased to a painful degree, in cases in 
which the lesion is irritative. 

Some of the motor impulses to the vagina may pass from the spinal 
cord (fourth lumbar segment) by way of the hypogastric, pelvic and 
vaginal plexuses, but I believe that most, if not all of them come from 
the sacral segments. A few cases of motor disturbances of the vagina 
have come under my care in which the lesions were undoubtedly in the 
lumbar area. The vaginal walls become relaxed if the motor impulses 
are shut off or even inhibited. This results in a large, patulous vagina 
with obliteration of the ruga?. If the motor impulses are increased in 
number or intensity, the muscle fibers of the vaginal walls contract. 
Vaginismus is the best example of this effect. 

In the male, the muscle fibers of the prostate may be affected by a 



278 APPLIED ANATOMY. 

lesion of the fourth lumbar in a way similar to that from a lesion of the 
third lumbar, which has been considered above. 

The vas deferens is supplied with motor impulses by the fourth lum- 
bar segment. Landois in speaking of ejaculation says, "The center 
(Budge's genito-spinal center) is situated at the level of the fourth lum- 
bar vertebra in rabbits. The motor fibers of the vasa deferentia are de- 
rived from the fourth and fifth lumbar nerves which enter the sympa- 
thetic and finally pass thence to the vasa deferentia. " From clinical 
observation in man it seems that the center is the same as that men- 
tioned above, viz., fourth and fifth lumbar. The peristalsis of the vas 
deferens is affected by a lesion of the fourth lumbar. The functions of 
this vessel are to convey the secretion of the testicle to the seminal ves- 
icles and to assist in ejaculation. These functions are impaired, because 
the peristalsis is decreased or increased to a pathological degree. 

The seminal vesicles are also affected by a lesion of the fourth lum- 
bar. 

The rectum and lower bowel are often affected by a lesion of the 
fourth lumbar. The effect is due rather to a disturbance of the secre- 
tory, sensory, vaso-motor and motor, than to a disturbance merely of 
the motor nerve. This lesion is most often found in diarrhea. It may 
stimulate the motor nerve thereby increasing the peristalsis, or it may af- 
fect the secretory, vaso-motor or sensory impulses. Peristalsis of the lower 
bowel is governed by motor impulses from the lumbar spinal cord, the 
fourth lumbar segment being very important. If the lesion is irrita- 
tive, peristalsis will be increased; if inhibitive it will be lessened. In- 
hibition applied to the fourth lumbar vertebra, or a great deal better 
still, a correction of the subluxations in the lumbar region, will relieve 
and cure flux and kindred disorders in practically all curable cases. The 
explanation is that the lesion irritates the motor or other nerves to the 
bowel and by correcting the displacement or subluxation of the bone, 
this irritative effect is lessened or entirely relieved. The nerves carrying 
these impulses are the hypogastric, pelvic and hemorrhoidal plexuses. If 
the lesion inhibits the impulses, constipation with relaxation of the mus- 
cle fibers in the lower bowel will result. 

The bladder may also be affected by the lesion. The effects are 
similar to those from other lumbar" lesions and have been considered. 

A lesion of the fourth lumbar may produce sensory disturbances in 
the skin of the lower limb, muscles innervated by the fourth lumbar seg- 



APPLIED ANATOMY. 279 

ment, the pelvic viscera and certain articulations. The cutaneous ef- 
fects of a lesion of the fourth lumbar articulation are manifested by pain 
or anesthesia, partial or complete, in the integument on the anterior 
portion of the thigh, inner and outer sides of the leg, inner side of foot 
and over a part of the gluteal region. If the lesion is irritative, there will 
be pain; if inhibitive, numbness. Many a pain in the lower limbs is due 
to a lumbar lesion. The explanation is that the anterior crural, and obtur- 
ator nerve sand lumbo-sacral cord, supply the limb with sensory impulses, 
or rather the sensory or efferent impulses from the lower limb pass through 
these nerves. These nerves are more or less involved by a lesion of the 
fourth lumbar, because some of their roots pass through the interverte- 
bral foramina in relation with the fourth lumbar articulation. 

The muscles supplied with motion by the anterior crural, obtura- 
tor, anterior tibial and posterior division of the fourth lumbar nerve, 
are also supplied with sensation by the same nerves. The lesion may pro- 
duce a numbness in them but more commonly a pain or ache. This 
painful condition simulates what is ordinarily called muscular rheumatism 
and is often confused with it. The sensory innervation of a muscle is 
not nearly so great as the cutaneous nerve supply, since sensory nerves 
principally supply the superficial structures to better insure protection 
of the organism. Aching of the limbs is often due to a lumbar lesion. 
This lesion irritates the sensory filaments of the nerves passing through 
the fourth lumbar segment and the impulses resulting, are referred by the 
sensorium to the limb, the supposed source. In acute pain in the mus- 
cles of the legs, the trouble is nearly always in the spine; in aches of the 
lower limb the cause may be in the spine or it may be the result of im- 
pure blood in the muscle itself. In cases of unusual activity of a muscle, 
there is excessive katabolism and this acts as a chemical irritation to the 
sensory nerves supplying the muscle. In back-ache in the lower lum- 
bar region, the cause may be" in the spine, which condition directly stim- 
ulates the nerve supply of the spinal muscles, this producing contracture. 
Often the lesion affects the viscus, which disturbance in turn causes re- 
flex contracture of the spinal muscles, and nearly all contractured 
muscles are tender and subject to ache. Aching of the lower lumbar 
region is indicative of (1) lesion of the lower lumbar or (2) pelvic dis- 
order of the uterus in the female, and prostatic disorder in the male. 

According to Head's chart no viscera are supplied with sensation by 
the fourth lumbar segment, but clinically there are indications that this 



280 APPLIED ANATOMY. 

segment controls in part, the sensory innervation of the bowel, bladder 
and pelvic genitalia. The writer has had many opportunities to test this 
in'cases of pain in these organs, and has often found that a slight twist of 
the 'fourth lumbar vertebra produces pain in the above mentioned parts 
and that a correction of the lesion brings relief. 

The fourth lumbar segment controls the sensory nerves supplying 
the hip-, knee- and ankle-joints, the sacro-iliac synchondrosis and perhaps 
the articulations of the foot. Pain in the hip-joint is often due to a 
lesion of the fourth lumbar articulation since it will irritate the anterior 
crural and obturator nerves, both of which send filaments to the hip- 
joint. The impulses arising from this irritation are carried by the same 
pathway that those from the hip-joint pass and the sensorium is mis- 
taken as to their source. This lesion produces symptoms that are often 
mistaken for those from injury to or dislocation of the hip, knee, ankle 
or innominate. In painful conditions of the knee-joint, the cause is 
often in the spine. Most cases of pain in the knee-joint are due to dis- 
ease or dislocation of the femur, but occasionally the lumbar region is 
responsible. 

Pain in the lower limb, lower bowel, and generative organs, is often 
the result of a lumbar lesion, and a lesion of the fourth lumbar articu- 
lation is the most important one of the lumbar lesions. 

The blood-vessels innervated by the fourth lumbar segment and 
the lumbar gangliated cord are more or less disturbed by this lesion. 
They are either lessened or increased in size, the first producing anemia, 
the second, congestion. The cutaneous blood-vessels are often disturbed. 
This disturbance may be indicated by coldness of the part or a conges- 
tion, this increasing the surface temperature and changing the color to 
a vivid pink or it may be mottled. The areas involved are the gluteal, 
and part of the thigh. The cutaneous circulation through these areas is 
poor in comparison to that of other areas of the body, hence the fre- 
quency of boils on the buttocks and the lowered temperature which is so 
common. These blood-vessels are supplied with vaso-motor impulses 
derived from the fourth lumbar ganglion; some probably coming from 
the segment, they passing out over the ventral root, common nerve and 
posterior division of the fourth lumbar nerve. The spinal blood-ves- 
sels are affected by this lesion since they are innervated by the fourth 
lumbar segment by way of the recurrent meningeal nerve. The effects 
of a lesion on this nerve have been considered. 



APPLIED ANATOMY. 



2S1 



The pelvic blood-vessels are affected by this lesion through a dis- 
turbance of the hypogastric and pelvic plexuses with their branches and 
communications. The blood-vessels most affected are the uterine and 
hemorrhoidal. Anemia or congestion may follow, it depending on 
whether the vaso-motor nerves are stimulated or inhibited by the lesion. 

The vessels of the lower limb are also affected by the lesion through 



'common iliac 
arteryamdvein 




INT. PUDIC 
ART. ANDVE1 



VENOUS PLEXUS 



Fig. 67. — Showing the veins of the female pelvic organs. Note their number 
and tortuosity. Displacements of the uterus or enteroptosis readily obstruct these 
veins and thus lead to congestion (after Spalteholz). 

disturbance of the crural nerve and the plexus around the iliac arteries. 
These plexuses are formed by branches from the spinal cord. Anemia 
of^the limb results if the blood-vessels are constricted; congestion, 
if^they become dilated. Varicose veins sometimes result from a lesion 
of the fourth lumbar, because it inhibits the passing of impulses to the 



282 



APPLIED ANATOMY. 



veins of the limb. There is usually some exciting cause which further 
dilates the veins, such as standing on the feet for long periods, enteropto- 
sis or pelvic enlargements. The primary and predisposing causes are 
in the spinal column. All parts below the occiput must connect with 
the spinal cord if it is to functionate properly. . The moment this con- 
nection is broken, the function of the part is affected and soon it becomes 
the prey of disease. Nature has arranged for compensation if the in- 



gJfillMK 



BODY OF THE 
\C PANCREAS 



£_ INF. MESENTERIC- 
V~ ' VEIN 



MID COLIC VEIN 




RIGHT COLIC 
VEINANOARTERY 



VEIN AND ARTERY 

OFTHEVERMIFORM 

APPENDIX 



Fig. 68. — Showing the veins of the intestines. 



2S3 APPLIED ANATOMY. 

jury is not too great; that is impulses may pass over other nerves in rela- 
tion and connected with, the affected part. A lesion of the fourth lum- 
bar, breaks the connection existing between the spinal cord and the blood- 
vessels of the lower limb. At first the circulation through the limb is 
slowed; this is accompanied by aching of the limb, or it may become cold. 
If only the superficial vessels are affected, varicosities result. The ex- 
planation is that the vaso-motor impulses to these vessels pass out from 
the spinal cord over nerve filaments that pass through the intervertebral 
foramina in relation with the fourth lumbar, and in lesions of this artic- 
ulation, the foramen is always lessened in size from change in position 
of the bone or by deposits from injur}' to ligaments. 

Secretory disorders resulting from a lesion of the fourth lumbar 
are most commonly indicated by catarrh of bowel, uterus and bladder 
and excessive perspiration of lower limbs. These disorders, particularly 
the catarrhal ones, are due to a great extent, to the vaso-motor disturb- 
ances but in addition the secretory nerves are also involved, this making 
the effect more marked. Lack of sweat or excessive perspiration of 
the lower limbs is sometimes encountered and can be traced to spinal 
lesions, the fourth lumbar being an important one. 

The trophic disorders are most marked in the lower limb and con- 
sist of malnutrition with atrophy. The nutrition of a part depends on 
amount and character of the blood supply and ability of the part to select 
from this blood, food that is nourishing. The trophic nerve is supposed 
to be a separate nerve filament which has the function of controlling this 
selective process. The trophic nerve cells are in the anterior horns of 
the grey matter of the spinal cord. Like other cells, these must have 
nerve filaments connecting them with the parts innervated. If this line of 
communication is broken or impaired, the part suffers, or if the cells are 
affected, a similar result follows. Infantile paralysis is a type in which 
the trophic cells are impaired or destroyed. If destroyed, the paralysis 
resulting from it is incurable; but if their function is only suspended a 
cure may be effected. It is advisable to treat the case for a while in order 
to ascertain which kind it is, since the diagnosis can not very well be made 
in any other way. The lesion is responsible for many cases of both forms 
because it disturbs the nutrition of the nerve cells or produces a conges- 
tion so severe that hemorrhage results. 

The hip-joint is especially affected in lesions of the fourth lumbar, 
which disturb the nutrition of the lower limb. As a result, the ligaments 




Fig. 69. — Showing the azygi veins and their tributaries. I. J., internal jugu- 
lar; E. J., external jugular; S., subclavian; S. V., superior vena cava; A., azygos 
major; I. V., inferior vena cava; A. L., anterior lumbar; I., iliac; L. A., left lower 
azygos; V., vertebral; A. V., anterior vertebral. 



APPLIED ANATOMY. 285 

become stretched and weakened, permitting the head of the bone to 
drop part way out of the acetabulum. This is especially true of anterior 
polio-myelitis and has given rise to many errors in diagnosis, as the con- 
dition resembles a dislocated femur. In congenital dislocations, the lack 
of development of the acetabulum and leg can be overcome to a marked 
extent, by spinal treatment applied at or near the fourth lumbar. In 
most cases of dislocated hip, some form of spinal lesion is present, the 
correction of which constitutes a preliminary treatment prior to the 
reduction of the dislocation. In hip-joint disease, the predisposing 
cause is the spinal lesion which interferes with the nutrition of the hip- 
joint, then the trauma or dislocation the more readily results in disease. 
If the vitality is lowered to a certain degree, the tubercle bacilli if present, 
become active and tuberculosis of the hip is the result. Most, if not all, 
of these trophic impulses that supply the hip-joint pass by way of the 
obturator, sciatic and anterior crural nerves, therefore a lesion of the 
fourth lumbar would interrupt the passing of these impulses, hence the 
malnutrition from the spinal lesion. 

The spinal column itself is also affected by this lesion through the. 
trophic nerves. The spinal ligaments are relaxed, the spine weakened, 
the vertebras abnormally separated on movement of the body. In 
chlorosis, the spine is often affected in this way and secondary spinal 
lesions are common. The vertebra* also receive trophic impulses from 
t he fourth lumbar segment by way of the recurrent nerve. Caries with 
psoas abscess, will often follow when the trophic nerve to the vertebra 
iti impaired. The ligaments of the sacro-iliac synchondrosis receive 
some trophic impulses -from the obturator nerve. A weakness of this 
joint will follow a lesion of the fourth lumbar if this particular function 
of the nerve is impaired thereby. 

There are certain centers located in this portion of the spinal cord. 
The center for erection is located in part, in this segment. Landois 
says: "The centripetal fibers are the sensory nerves of the penis. The 
centrifugal fibers are for the deep artery of the penis, the vaso-dilator 
nerves from the first, second and third sacral nerves, (Eckhard's erector 
nerves) for the ischiocavernosus and the deep transverse perineal muscle, 
the motor fibers from the third and fourth sacral nerves." The lesion 
may inhibit this center, thus making erection imperfect or impossible. 
This form of impotence is not unusual and is the result usually of two 
causes, (1) a lesion which inhibits the activity of the center and (2), 



SUP CIRCUMFLEX ILIAC 

'sup EPIGASTRIC 
^-SUP PUOIC 
FEMORAL 

^EXT.SUP 
FEMORAL 

- LONG 
'SAPHENOUS 

.1NT.SUP. 
FEMORAL 



^LONG- 
SAPHENOUS 



Fig. 70. — Showing the superficial veins of the lower extremity. Note the re- 
lation to the saphenous opening and that contracture of the tissues would obstruct 
the drainage of the limb 



APPLIED ANATOMY. 287 

abuses of the part. Taylor speaks of the fourth lumbar as the sexual 
center. Stimulation at the fourth lumbar or the sensory nerves (pos- 
terior division) supplying the buttocks will excite this center. If the 
lesion is an irritative one, frequent erection takes place. The probable 
explanation is that the lesion produces a congestion of the center. Sleep- 
ing on the back with an impacted bowel also produces a congestion of 
the spinal cord followed by erection and nocturnal emission. 

The center for ejaculation is also located in this segment. Landois 
says, "Ejaculation may be induced by mechanical stimulation of the lum- 
bar cord in guinea pigs." In man, a lesion of the fourth lumbar artic- 
ulation acts as a mechanical stimulation of this center and consequently 
emission takes place from any exciting cause. This, like other centers, 
may be inhibited or stimulated by a lesion. If inhibited, ejaculation is 
impossible or imperfect; if stimulated, it is frequent and takes place 
from trivial causes. Congestion of this part of the cord from other 
causes is also an important thing to be considered in such cases. Sleep- 
ing in the dorsal posture produces hypostatic congestion of this part. 

The disorders most commonly caused by a lesion at the fourth 
lumbar are flux, diarrhea, constipation; fibroid tumors of uterus, con- 
gestion and inflammation of the uterus; sexual disorders, such as im- 
potence, nocturnal emissions, satyriasis; disturbances of the lower limbs 
and their articulations, such as pain, atrophy, varicose veins, and in- 
flammation. The lesion produces disorders by lessening the size of the 
intervertebral foramina, thereby producing pressure on (1) nerves that 
pass through, and (2) blood-vessels that are in the foramina, thus af- 
fecting the drainage and nutrition of the spinal nerve cells. 

THE FIFTH LUMBAR. 

The fifth lumbar vertebra, in an osteopathic way, is one of the most 
important on account of the frequency of its subluxations. This verte- 
bra is characterized by a very large body which is thicker in front than 
along its posterior border. This produces in part, the anterior curve 
of the lumbar spine which is most marked at the fifth. Also the lower 
surface of the body seems to be cut away in order to secure better artic- 
ulation with the upper part of the sacrum. The transverse processes 
are heavier and longer than those of the fourth lumbar, giving better 
attachment to the lumbo-sacral ligaments. The superior facets face in- 
ward, the inferior forward and outward and are considerably wider apart 



288 



APPLIED ANATOMY. 



ERECTOR SPINft 
3.d1a~~ ~ INTERTRANSVERSE 

FROM 20. U. 

RAL 




TOFEMORALART^ 
'ANTTIBIALN- 
MUS.dUTA.TOPERONEI MS. TOKNEEdT' 



AOD.BREVIS 
ADD. LONGUS 
BRA.TOKNEEJT. 
GRACILIS M. \~AOD. MAGNUS 

CUTA.BRA. 

CONNECTS wiTh LOtiiGSAPHENOUS 



Fig. 71 — The fourth lumbar segment of the spinal cord, with its nerves and 
their distribution. 



APPLIED ANATOMY. 289 

than the corresponding facets above. The spinous process is usually 
smaller and situated more anteriorly than that of the fourth. The in- 
tervertebral disc below is quite thick and is the largest of all. The ver- 
tebra is located considerably anterior to the other lumbar vertebra, 
which fact may account for the frequency of its forward displacement. 

The movements of this part of the spine are normally, well marked. 
The antero-posterior movements are most marked and possibly on this 
account, anterior and posterior displacements are most common. The 
articulation between the fifth lumbar and sacrum is a weak point in the 
spinal column on account of the fact that a comparatively movable 
part articulates with an immovable part, the sacrum. This is also true 
of the dorso-lumbar articulation. 

The lesions, or subluxations, are similar in character to those of the 
lumbar vertebrae above; that is it may be anterior, posterior, or there 
may be torsion. The posterior subluxation is caused by extreme flexion 
with a strain, as in lifting in the stooping posture. It produces little 
trouble in comparison with an anterior deviation of the same degree. 
The spinous process is prominent and the distance between it and the 
first sacral spine is increased, that is there appears to be a break or sep- 
aration at this articulation. The anterior subluxation is more important 
than the posterior because it produces a greater effect on the interverte- 
bral foramina, that is it lessens their size. 

In addition to the usual spinal ligaments there are two special or 
accessory ligaments, the ilio-lumbar and the lumbo-sacral, which help 
to more securely bind the fifth lumbar to the sacrum. This apparent 
precaution against dislocation is taken, on account of the strain to which 
this (lumbo-sacral) articulation is subjected. 

The lumbo-sacral ligament is very strong and is intimately blended 
with the ilio-lumbar ligament. It is triangular below and blends with 
the periosteum lining the base of the sacrum and the iliac fossa. The 
internal and inferior border or edge, helps to form the foramen between 
the fifth lumbar and sacrum, through which the last lumbar nerve passes. 
The effect of an injury to this ligament on this nerve can be appreciated 
the better on account of this foramen and its relation to the nerves. 

The fibers of the ilio-lumbar ligament are about horizontal and 
attach the ilium to the transverse process of the fifth lumbar and pedicle 
and transverse process of the fourth lumbar vertebra. It is also tri- 
angular in shape but with the base attached to the vertebra instead of 



290 



APPLIED ANATOMY. 



ERECTOR SPINS. 
4lhL. 




F 



"SHT.SAPHENOUS 
ITOOUTERSI0EOFF 

CUTA.T0 OUTER SIDEOFLE' 

TO TOES 



ANT.TIBIAL 



MUSCULO- 
CUTANEOUS™ PERONEI MS. 



GRT. SCIATIC 
A00. MAGNUS 

EXT. POPLITEAL 

INT. POPLITEAL 
TO POPLITEUSANOPLANTARIS 



Fig. 72. — The fifth lumbar segment of the spinal cord, with its nerves and 
their distribution. 



APPLIED ANATOMY. 291 

the innominate. The fourth lumbar foramen is partly formed by it. 
This ligament helps to form the posterior boundary of the true pelvis, 
reinforces the sacro-iliac ligaments and in part, furnishes origin to the 
multifidus spinse and quadratus lumborum muscles. The sacro-lum- 
bar and ilio-lumbar ligaments are supplied with blood by the arteries in 
relation, the last lumbar, lateral sacral and- ilio-lumbar arteries. Their 
nerve supply is from the recurrent meningeal of the fifth lumbar and 
twigs from the fourth and fifth lumbar nerves. Many a case of lumbago 
results from a sprain of one of these ligaments. The movements of the 
joints in relation are impaired, that is there is a stiffening of the joint 
or hypermobility and the articulations are weakened. In cases in which 
the lumbo-sacral articulation is injured, that is if there is a lesion at this 
joint in addition to the injury to the tissues attached, the foramen formed 
by the fifth lumbar and sacrum is changed as to size, usually lessened. 
If it is increased, the foramen between the fifth and fourth is lessened, 
thus a lesion of the fifth lumbar articulation results in a lessening in 
size of the foramina. The foramen below the fifth conveys blood- and 
lymph-vessels and nerves. The effect on the vessels of a lessening of 
the size of the foramen is similar to that described under the various 
other vertebra. 

The nerves affected, that is those represented by filaments that 
pass through the foramen, are the posterior division of the fifth lumbar, 
superior gluteal, inferior gluteal, muscular to the quadratus femoris, 
obturator internus, erector and multifidus spinse muscles, the great 
sciatic and its branches, aortic plexus (perhaps only a few filaments) 
hypogastric plexus, recurrent meningeal and twigs to the vertebrae and 
ligaments. The malposition of the joint either exerts a stimulating or 
inhibitory influence on these nerve strands. 

The posterior division of the fifth lumbar nerve sends a filament to 
the first sacral nerve and assists in the formation of the middle clunii 
nerves. The internal division ends in the multifidus spina? muscle, 
while the external becomes cutaneous by piercing the gluteus maximus 
muscle. If the lesion causes a stimulation of this nerve, the posterior 
division of the fifth lumbar, there would be pain over the lower gluteal 
region and contraction of the multifidus spinas muscle. The result of 
the contraction is an approximation of the lumbar vertebras or a scolio- 
sis toward the affected side, and the movements of the spine wherein 
this muscle is used become difficult, the condition being commonly called 



292 APPLIED ANATOMY. 

lumbago or muscular rheumatism. This nerve is often the seat of pain 
referred from pelvic disorders. The anterior division innervates some 
of the pelvic viscera and when irritated, the pain is referred to the more 
highly sensitive part, the posterior division. The converse is possibly 
true; that is, a stimulation of the posterior division will cause a stimu- 
lation of the anterior division. If the lesion produces an inhibitory 
effect there is numbness or anesthesia in the above named parts with 
relaxation of the multifidus spina? muscle. 

The superior gluteal nerve is motor to the gluteus medius and min- 
imus. The function of these muscles has been given. If the nerve is 
stimulated, contraction of these muscles follows, which soon develops 
into a contracture. Movements of the lower limbs are difficult and 
adduction and abduction of the hip are restricted. If the superior glu- 
teal nerve is inhibited by the lesion, relaxation with atrophy of the mus- 
cles follows. This nerve is formed from several segments but the lumbo- 
sacral cord gives origin to the greater part of the nerve, and the impulses 
are carried from center to periphery by nerve filaments that pass through 
the fifth lumbar foramen, hence would be subject to injury in subluxa- 
tions of the fifth lumbar or sacrum. 

The inferior gluteal supplies the gluteus maximus. The function of 
this muscle is to produce powerful and forced extension of the hip as in 
ascending a stairway, running and jumping. It is an extensor of the 
pelvis when the fixed point is below, as in rising from a stooping posture, 
and is also called the muscle of copulation by some writers. If the le- 
sion interrupts the transmission of the nerve impulses to this muscle, 
extension of the hip-joint is weakened in proportion to the degree of 
interference, and movements of the body in which this muscle is used, 
as pointed out above, become labored or impossible. The opposite 
effects occur if the inferior gluteal nerve is stimulated, that is extension 
is exaggerated, and flexion both of the hip and pelvis, is opposed by these 
glutei muscles, hence is slow and difficult. 

The nerve to the quadratus femoris, controls the nutrition and activ- 
ity or function of this muscle. This muscle is a powerful external ro- 
tator of the femur. In case of inability to externally rotate the femur 
or in cases in which external rotation is extreme, this nerve may be at 
fault. The same is true of the obturator internus. Supposed rheuma 
tism of the hip and limb and stiffness of the hip-joint are due, in many 
cases, to contractured conditions of the above named muscles, caused 



APPLIED ANATOMY. 293 

by a lesion at the fifth lumbar which affects the nerves innervating them. 

The great sciatic nerve, the largest nerve in the body, is partly formed 
by the fifth lumbar segment and is more or less disturbed as to function 
by a lesion of the fifth lumbar vertebra; one of its roots passes through 
the fifth lumbar foramen and one through the fourth lumbar foramen, 
both of which are in relation with these articulations. These roots are 
compressed partly or completely by the malposed vertebra, and, although 
the other roots may partly take on the function of those disabled by the 
lesion, there will be some effect. These roots, like others, may be stim- 
ulated or inhibited by the lesion and since so many nerve filaments com- 
pose them, the effect may be localized or quite widely distributed, which 
conditions are well illustrated by a condition called Morton's toe, and 
general atrophy of one leg. This nerve ''supplies the muscles at the 
back of the thigh, and by its branches continued from it, gives nerves to 
all the muscles below the knee and to the greater part of the integument 
of the leg and foot. The several joints of the lower limb receive fila- 
ments from it and its branches." In short, it supplies the above parts 
with motor, sensory, secretory, vaso-motor and trophic impulses. As a 
result, a lesion of the fifth lumbar may produce motor paralysis or spas- 
ticity, anesthesia, or some form of it, or hyperesthesia, lessened or in- 
creased secretion, congestion or anemia, hypertrophy or atrophy of the 
greater part of the lower limb. This nerve will be discussed more thor- 
oughly in connection with the sacro-iliac joint; and suffice it to say in 
connection with the fifth lumbar that almost any disorder of the lower 
limb may result from a lesion of the fifth lumbar which affects the great 
sciatic nerve. 

The aortic plexus possibly receives some impulses from the spinal 
cord over filaments that pass through the fifth lumbar foramen. This 
plexus supplies the blood-vessels in relation and the lower bowel, thus 
disorders of the lower bowel may complicate a lesion of the fifth lumbar. 
The iliac arteries are supplied by branches extending from the aortic 
plexus along these arteries, hence the amount of blood in the lower 
limbs is determined to some extent by the size of these arteries, that is, 
the condition of the nerves supplying them. From the iliac plexus is 
derived the femoral plexus and from this the popliteal; the impulses 
originally coming from the lumbar spinal cord. 

The hypogastric plexus also receives impulses from the fifth lumbar 
segment by way of nerve filaments which pass out through the fifth 



294 APPLIED ANATOMY. 

lumbar foramen. These filaments are more or less affected by a lesion 
of the fifth lumbar, hence the function of this plexus of nerves would 
be disturbed. This plexus supplies the internal generative organs and 
the lower bowel. From a clinical point of view, the parts most fre- 
quently affected are the rectum, vesicle seminales, uterus, prostate, 
bladder, ureter and urethra. The diseases associated with a lesion of 
the fifth lumbar and resulting from a disturbance of the hypogastric 
plexus by the lesion are (1) rectal disorders such as prolapsus, eversion, 
ulcers, tenesmus, hemorrhoids, pruritus anior itching piles; (2) disorders 
of the vesicle sesminales and its adjacent structures, such as nocturnal 
emission, premature emission, imperfect emission, spermatorrhea; (3) 
uterine disorders, principally inflammatory conditions and relaxation, 
dysmenorrhea and reflex backache; (4) prostatic enlargement and weak- 
ness, such as prostatorrhea; (5) disorders of the bladder, such as frequent, 
painful and imperfect micturition, and cystitis with tenesmus and calculi; 
and (fi) pain in ureter and urethra, or congestion and inflammation with 
change in size. Each of the above groups, receives its nerve impulses 
almost entirely from the hypogastric via the pelvic plexuses. The le- 
sion of the fifth lumbar articulation affects the nerve filaments in rela- 
tion which represent some of the nerves forming the above named plex- 
uses. Even though these filaments be entirely destroyed, the other 
filaments helping to form these plexuses will, in part at least, take on 
the function of the disabled nerves but in most cases there is some effect 
on the structures supplied by these plexuses. The effects vary since the 
degree of disturbance, and the nerve filaments vary in cases in which 
the lesions are apparently the same. 

The recurrent meningeal nerve and the twigs to the vertebra and 
ligaments are affected in a way similar to that from a lesion of the other 
vertebral articulations. 

The fifth lumbar vertebra is a weak point in the spinal column and 
is the seat of reflex pains depending on disorders of the lower bowel and 
especially of the generative organs. In many cases the spinal column is 
turned or twisted on the pelvis or vice versa. In the first case there is 
no change in the relative position of the vertebra while in the second 
case, the other pelvic articulations are intact. The lesion is then en- 
tirely confined to the lumbo-sacral articulation. To differentiate 
between such conditions and a subluxation of the fifth lumbar vertebra, 
consider the articulations of the fourth and fifth lumbar vertebra? at 








Fig. 73. — Showing effects from a straight lumbar region. The dotted line in- 
dicates position of bodies in extension. In such a position, the intervertebral for- 
amina are lessened in size. 



296 APPLIED ANATOMY. 

which joints there will be changes such as irregularity, thickening with 
congestion and tenderness if there is a lesion of the fifth. 

Tenderness at the spine of the fifth lumbar vertebra, is not diag- 
nostic of a lesion of its articulation. In many cases the tenderness is 
due to visceral disease that causes a reflex congestion of the posterior 
division of the fifth lumbar nerve. It is not a true referred pain but 
one due to local changes in the circulation of the blood through the 
nerve affected. Pressure increases the amount of pain since it increases 
the blood-pressure in the nerve. The fifth lumbar vertebra is especially 
affected renexly and on this account, pain on pressure over the spine 
of the fifth, is not diagnostic of a lesion of the articulation. Of course 
in many cases the pain on pressure is due directly to a lesion of the 
vertebral articulations in relation. 

The sacEO-iliac articulation is classed by some anatomists, as a prac- 
tically immovable joint, that is as belonging to the amphiarthrodial 
joints, while it is described by others as having enough movement to be 
classed with the diarthrodial joints. This depends on the age of the 
patient as well as the condition of patient and joint. In a young person 
there is considerable movement at the' articulation, while in the old there 
is very little, if any. In the cadaver, the articulation is practically im- 
movable on account of the post mortem changes, on which account the 
various writers on the subject have determined that the joint is not sub- 
ject to dislocation and that there was practically no movement in it. 
There is a great deal of difference in the degree of mobility in a cadaver 
and a living body, which difference can be demonstrated very readily. 
This applies especially to the vertebral and sacro-iliac articulations. 

The articular surfaces forming the sacro-iliac articulation are auricu- 
lar-shaped, rough, irregular and covered by a thin layer of l^aline articular 
cartilage. They are about one and three-quarter inches in length and 
about one inch in breadth at the widest or upper part. The articular 
surface of the sacrum is concave and faces upward and backward 
when the patient is in the erect posture. The writer has found that in 
young subjects the surfaces are smooth and glistening, indicating a syno- 
vial membrane and sac and mobility. In old subjects the surfaces are 
often adhered and as Cunningham states "the joint cavity, which is 
little more than a capillary interval, may be crossed by fibrous bands." 

The joint is supported and strengthened on all sides by ligaments 
which have been arbitrarily divided into the anterior and posterior, 



APPLIED ANATOMY. 



297 



superior and inferior sacro-iliac, and the interosseus. The anterior and 
superior are short and comparatively thin; the posterior are larger and 
stronger. The fibers are almost transverse and arranged in ridges be- 
tween which are foramina, for the transmission of the posterior sacral 
nerves. The interosseus is the strongest of all these ligaments. The 
fibers are of unequal length and pass in different directions, thus pro- 

INTEG-.OVER 6l\UTEAL REGION BACK OF SACRUM 
5th.L7 




SKIN OFSCROTUM AND 
ROOT or PENIS OR 
LABIUM MJ.ANO CLITORIS 



EXT. SAPHENOUS TO 
OUTER SI DEOF FOOT 

CUTA'S TO-OU1ER SIDE LEG 

TOTOES 

ANT. TIBIAL 



EXT. POPLITEALOR PERONEAL 
INT.POPLITEALTOPOPLITEALANOPLANTARIS 



Fig. 74. — The first sacral segment of the spinal cord, with its nerves and their 
distribution. 



298 APPLIED ANATOMY. 

during a crossing or interlacement which strengthens the joint. The 
lumbo-sacral and ilio-lumbar, indirectly support and strengthen this 
joint since they help to support and steady the sacrum. 

The great sacro-sciatic ligament extends from the posterior crest 
of the ilium and posterior iliac spines downward and backward to the 
sacrum (the lower three segments) and upper part of the coccyx, while 
a part of the fibers reach the ischium. The sacrum is, to a great extent, 
supported by these ligaments. The sacrum is not the keystone of the 
pelvic arch but is shaped in just the opposite way, that is the widest 
part is anterior and inferior. The sacro-sciatic ligaments counteract 
the downward tendency of the upper part of the sacrum from the super- 
imposed weight of the body. They are important in determining the 
character of the innominate lesion. A great many of the lower fibers 
pass on into the tendon of the biceps muscle "so that traction on this 
muscle braces up the whole ligament, and the coccyx is thus made to 
move on the sacrum. " (Morris). 

The movement at this articulation is slight. In the young it is 
quite well marked, also during pregnancy, but in the old, it is slight and 
quite commonly, is entirely lost. From clinical indications in cases 
treated by the writer, from examination of pregnant cases and from 
dissections made there remains no doubt in my mind but that the sacro- 
iliac joint is a diarthrodial articulation. 

*"The large amount of clinical and anatomical study, which has 
been carried on in connection with this subject during the past two 
years makes it quite plain that the pelvic articulations, especially the 
sacro-iliac synchondroses, are by no means as stable as has been sup- 
posed, and that in man and woman under normal conditions, definite 
motion exists. It is also shown that the articulations are true joints 
having all of the common joint structures, and that this being the case, 
they are naturally subject to the same diseases and injuries as the other 
joints. When this is once appreciated the character of the articula- 
tions is considered, and especially when it is remembered that the ex- 
act apposition of these bones is maintained almost entirely by the lig- 
aments, the surprising thing is, not that abnormal mobility, and disease 
of the joints ever do occur, but that they do not occur more frequently." 
Its nerve supply is derived from the sacral plexus, first and second sacral 
nerves, posterior divisions, and the superior gluteal nerve. 

*Goldthwait, Boston Med. and Surg. Journal, Vol. CLII, No. 21, p. 594. 



Al'PLIED ANATOMY. 



299 



The structures in relation with this articulation and which would 
be affected by a subluxation of it are (1) ligaments uniting the two 
bones, sacrum and ilium; (2) nerves, the branches going from the sacral 
plexus and the anterior sacral nerves; (3) and some blood-vessels, mostly 
branches of the ilio-Iumbar vessels. The periosteum will be affected 
by a lesion at this joint, also what connective tissue there may be in 



EXT.BR/^ INTEG. BACK OF SACRUM 
■BRANl |sl? 




PLANTAR 

CUTA"S TO OUTER SIDE OF FOOT 



TO 
BICEPS 
SHT.HEAD 

ADD V MAGNUS 

GREAT SCIATIC 

INT.AMD EXT POPLITEAL 



Fig. 75. — The second sacral segment of the spinal cord, with its nerves and their 
distribution. 



300 



APPLIED ANATOMY. 



relation, which binds the roots of the sacral nerves quite firmly to the 
articulation and adjacent bones. 



MULTIFIOUS SPINS. /INTEG. BACK OF SACRUM 




COMM'GBRA. CUTAN.TO 
1St.ft2d.T0ES 

INT AND EXT. PLANTAR 



CUTAN.T0 

OUTER 5I0E0F FOOT 



TO ADD MAGNUS 
GREAT SCIATIC 



INT AND EXT POPLITEAL 



Fig- 76. — The third sacral segment of the spinal cord, with its nerves and their 
distribution. 



APPLIED ANATOMY. 



301 



THE INNOMINATE. 

The innominate, the bone which, according to the ancients, bore no 
resemblance to any known thing, is irregularly shaped and with its fellow 
of the opposite side, forms the lateral walls of the pelvis. In early life, 
it is composed of three parts, the ilium, pubis and ischium, which unite 
to form one solid bone. 











tf^F Jam 






■ 


Wr 1 -'- 












*■( 





Fig. 77. — The sacroiliac articulation, with bones in place. (Goldthwait) . 




Fig. 78. — Sacro-iliac articulations with the sacrum slightly tilted showing the 
separation of the iliac at the pubis as well as at the back. (Goldthwait). 



302 



APPLIED ANATOMY. 



The ilium is the upper part which helps to form the false pelvic 
cavity. It flares considerably, the degree of which determines the size 
of this cavity. It has anterior and posterior spines, which points are 
regarded as landmarks for the location of viscera and for the diagnosis 
of changes in the position of the trochanter, sacrum, spinal column and 
the relation of one innominate to the other. It has a crest, along which 

FORAMEN tor ANT. PRIM.BRA. OF FOURTH LUMBAR 

ILIO-LUMBAR LIGAMENT 

, FORAMEN FOR LASTLUMBAR N. 

SACRO LUMBAR 
LIGT. 




SUP. SACRO 
ILIAC LIGT 

jBjjr^ANT. SACRO- 
ILIAC LIGT. 



GRT. SACR0- 
SCIATIC LIGT. 

LESSER SACR0- 
SCIATIC LIGT. 



Fig. 79. — Anterior view of the posterior wall of the pelvis showing the ligaments 
connecting the sacrum, innominate and lumbar vertebrse. 



pain is often complained of in pelvic disease. The direction of the crest 
is changed in subluxations of the bone and it should be examined in all 
suspected cases. 



APPLIED ANATOMY. 303 

The ilium gives attachment to many muscles which, on account 
of the peculiar shape and size of the bone, are widely and firmly attached. 
In all pelvic examinations, the two ilia should be compared as to height, 
direction, degree of flare, spines, tenderness and condition of muscles 
attached. 

The ischium is of importance in that in subluxations of the innom- 
inate its position, is altered and the structures attached to it usually 
tightened. Falls on the tuberosities of the ischia often produce a sub- 
luxation at the sacro-iliac articulation. The tuberosities are made 
the fixed point in the reduction of many subluxations of the in- 
nominate, which is accomplished by firmly holding them against an 
unyielding surface while the body is bent in various ways. The ischia 
often retard the progress of the fetal head in parturition and in elderly 
primiparee, labor is often delayed on account of it. The landmarks ol 
the ischium are the tuberosity, spine and ramus. The tuberosity is 
that part which supports the body while in the sitting posture. It gives 
attachment to the hamstring muscles, adductor magnus, gemellus in- 
ferior and quadratus femoris. The spine gives origin to the levator 
ani, gemellus superior and coccygeus. The pudic vessels and nerve are 
in relation with this spine and are often affected by falls or by faulty pos- 
in sitting. The ischium helps to form the acetabulum. 

The pubes consist of a body and rami. They are of importance in 
that they form the anterior boundary of the pelvis, give origin to im- 
portant structures, are subject to slight separation during parturition, 
and their articulation, the symphysis pubis, is always affected in sub- 
luxations of the innominate. In rachitis, the pubic arch is generally 
flattened or distinctly angular. The principal landmarks are the rami 
and ilio-pectineal eminence. 

The innominate articulates with its fellow, the hip and the sacrum, 
and in all subluxations of it, all these articulations are more or less affected. 

The sacrum is a composite bone formed by the union of the five 
sacral vertebrae. It is a large, curved, triangular or wedge-shaped bone 
forming the posterior boundary of the true pelvic cavity. When the 
patient is in the erect posture, it is at quite an angle, the upper part 
receiving the weight of the body which is then passed through the long 
axis of the sacrum but at an angle with the body. On this account in 
cases of rachitis, the bone is likely to bend under the superimposed weight 
of the body and a deformity occurs. In other cases, the bone may turn 



304 



APPLIED ANATOMY. 



instead of bend, and a lesion at the sacro-iliac articulation is the result. 
It articulates above with the fifth lumbar, on both sides with the innom- 
inata, and below with the coccyx. The superior articular facets are sim- 
ilar to those of the lumbar vertebrae except that they are larger, more 
concave and considerably wider apart. This articulation has been con- 
sidered in the discussion of the fifth lumbar vertebra. 




COCCYX 



Fig. 80. — Showing the right side of the sacrum. Note the articular surfaces. 



The sacro-coccygeal articulation will be treated of under considera- 
tion of the coccyx. 

The posterior surface of the sacrum is convex, and quite rough on 
account of the spines of the coalesced sacral vertebra? and the ridges, 
the remains of the laminse. The posterior divisions of the sacral nerves 
emerge through foramina on this surface. On this account, these nerves 



APPLIED ANATOMY. 305 

can be reached quite directly and advantage is taken of this in cases in 
which a quick result is wanted; that is, palliative effects can be obtained 
by stimulation or inhibition of these nerves. As a rule irritation of the 
anterior divisions of these nerves, will produce some effect on the post- 
erior divisions, that is metritis is characterized by tenderness over the 
posterior surface of the sacrum, especially at the sacral foramina. The 
degree of convexity of this surface varies in different subjects. It is 
usually lessened in posterior conditions of the lumbar region and in- 
creased in anterior conditions. If the fifth lumbar vertebra becomes 
anterior it, in the average case, carries with it the upper part of the sacrum. 
If the upper part of the sacrum is anterior, a "hump" will be formed 
at the sacro-coccygeal articulation; in other words, the angle formed by 
the two bones becomes more acute. This surface gives origin to the 
multifidus and erector spinae muscles, and the gluteus maximus. 

The anterior surface is smooth and markedly concave. It is pierced 
by the sacral foramina for the transmission of the anterior sacral nerves 
which, after emerging, pass almost directly outward in grooves. There 
are indistinct ridges resulting from the union of the bodies of the ver- 
tebrae. This surface gives origin to the pyriformis and a part of the 
coccygeus muscles. In tumors or other enlargements of the pelvic vis- 
cera, these sacral nerves are subject to pressure which, in the average 
case, becomes quite painful. The degree of concavity differs in the 
male from that in the female and at different ages in the same subject. 
In the male, the sacrum is narrow, considerably more curved and not 
directed so obliquely backward as in the female. 

The lesions of the sacro-iliac articulation will be considered from 
two points of view: (1) those resulting from subluxations of the innom- 
inate bone; and (2) those from subluxations of the sacrum. 

The innominata are subject to partial displacements, in fact an in- 
nominate lesion is one of the most common of all bony lesions. The 
reason for it is (1), the large size of the bone and the small size of the 
articulation, which increase the lever power; (2), the many and power- 
ful muscles attached to it, which when brought into use, increase the 
lever power mentioned above; (3), the exposed position of the bone, it 
bearing the brunt of lifting and other muscular exertions and (4) trans- 
mitting at an angle the pressure exerted from below, as in jumping, or 
that from above, as in the cariying of a weight. 

The bone is most commonly rotated backward and upward on ac- 



306 



APPLIED ANATOMY. 




Sphincter ani 



Fig. 81. — A coronal section of the pelvis through the iliac crests,the acetabula, 
and the tuberosities of the ischium, showing the posterior part of the pelvis and the 
levator ani muscles and rectum in vertical section. (Kelly). 



APPLIED ANATOMY. 307 

count of the shape of the sacro-iliac articulation and since the force is 
directed most frequently and with greatest intensity, from below upward 
at a point anterior to the sacro-iliac synchondrosis, i. e., the acetabulum. 
The bone may be dislocated directly up, down or any other way; there 
may be a separation, but usually there is a combination of two or more, 
in the average case; that is, instead of being displaced directly upward 
it is at the same time rotated backward, or there is some other combina- 
tion. Many subluxations of this bone come from falls, muscular exer- 
tion or other conditions that exert a marked strain on the articulation. 
Parturition is an important cause. Straining while in a stooping pos- 
ture is another important one. 
^S^ The diagnosis is based on irregularity at the articulation, tenderness 
and disturbance of function of the structures attached to and in rela- 
tion with it. For example, if one of the posterior spines is more or less 
prominent than its fellow, or if there is a tenderness at the joint often 
accompanied by small tumefactions, or if there are pressure symptoms in 
some of the nerves in relation, such as the roots of the sciatic nerve, the 
chances are that the bone is subluxated. If there is a combination of 
two or more of these indications, the diagnosis need not be doubtful. 
As to the particular form of subluxation the height of the crest, spines 
and other landmarks must be compared with the sound side, as also 
must the prominence or other changes be compared. The length of the 
limb is indicative but not diagnostic; for example, if the limb is slightly 
shorter on the affected than on the sound side, it indicates an upward and 
forward displacement but is not diagnostic of it. In making the dif- 
ferential diagnosis, rely on palpation and inspection rather than on symp- 
toms, noting prominences, depressions, or in short the many slight 
•changes in contour. 

In order that this be done to the best advantage, the examination 
should be made in several different postures, i. e., the erect, sitting and 
dorsal and ventral. By so doing it will be easier to differentiate be- 
tween the changes produced by a slight shortening of one limb, a slight 
lateral curvature, a torsion of the spinal column on the pelvis and sub- 
luxations of the innominate. Of all these postures, the ventral is the 
best, since in this the relation between the spine and the pelvis can the 
better be ascertained. 

k The effects of a lesion of the innominate are many and varied. 
■Considerable force is usually exerted in the production of all lesions of 







/ 



308 APPLIED ANATOMY. 

this joint. This is because of the shape, size and character of the artic- 
ulation. The joint itself is injured to a greater extent than the joints 
in vertebral lesions. The articular cartilage is often torn and sometimes 
the synovial sac is broken, or at least impaired, as is indicated by the 
swelling and formation of lumps over the articulation. The sacro-iliac 
ligaments are stretched, or even partly torn in most instances, the effect 
is that of any sprain on the ligaments in relation. They become tender 
and thickened and their function is often considerably perverted. In 
chronic cases, the ligaments become shortened, and approximation with 
lessened mobility, as in the vertebral articulation, is the result. 

The "blood-vessels in relation with this articulation are the ilio- 
lumbar, lateral sacral and gluteal. The ilio-lumbar is nutrient to the 
ilium and furnishes a spinal branch, which passes upward into the spinal 
canal carrying nutrition to the lowest part of the spinal cord or cauda 
equina. The lateral sacral has to do with supplying the spinal mem- 
branes. The gluteal, supplies the muscles in the pelvic cavity also the 
pelvic bones, the gluteus maximus, the hip-joint, and the muscles con- 
tiguous to the hip-j.oint. These vessels are more or less' affected because 
they send branches to the articulation and are, in a part of their course, 
in relation with this joint. The effects of a disturbance of them can be 
determined by referring to their functions outlined above, the principal 
effect being that on the hip-joint and pelvic bones. Malnutrition of 
these parts may follow the lesion. This condition leads to hip-joint dis- 
ease, dislocation of the hip and imperfect development of parts if the 
lesion occurs before the parts are completely developed. 

The veins correspond to the arteries and would be affected by the 
lesion in a way similar to the arteries. The effects would be manifest 
in the muscles around the hip-joint, those inside the pelvis, and the hip- 
joint and pelvic bones. 

The nerves more or less affected by a lesion of this joint because of 
their relation and juxtaposition, are the pudie, small sciatic, muscular, 
visceral or nervi erigentes, and the great sciatic. The nerve impulses 
passing over the above named nerves come from the spinal cord, sacral 
segments, by way of the anterior nerve roots. Each of the above men- 
tioned nerves with its branches, is represented in these nerVe roots by 
filaments. These nerve roots, especially the lumbo-sacral cord, the 
first, second and third sacral, pass across and are quite firmly bound 
down to the anterior surface of the sacro-iliac articulation, and thus would 



APPLIED ANATOMY. 



309 



be affected by the slightest deviation of either of the bones forming this 
joint. On account of the great number of nerve filaments and the varia- 
tions in degree of the lesion, the effects are not the same for lesions that 
appear to be identical in different subjects. In one case there may be 
pressure on, or irritation of, the filaments which carry impulses to the 
uterus, while in another case apparently identical in character, the pres- 

PERINEAL BRATO SPHINCTER 
AND LEVATOR ANI 

COCCYGEUS 

TO FOLDOF NATES 

To OBT INT 




To SCROTUM OR LABIUM MAJUS 



INF. HEMORRHOIDAL 
TO SPHINCTER EXT. 
AND SKIN AROUNDTHE ANUS 
COMMUNICATING 

DORSAL OF PENIS TO 
CONSTRICTOR URETHRAL 
CORPUS CAVERNOSUM 
SKINOVER G.G.ANO GLANS 
COMMU.WITH SYMPATHETIC 
(IN FEMALE TO CLITORIS) 



Fig. 82. — The fourth sacral segment of the spinal cord, with its nerves and their 
distribution. 



sure or irritation caused by the subluxation may affect the nerve fila- 
ments controlling the second phalanx of the foot. 

The thickening of the ligaments in relation with the articulation 



310 



APPLIED ANATOMY. 



in consequence of the arthritis that often follows the injury to the joint, 
is responsible for many of the effects on the adjacent structures. Unless 
the subluxation is the result of a relaxation, this thickening will be pres- 
ent in practically all cases. In the worst cases an osteitis develops and 
this like the arthritis, leads to disturbances of the tissues in relation. 
Goldthwait points out that in some forms of arthritis the inflammation 
may extend to the neighboring parts. "It is in this hypertrophic form 
that the joints at times become entirely fused and that the persistent 
sciatica or leg pains are so commonly seen. These referred pains are 




Fig. S3. — The bon} r pelvis 'with its ligaments attached. Drawn from a dis- 
section. 



undoubtedly due to the pressure of the hypertrophic tissue upon the 
lumbo-sacral cord as it passes over the articulation. " 

These nerve roots also carry impulses for the innervation of the 
sacro-iliac articulation, thus furnishing an additional reason for the asser- 
tion that a lesion of the innominate will affect the sacral plexus. 

The pudic nerve is often affected by a lesion of the innominate be- 
cause the roots forming it are in relation with this articulation. This 
nerve is motor and sensory to the perineum and the external genitalia, 
and is the nerve of voluptuous sensation. It divides into the inferior 
hemorrhoidal and perineal branches and terminates in the dorsal nerve 



APPLIED ANATOMY. 311 

of the penis. The inferior hemorrhoidal is motor to the external sphincter 
muscle and sensory to the integument around the anus. The sphincter 
ani externus, is a voluntary muscle surrounding the anus and attached 
to the tendinous center of the perineum and the tip of the coccyx. Its 
function is to maintain closure of the anus and to retain the contents 
of the lower bowel, especially in muscular efforts in which the intra- 
abdominal pressure is markedly increased. In vomiting, coughing and 
difficult micturition, or any muscular exertion, the intra-abdominal 
and intra-pelvic pressure is increased to a great extent and the tendency 
is, to cause expulsion of the contents of the bowel. Exercise is almost 
absolutely necessary for the normal activity of the bowels since the 
contents are forced lower by it. Lack of exercise is a prolific cause of 
constipation. The lesion may stimulate the nerve to the external sphinc- 
ter muscle, hence the resistance offered to the expulsion of the feces 
would be increased in proportion to the degree of contraction. Con- 
stipation from obstruction is the result. In such cases the fecal con- 
tents are normal as to shape and consistency, but the stool is small and 
is expelled only after great straining. To cure such cases, correct the 
lesion, that is, remove the irritation. The muscular condition is the 
effect. To relieve, dilate the rectum thus overcoming or removing tem- 
porarily, the resistance offered by it. If the lesion inhibits this nerve, the 
sphincter muscle relaxes and its function is impaired, it failing to firmly 
close the anus. This muscle being voluntary, certain psychic effects 
may be obtained by an effort on the part of the patient. 

The inferior hemorrhoidal nerve is also sensory to the integument 
around the anus. The most common effect of the lesion on this nerve, 
is pruritus ani or itching piles. The disturbance is along the nerve trunk, 
the effect at the periphery. There may be anesthesia, numbness or dis- 
tinct pain in this area; it depending on the condition of the nerve and 
the kind of lesion. 

The perineal branch of the pudic is sensory to the integument of 
the perineum and a part of the external genitalia, and motor to the mus- 
cles of the pelvic floor. If the lesion is irritative there will be pain re- 
ferred to the perineal body, the integument of the scrotum, or the labium 
majus in the female; if paralytic, numbness or complete loss of sensa- 
tion in these parts will follow. The perineal branch of the pudic sup- 
plies the levator ani muscle. The function of this muscle in conjunc- 
tion with its fellow of the opposite side, is to close a greater part of the outlet 



312 



APPLIED ANATOMY. 






I 7 




Fig. 84. — Showing the mutual relations of the pelvic viscera as seen upon open- 
ing the abdomen through the superior strait. (Kelly). 



APPLIED ANATOMY. 313 

of the pelvic cavity, support the pelvic contents and, by its contracture, 
quite securely close the openings in the pelvic floor. By its contrac- 
tion, the perineal body is drawn upward and forward, and in the female, 
the posterior vaginal wall is drawn against the anterior, thus lessening 
the size of the vaginal canal. Morris says: "It is possible that it ex- 
ercises some influence upon the circulation in the prostatic plexus and 
in the large pelvic veins which occupy the recess between the muscle 
and the viscera, and may also assist in the expulsion of the prostatic 
secretion by direct lateral compression of the organ." If the lesion in- 
hibits this nerve, the muscle relaxes ; the above .named function would be 
partly or completely suspended; the openings in the pelvic floor become 
patulous and the floor sinks and remains in a position of descent, every 
pelvic structure resting on it sinks to a lower level, hence cystocele, rec- 
tocele and prolapsus uteri are the results; the veins dilate, resulting in 
malnutrition and varicosities. An innominate lesion produces such 
effects by breaking or otherwise interfering with the nerve connection 
existing between this muscle and the spinal cord. If the lesion irri- 
tates the nerve, the muscle will be in a state of constant contraction, and 
constipation and vaginismus are the most common results. 

The lesion may inhibit the nerves supplying the other perineal mus- 
cles, the compressor urethra and erector penis, causing imperfect erec- 
tion. If the lesion is irritative, priapism and satyriasis may develop, but 
ordinarily these diseases come from spinal cord affections. The perineal 
branch of the pudic also supplies a part of the urethra, the bulbous 
portion. 

The dorsal nerve of the penis, the terminal branch, supplies the corpus 
cavernosum, the skin of the dorsum of the penis, the prepuce and the 
glans. The dorsal nerve of the clitoris of the female is distributed in a 
similar way. This nerve is principally sensory and perhaps has a pecu- 
liar and distinct function. It supplies one muscle, the constrictor urinse. 
If the lesion affecting this part of the pudic nerve is paralytic in its ac- 
tion, there would follow lack of orgasm, numbness or anesthesia of the 
parts innervated and relaxation of the muscle supplied. Lack of orgasm 
in both male and female is not an uncommon condition and is due to 
disturbance of function, that is suspension of function of this nerve. 
Loss of sexual desire is another sequel of such a lesion. Impotency is 
also common. If the lesion is irritative, the opposite effects would re- 
sult, viz., priapism, premature ejaculation and orgasm, excessive or 



314 



APPLIED ANATOMY. 



unnatural sexual desires, or painful conditions of the glans penis and 
prepuce. Other disorders of the glans and prepuce may complicate 
the innominate lesion. A case of paraphimosis in a baby was reported 
to me as cured by correcting a slight subluxation of one innominate. 
The pudic nerve was undoubtedly affected by the lesion with the rather 
unusual effect, paraphimosis. The pudic nerve may be affected by other 
lesions or disturbed by pressure from faulty posture in sitting, being com- 
pressed between the tissues and the spine of the ischium around which 
it turns. This nerve has to do mostly with the sexual function but 
also supplies the muscles of the pelvic floor. If it is stimulated by a le- 







U 03 P<T""> 



UDIC 
PERFORATINO 



Fig. 85. — The fifth sacral segment of the spinal cord, with its nerves and their 
distribution. 



sion or otherwise, the muscles contract and the activity of the sexual 
apparatus is increased. This is well illustrated in cases of masturba- 
tion in the early stages. If the nerve is inhibited, whether from a lesion 
or by abuse, the muscles of the floor relax and the sexual sense is dulled 
or entirely lost. The condition of the pelvic floor is a pretty sure indi- 
cation of the condition of the sexual organs. This can be better dem- 
onstrated in the female than in the male. A relaxed and patulous 
vagina is almost diagnostic of loss, partial or complete, of the sexual 
function, that is orgasm is partly or completely gone. The opposite 
condition is almost diagnostic of a normal functioning of the part. 

The small sciatic nerve is almost if not entirely sensory in function. 



APPLIED ANATOMY. 315 

It arises from the first, second and third sacral segments, passes out in 
relation with the lower border of the pyriformis muscle and descends in 
relation with the great sciatic nerve and the gluteus maximus. It 
gives rise to three principal branches, the gluteal cutaneous, femoral 
cutaneous and the long pudendal. If the lesion affecting the filaments 
of the gluteal branch is irritative, there will be superficial pain over the 
lower and outer part of the gluteal region; if inhibitive, there will be 
numbness or perverted sensation in this area. 

The femoral cutaneous filaments supply the integument over the 
back and inner side of the thigh. The inferior pudendal is distributed 
"to the skin of the upper and inner part of the thigh, and is continued 
forward to the outer part of the scrotum (or external labium pudendi), 
where its terminal filaments are distributed, after forming communcia- 
tions with the external superficial perineal branch of the pudic nerve." 
(Quain). An irritative lesion of the innominate will cause pain or per- 
verted sensation in the above named parts. Pruritus vulvae is an ex- 
ample. Nymphomania and masturbation or excessive venery, often 
result from such a lesion on account of the effect on the labia. Lack of 
sensation would follow a paralytic lesion. 

The small sciatic, extends down the limb and becomes subcutaneous 
a little below the knee. It supplies the integument over the calf of the 
leg. On account of its origin, the sacral segments, its communications 
with the pudic nerve and its branch, the long pudendal, diseases of the 
genitalia often produce cramping or pain in the calf of the leg. This 
may be due to a disturbance of the great, as well as the small sciatic 
nerve. On account of its cutaneous distribution over the gluteal and 
femoral regions and its connection with the pudic, and the fact that it 
also supplies the pudendum, stimulation of the gluteal region excites the 
sexual passion. In sexual perverts, this sort of stimulation is resorted 
to in order to arouse the sexual passion. Some writers have pointed 
out that the frequent spanking of a child often leads to sexual irritation 
or disorder. Perhaps this is true in exceptional cases since it is ana- 
tomically possible, on account of the distribution of the small sciatic and 
and pudic nerves. 

There is a perforating cutaneous nerve, which receives its name 
from the fact that it penetrates the great sacro-sciatic ligament, and 
becoming cutaneous, supplies a part of the integument over the gluteus 
maximus muscle.. 




Fig. 86. — A sagittal section of the pelvis, showing the rectum drawn away from 
the sacrum in order to demonstrate the arteries, veins, and nerves of the sacral and 
lateral pelvic regions. (Kelly)- 



APPLIED ANATOMY. 317 

The nerve to the quadratus femoris muscle, is represented by fila- 
ments in the anterior roots of the sacral nerves, and would be more or 
less disturbed by a lesion of the innominate. The function of this mus- 
cle is to externally rotate the femur. If the nerve were stimulated, the 
muscle would contract and external rotation would result so long as 
internal rotation of the femur would be difficult. 

The nerve to the obturator interims would also be affected by this 
lesion, the effect being very similar to that on the quadratus femoris. 

The superior and inferior gluteal nerves have been considered. The 
effect of an innominate lesion on them would be similar to that of a lesion 
of the fifth lumbar. 

Cunningham speaks of the visceral branches of the anterior sacral 
nerve roots as white rami communicantes. Another writer has spoken of 
them as the pelvic splanchnics of Gaskell. At any rate, branches are 
given off from the second, third and fourth sacral roots that pass into the 
inferior hypogastric or pelvic plexuses and eventually reach the pelvic 
organs. The function of these visceral branches is principally motor, 
but possibly in addition, vaso-motor, trophic, secretory and sensory im- 
pulses are transmitted by them unless they are very different in charac- 
ter from the average white rami. Some of these branches, called the 
middle hemorrhoidal, supply the rectum. If the lesion stimulates this 
nerve, the longitudinal fibers of the rectum contract, the lumen of the 
bowel is lessened and constipation from obstruction is the result. Quain, 
in speaking of the nerve supply of the rectum, says: "Experiments 
upon animals have shown that the longitudinal muscular fibers of the 
rectum are supplied with motor fibers from the anterior roots of certain 
of the sacral nerves (second, third and in part, the first in the dog) which 
nerves also supply inhibitory fibers to the circular coat, whereas the 
fibers of the hypogastric plexus which supply the circular muscular tissue 
with motor fibers, are derived from white rami communicantes of the 
anterior roots of certain of the lumbar nerves, which join the sympathetic 
chain and lose their medullary sheath before passing to their distribu- 
tion in the muscular coat. " Thus the effects of a lesion disturbing these 
nerves can be the better understood when their function is known. 

The second, third and fourth send fine medullated branches directly 
to the pelvic plexus and indirectly (possibly directly) through the plexus 
to the bladder. Quain says that they are the chief motor nerves to the 
bladder and are probably distributed to the longitudinal muscle fibers. 



318 APPLIED ANATOMY. 

An innominate lesion may thus affect the bladder from injury to these 
nerves. Any sort of motor disorder of the bladder may be the result. 
If the lesion is irritative, there will be frequent micturition and tenesmus; 
if the lesion inhibits the passing of the motor impulses designed for the 
bladder, there will be difficult and imperfect micturition or motor par- 
alysis of the bladder with dribbling of urine. 

The nervi erigentes comprise the principal visceral branches of the 
sacral nerves. These are named the pelvic nerve by Langley and Ander- 
son. The origin of the pelvic nerve varies in different animals but ordi- 
narily it is formed by the visceral branches of the second, third and 
fourth with the first usually contributing a few fibers. *"Stimulation of 
the pelvic nerve causes strong contraction of the bladder, but has no 
certain effect on the blood-vessels of the organ; it causes contraction 
varying in strength, of both coats of the descending colon and rectum, 
the effect being much more constant, and generally greater, in the rabbit 
than in the cat and dog; strong contraction of the recto-coccygeal mus- 
cle and of the other special muscles of the rectum; dilatation of the 
vessels of the mucous membrane of the end of the rectum, and of the 
external generative organs; inhibition of the proper unstriated muscle 
of the external generative organs, notably the retractor of the penis; 
inhibition in the rabbit of the internal anal sphincter, and of some un- 
striated muscle in the skin of the ano-genital region." 

The distribution and function of this nerve in the human, is proba- 
bly very similar to that in the above named animals and consequently, 
the effects obtained from stimulation of the one, will in a measure apply 
to the other. These nerves that go to form the pelvic nerve, are in rela- 
tion with a part of the sacro-iliac synchondrosis and will be more or less 
affected by a lesion at this articulation. The lesion will either stimulate 
or inhibit the passing of impulses over this nerve as a result of which 
there may be two effects from the lesion, that of lessened activity and 
that of increased activity. The function of this nerve, its relation to the 
synchondrosis and the effect of the lesion on it, explain many of the cases 
of disorders in which the bladder, bowel and genitalia are involved. 

Some of these visceral branches go across to the vagina, supplying 
it with motor impulses. The size of the vagina, unless its muscle fibers 
have been torn, is determined by the condition of the nerves supplying 
its muscle fibers, hence these branches help to control the lumen of the 

*Schsefer's Phys. Vol II, p. 667. 



APPLIED ANATOMY. 319 

-vagina. An irritative lesion will, if the irritation is marked, produce 
vaginismus, a sort of spasmodic contraction of the vaginal walls. Inhi- 
bition over the sacrum will often temporarily relieve this condition. 
The explanation is that the anterior branches corresponding numerically 
to the ones inhibited by the treatment, supply the vaginal walls and 
through the effect on the posterior division and effect on the correspond- 
ing segment, the irritation is overcome, or the transmission of the motor 
impulses is suspended or checked. The better explanation of the effect of 
the sacral treatment is that the lesion is corrected and thus is removed 
the cause of the irritation to the vaginal nerves. The opposite condition 
exists if the lesion inhibits, instead of stimulates these visceral branches. 

The motor filaments to the circular muscle fibers of the uterus come 
almost entirely from the visceral branches of the sacral nerves. The 
function of these circular fibers of the uterus is to oppose the contrac- 
tion or rhythm of the longitudinal fibers and to regulate the size of the 
outlet or os uteri. In normal cases, the longitudinal and circular fibers 
work together; that is, when the longitudinal fibers contract, the circu- 
lar fibers relax, as in menstruation and parturition. At other times the 
circular resist the action of the longitudinal. The condition of the cir- 
cular fibers is governed by the number and character of the motor nerve 
impulses reaching them. If they are stimulated, the size of the os is 
lessened and vice versa. In innominate lesions, these visceral branches 
supplying the uterus are more frequently affected in the female than 
any other of the visceral nerves. If the lesion stimulates the nerve, 
contraction of the cervix follows, producing dysmenorrhea and dystocia. 
If the lesion inhibits the nerves, the cervix and a great part of the body 
relax, the os uteri becomes patulous, the blood-vessels are engorged, the 
weight of the uterus increases, and its secretions are increased and per- 
verted. The size of the uterine blood-vessels is determined to a great 
extent by the degree of contraction of the uterine muscle fibers. Menor- 
rhagia sometimes results from a subluxated innominate because of ef- 
fect on the muscle fibers of the uterus which relax, the blood-vessels 
becoming larger, hence congested. Any motor disturbance of the 
uterus may follow an innominate lesion on account of its effect on the 
uterine muscle fibers. It has not been definitely determined as to 
whether or not these visceral uterine branches carry other than motor 
impulses, but I surmise that they, like the splanchnic nerves, do. 

The various uterine disorders resulting from innominate lesions could 



320 APPLIED ANATOMY. 

the more easily be explained if this assumption were definitely proven. 

Some of these nerve fibers supply the posterior uterine ligaments, 
especially the sacro-uterine, the function of which ligament is to sup- 
port, to a great extent, the uterus. The attachment of these ligaments 
furnishes a pivot around which the uterine movements take place. If 
this nerve is stimulated, the uterus will be drawn upward in ascent; if 
inhibited, the uterus retroverts and prolapses. In the treatment of 
such uterine displacements, the sacro-uterine ligaments must be strength- 
ened or a cure is not possible. To do this the lesion, often an innominate 
subluxation, must be reduced. 

According to Quain, the visceral branches of the anterior sacral 
nerves that innervate the prostate gland, are secretory in character. 
The gland has a secretion which has to do with thinning the seminal 
fluid. Prostatorrhea so often mistaken for spermatorrhea, is a result 
of an abnormal activity of this gland. If the lesion is irritative, secre- 
tion of the prostate will be increased; if paralytic, it is lessened. The 
prostate, in all probability, receives vaso-motor and motor impulses in 
part, from the sacral nerves. If this is true, a lesion of the innominate 
may produce motor and vascular disturbances of the gland. The ves- 
icle seminales and vas deferens also receive some impulses from the 
spinal cord by way of the pelvic plexus. 

An articular branch from the anterior sacral nerves passes to the 
hip-joint. Disturbances of the joint may be the effect of an innominate 
lesion on account of disturbance of this nerve filament. 

The great sciatic, is the principal nerve coming off from the sacral 
plexus, in fact it seems to be a continuation of the plexus. It is com- 
posed of two parts, the one portion going to form the external popliteal, 
the other, the internal popliteal. The former is derived from the anterior 
division of the fourth and fifth lumbar and first and second sacral nerves; 
the latter, from the anterior divisions of the fourth and fifth lumbar and 
the first, second and third sacral nerves. These parts unite to form a 
thick band which passes out of the pelvic cavity through the great sacro- 
sciatic foramen in relation with the pyriformis muscle. It then passes 
through the buttocks into 'the thigh in the hollow between the great 
trochanter and the tuberosity of the ischium. The upper part is covered 
by the gluteus maximus and is most superficial while in relation with 
the trochanter and tuber ischii. In the thigh, it lies on the adductor mag- 
nus muscle, and terminates at or near the popliteal space, where it divides 
into two branches, the internal and external popliteal. 



APPLTED ANATOMY. 321 

The internal popliteal continues as the posterior tibial, which in 
turn divides into the internal and external plantar. 

The external popliteal divides into the anterior tibial and musculo- 
cutaneous. This nerve is chiefly motor and sensory, although it has 
vaso-motor, secretory and trophic functions. It supplies motor im- 
pulses to some of the muscles on the posterior aspect of the thigh and 
practically all those below the knee. It supplies sensation to about the 
same areas; also supplies the various articulations of the lower limb. 
It is vaso-motor and trophic to the same areas and secretory to the 
sweat glands of the lower part of the thigh, leg and foot. 

This nerve is affected by an innominate lesion (1), because of the 
relation of its roots to the sacro-iliac articulation, and (2), because of 
contracture of certain muscles and tissues that are in relation with this 
nerve and would be affected by the lesion and (3), because of the vascu- 
lar changes in the nerve that are produced by the lesion. 

The lesion may stimulate or inhibit the nerve filaments or roots 
that go to form this nerve. Only a few of these filaments may be af- 
fected, or in marked innominate lesions, many may be disturbed. This 
accounts for the variable effects on this nerve and its branches, from a 
lesion affecting it. If the lesion is irritative, that is if it produces a 
stimulating effect on this nerve, all or only some of its functions will be 
disturbed, this depending on the degree and length of the stimulation. 

The motor effect varies in different cases, but cramping of the leg 
or foot is fairly common. "Morton's toe" is an example. Contracture 
of any of the leg muscles may result. If the nerve were inhibited 
by the lesion, there would be relaxation of some or all of the muscles sup- 
plied by it. Atrophy is present, and if the lesion is extensive, the relax- 
ation and weakness are so marked that the function of the limb is almost 
completely lost. 

The sensory effects of a lesion of the innominate disturbing the great 
sciatic nerve, are most common and pronounced. If the lesion is irritative, 
sciatica in some form is the usual effect. This disease is characterized 
by pain in and along the course of the nerve, which is more or less severe. 
Inflammation is usually pi-esent. The disorder follows soon after an 
injury to the innominate, sometimes as an ache, sometimes as an acute 
pain. Any movement of the hip increases the pain, which is so excru- 
ciating in some cases that the patient is scarcely able to endure it. The 
patient favors the affected side and in chronic cases, a scoliosis develops, 



322 APPLIED ANATOMY. 

called sciatic scoliosis, in which the concavity is directed toward the 
affected side. The pelvis is usually tilted, but this is the result of the 
subluxation as often as the result of posture. 

Sciatica is diagnosed by discovering tenderness of the sciatic nerve 
at the points at which it is most superficial. These points are (1), a 
point about midway between the great trochanter and the tuberosity 
of the ischium, and (2), the popliteal space, the first named being the 
more important of the two. The innominate lesion produces sciatica 
by directly irritating the roots that go to form the sciatic nerve, which 
roots cross and are bound down to the sacroiliac joint. In acute cases 
in which the pain is intense, the nerve roots are considerably injured. 
In the milder and more chronic forms the subluxation is not so marked, 
but the long continued irritation produces the chronic sciatica. The 
author recognizes other causes of sciatica, but the most common and 
important oae is the innominate lesion. 

This subluxation may disturb the function of the nerve by causing 
contracture of muscles in relation with the nerve, viz., the pyriformis and 
the hamstring muscles. Pressure is exerted directly on the nerve by 
contracture of these muscles, and if very marked or continued for any 
great length of time, the nerve becomes irritated, congested or inflamed 
and the condition is called sciatica. In all cases in which the disorder is 
well marked there is a perineuritis, while in ordinary simple cases there 
is only a congestion of the nerve and the tissues immediately surrounding 
it. 

Other sensory effects result from an innominate lesion, such as 
"neuralgia" of different parts of the leg and foot, cramping of the lower 
limb, numbness, itching and burning sensations usually in the bottom 
of the foot. This is called erythromelalgia or red neuralgia, of the feet. 
As stated in the discussion of the effect on this nerve of a lesion of the 
fifth lumbar, any sensory, motor or trophic, or even vaso T motor dis- 
turbance of the lower limb may be the result of an interference with the 
functioning of the great sciatic nerve. An innominate lesion is the 
most frequent and important of causes that affect this nerve. 

*" Referred pains are quite common, and are probably due to the 
pressure or pull upon the nerves in the sacral region. The lumbo- 
sacral cord passes directly over the upper part of the sacro-iliac articu- 
lation, and it is easy to see that a slight displacement or the thickening 

*Goldthwait, Loco citra. 



APPLIED ANATOMY. 



323 




Fig. 87. — Showing a twisted pelvis slightly exaggerated. (From photo). The 
waist line on the right was almost obliterated while that on the left was deepened. 



324 APPLIED ANATOMi". 

or nodes resulting from disease might cause pressure upon this nerve 
trunk. Undoubtedly the pressure or irritation of the nerve received in 
this way causes many of the pains referred to the leg. They may be 
referred to any part below the seat of the trouble, to the thigh, the hip, 
the calf, or down the back of the le"g following the sciatic distribution. 
That the nerves are pressed upon or irritated is not to be wondered at 
when the anatomy is considered. In fact, in any displacement that 
may occur, or in the hypertrophic arthritic thickening, the edge of the 
bone is so exposed that pressure or irritation of the nerve is almost to 
be expected. " 

Disturbances of the sciatic nerve may cause congestion of the lower 
limb, varicose veins, ulceration, caries, or any pathological vascular or 
trophic effect, since the function of the nerve is in part vaso-motor and 
trophic. Pathological sweating of the feet may also be a result of an 
innominate resion producing a disturbance of the great sciatic. 

Hilton, in speaking of the sacro-iliac joint, says that affections of it 
may be mistaken for hip-joint disease. He says, "it is impossible to look 
at the form of the sacrum — its wedge-shape, the broad or massive part of 
the wedge being above — or to regard the extent of the articular surfaces 
of these bones and the strong ligaments which fix them together, without 
percieving that great strength is a part of their natural function. If 
any disease should occur at the sacro-iliac joint (and I would add sub- 
luxation,) I think it will be apparent what the symptoms may be. 
If a patient should have disease there, he could not sit very comfort- 
ably even On the sound side, because then the whole weight of the body 
would be transferred through the medium of the spine to the sacrum, and 
thence produce pressure upon the articular structures of the joint, 
which would, if diseased, produce pain. Nor could the patient stand 
upright without great pain. " He further mentions the effect on the 
obturator, great sciatic and superior gluteal nerves and the psoas magnus 
muscle. A great many cases of supposed hip-joint disease are in real- 
ity a sacro-iliac subluxation. 

The obturator nerve, on account of its relation to the sacro-ihac 
joint, is sometimes affected by a lesion of the innominate. Pain in the 
hip, but especially on the inner side of the knee on the same side, is the 
most common effect. 

In innominate subluxations, everything attached to the bone is 
more or less affected, because in the production of the lesion the move- 



APPLIED ANATOMY. 



325 




Fig. 
photo.) 



1. — Lateral curvature of spine. Note effect on contour of hips. (From 



326 APPLIED ANATOMY. 

merit of the bone was carried beyond the normal range of movement. 
The muscles attached to the innominate are noted for their size and 
strength, which factor must be considered in the production of innom- 
inate lesions. The muscles affected most are in front, the rectus fem- 
oris and sartorius; on the side, the glutei and iliacus; and inferiorly, the 
hamstring muscles. If the bone is rotated back and up, the most com- 
mon form of lesion, the anterior muscles are put on a tension. This 
produces a stiffening of the limb followed by impaired movement, and 
in many cases, an interference with the return circulation from the lower 
limb. Varicose veins sometimes complicate such a displacement. If 
the- bone is displaced upward it will affect the iliacus. The muscle 
often becomes thickened, and on this account, leads to an error in diag- 
nosis in that it is mistaken for some form of tumefaction of the pelvis. 
This condition produces a pain or drawing sensation referred to the 
iliac fossa. The glutei muscles, when put on a tension, interfere with 
the position of the coccyx and the movement of the lower limb. In 
lesions in which the ischium is displaced upward or backward, the ham- 
string muscles are put on a tension. This produces (1), pressure, directly 
or indirectly, on the great sciatic nerve, and (2), interferes with extension 
of the leg and flexion of the thigh and both assume a state of partial 
flexion. In lesions in which the posterior spines and crest in relation 
are displaced backward or downward, the erector and multifidus spina? 
muscles are put on a strain which, when continued for a while, produces 
an ache in that region. In addition to the muscular effects the various 
ligaments are disturbed, not only those of the sacro-iliac joint, but the 
uterine ligaments, the broad and ovarian. All these tissues are affected 
by the lesion, the result of which is a thickening of the parts and a sense 
of pulling or drawing. 

The contour of the pelvis and hips is changed by the innominate 
lesion, one side or hip becoming larger and higher than the opposite 
one. This is more common and noticeable in the female than in the 
male. This unsymmetrical condition may in turn affect the spinal 
column and often a well defined scoliosis develops. 

The length of the lower limb is usually, although not necessarily, 
affected. In recent and typical cases, there is a slight shortening of 
the limb although the opposite condition may exist. 

The mobility of the hip-joint is lessened and the patient complains 
of a neuralgia or "rheumatism," as it is most frequently diagnosed by 



APPLIED ANATOMY. 327 

the layman. The limb may ache or become congested and edematous. 

The sensory disturbances come most frequently from the effect on 
the sciatic nerve. The congested condition, from obstruction at or 
below the saphenous opening; the edematous condition from obstruction 
to the lymphatic return. Many a case of pain along the thigh, varicose 
veins or congestion of the lower limb, or marked edema of the ankle, 
is due to a lesion of the innominate on the affected side. 

In all innominate lesions there is some change at the symphysis 
pubis. It may not be enough to be palpated but in many cases it is, 
and it is a good plan to examine, what Dr. Still has so often called the 
" cross bones," for tenderness and irregularity. 

In the correction or reduction of innominate lesions, the limb should 
be used as a lever and on this account care should be taken not to un- 
derestimate the amount of force it is possible to exert when using it as 
such. 

THE SACRUM. 

The sacrum, so-called by the ancients because it was regarded as 
the sacred part of an animal and was offered as a sacrifice, is a large 
curved triangular bone formed by the union of five separate vertebra?. 
It is joined to the innominate by the sacro-iliac articulation, hence dis- 
placements of this bone affect the joint and the adjacent structures in a 
way similar to that of an innominate lesion. The sacrum has a possible 
movement; that is, one of antero-posterior rotation around the sacro- 
iliac articulation as a pivot. This takes place to a certain extent during 
parturition. 

It is subject to displacement downward, forward, backward, or a 
combination of two or more of these; that is, rotation and torsion. It 
is placed at quite an angle with the spinal column, an angle of about 
50 degrees. In subluxations of the sacrum this angle is changed, there 
is tenderness at its articulations and possibly irregularity. Forward 
rotations of the sacrum are diagnosed by prominence of the lower part 
and the angle. If the upper part is rotated forward, the lower part is 
brought into prominence and the sacro-coccygeal articulation becomes 
more angular. If the upper part is rotated backward the angle is lessened, 
the upper part is prominent, the lower part is almost on a line with the 
upper part. Descent is diagnosed by height of the innominata as com- 
pared with the spines of the lower lumbar vertebrae. In making a diagnosis 






32S 



APPLIED ANATOMY. 



of a lesion of the sacrum consider (1), tenderness at the sacro-lumbar. 
sacro-iliac and sacro-coccygeal articulations, and (2), irregularity at 
one or all of these joints, height of innominata and angle or position of 
the sacrum. In addition to this consider the character of the symptoms, 
location of pain and history of injury to part. 

The lesions of the sacrum come from causes that ordinarily produce 
innominate lesions and in addition, lumbar disturbances such as curva- 
ture; falls in the standing posture, the superimposed weight of the body 




SPINOUS 
PROCESSES 



ERECTOR SPIN* 
MULTiriOUSSP/N* 



Fig. S9. — The posterior aspect of the sacrum, 
and the arrangement of the foramina. 



SACRAL CANAL 



Note the superior articular facets 



driving the sacrum downward; and direct injury or certain occupations 
that necessitate the patient's sitting bent over a desk or working in a 
stooped posture. 

The effects on the sacro-iliac joint are the same as those from an 
innominate lesion. The effects on the sacro-lumbar articulation are 
practically the same as those from a lesion of the fifth lumbar vertebra. 



APPLIED ANATOMY. 



329 



The sacro-coccygeal articulation will be affected and will be considered 
in the study of lesions of the coccyx and their effects. 
• The structures attached to the sacrum will be more or less affected 
by a lesion or partial displacement of it. The glutei and erector spinae 
muscles and the great sacro-iliac and sacro-sciatic ligaments are at- 
tached. Anteriorly the pyriformis is the principal muscle, and the 
sacro-uterine the most important ligament. If the sacrum becomes 
more nearly vertical, as is often the case, all these structures will be 



1LIACUS 



ipBlL '" :i 



SACRAL 
FORAMINA 




BROOVE FOR 5th SACRAL N 



Fig. 90. — Anterior view of the sacrum. 

changed. If the change of position of the sacrum is gradual, there will 
be 'few, if any, indications or disturbances other than a weakening of 
this part of the back. The change in the sacro-uterine ligaments usual- 
ly affects the uterus. The downward displacement of the sacrum or 
a forward rotation of its upper part, lessens the size of the inlet of the 
true pelvis, that is the true internal conjugate diameter of the inlet is 
lessened so that parturition is difficult on account of delayed engagement 



330 APPLIED ANATOMY. 

of the fetus. In rachitic subjects, the promontory is bent downward, 
often to such an extent that delivery is impossible without resorting to 
an operation. 

In subluxations of the sacrum, the contour of the spinal column is 
changed. The more nearly vertical the sacrum, the more posterior the 
lumbar spine and the more nearly straight the entire column. If the 
sacro-lumbar angle is lessened, the anterior curve of the lumbar region 
is increased. There may be muscular effects. If the lesion is irrita- 
tive on only one side, the contracture of muscles on that side will draw 
the spinal column to that side. 

The condition of the spinal column has a great deal to do with the 
position of the sacrum. A posterior lumbar spine will produce a straight 
sacrum. The way a great many people sit is responsible for sacral 
deviations. They sit on the sacrum instead of the tuber ischii, and the 
lumbar spine, is forced into a position of posterior curvature and the 
sacro-lumbar angle becomes almost a straight angle. This continued, 
will lead to a change in position of the sacrum, which is pathological. 

*"The lateral deformities or deviation of the body to one side, due 
to the displacement of the bones on one side and not on the other, are 
common. The onset may be sudden. The so-called "stitch" in the 
back following strain or overwork, is in most instances, due to the slip- 
ping of these bones, and in these cases the lesion represents a definite 
sprain, the severity of the symptoms depending on the severity of the 
injury as with sprains of other joints." 

A displacement of the sacrum will affect the sacro-coceygeal artic- 
ulation and produce symptoms and signs that are ordinarily attributed 
to a subluxated or dislocated coccyx. The sacro-coccygeal articulation 
is formed by the articular facets of the last sacral and first coccygeal 
vertebrae. The articular surface of the first coccygeal segment is oval 
shaped and faces forward and upward. From the upper part two cornua 
or projections pass upward and inward and are connected with the 
sacral cornua by the sacro-coccygeal ligaments. A foramen is formed 
by these through which the fifth sacral nerve passes. This articula- 
tion is a hinge joint, its movements being antero-posterior. These 
movements are pronounced in parturition and defecation. The con- 
traction of the levator and sphincter ani muscles causes it to be 
drawn forward; contraction of the gluteus maximus, drawing it back- 
ward and to one side. 

Goldthwait, Boston Med. and Surg. Journal, 1905. 



APPLIED ANATOMY. 331 

Lesions at this joint result from displacement of the sacrum or 
coccyx. Trauma and strain are responsible for many cases, but muscular 
contraction is an important factor in the production of coccygeal sub- 
luxations. If the lower part of the sacrum is rotated backward, the sacro- 
coccygeal articulation or angle is affected and becomes more acute, 
since the tip of the coccyx is not displaced, but held in position by struc- 
tures attached to it. If the sacrum is displaced downward the effect 
is about the same. Often this sort of sacral lesion is mistaken for an 
anterior luxation of the coccyx. In either case the sacro-coccygeal 
articulation is affected. In determining which is at fault, the sacrum 
or the coccyx, both should be examined for irregularity, tenderness and 
disturbances resulting. 

In lesions of this joint the ligaments, first of all, would be involved, 
that is they are stretched and thickened as in a sprain of any joint. The 
muscles attached to the coccyx are affected more than those attached 
to the sacrum, since the coccyx is the more movable of the two and is 
the one displaced most in ordinary cases. 

The muscles attached to the coccyx are the levator ani, coccygeus, 
external sphincter ani and gluteus maximus. Their function will be 
affected to some extent by the lesion. Contraction is a common sequel 
which is followed by rectal tenesmus and constipation, from a lessening 
in size of the lumen. Hilton, in speaking of this joint and the glutei 
muscles, says: "It must be obvious that if the sacro-coccygeal articu- 
lation or the coccyx itself be inflamed, and the gluteus maximus be used 
to any extent in the act of elevating the body from the sitting posture 
or in sitting down, or in rapid progression, the coccyx or sacro-coccygeal 
articulation must be much disturbed. Hence, although the patient 
may be able to walk gently, slowly, and carefully, yet on attempting to 
stride out he suffers considerable pain from the disturbing influence of 
the gluteus maximus During defecation, this muscle (speak- 
ing of the external sphincter ani) and the levator ani contracting would 
tend to disturb or displace the coccyx and pull it away from the sacrum. 
Some of the symptoms of which such patients generally complain are 
thus explained. " I would offer in addition to this, cases in which there 
is a partial displacement of the coccyx, which is by far more common 
than disease of the joint, in which the symptoms would be similar to, 
or almost identical with, those outlined above. 

The nerves in relation with this joint and which supply the tissues 



332 APPLIED ANATOMY. 

in relation are (1 ), the pudic, the perineal branches; (2), posterior branches 
of the lower sacral nerves; and (3), the sacro-coccygeal. All of these 
send sensory filaments to the perineum. The effects of a lesion involv- 
ing these nerves would then be sensory in character. Pruritus ani is 
the most common sensory effect. Sexual passion is increased, sometimes 
to a pathological degree, which is explained by the disturbance of the 
pudic nerve or one of its branches. Pain in the perineum is not un- 
usual, this resulting from a displacement of the coccyx or abuse of the 
function of the pudic nerve. 

The coccyx, when displaced, often produces disorders by pressure 
or traction on, the tissues attached and the bowel is most affected. If 
displaced forward the pressure may obstruct the veins of the rectum, 
thus producing hemorrhoids, or it may affect the nerves in relation, 
producing effects varying with the degree of pressure and the nerves 
involved. This displacement will interfere with defecation and parturi- 
tion, and especially if anchylosis of the sacro-coccygeal articulation has 
taken place. Falls and blows on the coccyx are most responsible for 
its forward displacement. Such injuries dislocate the coccyx and force 
it forward into the rectum. The point of the bone mechanically ob- 
structs the lumen of the bowel and presses on important structures in 
relation, viz., the hemorrhoidal veins, nerves and arteries, thus almost 
any disease of the part, such as hemorrhoids, ulceration, constipation, 
diarrhea and painful affections, may result. The displacement may be 
at the sacro-coccygeal articulation but more commonly at the last 
coccygeal joint, and on rectal examination the tip of the coccyx is found 
to be directed inward and the angle formed is very acute. The coccygeal 
nerves are affected by such a displacement. These nerves are sensory 
to the integument in relation and the anterior is motor to the coccygeus. 
Coccydynia is a result of this coccygeal lesion. 

THE BACK AS A REGION. 

The Back as a Region. The surface markings of this region are the 
median furrow, the spines of the vertebra, especially the vertebra prom- 
inens and first dorsal, the trapezii muscles and the scapulae. The spinal 
furrow is formed by two masses of muscles; the erector spinse masses, 
which fill in the groove on the sides of the spinous processes, and the 
bottom is adhered to and conforms with, the spinous processes. The 
spines are most prominent in the upper and lower dorsal areas when 



APPLIED ANATOMY. 333 

sitting erect, but most prominent in the lumbar region on flexion of the 
body. The outline of the trapezii muscles can ordinarily be distinctly 
seen. The scapula is quite prominent, its spine and inferior angle being 
the parts used as landmarks. The interscapular space varies in differ- 
ent individuals, the average distance being about five inches. When 
the arms are thrown backward the scapulae touch, when thrown forward 
they (the inferior angles) are separated about twelve inches. 

According to McClellan, "the most reliable landmarks for clinical 
purposes in this region are as follows: The third dorsal spine is about 
opposite the bifurcation of the trachea; the fourth dorsal spine indi- 
cates the position of the base of the heart, while the eighth dorsal spine 
corresponds to the lower borders of the lungs, which, when fully ex- 
panded, follow the upper borders of the eleventh ribs. The second 
lumbar spine is opposite the termination of the duodenum and also op- 
posite the commencement of the cauda equina within the the spinal 
canal. The fourth lumbar is opposite the bifurcation of the aorta. " 

The integument over the shoulders and upper part of the back is 
quite thick and closely adherent to the fascia beneath. On this account 
and that of friction from clothing, boils and carbuncles often form in 
this area, since the vitality is poor and the circulation not good. The 
skin of the lower part of the back is not quite so thick and becomes 
thinner from the spine outward. Few sebaceous glands are in the lower 
part, while many are located in the upper part, especially over the 
scapulae. This leads to the formation of pimples on the upper part of 
the back and shoulders. The sensibility of the integument is less along 
the spine than at the sides of the thorax. The integument of the back is 
innervated by the posterior divisions of the various thoracic nerves, the 
internal branches of the upper six and the external branches of the lower 
six, supplying it. 

The skin may be pigmented from deposits in it from jaundice, or 
from friction. If the spinous processes in the lumbar region are yellowish, 
it is indicative of a posterior condition with friction from the clothing or 
the backs of seats. Leucoderma is present in some cases, being well 
marked along the back. In some diseased conditions dermography is 
possible. The writer has seen cases resulting from a "going in" of the 
rash in measles, in which the least friction would raise a large welt which 
at first was white, then becoming congested and red, lasting for several 
hours. 



334 APPLIED AJVATOMY. 

In the examination of the back, it is well to make a test for the 
capillary reflex. This is done by pinching up the skin. This, in the 
normal patient, immediately produces a red area corresponding in size 
to that pinched. If this reflex is slow in responding to the test, or does 
not at all respond, it is suggestive of a lack of red blood corpuscles as in 
anemia. If the redness remains for quite a length of time, it is sug- 
gestive of an impairment of the nervous system and especially of disorder 
of the meninges of the cord. The tache meningeale of spinal meningitis 
is an example. 

To the osteopathic physician, the most important part of the human 
body is the spinal column. By its changes in contour and condition the 
various visceral diseases can be diagnosed, in most cases. I believe that 
every disease is characterized by external changes or signs, and I further 
believe that every chronic visceral disorder is manifest by changes in 
the spinal column that can be, by the practiced eye and touch, readily in- 
terpreted. In short, there are various signs along the spinal column 
that point out the weakened or diseased parts of the body. This method 
of diagnosing diseases, that is by noting these spinal changes, is dis- 
tinctly osteopathic, and I believe the time will come when it will become 
such an exact science that the character of the spinal change or lesion 
is diagnostic not only of the viscus affected, but the way it is affected. 
On account of the importance of the spine in diagnosis, particular study 
of it should be made, as to contour and condition, and the various 
conditions that change them. 

In examining a normal spine note that the spinal furrow is of about 
equal width and depth along its entire course, being slightly wider in 
the upper thoracic area and slightly deeper in the upper lumbar region 
than elsewhere; the spines are regular and in line; that there are four 
curves, the anterior cervical, posterior upper dorsal, anterior lumbar 
and posterior sacral; that the seventh cervical and first dorsal spines 
are large, the spines of the thoracic region small and oblique, while the 
lumbar spines are largest. The mobility is good and most marked at the 
dorso-lumbar articulation. The normal contour depends on the above 
named curves and the development of certain muscles. The spine of a 
new-born baby is about straight. When the child begins to sit erect it 
forms one continuous posterior curve, and when the child begins to sit, 
stand and to walk, the curves begin to form. Eisendrath says: "When 
the infant begins to sit up, the weight of the head and shoulders and the 



APPLIED ANATOMY. 



335 




Fig. 91. — Showing the sensor}' innervation of the posterior aspect of the body. 
(After Eisendrath). 



336 APPLIED ANATOMY. 

forward traction on the part of the viscera cause the development of a 
backward curve or kyphosis which extends over the whole spine. With 
the effort of the child to hold up its head the cervical portion of the 
spine gradually bends forward (lordosis). The third curve appears 
when the child begins to walk. In order to maintain the upright posi- 
tion the child uses its back and gluteal muscles. At the same time the 
pelvis is inclined downward, thus throwing the center of gravity of the 
body further back. In order to compensate for this the lumbar portion 
of the spine is bent forward resulting in the above referred to, lordosis 
of that region. These curves are not well marked until the seventh 
year, and can be entirely obliterated by traction upon the child's head."* 
These curves are maintained in the adult to a great extent by the inter- 
vertebral discs which are most developed in the lumbar region where move- 
ment is quite free. These discs are very elastic and the elasticity of the 
spine is due almost entirely to them. The natural curves of the body 
are the anterior and posterior, the least lateral deviation being abnormal. 

The muscles that go to make up the normal contour are the erector 
spina?, latissimus dorsi, trapezius and rhomboidei; at least these are 
the most important. The normal contour varies with the degree of devel- 
opment of these muscles and the degree of curvature of the spine. 
Certain occupations increase the curves and still the spine is normal. 
In occupations in which the patient has to stoop a great deal, the pos- 
terior thoracic curve increases and still the contour is, as a rule, normal 
for that individual. 

The functions of the spinal column are to protect the spinal cord 
and its membranes and to permit the spinal nerves to emerge without 
injury in all normal movements of the spine, to furnish a fixed point for 
action of muscles that move the body, and to support the head and 
trunk. If the contour is changed, any or all of these functions may be 
impaired, the most common result being the disturbance of the spinal 
cord, its membranes, and the nerves branching from the cord. Change 
of contour is of great importance to the osteopathic physician, for upon 
these changes is the diagnosis best made in many cases and the cause of 
disease ascertained. The effects of changes in contour on the spinal 
nerves may be overlooked or an error be made in diagnosis unless it be 
recalled that the segment that give rise to these nerves, their points of 
exit and the level of the corresponding spinous processes vary in differ- 
ent regions. The description given by McClellan is as correct as any. 
*Clmieal Anatomy, Eisendrath, P. 488. 



APPLIED ANATOMY. 337 

He says : " There is no means of foretelling the absolute relative positions 
of the origins of the individual spinal nerves from the spinal cord but they 
may be approximately considered to be as follows: Collectively, the eight 
cervical nerves arise between the medulla oblongata and the cord op- 
posite the spine of the sixth cervical vertebra. Individually, the first 
cervical nerve arises at the interval between the margin of the foramen 
magnum and the atlas vertebra, the second and third cervical nerves 
arise opposite the axis vertebra, while the fourth, fifth, sixth, seventh 
and eighth cervical nerves arise respectively opposite the bodies of the 
third, fourth, fifth, sixth and seventh cervical vertebrae. Collectively, 
the upper six dorsal nerves arise from the cord between the spines of the 
sixth cervical and fourth dorsal vertebrae. Individually, the first, second, 
third and fourth dorsal nerves arise respectively, opposite the inter- 
vertebral discs below the seventh cervical and the first, second and 
third dorsal vertebra?, while the fifth and sixth dorsal nerves arise op- 
posite the bodies of the fourth and fifth dorsal vertebrae. Collectively, 
the lower six dorsal nerves arise from the cord between the spines of the 
fourth and eleventh dorsal vertebrae; individually, they arise opposite 
the bodies of the sixth, seventh, eighth, ninth, tenth and eleventh ver- 
tebra?. Collectively, the five lumbar nerves arise from the cord between 
the eleventh and twelfth dorsal spines. Individually, the first, second 
and third lumbar nerves arise opposite the body of the twelfth dorsal 
vertebra, and the fourth lumbar nerve arises opposite the intervertebral 
disc between the twelfth dorsal and first lumbar vertebra?. The fifth 
lumbar nerve, the five sacral nerves, and the coccygeal nerve all arise 
from the conus medullaris opposite the body of the first lumbar vertebra, 
which corresponds to the spines of the last dorsal and first lumbar ver- 
tebra." By referring to the above and recalling the obliquity of the 
spines in the various regions, the lesion can be located without much 
trouble, in case of injury to the spinal cord or subluxation of a vertebra 
that produces pressure on a spinal nerve at its exit. 

The tips of the spinous processes are used as landmarks for locating 
various structures. Some of these landmarks have been given. Deaver 
gives in addition: "The sixth cervical spine corresponds to the highest 
level of the apices of the lungs. The third dorsal spine lies opposite the 
point where the aorta approaches the spinal column, the highest level of 
the lower lobes of the lungs and the bifurcation of the trachea. The 
ninth dorsal spine marks the level of the cardiac orifice of the stomach 



338 APPLIED ANATOMY. 

and the upper limit of the spleen. The tenth dorsal spine locates the 
lowest level of the bases of the lungs and the level at which the liver 
reaches the abdominal walls posteriorly. The eleventh dorsal spine 
locates the lower limit of the spleen, the position of the suprarenal cap- 
sule and the upper border of the right kidney. The twelfth dorsal spine 
is on a level with the lowest part of the pleura?, the aortic opening of the 




Fig. 92. — Model with spine flexed and bent to the left. The boards show the 
planes of chest and pelvis. The boards marking the chest, have rotated backward on 
the convex side of the curve. (Lovett). 

diaphragm, and the pylorus. The spine of the first lumbar vertebra is 
situated opposite the renal vessels, the pelvis of ureter, and the pancreas. 
The second lumbar spine lies opposite the end of the spinal cord, the 
third portion of the duodenum, and the receptaculum chyli. The third 
lumbar spine is found just above the level of the umbilicus and below 
that of the lower border of the right kidney. The fourth dumbar spine 



APPLIED ANATOMY. 



339 



is located opposite the bifurcation of the aorta and the highest part of 
the crests of the ilia. The fifth lumbar spine marks the origin of the 
inferior vena cava. The third sacral spine lies opposite the termina- 
tion of the sigmoid flexure and the lowest level of the spinal membranes. 
The tip of the coccyx marks the junction of the first and second portions 
of the rectum." 

The movements of the spinal column are of great importance to 
the physician in that lesions of the vertebral articulations are indicated 
best by disturbances of these movements. A spinal column in which 




Fig. 93.-- Experimental double curve (right dorsal, left lumbar) produced in 
the model by elevating the right side and having the model twist the upper part to 
the left. (Lovett). 



340 



APPLIED ANATOMY. 



the movements are normal, is as a rule a normal one and if there are 
visceral disorders they are due to other causes. These movements are 
distributed amongst all the vertebral articulations, that is there is move- 
ment at every articulation in the normal spine. In the examination of 
patients, this point is often overlooked on account of the compensatory 
hypermobility of other articulations. 




Fig. 94. — Experimental double curve (right dorsal, left lumbar) produced in 
the cadaver by elevating the right side of the pelvis and twisting the upper end of 
the spine, face to the left. (Lovett). 

These movements are produced by muscular contraction and by 
gravity. In flexion, the muscles of the front of the column are active, 
while in extension the muscles of the back contract. The muscles that 



APPLIED ANATOMY. 



341 



produce extension are stronger than those that produce flexion, hence 
in spasms, there is a drawing back of the body as in opisthotonus. Grav- 
ity begins to assist just as soon as the body is drawn away from the 
perpendicular by the muscular contraction. 

The movements are most free in the cervical and lumbar articula- 
tions and in these regions, at the atlanto-axoidal and dorso-lumbar 
joints. They are considerably less than one would suppose when the 
extent of the spinal movements is considered, the explanation being 




Fig. 95. — The right side of the pelvis of the cadaver is raised and the upper part 
of the spine falls to the left, making a lateral curve convex to the right. (Lovett). 



that much of the supposed movement takes place at the hip-joints and 
the lumbo-sacral articulation. For example, in flexion the greater part 
of the forward movement is in the hip-joints while if you ask the patient 
to bend to the side, the pelvis will be tilted to the opposite side, this ex- 
aggerating the apparent lateral bending. 

There are essentially three movements of the spinal column: flexion 
or forward bending, extension, or backward bending, and lateral bend- 



342 APPLIED ANATOMY. 

ing with rotation. Flexion and extension are most free in the cervical 
and lumbar regions while rotation and lateral bending are most 
marked in the thoracic, the atlanto-axoidal articulation being excepted. 
Flexion in the cervical region is not very marked since much of the 
movement is between the occiput and the atlas, and the second cervical 




Fig. 96. — The right side of the pelvis of the model is raised and the upper part 
of the spine is carried to the right, making a lateral curve convex to the left. (Lovett) . 

vertebra or axis. Ordinarily the anterior curve only can be obliterated. 
In hyperextension the normal curve can be increased. In side bending, 
the movement is fairlv well distributed amongst all the articulations but 



APPLIED ANATOMY. 



343 



the greater part is in the upper part of the neck. There is rotation of 
the bodies of the vertebrae to the opposite side, that is, toward the con- 
vexity of the curve. 

In the thoracic region, there is little flexion or extension, the prin- 
cipal movement being that of rotation which seems to be a part of the 




Fig. 97. — The right side of the pelvis in the cadaver, is raised and the upper part 
of the spine firmly held, making a lateral curve with convexity to the left. (Lovett). 

movement in side bending. This movement is practically the same as 
that in the neck, the bodies of the vertebras rotating to the convexity, 
and the spines toward the concavity of the curve. This should be re- 
membered in the treatment of scoliosis since the opposite rotation of the 
spines would be expected on first examination. The greater the degree 



344 APPLIED ANATOMY. 

of flexion of the body at the time of the side-bending, the greater the 
degree of rotation, and the higher it occurs in the spine. Side-bending 
in the erect posture is accompanied by rotation low in the spine which 
is best marked at the dorso-lumbar articulation. 

Flexion and extension are the principal lumbar movements, rotation 
and side-bending being slight. These movements are not so free as one 




Fig. 98. — Model flexed and bent to the left. The card-board indicators have 
turned to the left. (Lovett). 

would at first think on account of the free movements of the hip-joints 
and the lumbo-sacral articulation. *Lovett arrived at the following con- 
clusions after careful investigation: " (1) In the lumbar region flexion 
♦Boston Med. and Surg. Jour. p. 355, Vol. CLIII. 




Fig. 99. — Showing the multifidus spina; muscle. This muscle is involved in 
scoliosis. Its contraction produces lateral flexion with rotation to the opposite side. 



346 



APPLIED ANATOMY. 



diminishes mobility in the direction of side-bending and rotation, and 
extreme flexion seems to lock the lumbar spine against these move- 
ments. (2) In the dorsal region hyperextension diminishes mobility 
in the direction of side-bending and rotation. Extreme hyperextension 
seems to lock the dorsal spine against these movements. (3) In flexion 




Fig. 100. — The trapezii muscles. In colds of the upper respiratory tract, the 
parts covered by these muscles are always tender on pressure. 

of the whole spine, side-bending is accompanied by rotation of the ver- 
tebral bodies to the convexity of the lateral curve, the characteristic 
of the dorsal region. (4) In the erect position and in hyperextension 
of the whole spine, side-bending is accompanied by rotation of the ver- 



APPLIED ANATOMY. 347 

tebral bodies to the concavity of the lateral curve, the characteristic of 
the lumbar region. (5) The dorsal region rotates more easily than it 
bends to the side, whereas the lumbar region bends to the side more 
easily than it rotates. (6) Rotation in the dorsal region is accompanied 
by a lateral curve, the convexity of which is opposite to the side to which 
the bodies of the vertebrae rotate." 

Abnormal changes in contour of the back are clue to muscular con- 
tractures, curvatures, tumors, enlarged viscera, certain occupations and 
some forms of visceral diseases. The muscles most commonly involved 
are the erector spina? mass, trapezius, quadratus lumborum, serratus 
magnus and the rhomboid muscles. If contracture of any of these mus- 
cles takes place, it becomes enlarged and prominent and has a tendency 
to draw the spine to that side. Relaxation of any one would make it 
appear that the opposite one was contractured or enlarged. Contrac- 
ture of the erector spinas mass of muscles produces enlargement on that 
side; relaxation or atrophy has the opposite effect. The trapezius when 
contractured makes the suprascapular region more prominent. Relax- 
ation of the serratus magnus causes the scapula on the same side to be- 
come prominent, that is, it becomes winged, thus changing the contour. 
If the rhomboids are also relaxed, the interscapular region is widened 
and the spine becomes flattened. If there is general spinal atrophy, the 
ribs become displaced downward, the normal curves of the spine are 
obliterated and the spinous processes become plainly visible. 

Curvature of the spine is the most common and important of all the 
causes of change in contour of the back. By curvature of the spine is 
meant an abnormal bending or swerving of the spinal column, which 
is ordinarily accompanied by disturbance of function of that part of the 
spine, and of viscera and structures innervated by the nerves that are 
in relation with the points of the spine affected. Most curvatures start 
from a single lesion, that is, subluxation of a single vertebra or abnormal 
movement of one part of the spinal column on another. These lesions 
produce curvature either by interfering with the nutrition of that part 
of the spinal column, or by causing muscular atrophy or contracture. 
Muscular contracture from other causes often leads to curvature. Mus- 
cular atrophy produces curvature since the sound side is unaffected and 
the muscles unopposed, draw the spine to that side. 

The size of the viscera in relation has to do with the contour of the 
spinal column, as is evidenced by curvature following a collapse of one 
lung. Faulty posture often leads to curvature, and unequal length of 



348 APPLIED ANATOMY. 

the lower limbs, a tilted pelvis and diseases of the bones,' as in rickets, 
are also responsible for many cases. 

The forms of curvature vary from a slight flattening of the dorsal 
area to a well marked case of scoliosis. Posterior curves are most fre- 
quent in the lumbar, and are called kyphoses. An anterior curve is 
called a lordosis, and scoliosis is the name given to a lateral curvature. 

The kyphosis is possibly the least harmful, compared with the ex- 
tent or degree of variation, since the intervertebral foramina are en- 
larged rather than lessened by it. This form results most frequently 
from occupations involving the stooping posture or faulty methods of 
standing and sitting. A general spinal weakness is responsible for most 
cases coming under the last named class, and the patient no longer at- 
tempts to sit erect but sits with a marked posterior lumbar curve. If 
the patient by attempting to sit erect is unable to obliterate the pos- 
terior conditio^, it is a pathological kyphosis. Occupational kyphosis 
is seldom pathological, neither is the posterior curve is the upper dorsal 
region, from old age. Enlargement of the lungs, as in asthma, produces 
a kyphosis in the thoracic region. Disease of the body of the vertebra, 
as in tuberculosis of the vertebra, will produce an angular curvature 
commonly called Pott's disease of the spine. 

In order for the spine to be curved abnormally far posteriorly, there 
must be a. separation of the spines from thickening of the posterior part 
of the disc, partial flexion or compression of the bodies and anterior 
portion of the intervertebral disc, or all. In most cases there is simply 
a relaxation of the ligaments and muscles along the posterior aspect of 
the vertebral column, which weakens the supports and consequently 
the spine seeks a position of most ease, that is the patient sits in a semi- 
reclining posture. Such conditions are not in reality curvatures, but are 
indicative of weakness which will lead to curvature if not soon overcome. 
This weakening may be due to a single vertebral lesion or it may be a 
part of a general disturbance of nutrition, as in anemia, rickets or any 
disease in which the body is poorly nourished. Compression of the discs 
may be due to constant pressure on the anterior portion, or it may be 
due to disease or loss of elasticity of the disc on account of a vertebral 
lesion or injury. The body of the vertebra may be compressed, as in 
Pott's disease, thus producing an angular curve. The compression of 
of the disc and body of the vertebra is always present in pathological 
curves. 

A kyphosis produces disease by interfering with the function of 



APPLIED ANATOMY. 



349 



the spine, structures attached, nerves and vessels in relation and viscera 
innervated by that area. A pathological posterior curvature weakens 
the spinal column, thereby interfering with the support of the head and 
body and attachments of muscles. This weakness is directly the result 
of mal-alignment of the vertebra;, mal-nutrition and changed relations 
of the muscles attached. On account of the change in position, the 



_ Ji 




Fig. 101. — Lateral view of a boy suffering with Pott's disease of the spine. Note 
the angular enlargement. The symptoms in this case were almost completely re- 
lieved but the deformity was not materially changed. (From photo). 

structures attached will also be changed. This is not an important ef- 
fect. The intervertebral foramina depend for their size on the amount 
of separation of the vertebra;. In pathological kyphosis the discs are 
usually thinned, from the pressure, to such an extent that these foramina 



350 



APPLIED ANATOMY. 




Fig. 102. — Posterior curvature of the lumbar region. (From photo). The pa- 
tient had bowel and uterine trouble. 



APPLIED ANATOMY. 351 

are lessened in size. In order to get this effect, the compression of the 
disc must be more marked than in lordosis. In cases in which the fora- 
mina are lessened in size, the blood-vessels are compressed and the 
passing of nerve impulses over the nerve interfered with. The effects 
vary with the degree of compression and the character and function of 
the parts innervated by these nerves. 

Posterior curvature in the lumbar region is more often pathological 
than in other regions. One reasion for this is that it occurs most fre- 
quently in this region. The bowel (lower) and pelvic organs, especially 
the uterus in the female, are more frequently affected than other viscera. 
The impulses supplying these parts are partly or completely cut off and 
a form of paralysis of the parts follows. The curvature may be irritative, 
but is most commonly inhibitory, therefore there is lessened activity of 
the viscera supplied by the nerves affected. Kyphoses produce most of 
their effects by lessening the size of the intervertebral foramina, thus in- 
terrupting the passing of blood and nerve impulses through them. Pott's 
disease comes from an injury to the spine in a child who has a tubercular 
taint. The lesion weakens and lowers the vitality of the part to such 
a degree that a nidus favorable to the propagation of the tubercle bacilli, 
is formed. The body of the vertebra is honey-combed, sometimes 
breaks down and in many cases becomes ankylosed. When this takes 
place it is called the quiescent stage. If the case is seen soon after the 
primary injury, the condition can be cured. A very slight twist of the 
spine, a sudden though gentle push in the back, as school children are 
wont to do, are usually the initial injuries; in short, a subluxation or 
sprain of a vertebral articulation from some cause or other, is the cause. 

In the treatment of a posterior curvature ascertain the primary 
lesion and correct it if possible. The things to be accomplished in order 
to effect a cure in an ordinary case are (1), restoration of elasticity to the 
intervertebral discs, this being done by restoring normal nutrition; (2), 
the regaining of normal tone to the spinal ligaments, and (3), restoring 
the vertebra; to their normal position. The first and second can be 
accomplished by repeated attempts at replacement of the displaced ver- 
tebrae, and certain exercises that build up the general strength. The 
third is usually accomplished gradually by developing ligaments and 
muscles, and by repeated attempts at replacement or straightening of 
the spine. It is well to ascertain whether or not the curve is pathological, 
or whether it is the effect, rather than the cause of the other disorders, 



352 



APPLIED ANATOMY. 



since a great many cases of supposed posterior curvatures are not real, 
but assumed, on account of spinal weakness. 

Lordosis in a marked form, is most common in the lumbar region 
but in mild cases the dorsal region is the usual seat, this being not a 
real curvature but a flattening of the normal posterior curve in this 
region. Dislocation of the hip, whether congenital or acquired, also 






Fig. 103. — Showing contour of spine in a marked case of lordosis in lower thoracic 
and upper lumbar regions. These deformities usually start in children, from a le- 
sion of a single vertebra. (From photo.) 



APPLIED ANATOMY. 



353 




Fig. 104. — Showing an anterior condition of the upper thoracic region, 
photo). Note the compensator}' posterior curve in the lumbar region. 



(From 



354 APPLIED ANATOMY. 

hip-joint disease, are causes of importance. Malnutrition of the lumbar 
vertebrae and ligaments, will permit of an exaggeration of the normal 
anterior curve in that region. In pregnancy and obesity, the traction 
exerted on the lumbar spine pulls it forward and the throwing back of the 
shoulders to retain equilibrium, is another important cause. In Pott's 
disease of the dorsal vertebrae, a lordosis in the lumbar region forms as a 
compensatory curve. Injury to the lumbar articulations, especially the 
upper lumbar, by which the vertebrae are forced directly forward, often 
leads to a curvature on account of the weakness, change of position and 
malnutrition that so often follow such lesions. 

In typical cases the discs are compressed, especially the posterior 
parts, the articular facets forced tightly together and the interverte- 
bral foramina lessened in size. As a result, the functions of the spinal 
column, spinal cord, spinal nerves in relation and muscles attached, are 
disturbed. In addition to this the function of viscera, innervated from 
this part of the spinal cord, is nearly always affected. The greatest ef- 
fect results from a lessening in size of the intervertebral foramina. This, 
as in kyphosis, interferes with the blood-vessels and nerves in the fora- 
mina. Atrophy of the spinal muscles is a fairly common sequel, while 
visceral disease is frequent in typical cases. The flattening of the thor- 
acic spine, while not a typical lordosis, produces about the same effects. 

Scoliosis or lateral curvature of the spinal column is the most com- 
mon and important of all the spinal curves. It is defined by Walsham 
as a " complicated distortion in which the spine forms two or more lateral 
curves with their convexities in opposite directions, whilst the vertebrae 
involved in the curves are rotated on their vertical axes so that the 
spinous processes are directed toward the concavity of the curves." 
According to the same writer, "the immediate cause that underlies the 
formation of lateral curvature is the unequal compression of the inter- 
vertebral cartilages for long periods." I would add that malnutri- 
tion of a part of the disc from a vertebral subluxation or other injury, 
is one of the frequent and important of causes. 

There are many causes of unequal pressure on the discs. Unequal 
length of the lower limbs will produce compensatory lateral curve in the 
spine. The unequal length may be real, as in hip-joint disease, disloca- 
tion of the hip, and fracture; or apparent, as in a twisted pelvis or in 
disease of a leg or foot which causes the patient to favor one side. Col- 
larjse of one lung, enlargement of the heart or one lung, or muscular con- 



APPLIED ANATOMY. 



355 



tracture or hypertrophy of muscles on one side, may produce scoliosis. 
Muscular contracture is usually secondary to spinal lesions, a tilted pelvis, 
or irritative disorders of viscera. Hypertrophy is due to certain occupa- 
tions in which one side is used to the exclusion of the other, faulty posture, 
as is seen in school children attempting to write on a desk either too high 




Fig. 105. — A right lateral scoliosis in a young girl brought on as a result of a le- 
sion in the mid-dorsal region and fault}' posture while attending school. (From 
photo). 



356 



APPLIED ANATOMY. 



or too low, and the carrying of heavy weights or loads by children. 
Muscular atrophy from effects of a vertebral lesion, spinal cord disease, 
non-use, or disease of membranes of the cord, permit the unimpaired 
muscles to draw the spine to the opposite side. Scoliosis is a common 
sequel to cerebro-spinal meningitis and other diseases, such as fevers, 






Fig. 106. — Showing a double scoliosis. Note the rotation, flexion line on the 
right and atrophy on the concave side. (From photo). 

especially typhoid. In children the curvature starts from a wrench or 
strain of the spine in which the ligaments and muscles are irritated. 

After all the essential cause of scoliosis is faulty posture. If there 
is a spinal lesion the patient assumes a position of greate'st ease, that is, 



APPLIED ANATOMY. 



357 




Fig. 107. — Showing the contour of the spine in a case of simple lateral curvature 
in a girl seven years of age. Note the scapula;, shoulders, hips and waist line. (From 
photo). 

tries to protect the weakened or painful part. If from muscular dis- 
orders, the posture is the real cause of the unequal pressure on the discs. 
If from a diseased lung, the patient assumes an improper posture to pro- 
tect the part as well as is possible. In recounting all the causes com- 
monly mentioned as responsible for scoliosis, faulty posture is the im- 
mediate cause. This may be directly the cause or the faulty posture 



358 APPLIED ANATOMY. 

may be the result of something else such as a fractured rib, in either 
case, the faulty posture is the immediate cause of the curvature. 

The effects vary with the degree of curvature, rapidity of develop- 
ment, care that the patient takes of the spine, and methods of treatment. 
In all cases the spinal column is weakened and the functions disturbed. 
The spine is not only bent, but rotation of the vertebra? on a vertical 
axis takes place. In ordinary cases the body of the vertebra is rotated 
toward the convex side while the spinous processes point toward the 
concave side. This is probably due to the fact that the bodies of the 
vertebra offer less resistance to the pressure and traction than do the 
articular processes, the posterior part of the vertebra being held more 
securely than the anterior part by the various spinal ligaments. "The 
theory, perhaps, most generally accepted is that of Dr. Judson, who be- 
lieves that the rotation is due to the fact that the posterior portion of 
the vertebral column, being a part of the dorsal parietes of the chest 
and abdomen, is confined by the ligaments and muscles to the median 
plane of the trunk; whilst the anterior portion, projecting into the thor- 
acic and abdominal cavities, being devoid of lateral attachments, is free 
to move either to the right or left of the median plane when the spine is 
inclined to either side. " 

Another theory offered in the explanation of the torsion or rotation 
accompanying scoliosis is that a flexible body bent in two planes at the 
same time, is accompanied by rotation. The vertebral column, if normal, 
has a series of antero-posterior curves. It is a homogeneous column, con- 
sequently side-bending would result in rotation since the flexible spinal 
column would be bent in two planes at the same time,viz., antero- 
posteriorly and laterally. This is true of all flexible bodies. 

In the initial stages only the intervertebral cartilages are affected, 
but later on as the curvature progresses and develops, the vertebrae, the 
bodies' in particular, become compressed on the concave side after which 
it is almost, if not entirely impossible to correct the deformity. The 
mobility of the spine is lessened; the muscles on the concave side undergo 
atrophy on account of pressure on their trophic nerves and from imper- 
fect, or non-use. Those on the convex side increase in size and are made 
prominent, partly by increase in size and partly by change in contour of 
the thorax. 

One of the earliest signs of a scoliosis is a hypertrophy of the muscles 

Practical Surgery, Walsham. p, 581. 



Al'PLIED ANATOMY. 



359 



on the convex side of the spinal column, especially the erector spinse mass. 
This appears before any palpable deformity of the vertebrae takes place, 
or at least before it can be recognized. 

The hypertrophy of the muscles on the convex side is the result of 
the disturbance of the equilibrium of the body. Immediately after the 



L 




Fig. 108. — Showing a simple scoliosis to the right, from atrophy and non-use of 
the back muscles. The thoracic muscles were almost entirey paralyzed so that there 
was practically no movement of the chest on respiration. (From photo). 



360 APPLIED ANATOMY. 

body has lost its poise, say for example, it is tilted to the right, the mus- 
cles on the left side are brought into activity to prevent gravity from 
drawing it further to that side. In the constant effort on the part of the 
muscles on the left side to prevent this, they necessarily undergo hyper- 
trophy. This muscular enlargement and contracture is the result of the 
curve rather than the cause. Some believe that muscular contracture 
is an important cause of scoliosis but this is scarcely possible. Muscu- 
lar relaxation is by far the more important of the muscular causes. 
The character of the rotation which accompanies practically all cases 
of scoliosis, contradicts the theory that muscular contracture or con- 
traction produces the curve, since it is opposite in direction to that pro- 
duced by the action of the muscles. 

The foramina on the convex side are increased in size, those on the 
concave side lessened. The lessening in size of the foramina produces 
more or less pressure on everything that is in them. Pressure on the blood- 
vessels interferes with the nutrition of the spinal cord, column and other 
structures in relation, such as the spinal membranes and ligaments. 
This leads to muscular atrophy and visceral weakness. Pressure on the 
nerves results in (1), sensory disturbance, such as pain or weakness in 
the spine on movement, a careful gait, stooping posture and lack of inclina- 
tion on part of the child to enter into play as do other children; and (2), 
motor and trophic disturbances, as are manifest in the atrophied muscles. 
Vaso-motor and secretory impulses may be interrupted, leading to se- 
cretory and vascular disturbances in areas supplied by these nerves. 
The recurrent meningeal nerves are compressed, this leading to vascu- 
lar and trophic disturbances of spinal cord and column. These effects 
are the same as from lesions of individual vertebra? with the exception 
that they are more general. 

The scapula on the convex side, if the curve is in the thoracic region 
as it is most commonly, is thrown upward and backward, giving it a 
winged appearance. The shoulde*- is also higher on that side. This 
change in the scapula is one of the very early signs and should be regarded 
as an important one. One side of the pelvis soon becomes prominent, 
that is the crest on the convex side. The ribs on both sides of the thorax 
are changed in position, giving a misshapen appearance to the chest. 
Posteriorly, the chest is prominent on the convex side and depressed on 
the concave side. Anteriorly, the side of the chest bulges on the side of 
the concavity of the curve and the opposite side is depressed. These 



APPLIED ANATOMY. 



361 



changes occur early and -are important signs of a lateral spinal curva- 
ture. The deformity of. the thorax is most marked when rotation is 
greatest, since the ribs follow the transverse processes of the vertebrae 
with which they articulate. In some cases the spinous processes may 
remain in the median line until the curvature is well under way, hence 




Fig. 109. — Simple lateral curvature of the spine. P. , prominence of the scapula 
and ribs. Compare the points marked with an X. There is some rotation as is in- 
dicated by the prominence on the right side. (From a photo). 

scoliosis should not be diagnosed in every case by position of the spinous 
processes. 

A scoliosis is primarily caused by an injury to a vertebral articula- 
tion Or by any other cause producing fault}" posture, which in turn pro- 



362 APPLIED ANATOMY. 

duces unequal pressure on the discs. It produces disease by interfering 
with the functions of the spinal column, cord, nerves and nerve roots, 
muscles, vessels and viscera in relation or connected with the affected 
part. Most of these effects result from a lessening in size of the inter- 
vertebral foramina. All curvatures are not pathological since compensa- 
tion may be complete. In cases in which compensation is not perfect, 
the curvature is pathological. 

The condition known as a straight spine, is common in certain classes 
of people. It is primarily due to weakness of spinal ligaments and 
muscles and is found in malnourished, anemic, tubercular patients and 
those predisposed to lung diseases, particularly phthisis. It is caused 
by relaxation of the ligaments, cartilages and muscles that hold the 
spine in its normal position. In most cases a single vertebral lesion is 
found, usually at the fourth dorsal articulations, but sometimes slightly 
higher or low'er in the spinal column. The effects are explained in the 
same way as those in anterior and posterior curvatures, with the ex- 
ception that the trophic effects are more marked since the upper and 
middle thoracic regions are affected most. 

The rigid and hypermobile spines have to do with changing the con- 
tour of the back. The rigid spine results from abnormal approximation 
of the vertebrse or impairment of the ligaments and muscles which sup- 
port and move the spinal column. Old age, standing on the feet a great 
deal, inflammatory conditions of the spine, as in meningitis and la grippe, 
lesions, thickening of; the spinal ligaments, and rigidity or inflammation 
of the spinal muscles all tend to lessen mobility. Fractures, sprains, 
subluxations and dislocations of vertebrse are also important causes. 
Long continued muscular contracture exerts such a pressure on the 
discs that they are abnormally, thinned and flattened. Such a condi- 
tion interferes with the function of the spine and lessens the size of the 
intervertebral foramina. In constipation and fibroid tumors of the 
uterus, a rigid lumbar spine is nearly always found. In the aged, a rigid 
spine is not uncommon and is not usually regarded as pathological, yet 
in every case in which the intervertebral foramina are lessened in size, 
pathological conditions result. In many cases in which the spine is 
apparently mobile, there will be found areas of several adjacent vertebrae, 
in which motion is decidedly lessened or entirely lost. The movement of 
the vertebral articulations should be distributed amongst all of them, 
but this is not the case in many spines. At some place, Usually at a 



APPLIED ANATOMY. 



363 




Fig. 110. — Showing a straight spine. (From photo). Note the spinous processes 
are visible throughout the entire spine. 



364 APPLIED ANATOMY. 

break or separation, there is hypermobility, which compensates, so far 
as mobility is concerned, for the rigid, immovable area. As mentioned 
above, a rigid spine, or even one rigid immovable vertebral articulation, 
is abnormal and produces disorders of structures in relation and of viscera 
supplied by the nerves passing through the obstructed foramina in rela- 
tion. 

Hypermobility is the result of relaxation of the supports of the spinal 
column, viz., the ligaments and muscles. It occurs most frequently in 
improperly nourished young girls. This weakness may be the result of 
lesions disturbing the centers for nutrition or it may be the result of 
some visceral disturbance especially derangement of the sexual organs. 
In all cases of general hypermobility of the spine, the dorsal curve is 
lessened, often entirely obliterated, and the lumbar spine is posterior. 
The spines of the vertebra? appear to be larger than those of normal 
vertebrae; the patient tires easily on the slightest exertion, cannot or 
does not sit erect and suffers with various spinal aches which are increased 
in intensity with extra Work or strain. This condition produces dis- 
orders by interfering with the function of the spinal column, spinal cord, 
nerves, muscles and viscera. The spinal column is weak, the spinal 
cord poorly nourished, the spinal membranes often congested and in- 
flamed, the nerves irritable and the viscera weak, so that almost any 
exciting cause will produce marked disorders. 

Enlargement of the lungs, liver, distension of the stomach, tumors, 
aneurysm and abscesses sometimes change the contour of the back. 
Displacement of the ribs, paralysis of the serratus magnus muscle and 
contracture of muscles from the various causes, also change the contour 
of the back. 

Congenital defects, such as spina bifida, produce abnormality in con- 
tour of the spine. Spina bifida is a condition in which there is absence 
of a portion of the lamina, causing imperfect closure of the spinal canal 
at that point. As a result the pressure from within causes a protrusion 
of the membranes of the cord, which is characterized by a soft, fluctuating 
tumor varying in size with that of the opening. The tumor or sac is 
filled with the cerebro-spinal fluid that normally surrounds the spinal 
cord. This condition may seriously impair the function of the spinal 
cord at and below the seat of the tumor. Paraplegia is a common sequel. 

In some cases there is an abnormal development of a spinous process 
which is mistaken for a lesion. There are other causes and forms of 



APPLIED ANATOMY. 365 

irregularities, such as large, uneven spines and breaks or separations that 
are often due to changes confined to the spinous processes; that is, it is 
an apparent, not a real, lesion since the articular processes are not in- 
volved. In chronic cases of diabetes mellitus the spinous processes of 
the lower dorsal and upper lumbar vertebra? are enlarged and prominent. 
Often there will be found lateral deviations that are simply irregular- 
ities due to a bending of the spinous process. Changes in contour of 
the upper dorsal spine, indicate weakness of lungs; middle dorsal, weak- 
ness of stomach and liver; lower dorsal, weakness of kidneys; lumbar 
region, weakness or disease of the lower intestinal tract and pelvic organs. 
These changes of contour, if pathological, are accompanied by either 
tenderness, muscular relaxation or by weakness of viscera innervated by 
that part of the spinal cord in relation. 

Tenderness and aching of the spine are very common symptoms. 
When in the upper thoracic region, they are suggestive of colds, la grippe 
and lesions of the vertebrae or ribs. In the interscapular region, they are 
suggestive of lung and heart disease, occupation neuroses and pelvic and 
mammary disorders ; in the middle and lower portions of the thoracic spine, 
they are indicative of stomach and liver disorders ; lower dorsal and upper 
lumbar, disorders of kidneys, spleen and small intestines; in the lumbar 
region, they are almost diagnostic of disorders of the bowel and pelvic 
generative organs. In all of these areas the tenderness or ache may be 
due to a subluxation of a vertebra or rib, in fact tenderness of a verte- 
bral spine is one of the most certain indications of a lesion of that ver- 
tebral articulation. Tenderness of the spine may be due to reflex irrita- 
tion of the sensory nerves supplying the spinal column; that is, if there 
is an irritative disease of a viscus the segment of the spinal cord that 
supplies the viscus, will be affected, which in turn causes the pain to be 
referred to the spine. Similarly, the muscles supplied by the affected 
segment undergo contracture, hence contracture of spinal muscles is 
indicative of an irritative disorder of viscera in relation. 

If there is excessive tenderness along the spine, it is suggestive of 
spinal irritation or neurasthenia. In many cases there is ovarian irri- 
tation. In all cases there is a congested condition of the nerves of the 
back and disturbances of the spinal cord and its membranes. In other 
cases, the toxemia is the cause of the irritation of the sensory nerves of 
the back, this giving rise to the extreme tenderness on account of the 
malnutrition. An error in diet will produce both tenderness at or near 



w'ja 



'Hi:,!!*'}' 



JjKHt" 






&*m 




Fig. 111. — Lateral view of the spinal column. Note the relation of spinous pro- 
cesses, foramina, bodies and nerves 



APPLIED ANATOMY. 367 

the fifth dorsal spine, and contracture of muscles in this region. In 
railway spine, in which there is concussion of the spinal cord, the effects 
vary with the degree of disturbance of the cord. In some cases there is 
a dislocation, in others a subluxation, or a fracture or crushing of the 
vertebra;. In the so-called railway spine, I believe the trouble in the 
average case, is due to a vertebral subluxation which produces the pain 
or anesthesia or the paralysis. The symptoms in railway spine are often 
anomalous from the usual viewpoint, but from the standpoint of sub- 
luxations of the vertebra?, most of the symptoms are explainable. 

Fracture of the spine is rare and is the result of severe trauma. If 
it occurs above the fourth cervical vertebra, death is the result, but if 
at points below, paraplegia is the sequel. Death may result from frac- 
tures at these points on account of hypostatic congestion of the lungs 
or other viscera, interference with nutrition and elimination or, from 
exhaustion. The effects are determined by the location and degree of 
the fracture. It is hard in many cases to differentiate between fracture 
and dislocation or subluxation. Careful palpation, by which crepitus 
can be discovered if it is a case of fracture; the severity of the paralysis 
or effects on the spinal cord, they usually being very marked in cases of 
fracture; and the use of the X-ray, especially if the lumbar region is the 
seat of the injury, will reveal the nature of the injury. 

THE SPINAL CORD. 

The vertebral column is tunneled by a foramen in which the spinal 
cord is located. The cord is much shorter than the spinal canal, reach- 
ing only to the upper border of the second lumbar vertebra in the adult 
and in an infant, to the third lumbar vertebra. It is about eighteen 
inches long and varies in its diameter, being smallest at points of greatest 
mobility. It is surrounded and protected by the meninges and the 
cerebro-spinal fluid. The cord is well protected, a thing that is essentially 
necessary on account of its delicacy and function. Deaver says in re- 
gard to its protection: "The free mobility of the spinal column as a 
whole; the slight amount of movement between any two vertebra?; the 
elastic intervertebral discs which break up force and shock applied to 
the spinal column; the comparatively large size of the spinal canal in 
the cervical and lumbar regions where the mobility is most marked; the 
curves of the spinal column which lessen shock and force; suspension of 
the cord in the spinal canal by the ligamenta denticulata; the spinal dura 



368 



APPLIED ANATOMY. 



> Mr 



Fig. 112. — Lateral view of the spinal cord. 



APPLIED ANATOMY. 369 

mater which is so tough that the cord may be ruptured without lacera- 
tion of the dura; and the cerebro-spinal fluid." Although the cord is 
surrounded by these safeguards, it is often affected in many ways, as 
stated below. 

The cord is composed of white and grey matter. The white matter 
contains the nerve fibers cemented together by the neuroglia. These 
nerve filaments are divided, on account of function and relation, into 
columns, the anterior and lateral being motor, the posterior, sensory. 
Dana says, "On physiological and embryological grounds the columns are 
further subdivided as follows: The anterior columns are divided into 
direct pyramidal tract and anterior fundamental column. The lateral 
columns are divided into lateral fundamental columns, lateral limiting 
layers, crossed pyramidal tracts, direct cerebellar tracts and antero- 
lateral ascending and descending tracts, or Gower's column. The pos- 
terior columns are divided into the posterior internal column or column 
of Goll, postero-external columns, or column of Burdach, the ventral 
zone, the comma, the oval zone, the triangular column and rim zone or 
column of Lissauer. " 

The grey matter occupies the center of the cord and its parts are 
arranged like the letter H. It is composed principally of nerve cells 
with some nerve fibers and neuroglia. Each lateral half presents two 
horns, the anterior and posterior, the two halves being connected by a 
commissure. The nerve cells are arranged in groups. Dana says: 
"The cells are surrounded by a rich plexus and end brushes, as well as 
by the supporting neuroglia matrix, a little connective tissue and many 
small blood-vessels. The cell groups are named in accordance with 
their position, internal, antero-lateral, median, posterior or sensory cells, 
cells of Clark's column. " The blood supply of the cord, and especially 
of the grey matter, is of great importance since many diseases of the 
cord are the direct result of conditions that affect it. It is supplied 
with blood from the vertebral, ascending cervical, superior intercostal, 
dorsal intercostal, lumbar and sacral arteries. The vertebral artery 
gives off the anterior, posterior and lateral spinal. The anterior, 
according to Church "gives off about three hundred branches called the 
anterior median arteries which penetrate the anterior fissure at a right 
angle to the parent stem. At the commissure they enter the cord and, 
without dividing, turn toward the right or left anterior horn." The 
white matter in the anterior portion of the cord is also supplied by 



^ 



Fig. 113. — The spinal and gangliated cords. 



APPLIED ANATOMY. 371 

branches from this artery. This artery is reinforced by the lateral 
spinal branches. The posterior spinal arteries enter into an anastomosis 
with the lateral spinal, thus forming a plexus extending along the entire 
cord. Twigs are given off which supply in particular the posterior 
horns' of the grey matter. They are regarded by most observers as "of 
the terminal variety and therefore do not anastomose." According 
to Church there are three arterial districts: (1), "That only supplied by 
the anterior system; (2), that supplied only by the posterior system; and 
(3) that irrigated by both systems. It will be apparent from these facts 
that arterial disease may induce lesions mi the posterior half of the cord, 
or in the anterior half. Further, the infection or obliteration of a single 
anterior median artery will practically destroy the corresponding horn. " 
The lateral spinal branches pass through the corresponding foramina 
with the nerves and in its sheaths of dura mater, and supply in particular 
the corresponding segment of the spinal cord. The lateral spinal, for 
the upper part of the spinal cord, come from the subclavian, while the 
lower part is supplied with blood by the thoracic and abdominal aorta. 
Dana says: "It is an interesting fact that at or a little below' the point 
where the blood supply changes from the subclavian above the heart to 
the aorta, below, pathological disturbances frequently occur (transverse 
myelitis). " On account of the length of the anterior and posterior spinal 
arteries they are not subject, according to Church, to the direct impact 
of the cardiac impulses. "Arterial pressure is also slight, and the venous 
outlet into the plexuses about the dura mater is not an advantageous 
one in the erect position." The lateral spinal branches come from the 
dorsal branches in the different regions. This artery sends a branch 
into the cord, the lateral spinal, and continues as the muscular artery 
to the muscles of the back. In contractured conditions of muscles as we 
ordinarily find them, the muscles are congested. In such cases, the 
circulation through the muscular branch is practically obstructed, the 
blood backs up into the lateral spinal branch and the spinal cord becomes 
congested. The conclusion from this is that contractured muscles of 
the back produce congestion of the spinal cord, and that any treatment 
which lessens the contracture of these muscles, will better the circulation 
through the spinal cord. 

The veins correspond in their distribution to the arteries. The 
blood from the cord substance is gathered into the anterior and posterior 
system of veins, which empty into the lateral spinal except at the ex- 



372 APPLIED ANATOMY. 

treme upper part of the cord, at which place some of the blood passes 
into the sinuses of the brain. Most of the venous blood is gathered by 
the venae azygi. These veins are subject to pressure, on account of their 
position, from enlargement or congestion of viscera in relation or from 
long continued pressure, as in a lingering illness in which the patient 
assumes the dorsal posture without much change. Contractured mus- 

. cles have an effect on the veins similar to that on the arteries, that is the 
spinal cord becomes congested in such cases. 

The spinal cord has the following functions: (1) conductivity, 
conveying motor impulses from, sensory impulses to the brain; (2) 
centers that control the activities of viscera and the size of the blood- 
vessels; (3) centers for reflex action; and (4) control of nutrition of parts 
to which its nerves extend. In short, its functions may be classified as 

■ (1) a conductor of impulses, and (2) a series of nerve centers. These 
functions of' the spinal cord may be disturbed by many things. 

Lessened mobility of the spine weakens nature's protection of the 
spinal cord against injuries. The various shocks are less completely 
broken, the discs are less elastic, the ligaments are more tightly drawn, 
and the spinal column usually impacted, thus lessening the size of the 
intervertebral foramina. Lessened mobility of the spine produces a 
vascular change in the cord, since the contractions of the spinal muscles 
are of great value in the circulation of the blood through the spinal cord, 
and these contractions have almost, if not completely, disappeared in 
stiff spines. This is explained by the relation of the muscular, to the 
spinal branch of the artery that supplies both. Instead of the normal 
contractions, are found muscular contractures which interfere with the 
circulation to the cord. If the lessening of mobility is localized in one 
or two intervertebral joints, the effects are not so marked but the func- 
tion of that part of the spine is suspended. Lessened mobility of the 
spine then affects the spinal cord principally through the effects on its 
circulation, this coming about through a lessening of the size of the in- 
tervertebral foramina, lack of normal contractions of the spinal muscles 
in relation, and the presence of muscular contractures in these same 
muscles. This condition also lessens the elasticity of the spine, hence 
the spinal cord is not so well protected against jars of the body or in- 
juries. A stiff spine is more easily injured than one in which the motion 
is good, other things being equal, and when fracture, dislocation or 
subluxation of a vertebra occurs, the spinal cord is always affected. 




Fig. 114. — Showing changes in contour of the spine. B., normal spine; A., Flat- 
tening of the thoracic region; C, posterior in lower thoracic and upper lumbar re- 
gions. Note the effects on the size of the intervertebral foramina. Compare posi- 
tion of the coccyx, angle of sacrum and line of gravity. 



374 APPLIED ANATOMY. 

The intervertebral discs assist in the protection of the spinal cord 
in that they lessen the jar on the cord from running, etc., and permit of 
free movement of the spinal column. If their elasticity is lessened, 
if they are thinned, or if one side is malnourished, they the less securely 
protect the spinal cord since the spinal cord is more easily disturbed, 
as in concussion; the foramina are lessened, hence impairment of nutri- 
tion from which spinal curvature develops. 

A change in the normal curves of the spinal column, as in straight 
spine or any curvature, will more or less affect the spinal cord, depend- 
ing on the character, rapidity, and degree of the change. The normal 
curve lessens,to the greatest extent,the effects of shock and force. A change 
in the curve of the spine thus makes the cord more susceptible to shock 
and concussion. In addition, the circulation and nutrition are affected 
on account of the change in size of the intervertebral foramina; thus 
producing pressure on blood-vessels and nerves. The functions of the 
cord are impaired then, from the interference with the passing of nerve 
impulses and of blood, to and from the cord. 

The cerebro-spinal fluid commutes the force of a shock and thus 
prevents injury to the cord. This fluid may be pathologically lessened 
or increased in amount, which conditions predispose to injury of the cord. 

Lesions of the articulations of the vertebra? and ribs are responsible 
for most disturbances of function of the spinal cord. As in some of the 
conditions described above, I believe most of these effects come from a 
partial or complete closure of the intervertebral foramina. If a vertebra 
be subluxated in any way, either the foramen above or below it, is lessened 
in size, the amount of change depending on the degree or extent of the 
lesion. The artery supplying the cord with nutrition is thus partly or 
completely ligated. The same is true of the veins and lymphatic vessels. 
Circulatory disturbances of any character may then follow the lesion. 
Congestion, especially venous, is the most common since the vein is af- 
fected more in proportion than is the artery. Contracture of muscles of 
the back will have a similar effect. The nerves passing through the 
foramen, the recurrent meningeal and the common trunk of the spinal 
nerve, are also compressed. The recurrent, carries trophic and vaso- 
motor impulses to the cord and its membranes. The effect is that of 
congestion or anemia with its consequent disturbance of function. The 
common trunk carries afferent impulses to and efferent impulses from 
the spinal cord. The cord may suffer especially from the effects on the 



APPLIED ANATOMY. 375 

afferent roots. This disturbance of the afferent roots often comes from a 
spinal lesion, that is from subluxation of a vertebra. The pressure on the 
efferent nerve fibers produces muscular and visceral disorders, which in 
turn, disturb the circulation of the spinal cord, affecting its functions. If 
the lesion be irritative, it will produce a thickening and increased vas- 
cularity of the ligaments, a stimulation of the nerves, contracture of 
muscles and disturbance of the meninges, this being in the form of a 
congestion or inflammation. Hyperesthesia of the spine is a sequel to 
the last named condition. 

The functions of the spinal cord may be affected by pressure, as 
in complete dislocation or fracture of a vertebra, and in tumors, whether 
vascular or otherwise. The effects vary with the degree of pressure, 
jDaraplegia, however, being the most common effect. The pressure_ is 
not only on the blood-vessels and nerve roots, but is directly on the cord 
itself and results in interference with both conductivity and the gen- 
erating of nerve impulses. Transverse myelitis occurs in cases of frac- 
ture and complete dislocation. 

The condition of the spinal column is a good index to the condition 
of the spinal cord, or conversely, disturbance of function of the spinal 
cord is manifest by changes in the spinal column. A rigid spine, in which 
the rigidity is due to muscular contracture, is suggestive of disease of 
the anterior or lateral columns, as in spastic paraplegia. General re- 
laxation or paralysis of the spinal muscles indicates a chronic transverse 
myelitis. A tender spine is suggestive of a congested cord or inflamed 
or congested spinal membranes. Atrophy of a localized portion of the 
erector spina? mass of muscles, in indicative of inactivity of the trophic 
and motor cells in the corresponding segments. 

Abuse of function of certain viscera, especially the gastro-intes- 
tinal and genital tracts, will affect the functions of the spinal cord. It 
is a general law that activity produces congestion or hyperemia. If the 
fingers are vigorously opened and closed, hyperemia follows. If the 
brain is used, a greater amount of blood flows to it. If the stomach is 
stimulated from the ingestion of food, it becomes congested and in addi- 
tion the nerve centers in the spinal cord become congested. If sexual 
intercourse is indulged in, not only the parts directly concerned become 
hyperemic, but the spinal cord — that part giving rise to the nerves that 
take part in the process — also becomes hyperemic. In abuse of function 
of the viscera the congestion in the spinal cord becomes pathological. 



'376 APPLIED ANATOMY. 

Paraplegia from hemorrhage in the cord has resulted from vigorous 
coitus. Contracture of the spinal muscles follows a short while after 
the ingestion of something indigestible. Overactivity leads to path- 
ological congestion. In cases of insanity due to worry, I believe that a 
localized part of the brain is overworked, is constantly used to the ex- 
clusion of other parts, consequently, after a while the congestion becomes 
a pathological one. The treatment is rest, diversion of the mind, or 
anything to equalize the cerebral circulation. Thus it is with the spinal 
cord, sexual abuses repeatedly produce congestion of the genital cen- 
ters until finally they become pathologically congested and thus the 
cord is affected as to function. 

The functions of the cord are often disturbed by a toxemia. This 
may come from tetanus, syphilis, or in fact from any form of toxic ma- 
terial that may be in the blood. This toxemia produces at first a con- 
gestion, but later on in chronic cases, an inflammation. The disturb- 
ance of function varies with the kind and intensity of the poisonous ma- 
terial, opisthotonous occurring in acute cases, sclerosis in chronic cases. 

The effects of disturbance of function of the spinal cord, vary with 
the part affected and the way it is affected. If the white matter is dis- 
turbed, conductivity is impaired. The motor columns may alone be- 
come diseased as in spastic paraplegia, or the sensory columns may be 
affected as in tabes dorsalis. If the motor columns are affected by the 
lesion, the brain can no longer exert an inhibitory influence on the various 
muscles and nerve centers, and the reflexes are exaggerated. The 
various centers often act independently of the higher centers as is dem- 
onstrated by the involuntary evacuation of urine and feces. If the part 
of the cord below these centers is involved, there will be retention or 
dribbling of urine. In other cases of transverse myelitis, motion and 
sensation are lost in parts below the lesion, since motor impulses arise 
in the brain and the sensorium is the .receiver of all sensory impulses. 
If conductivity is only disabled or partly lost, there will be a partial 
connection between the brain and parts below the lesion. Painful im- 
pressions are supposed to be carried by the grey matter; sensations of 
touch by the lateral columns and the grey matter. Both of these col- 
umns are in the side of the cord opposite to that of the stimulus; that 
is, if the left side of t-he cord were affected, the effects would be on the 
right side of the body. 

The vaso-motor centers in the cord are usually affected by lesions 



APPLIED ANATOMY. 377 

of the vertebral articulations and by disease of the cord. Gowers says : "The 
sympathetic nerves to the vessels are influenced from the spinal cord. 
It is probable that the path is by the fine fibers of the anterior roots and 
that most of the constrictor fibers leave the cord between the third dor- 
sal and second lumbar, while the dilator fibers are more widely scattered, 
many arising in the upper dorsal region, while others leave the cord in 
its lumbar and sacral portions (pelvic outflow). Some facts of disease 
suggest that the subsidiary vaso-motor centers are situated in the inter- 
mediate grey matter; and this conclusion is supported by the important 
researches of Gaskell, which refer the function to the small cells of the 
intermedio-lateral tract which he traces upward to the vaso-motor 
center in the medulla. " The effect on the cord of a lesion or other dis- 
turbance may be that of stimulation or inhibition. If the former, con- 
traction at least for a while, of the blood-vessels governed by that part 
will take place, while if the vaso-motor centers are inhibited, dilatation 
of the vessels will result. Thus congestion or anemia may result from 
these vaso-motor disturbances. The head and face have their vaso- 
motor centers in the lower cervical and upper dorsal portions of the spinal 
cord. If the lesion inhibits these centers, congestion of the above 
parts takes place; if the lesion is irritative, anemia is the result. Con- 
gestive headaches, congestion of the eyes or any part of the head and 
face, can often be cured by correcting a lesion of an upper dorsal vertebra. 
I believe that every muscle fiber of every artery and vein in the body is 
represented in the spinal cord by a cell which nourishes it and controls 
its action. These cells are grouped and constitute the vaso-motor cen- 
ters. The cell must be properly nourished and the line of communica- 
tion between it and its muscle fiber must be clear, if it is to act normally. 
If the impulses are interrupted or if the cell is inactive, the muscle fiber 
is not properly nourished and becomes relaxed. If the cell or its nerve 
filament is stimulated, contraction of the muscle fiber results. 

The sensory effects are manifest on the opposite side of the body; 
that is, a lesion of the left side of the cord would be manifest by sensory 
disturbances on the right side of the body. Girdle pains, as in locomo- 
tor ataxia; numbness or anesthesia, as in atonic paraplegia from trans- 
verse myelitis; perverted sensation, as in syringomyelia; and disturb- 
ances of tactile sensations and of heat and cold are the principal sensory 
effects of lesions or diseases that disturb the sensory columns of the 
spinal cord. 



378 APLLIED ANATOMY. 

The motor effects of disturbance of the functions of the spinal cord- 
are paralysis, with atrophy or with spasticity, which are represented by 
simple paraplegia and spastic paraplegia. The motor impulses may be 
entirely cut off, partly inhibited or stimulated by the disturbance in the 
spinal cord. The muscular fibers in the various viscera are more or 
less under the control of the spinal cord. Gowers says: "Although 
the viscera are under the immediate control of the sympathetic system 
of nerves, they are related to centers in the spinal cord, and it is from 
these centers that the controlling influence is really derived, probably 
by means of the finer fibers of the anterior roots. The relation is the 
most direct and important so far as concerns the disease of the spinal 
cord, in the case of the organs over which the will has an influence, the 
rectum and the bladder. " The visceral effects of a disturbance of the 
spinal cord would therefore, be increased or lessened peristalsis, that is 
increased or 'decreased activity above or below the normal. Diarrhea 
is an example of the former, constipation of the latter. In chronic spinal 
cord diseases, the sympathetic gangliated cord attempts to take on the 
function of the spinal cord, sometimes successfully, as is illustrated in 
cases of transverse myelitis in which the sympathetic cord controls- 
nutrition, circulation and, to a certain extent, the various reflex pro- 
cesses. 

The sexual function is always disturbed in spinal cord disease. 
This disturbance ranges from complete impotence to priapism. This 
applies especially to diseases that involve the lumbar enlargement of the 
cord. 

The trophic effects of spinal cord disease are sometimes wonder- 
fully rapid and extensive. The trophic cells are in the anterior horns of 
the grey matter of the spinal cord. Every part of the body receiving 
impulses from the spinal cord would be affected by any disease of the 
cord involving these centers. This trophic influence is exerted prin- 
cipally through the motor nerves. It involves muscles, ligaments, bones, 
skin and viscera. The tone of muscles depends on activity of the center. 
The effects of impairment of this function of the spinal cord would be 
malnutrition, relaxation, caries and the formation of bed sores or necrosed 
areas, if the disturbance is acute or destructive, as in some cases of mye- 
litis. 

The spinal cord is a very important part of the cerebro-spinal axis. 
It not only transmits impulses to and from the brain, but originates 



APPLIED ANATOMY. 379 

many •impulses. Its activity or function depends on the condition 
and amount of blood circulating through it. Lesions of the vertebrae 
affect both and give rise to disturbance of function. Many of the re- 
sults obtained by osteopathic treatment come from restoring normal 
circulation to and from the spinal cord. To do this, correct all anatomical 
derangements, such as subluxated vertebra? and contractured muscles, 
that lessen the size of the intervertebral foramina or produce in any 
way, congestion of the muscles or cord. 

THE RIBS. 

The ribs, together with the sternum, form the thorax on the sides 
and front, the bodies of the thoracic vertebra? forming the posterior 
wall. They are flattened, twisted, hoop-like bones which articulate 
with the bodies and transverse processes of the thoracic vertebra? and 
are so arranged that their length and obliquity increase from above 
downward, the former to the false ribs, the latter to the tenth. This 
obliquity is so great that the sternal end of the rib is several vertebra? 
lower than the vertebral end of the same rib. They are divided into 
true, false and floating, which number seven, three and two, respec- 
tively. 

A typical rib consists of a head, neck, tubercle, angle and shaft. 
The head is divided into two parts by a ridge which gives attachment to 
a ligament, the inter-articular. The facets are slightly concave, the 
lower usually being slightly the larger and articulates with the upper 
part of the body of the vertebra in numerical correspondence. The upper 
articulates with a facet on the lower part of the vertebra above. The 
movement at these facets is slight, being a sort of rotation. The neck 
is the constricted portion between the head and tubercle. It is smooth 
anteriorly but its posterior surface is rough for attachment of ligaments 
and muscles. The tubercle consists of an enlargement which has two 
parts, an articular and a non-articular. The articular part is slightly 
convex, of oval shape, faces downward, backward and slightly inward 
and articulates with the facet on the transverse process of the corres- 
ponding vertebra. The movement at this articulation is a slight up and 
down one with some rotation. The non-articular part gives attachment 
to the costo-transverse ligament. The angle of the rib corresponds to 
the point of greatest curve, there being a rough ridge which runs ob- 
liquely across the shaft. It is the part that can be best palpated in up- 



380 



APPLIED ANATOMY. 



NECK 



ANGLE 




FOR COSTAL 
CARTILAGE 



Fig. 115. — A typical rib. 



APPLIED ANATOMY. 381 

ward subluxations of the rib, in which case the angle appears at a prom- 
inence which is usually quite tender. The prominence is due partly 
to thickening of the tissues and partly to the displacement upward. 
Beyond the tuberosity, each rib is prolonged as a twisted, flattened, thin 
hoop, which part is called the shaft. It presents an upper border which 
is rounded and smooth and considerably thicker than the lower border. 
This gives attachment to the internal intercostal muscles and a few 
fibers of the external intercostals. In upward subluxations of the rib, 
this border can be quite clearly outlined. 

In enlarged chests, as in asthmatic patients, the ribs are drawn up- 
ward and forward, thus bringing into prominence the upper border of the 
rib. The lower border or edge is quite thin. It is grooved for the 
passage of the intercostal nerve and vessels, the outer edge of the groove 
being quite sharp. It gives attachment to the external muscle, while 
the inner edge gives attachment to the internal intercostal muscle. 
Near the anterior end of the rib, the groove disappears and its lips or sides 
unite to form a rounded edge. The openings in the rib for the passing 
of blood-vessels are in the floor of the groove. They are called nutri- 
ent foramina. This border of the rib can with difficulty be palpated in 
a full chested subject, but in patients suffering with pulmonary tuber- 
culosis, or from emaciation from any cause, it can be readily outlined. 
In such cases the ribs are in a position of descent, and the lower the 
sternal end, the shorter the antero-posterior diameter and the more 
prominent the lower edge. In downward displacement of the anterior 
end of the rib, the lower edge can.be plainly outlined. This furnishes 
a reliable sign in the diagnosis of a rib lesion. In collapse of the lungs 
the lower edges almost, if not actually, overlap, as does the weather- 
boarding of a house. 

The external surface is smooth and convex, thus conforming to the 
general curve of the thoracic wall; that is, the first rib faces upward; 
the upper ribs, .upward and outward; the middle, outward; and the 
lower ribs outward and slightly downward. Some muscles are attached 
to this surface, such as the pectoralis major and serrati muscles. The 
inner surfaces face opposite to the external and give attachment to the 
parietal layer of the pleura. As each rib approaches the sternal end it 
becomes twisted on its axis in addition to the curve. This gives it a 
spiral shape which can best be appreciated by placing the rib on a plane 
surface, it being found that the two ends can not be kept down at the 



382 APPLIED ANATOMY. 

same time. The curve and twist are most pronounced at the angle of 
the rib. Many a person owes his life to the obliquity and curvature of 
the rib, since they the better deflect the course of a pistol ball, which 
follows the rib instead of directly entering the thoracic cavity. The 
anterior end of the rib is larger, more porous and has a cup shaped de- 
pression for articulation with the costal cartilage. 

A typical rib has three articulations, two with the vertebra and one 
with the costal cartilage. The articulation of the head of the rib with 
the bodies of the vertebras is a diarthrodial one and is classed as a hinge- 
or ginglymoid joint on account of the character of its movement. The 
head has two facets, the upper one articulating with the vertebra above, 
the lower one with the vertebra below and the center of the head articu- 
lates with, or rather is attached to, the intervertebral discs by means 
of the interarticular cartilage. On account of this arrangement, sub- 
luxation of a .vertebra will quite readily affect the head of the rib. 

The ligaments of the costo-vertebral articulations are the capsular, 
stellate or costo-vertebral, and the inter-articular. There are also two 
membranes corresponding to the two articular facets of the head and 
separated by the interarticular cartilage. Perhaps they have something 
to do with the "popping" sound which is often heard on movement of 
the head of the rib. The capsular ligament entirely encloses the articu- 
lation and is attached to the contiguous vertebrae, intervertebral disc and 
rib a little beyond the articular margins. The stellate seems to be a 
thickened portion of the anterior part of the capsular and consists of 
three glistening bands which pass upward, forward and downward from 
the head of the rib to be attached to, or inserted in the bodies and disc 
of the adjacent vertebras, the upper fasciculus going to the lower part 
of the vertebra above, the middle to the disc and the lower to the upper 
border of the vertebra in numerical correspondence. These fasciculi 
are in relation with, and to a certain extent reinforced by, the anterior 
common ligament of the vertebral column. 

The interarticular, attaches the ridge on the head of the rib to the 
intervertebral disc in relation, thus dividing the joint into two separate 
compartments. It does not hold the head of the rib tightly against the 
vertebra, but permits of a moderate amount of motion, as in rotation of 
the rib in respiration. In subluxations of the rib, this ligament is in- 
jured which often results in a deposit, this thickening it and interfer- 
ing with the movement of the head of the rib. These costo-vertebral 



APPLIED ANATOMY. 



383 



articulations are innervated by filaments from the anterior divisions 
of the thoracic nerves in relation. 

Each typical rib articulates with the tip of the transverse process 
of its corresponding vertebra. This articular facet, in the case of the 
upper five thoracic vertebra, faces forward and slightly upward, thus 
giving support to the parts above, while the facets on the transverse 



SUP PROG. 



TRANSVERSE PROC 



POST. COSTO 
TRANSVERSE 




Fig. 116. — Costo-vertebral articulations viewed from the right tide. 

processes of the remaining thoracic, face forward and slightly downward. 
There are two ligaments uniting the tubercle of the rib to the transverse 
process, the capsular and costo-trans verse, the latter being subdivided 



384 APPLIED ANATOMY. 

into the anterior or superior, posterior and middle costo-transverse. 

The capsular is a loose, thin envelope that surrounds the articula- 
tion, enclosing a synovial membrane. The superior or anterior costo- 
transverse ligament, consists of fairly strong bands which pass upward 
from the upper border or crest of the neck to be attached to the trans- 
verse process of the vertebra immediately above. The inner border helps 
to form the foramen through which pass the posterior branches of the 
intercostal nerves and vessels. In cases of subluxations of the rib in 
which this ligament is injured or impaired in any way, the size of this 
foramen would be lessened, hence there would be pressure on the nerves 
and vessels passing through. This applies especially to the veins and 
nerves. Pain or tenderness at the tuberosity of the rib or congestion of 
the integument, in relation often results from pressure on the sensory 
nerves and veins. The posterior costo-transverse ligament runs trans- 
versely and attaches the non-articular part of the tuberosity of the rib 
to the top of the transverse process. The middle costo-transverse, con- 
sists of short fibers that connect the posterior aspect of the rib with the 
front of the transverse process. It is always affected in an ordinary 
lesion or subluxation of the rib. The innervation is the same as that of 
the costo-vertebral articulations, viz., filaments from the intercostals 
in relation. 

The movement of a typical rib is essentially one of rotation upward 
and outward on its axis which is directed obliquely forward and inward, 
passing through the costo-transverse and costo-vertebral articulations. 
In inspiration, the rib rotates upward on its articulations, thus drawing 
the anterior end upward and forward as it tends to assume the horizontal 
position. Perhaps, in addition to the rotary movement at the costo- 
transverse articulation, there is also a gliding one, the rib moving di- 
rectly upward, especially in case of the lower ribs. 

THE FIRST RIB. 

The first rib is distinctly peculiar on account of its size, form, it 
being almost flat, and its degree of curvature. The head is small and 
has only one facet for articulation with the side of the body of the first 
thoracic vertebra. The neck is slender, longer and more nearly round 
than that of other ribs. It is slightly flattened from above downward, 
is smooth anteriorly and rough posteriorly for attachment of ligaments. 
The angle is exaggerated by the tubercle which is quite .large. The 



APPLIED ANATOMY. 



385 



facet on the tubercle is small and articulates with a corresponding one 
on the transverse process of the first dorsal vertebra. This facet on the 
transverse process of the vertebra, is concave and faces slightly upward. 
On this account the weight from above is the better supported and in 
displacements of the first rib, it determines to a great extent the direc- 
tion of the deviation, that is, it is most easily displaced upward. The shaft 
lies practically in one plane,so that if the rib is placed on a plane surface, 
it lies almost flat. Its superior surface looks forward and upward and 
has a tubercle for the attachment of the scalenus anticus muscle, and a 
groove immediately behind the tubercle for the artery, also a groove in 



COSTO-CENTRAL 
SYNOVIAL SAC 




ANT. COSTO- CENTRAL 
OR STELLATE LI GMT. 



MID. COSTO- A0^& 11% 

TRANSVERSE LIGT. / gfM ''/$*&$. 



POSTERIOR COSTOTRANSVERSE LIG MT W$$ COSTOTRANSVERSE SYNOVIAL SAC 

1 

Fig. 117. — The costo-vertebral articulations viewed from above. 



front for the subclavion vein, thus the muscle separates the artery 
and vein. To this surface are attached from before backward, the follow- 
ing muscles: subclavius, scalenus anticus, serratus magnus, scalenus 
medius, levator costse and accessorius. These muscles on contracting, 
either fix or draw upward the rib. If they are in a state of contracture, 
they displace the rib upward. On account of attachment of most of the 
muscles posterior to the middle of the rib, the posterior end of the 
rib would be moved most on contracture of the muscles attached to the 
upper surface. The lower surface, smooth and flat, acts as a subcostal 



386 APPLIED ANATOMY. 

groove and gives attachment to the external intercostal muscle; the 
inner edge thin, sharp and markedly concave, gives attachment to fascia. 

The movements of this rib are slight, consisting of a slight up and 
down or gliding movement with some rotation. As in any rib, if it were 
not curved, the movement at the transverse process would be greater than 
at the head, but the twist in the rib permits of elevation of the anterior 
end with rotation at the costo-transverse articulation. This will apply- 
better to the ribs that have a marked twist than to the first rib. 

The landmarks used for locating this rib are for the sternal end, the 
sterno-clavicular articulation; the rib being immediately below and 
back of it; for the vertebral end, the vertebra prominens and transverse 
process of the seventh cervical, the angle of the rib being at the point 
of intersection of a horizontal line passing through the spine of, and a 
vertical line passed through the tip of the transverse process of, the 
seventh cervical. The angle and posterior part of the shaft can be 
palpated at the anterior border of the trapezius. 

The vessels in relation are the subclavian artery and vein, which 
■cross its upper surface, and the superior intercostal artery and vein, 
which cross the head of the first rib. The superior intercostal artery 
supplies the muscles, in relation, the rib and a part of the spinal column 
and cord, the spinal branch entering through the intervertebral foramen 
with the eighth cervical nerve. The corresponding veins drain the muscles 
and spinal cord in relation. The subclavian vessels at this point carry 
the blood to and from the arm. Some lymphatic vessels are in relation, 
principally those draining the mammary gland, axilla and arm. 

The nerves in relation with the first rib are the first intercostal, 
nearly all the nerves going to make up the brachial plexus, the recurrent 
meningeal and the stellate ganglion with its branches and communica- 
tions. In addition to the above, the inferior cervical ganglion would be 
affected since it is in relation with the head of the first rib. As a result 
of a lesion affecting the nerves in relation, many organs and structures 
some distance from the seat of the disturbance would be affected. 

The lesions or subluxations of the first rib in nearly every case, con- 
sist of an upward and backward displacement of the vertebral end. 
This increases the obliquity of the rib and the fullness or prominence of 
the muscles and tissues in relation with the vertebral end. The upward 
subluxation results most frequently from muscular contracture or spas- 
modic contraction. The most important muscle is the scalenus medius. 



APPLIED ANATOMY. 



387 



In spasms of the neck and shoulders the rib may be forcibly drawn or 
forced out of place. The deviation is indicated by the tense condition 
of the scaleni muscles and the prominence of the rib particularly at the 
vertebral end. If both upper ribs are involved, the sternum is drawn 
inward and the clavicles down, so that the space between the clavicle 




SERRATUS 
MAGNUS 



Fig. 118. — Showing the first and second ribs. 



and first rib is lessened in size. There is tenderness at the costo-trans- 
verse articulation and, in some cases, along the upper surface of the rib. 
There is disturbance of function of tissues in relation and structures in- 
nervated by nerves that are commonly affected by a lesion of the first 



388 APPLIED ANATOMY. 

rib, viz., the stellate and inferior cervical ganglia and the first thoracic 
nerve. 

The effects vary considerably in the different cases. The muscles 
attached to the rib are usually contractured but this is often a cause of 
the displacement as well as an effect. The tissues attached to the rib 
are disturbed, such as the fascia and pleura. Sometimes these effects 
are manifest only or principally by soreness on deep inspiration. The 
blood-vessels in relation are disturbed either by direct pressure or con- 
traction of tissues with which they are in relation. Congestion of the 
spinal muscles, the spinal cord and possibly the upper limb is a common 
sequel. The muscles undergo contracture and the centers located in 
the eighth cervical and first dorsal segments of the spinal cord, are dis- 
turbed as to function. Pain in the arm and along the first intercostal 
space is a sequel. Heart disturbances, principally functional in char- 
acter, are riot unusual. This comes from effect on the stellate ganglion 
which is in relation with the head of the rib. Lung and bronchial dis- 
orders are more common than heart affections, as a result of this lesion. 
This is because of the filaments from the spinal and gangliated cords that 
pass to the lungs and bronchi are impinged by the subluxated rib. 

The circulation to the head and face may be disturbed on account 
of the rib lesion interfering with the passing of the vaso-motor impulses 
to the head and face, they going over the gangliated cord and ganglia. 
The throat is often affected by this lesion, through the effect on the in- 
ferior cervical ganglion and its connection with the laryngeal nerves. 
A hacking cough is very often caused by such a lesion. In the various 
disorders of the throat characterized by congestion or inflammation, it 
is advisable to examine the first rib for the suspected cause. It may be 
that the subluxation is producing the effect by direct pressure on blood- 
vessels, but I believe these effects result from disturbance of the vaso- 
motor supply to these parts, which conies to a great extent from the in- 
ferior cervical ganglion and spinal cord, the upper thoracic portion. 

The thyroid gland is in many cases, affected by a subluxation of the 
first rib. The effect is one of congestion and hypertrophy. The best 
explanation is that the subluxated rib, by disturbing in some way the 
inferior cervical and stellate ganglia, interferes with the vaso-motor 
supply to it, which seems to be principally along the inferior thyi-oid 
arteries. The inferior cervical ganglion gives off a branch to this artery 
and vein which controls, to a large extent, the amount of blood in the 






RECTUS 
CAPITIS ANT MINOB 



RECTUS CAP. ANT. MAJOR 



RECTUS 
CAPITIS LATERALIS 



INTERTRAMSVERSALIS 



LONGUS- COLLI 




SCALENUS ANTiaJS 
SCALENUS MEOIUS 
SCALENUS POST, 



BRACHIAL 
PLEXUS 



AXILLARY 
ART. 



£-***, 



LYMPHATICS 



Fig. 119. — Front view of the neck showing the relation of the scalene muscles to 
the ribs. Note that their contraction will lessen the space between the first rib and 
the clavicle and thus compress the structures in this area. 



390 APPLIED ANATOMY. 

gland. The vertebral end of the rib is usually displaced upward and 
backward, thus forcing the head of the bone against the gangliated cord 
or directly against the ganglion. This is not the only bony lesion found 
in diseases of the thyroid gland, but forms the most common and im- 
portant. 

The character and causes of subluxation of the first rib are not 
rightly understood in_many cases, since the contracture of the muscles 
attached to it is of prime importance, while the usual treatment to 
"lower" the rib is ordinarily useless in such cases. In other cases, 
the rib may be displaced from trauma as in a fall, in which the neck is 
jerked violently to one side or the shoulders thrown upward as in falls 
on the arms and hands. By the powerful and sudden contraction of the 
scalene muscles, the rib in such cases, is drawn upward at the vertebral 
end. In all such lesions, a lowering of the rib is indicated since it is not 
held out of place by contracture of the muscles yet in some cases, the 
muscles become contractured on account of the injury to them. Pos- 
terior luxations of the first thoracic vertebra are responsible for many 
of the displacements of the first rib. In the carrying of weights on the 
shoulders it is possible, in fact common for some change in contour to 
take place in the upper thoracic vertebrae. As is the case with most 
rib lesions, the corresponding vertebrae are usually subluxated, which is 
the cause of the rib lesion. 

Lesions along the middle and lower parts of the neck are primarily 
responsible for the rib disturbance, on account of effect on muscles. 
On the other hand, many disorders attributed to a displacement of the 
clavicle are due to upward subluxation of the first rib, as in some affections 
of the arm. 

THE SECOND RIB. 

The second rib is somewhat larger than the first, but like it, is con- 
siderably curved and little twisted. The head has two facets which 
articulate with the first and second dorsal vertebra?. An angle is pre- 
sent which is external to the tubercle. The shaft presents two surfaces 
which are almost plane. The upper faces upward and outward. Near 
the middle of the shaft is a roughened eminence for attachment of the 
digitations of the serratus magnus. Between this roughened eminence 
and the tubercle there are attached five muscles: the scalenus posticus, 
serratus posticus superior, musculus accessorius, the cervicalis ascendens 
and the levator costaa. 



APPLIED ANATOMY. 391 

The principal landmark of the second rib is its articulation with the 
sternum, it forming a transverse ridge across the sternum which cor- 
responds to the junction of the first and second parts of the sternum. 
Posteriorly, it can be indistinctly outlined by pressure at the transverse 
process of the second dorsal vertebra on a level with the spine of the first 
dorsal. If the muscles are contractured or if there is much adipose tissue, 
it is very hard to accurately outline it. The pleura is attached to the 
inner surface of the rib, while to the outer surface are attached the lig- 
aments and muscles which are, in addition to those named above, the 
intercostals. The intercostal vessels are in relation with this rib and 
are, in all likelihood, always more or less affected by a subluxation of it, 
either directly or indirectly, through traction on adjacent tissues. 

The nerves in relation with the second rib are the second thoracic 
nerve, with its anterior or intercostal branch, and its posterior division; 
the sympathetic gangiiated cord; the second thoracic sympathetic gang- 
lion and its branches, the pulmonary, cardiac, aortic; and branches that 
go to the vertebra, ligaments, spinal cord and meninges. 

The movements of this rib are like those of a typical rib except that 
they are less marked. Like the first rib, it is fixed by muscular con- 
traction during deep inspiration. 

The most common lesion or subluxation, on account of the attach- 
ments of muscles, is an upward and backward deviation of the verte- 
bral end. The scalenus posticus and levator costa? muscles are attached 
near the tubercle and by their contracture, the vertebral end will be 
drawn upward and backward and held in that position. This can be 
diagnosed by the condition of the muscles, they being contractured; prom- 
inence of vertebral end; retraction of sternal end; and by the fact that 
usually the sternum is also less prominent; tenderness at the costo- 
transverse and chondro-costal articulations and disturbance of function of 
structures attached, or viscera innervated by nerves in relation with the rib. 

The effects of a lesion of this rib are most pronounced in the lungs, 
pleura, bronchi and second intercostal nerve. 

Broncho-pneumonia is dependent, to a certain extent, upon a sub- 
luxation of this rib. The lesion may be secondary to repeated colds in 
which the upper thoracic muscles are always contractured or it may 
be the result of trauma or sprain. These conditions result in displace- 
ment of the ribs, which is usually very slight. The subluxation affects 
the passing of vaso-motor and other impulses from the spinal and gang- 



392 APPLIED ANATOMY. 

Hated cords to the lungs and bronchi, by producing pressure on the 
gangliated cord, second thoracic sympathetic ganglion or the pulmonary 
branches. These impulses arise in the spinal cord, upper thoracic seg- 
ments, pass out over the anterior nerve roots, common nerve trunk, 
white ramus, second thoracic ganglion and efferent branches which go to 
form the posterior pulmonary, plexus. On account of the relation of the 
second rib to these nerves, the connection between the spinal cord and 
lungs is impaired or entirely broken, hence vaso-motor, secretory and 
trophic disorders follow. 

In tuberculosis of the lungs, these rib lesions are present in nearly 
all cases. They are causative in some cases, while in others they are 
resultant. Repeated colds produce repeated contractures of the spinal 
muscles. These contractures interfere with the circulation of blood to 
the spinal cord and the position of the vertebrae and ribs. The ribs are 
drawn up at.the vertebral end and depressed at the sternal end. The 
nerves that innervate the muscles of respiration are inhibited, respira- 
tion is shallow and the chest movements are lessened; trophic and vaso- 
motor nerve impulses are to a great extent cut off, and venous conges- 
tion of the bronchial circulation with degeneration of the living tissue 
takes place. The tubercle bacillus, which is ever ready, finds in this 
devitalized area a nidus favorable for its propagation, hence the disease 
known as tuberculosis of the lungs. 

The explanation of a subluxation of the second rib producing tuber- 
culosis of the lungs is, that the subluxation of the rib interrupts the tro- 
phic and vaso-motor lines of communication between the spinal cord and 
the lungs or else it produces direct pressure on the lung substance. 

Pleurisy may be a complication of lung disorders or pleuritis, but in 
many, is also an effect of a lesion of the second rib. The explanation is 
(l),that the displaced rib presses directly on the intercostal nerve, thus 
producing pain in the parietal layer of the pleura to which it is distri- 
buted, and (2), since the pleura is directly attached to the rib a sublux- 
ation of the rib, however slight, would produce traction on, or injury in 
some way to, the pleura. Bronchitis is often the result of lesions of the 
upper ribs. Chronic bronchitis with cough is in most cases the result 
of a subluxation of the second or third rib. The reason for it is the fact 
that these rib lesions disturb the innervation of the bronchial tubes which 
are almost entirely innervated by way of the pulmonary plexus. Chronic 
cough of a bronchial nature,is the result of irritation of the sensory nerves 



APPLIED ANATOMY. 393 

lining the tubes, the irritating factors being congestion and hypersecre- 
tion of the bronchial mucous membrane. It may be due to irritation 
of the pleura or lungs, the cough being an attempt on the part of the 
body to eject or otherwise rid itself of the irritating factors. The motor 
nerves supplying the bronchioles may be affected by this rib lesion and the 
size of the lumen changed. If the nerves are stimulated the bronchioles 
contract and the condition is called asthma on account of its effects on 
respiration. The coughing is due to irritation of the bronchial mucous 
membrane and that lining the larynx as well. The different parts of 
the respiratory tract are correlated so that a disturbance of one part will 
usually manifest itself in another part of the same tract. It is a well 
known clinic fact, that chronic cough, bronchial or laryngeal, in most 
cases, comes from a subluxation of the second rib, but may be a reflex 
effect of many visceral disorders and irritation applied to distant parts. 

Many impulses arising in the upper part of the thoracic spinal cord 
pass out over the white rami into the gangliated cord, thence upward to 
the head and face. These have been described before. (See second 
thoracic segment). These impulses supply blood-vessels, glands, mucous 
membranes and muscles with vaso-motor, secretory, motor, and trophic im- 
pulses and possibly control sensation. In this connection should especially 
be mentioned the circulation of the brain, the pupil of the eye and the 
salivary glands, the submaxillary in particular. 

Congestive headaches often follow subluxation of the second rib 
especially on the left side. The explanation is, (l),that the vaso-motor 
impulses to the various cerebral vessels are inhibited by pressure of the 
head of the rib on the nerve trunk conveying these impulses, hence 
dilatation of the blood-vessels of the head, and (2), this lesion in addi- 
tion, may excite the cardiac accelerators, which condition results in the 
forcing of more blood into these already dilated vessels of the brain. 

Displacement of the second rib is associated in some cases with 
mammary disturbances. Extirpation of one breast causes a weakness 
of the eye on the same side. The connection is through the upper spinal 
segments. A subluxation of the second rib will interrupt this connec- 
tion, or perhaps in some cases, irritate the nervous mechanism, since the 
nerves tracts or trunks are in relation with the rib and are subject to 
pressure when the rib is out of its normal position. The mammary gland 
may be affected in different ways by this rib lesion. Imperfect or non- 
development, mastitis and disturbances of secretion and nutrition can 



394 



APPLIED ANATOMY. 



be rightfully attributed to disorders of the upper ribs. The explana- 
tion is that the rib lesion disturbs the innervation of the gland, which 
comes by way of the intercostal nerves. 

The arm on the same side is often affected by a lesion of the second 
rib. Most of the trophic and vaso-motor impulses to the upper extrem- 
ity come from the upper thoracic spinal cord. These impulses pass out 



611..CERVICAL VERTEBRA 



SYMPATHETIC GANGLIA 




Fig. 120. — Showing the relation of the structures in the intervertebral 
foramina to each other and to the ribs and vertebra?. 



APPLIED ANATOMY. 395 

from the spinal cord over the anterior nerve roots, through the inter- 
vertebral foramen over the common nerve trunk and reach the arm by 
passing into and up the sympathetic gangliated cord and over the 
brachial nerves. This cord with its second thoracic sympathetic gang- 
lion, is in relation with the head of the second rib. In all subluxations 
of the rib, the head of the rib is changed as to position and often presses, 
directly or indirectly, on the gangliated cord, thus interfering with the 
line of communication connecting the upper thoracic segments of the 
spinal cord and the arm. 

The muscles attached to the rib and those innervated by the nerves 
in relation with the second rib are affected by this lesion. If contrac- 
tured, which they will be if the lesion is irritative, their function is dis- 
turbed, circulation through them altered and a sense of ache usually 
accompanies the condition. In acute cases there may be a distinct 
pain which will ascend to the back of the neck and head. In occupation 
neuroses, an ache is very commonly found between the shoulders or on 
the affected side. Relaxation with atrophy and weakness may follow 
instead of contracture, but irritation seems to be the usual primary effect 
of a typical subluxation of any bone. 

In recent cases of a subluxated second rib, pain or ache along the 
course and distribution of the second intercostal nerve, combined with 
a dry, irritative cough often leads to the diagnosis of tuberculosis of the 
lungs. Deep inspiration is painful, the patient is drawn forward to 
better shield the affected side, circulation through the lungs is lessened 
in amount and rapidity, and the patient has the general appearance of a 
consumptive. In some cases tuberculosis develops but can be pre- 
vented by the proper treatment, which consists of correction of the rib 
lesion. Tenderness on pressure along the course of the second rib is 
present in practically all lung affections. The intercostal nerve and its 
branches are congested in such cases as well as the tissues in relation. 
Tenderness here may be the result of over use of the intercostal and 
serrati muscles. 

THE THIRD RIB. 

The third rib is classed with the typical ribs, hence needs little, if 
any, separate mention. It is longer, more twisted and curved than the 
second, but not so much so as the fourth rib. Its external surface faces 
more nearly directly outward than that of the second rib. The sternal 



396 APPLIED ANATOMY. 

end can be readily located by refering to the sternal end of the second 
rib which forms a ridge on the sternum at the junction. of the first and 
second portions. The third intercostal space is the largest, and unless 
this is remembered when making a physical examination of the chest, 
it might be regarded as an abnormality. The second intercostal space 
is next in size. 

This rib gives attachment to the pleura and the various chest mus- 
cles. Among the most important are the levator costae, serratus magnus 
and intercostals. The third intercostal artery and vein are in relation 
with the shaft and head. The third thoracic nerve with its anterior and 
posterior divisions, the sympathetic gangliated cord, and the third sym- 
pathetic ganglion with its branches, are also in relation. The viscera 
in relation are the heart on the left side, and the lungs. 

The movements of this rib are not so marked as those of ribs lower. 
They consist, of a rolling and gliding movements at the costo-trans- 
verse articulation. There is some rotation at the head but the move- 
ment here is less than at the costo-transverse articulation. The rib is 
thus everted and elevated at the sternal end and with this, all the diameters 
of the chest are increased. 

The third rib is a typical one and on this account, its lesions are 
typical and the kinds of lesions and their description that apply to this 
rib, will apply to all of the true ribs. The subluxations of this rib vary 
but the most common is the one in which the rib is drawn up at the ver- 
tebral end and inward and downward at the sternal end. This sort of 
displacement is characterized by increased obliquity of the rib; depression 
at the sternal end, it being displaced slightly inward and downward; un- 
due prominence of the tubercle which is due to the displacement upward 
at this point so that it is the more easily palpated, and to a great extent 
this prominence is due to the ligamentous thickening at the costo-trans- 
verse articulation; increased prominence of the lower edge; a lessening 
in size of the interspace below at the sternal end and increase in size of 
the corresponding space at the vertebral end; tenderness at both ends 
and often along the lower edge of the rib ; and disturbance of function of 
the rib so that its movements are impaired and painful. The function 
of the costal joints, like that of any joint is movement and in diagnosing 
any osseous subluxation, a test of the mobility should be made. This is 
done in the case of the costal articulations by causing the patient to fill 
the lungs to their utmost capacity. In practically all rib subluxations 



APPLIED ANATOMY. 397 

that are really causing trouble, unless it is a very chronic case, there 
will be some sort of pain or discomfort on deep respiration since the move- 
ment of the rib is greatest in deep inspiration. In chronic cases, the 
movement may only be restricted and not necessarily painful. 

The rib may be displaced upward at both ends. This is diagnosed 
by the change in the intercostal spaces, the one above being lessened and 
the one below increased, throughout their entire course. 

A twisting of the rib is indicated by prominence of one of the edges 
it depending on the character of the twist as to the edge involved. The 
most common type is an upward twisting in which the lower edge is 
thrown outward. Such subluxations are diagnosed by the prominence 
of an edge. 

It is possible for the vertebral end to become displaced downward 
from trauma or severe sprain of the body, this displacement could 
scarcely result from muscular contracture on account of the direction 
of the muscle fibers attached to the rib. 

In all rib lesions, it is well to remember that both ends of the rib 
are affected but the degree of movement is greatest at the sternal end. 
Inflammatory material collects around the vertebral end in traumatic 
cases and is responsible for many of the effects. There is an enlargement 
at the articulation which can be palpated in the case of the costo- 
transverse joint. 

The effects of a lesion of the third rib vary with the degree of the 
subluxation, length of standing, cause of the lesion and condition of the 
body. It directly affects the pleura, lungs and possibly the pericardium 
and heart by pressure. Through disturbance of nerves, it will affect 
the head and face, arm, lungs, bronchi, heart, mammae, spinal cord and 
muscles of the back in relation. Pleurisy is an effect because of direct 
irritation of the pleura. Pneumonia and pulmonary tuberculosis re- 
sult because of the effect on the nerve supply to the lungs, the sympa- 
thetic cord being affected by the subluxation partly from pressure of the 
rib and partly from the inflammatory material. 

Angina pectoris and the various functional disorders of the heart, 
result because the displaced rib produces pressure on the third sympa- 
thetic ganglion, thus interfering with the connection between the cardiac 
centers in the spinal cord and the heart. The head and face receive im- 
pulses from the spinal cord as low as the third dorsal. 



398 APPLIED ANATOMY. 

A lesion of the third rib interferes with the nervous connections as 
well as the activity of the spinal cord centers by pressure on the gang- 
liated cord. The centers for the arm are as low in the spinal cord as the 
fifth dorsal and the lesion of the third rib will break the line of communi- 
cation between these centers and the arm. 

The mammary gland is affected from disturbance of the intercostal 
nerves and blood-vessels. The muscles in relation are contractured or 
relaxed by a lesion of this rib on account of effect on the third pair of 
thoracic nerves. The spinal cord is disturbed by the lesion through its 
effect on the blood-vessels that supply it, particularly the veins. The 
veins draining the cord are in relation with the ribs, and any deviation 
will more or less affect the drainage. 

THE FOURTH RIB. 

The fourth rib is slightly longer, more twisted and more curved 
than the third. It is of greatest importance on account of the fre- 
quency of its lesions, in relation to heart and pleural affections. The 
sternal end is most easily located by noting the position of the nipple, 
it being on the rib, or by counting down from the second rib which can 
always be found on account of the ridge across the sternum. 

The movements are a little more marked than those of the third 
and it is oftener subluxated than the ribs above. It has in relation with 
its principal articulations the costo-vertebral and costo-transverse, the 
fourth sympathetic ganglion with its branches, and the fourth pair of 
thoracic nerves and their anterior and posterior divisions, the recurrent 
meningeal nerve, the rami communicantes and the various arteries and 
veins going to and from the spinal cord and thoracic structures. 

Perhaps the structures most easily and most frequently affected of 
those named above, is the vein which drains the spinal cord and muscles. 
Any or all of them are more or less affected in a typical case. 

The lesions or subluxations of the fourth rib are like those of a 
typical rib, the most common form consisting of an upward movement of 
the vertebral end, while the sternal end is drawn downward and inward, 
and with this there is rotation so that the lower edge is brought into 
prominence and the intercostal space above is enlarged at the sternal 
end. There is tenderness at all its articulations and usually a thicken- 
ing of the ligaments, which is most marked at the costo-transverse joint. 

Affections of the heart are the most common effects of a subluxa- 



APPLIED ANATOMY. 



399 



tion of the left fourth rib, while lung, pleural and bronchial disorders 
often result from a lesion of the fourth rib on the right side. Angina 
pectoris, especially the false type is in almost, if not all cases, due to a 
lesion of this rib. The reason for it is that the innervation of the heart 
is .by way of the sympathetic ganglion and its efferent branches, all of 



INT. bra. (cutaneous) 

POST PRIM. DIVISION. 



EXT bra/muscular) 



RECURREMT BRA." 




ANT CUTANEOUS" 



Fig. 121. — Showing origin, course, relations and distribution of a typical thoracic 
nerve. 

which are in relation with the head of the fourth rib. The efferent im- 
pulses come primarily from the spinal cord (the fourth segment in par- 
ticular). The fourth intercostal nerve is also derived from the fourth 
segment of the spinal cord. An irritation applied to the sympathetic 
ganglion or cord will cause the pain to be referred to the cerebro-spinal 



400 APPLIED ANATOMY. 

nerves in close relation, which, in this case, is the fourth thoracic and 
its branches. The pain in angina pectoris seems to be mostly in the 
intercostal nerves while some of it is in the posterior division, in the ulnar 
and possibly the pneumogastric and cardiac plexuses. In some cases, 
the rib undoubtedly presses directly on the heart, thus interfering with 
its contractions. In true angina, there seems to be a disturbance of nutri- 
tion of the heart, which is due, partly at least, to a lesion of the fourth 
rib. The entire left side of the chest becomes tender and remains so 
nearly all the time. This signifies that the intercostal nerves are con- 
gested or slightly inflamed. This is the result of some vaso-motor dis- 
turbance, principally at the vertebral end, or the drainage is interrupted, 
thus leaving the nerve engorged with blood or otherwise stimulated 
Nearly all pain is due to pressure on a nerve, the most frequent form of 
pressure being congestion of blood in and around the nerve. This con- 
gestion is, in -many instances, I believe, the result of muscular con- 
tractures. Again, angina pectoris may be the result of some disturbance 
of the accelerator cardiac nerves which causes painful contraction of the 
heart, as in the case of the stomach, uterus or small intestine. We do 
know that in nine-tenths of all cases of angina pectoris there is a lesion 
of the fourth or fifth rib on the left side and that the correction of the 
lesion brings relief. We also know that in such a lesion, the cardiac 
accelerators, the sensory cardiac, also the trophic and vaso-motor nerves 
to the heart are in relation with the rib and would be disturbed by a 
lesion of the rib. We also know that these nerves connect with the 
fourth intercostal. Our premises being true, since they have been proven 
by clinical experience, the conclusion is that the rib lesion produces 
angina pectoris by (1) producing pressure on the nerves connecting the 
spinal cord and heart, thus interfering with the motor, sensory, trophic 
and vaso-motor impulses; (2) by producing pressure on or irritation of 
the fourth or fifth intercostal; (3) or by producing pressure directly on 
the heart, thus lessening the space in which it has to beat. 

Conditions usually described by the layman as "smothering spells." 
are also due to lesions of the fourth or fifth rib on the left side. They 
produce effects in two ways: (1), by pressure on the heart, and (2), by 
disturbing the motor impulses so that the heart has great difficulty in 
beating, which condition is always accompanied by dyspnea or a choking 
sensation. 

Palpitation is another form of heart disorder that 'follows a 



APPLIED ANATOMY. 



401 



lesion of the fourth rib on the left side. The subluxated rib in some 
way interrupts or otherwise impairs the motor supply of the heart so 
that the amount of nerve force varies instead of being regular. The 
rapidity of contraction of the heart is determined by the number and 
intensity of the motor impulses sent to it; in other words, the contrac- 

SYMPATHETIC CORD 
FOURTH DORSAL VERT 
INTERVERTEBRAL OR SPINAL GANGLI/ 
RAMI COMMUNICANTESx 




Fig. 122. — Showing the relation of the gangliated cord and its branches, to the 
heads of the ribs. A portion of the bodies of the vertebra? has been removed thus 
exposing the spinal cord and its nerves. Rib lesions affect these nerves. 



402 APPLIED ANATOMY. 

tion in an effect. The rib lesion, by stimulating the cardiac nerves, in- 
creases these impulses, hence an effect in proportion to the degree of 
stimulation. The nerves become more irritable, responding to any stim- 
ulation, as from exertion, fright, etc. In short, the displaced rib affects 
the motor supply of the heart by pressure on the gangliated cord, the 
rami communicantes, nervi efferents, or it affects the cardiac centers in 
the spinal cord by interfering with the circulation of blood through 
them. 

Arrhythmia is explained in a similar way. The nerve feed to 
the heart is not regular, hence the contractions of the heart are not reg- 
ular. The interruption of the nerve impulses is caused partly by the 
rib pressing on the nerve over which the impulses pass, viz., the white 
rami, sympathetic gangliated cord or the nervi efferentes. What is 
known as an irritable heart is the result of a similar condition. The 
nerve supply, is unstable, irregular and subject to increase from almost 
any exciting cause. The rib lesion is the cause, as it interferes with 
the passing of various impulses to the heart. 

In some dissections made by the author it was found that some of 
the efferent branches of the upper thoracic ganglia passed forward di- 
rectly into the pneumogastric nerve. These fibers were traced down the 
sheath'of the nerve and finally appeared to form a component part of 
the tenth. This condition very materially helps the explanation of why 
upper thoracic and rib lesions affect the heart, producing palpitation, 
arrhythmia and other disorders. In all cardiac affections the fourth 
and fifth ribs on the left side should be carefully examined, since clin- 
ically, lesions of these have been found in nearly all cases. Even in organic 
heart disease these ribs are found to be in an abnormal condition. 

Mammary disorders, such as non-development, tenderness, mastitis, 
ulceration, abscess, tumors and disturbances of milk secretion, often 
result from a lesion of the fourth rib on the same side. The explana- 
tion lies in the fact that the innervation, blood supply, drainage and 
lymphatic vessels are in relation with the fourth rib, as well as the gland 
itself. A displacement of the rib, however slight, will in some way af- 
fect the gland directly or indirectly through the effects on the blood sup- 
ply and innervation. Many cases of ulceration that had been diag- 
nosed as cancer, have been cured by adjusting a rib that intercepted the 
venous drainage of the breast, thus causing the blood to stagnate and 
undergo decomposition. 



APPLIED ANATOMY. 403 

Disorders of the lungs and pleura arise from a subluxation of the 
fourth rib. They are similar to those arising from a lesion of the third 
rib, hence do not merit a separate description here. Pain or ache be- 
tween the scapula? is most often the result of a rib lesion, the fourth 
being most frequently out of place, in such cases. The explanation is 
that the deviated rib produces an impingement on the posterior division 
of the fourth thoracic nerve. This division passes through a ligamentous 
foramen formed by the costo-transverse ligaments and this foramen is 
usually lessened in size by the rib lesion. As a result either the sensory 
filaments are directly affected or else muscular contractures arise from 
irritation of the motor filaments. A lesion of the fourth rib may also 
produce an inflammation of the intercostal nerve or what is commonly 
called "shingles." This, however, may follow lesion of any rib. 

THE FIFTH RIB. 

The fifth rib is a typical one and differs in appearance and shape in 
no particular from that of the fourth. It is slightly longer, a little more 
curved and quite commonly dislocated and fractured. It furnishes a 
landmark for the heart (apex beat) and its subluxation is the cause of 
many sensory disturbances usually referred to the lungs and heart. It 
has in relation with it the usual intercostal vessels and nerves, all of 
which are more or less involved by a subluxation of the rib. The most 
important muscles attached to it are the levator costse and serratus 
magnus. A lesion of this rib especially affects its movements, thus 
hampering respiration, making it painful and shallow. 

The pleura is attached to this rib and is the seat of much of the pain 
which comes from the rib lesion. In lobar pneumonia this is particu- 
larly marked. The viscera in relation which would be affected by the 
lesion are the lungs, heart and sometimes the stomach. The right 
fifth rib may by its displacement affect the liver. The lungs and heart 
are affected in a way similar to that in lesions of the fourth rib. Also the 
mammary gland is affected (see fourth rib). The special points to be 
remembered in connection with a lesion of the fifth rib are (1), pleurisy, or 
what is commonly called a catch in the side; (2) functional disorders of 
the heart when the left fifth rib is involved; (3) affections of the lobes of 
the lung, and (4), disturbances of that part of the chest wall, as in lobar 
pneumonia.' The fifth rib is more often fractured than any other on 
.account of its position, it being most exposed of all the true ribs. 




Fig. 123. — Showing the course, relation to ribs, and distribution of the inter- 
costal nerves. 



APPLIED ANATOMY. 405 

In experiments performed on dogs, *McConnell states: "Under 
anesthesia the dog's middle and lower dorsal region was sprung forward 
with fairly moderate force. 

Six weeks later dissection revealed an anterior "break" between 
the tenth and eleventh dorsal vertebrae. Also, the fourth and fifth ribs 
on the right side were sprung upward at the vertebral ends. Muscles 
and ligaments over and between the injured vertebras and ribs, very tense 
and rigid. 

Macroscopic hemorrhagic spots from the size of a pin-point to head 
of a pin were found in the sympathetica opposite the "break" and in the 
corresponding rami on both sides. Congestion of spinal nerves between 
the tenth and eleventh ribs. 

Stricture in the lower third of the jejunum. 

The microscope revealed pathological congestion of the above af- 
fected nerves, that is, intracellular congestion." 

THE SIXTH RIB. 

The sixth rib is slightly more obliquely located than those above, 
its costal cartilage is longer and forms a more acute angle with the ster- 
nal end of the shaft. The interspaces are not so wide, decreasing in size 
from the third down. The sixth intercostal vessels are in relation with 
this rib, a groove being formed for them on the under surface of the 
rib. The vein is most easily affected. The sixth intercostal nerve, the 
gangliated cord, sixth thoracic ganglion, great splanchnic nerve and the 
rami are also in relation. The pleura, liver and stomach are in rela- 
tion ar"i are affected by direct pressure in inward subluxations, or what 
is usually called, a depressed condition of the rib. This rib is subject to 
the usual rib subluxations and the diagnosis is based, as in other ribs, 
on effects; position and comparsion, with other ribs. 

The sensory effects are characterized by disturbances of sensation in 
region supplied by the sixth intercostal and its branches and in the 
region supplied by the posterior division of the sixth thoracic 
nerve. The lesion is most commonly an irritative one, therefore pain 
is the most common of the sensory effects. The pain is felt at the sternal 
end of rib, along the lateral cutaneous branch and at the vertebral end. 
The integument is tender to the touch and respiration is "catchy." 
There may be numbness or complete anesthesia in the same areas. The 

♦Journal of A. O. A., Vol. V, p. 16. 



406 APPLIED ANATOMY. 

explanation of these sensory effects lies in the fact that when the rib is 
displaced it presses on or otherwise irritates or affects the sixth thoracic 
pair of nerves. In some instances the pain or ache is undoubtedly due 
to the congestion of the nerve which results from the subluxated rib. 

There will be some thermic effects along the sixth intercostal space 
in a lesion of the sixth rib. The surface temperature is most commonly 
lowered. Some disturbance of the sensibility of the liver and stomach 
result from this lesion, since the afferent impulses from these viscera 
pass through the sixth ganglion which is in relation with the head of the 
rib .and would be disturbed by a lesion of the rib. If the impulses are 
increased, there will be pain either in the viscus or in the cerebro-spinal 
nerve — the sixth intercostal. This nerve is the seat of pain in a great 
many visceral disturbances, especially of the stomach and liver, the pain 
being a referred one and is explained by Head's law. The muscles of 
the back and chest supplied by the sixth thoracic segment, become tender 
as a result of the contracture and irritation of the muscular sensory nerves. 

The motor effects of a lesion of the sixth rib are muscular contrac- 
tures and perverted peristalsis of the liver and stomach. The muscles 
in relation with the rib and those supplied by the sixth thoracic segment, 
become contractured in cases of lesion of the sixth rib. This is the re- 
sult of irritation (fatigue or over-stimulation) of the motor nerves or 
the result of traction on the muscle. The motor Impulses that pass to 
the liver and stomach, in part pass through the sixth thoracic sympathetic 
ganglion. A lesion of the sixth rib will interrupt or in some way disturb 
the function of the ganglion, hence some motor effect in the above named 
viscera. If the lesion irritates the ganglion, splanchnic nerve or ramus, 
there is usually excessive peristalsis in the viscus supplied. This lasts 
as long as does the stimulation, after which the opposite effect sets in. 
If the lesion is paralytic, the opposite result will occur. Experimentally, 
it seems that stimulation of the splanchnic nerves causes a lessening of 
peristalsis in the viscera, while inhibition produces the opposite effect. 
Clinically, it is proven that inhibition applied to the spine will tend to 
lessen peristalsis if the parts are not in a normal condition. The more 
nearly normal the parts the less the effect of either stimulation or inhi- 
bition. After all it is a question of adjustment. If the rib lesion is 
causing an irritation and the disturbance is overcome, whether by stim- . 
ulation, inhibition or some other means, the effect must be the same, 
that is inhibitory. If the rib lesion is producing an inhibitory effect, 



APPLIED ANATOMY. 407 

correction of the lesion will necessarily produce a stimulation, regard- 
less of the way in which it is corrected. 

A lesion of the sixth rib will cause a lessened or increased secretion 
in the liver, stomach and sweat glands, it depending on the character 
of the lesion, that is whether it is irritative or paralytic. In the case of 
the viscera, secretory impulses pass from the spinal cord by way of the 
sixth thoracic sympathetic ganglion, thence over the great splanchnic. 
A displacement of the sixth rib will intercept or stimulate these impulses. 
If they are intercepted, secretion is lessened although it does not depend 
entirely on the secretory nerves, but in part upon the quantity and 
quality of the blood. If they are stimulated, secretion is increased. 
This is true experimentally in cases in which the parts are in a 
healthy condition. Clinically, it seems that the opposite is true. This 
is best demonstrated in catarrh of the stomach. There is a sort of par- 
alytic condition of the spinal muscles, stomach, and in fact all the tissues 
in relation. The accumulation of mucus in the stomach may be due to 
weakness of the muscles of the stomach wall, the peristalsis not being 
strong enough to expel it, but I am of the opinion that there is a hyper- 
secretion of mucus, and that the lesion produces inhibition rather than 
stimulation. 

Excessive secretion of sweat along the sixth interspace is explained 
by the rib lesion disturbing the function of the sixth intercostal nerve, 
one of its functions being that of carrying secretory impulses from the 
sixth ganglion to the sweat glands in the integument over the sixth in- 
terspace. 

Vaso-motor impulses to the intercostal arteries, spinal branch, mus- 
cular branches to the spinal muscles, and the various abdominal arteries 
supplied by the great splanchnic nerve, pass through the sixth thoracic 
sympathetic ganglion and white rami and would be involved in a typical 
lesion of the rib. Congestion of the parts supplied by the arteries named 
above will result if the lesion inhibits the passing of the vaso-motor im- 
pulses, while anemia will result if the lesion is irritative. The veins are 
similarly supplied with vaso-motor impulses and will be affected by this 
lesion. The venae azygi are also affected by this lesion, through disturb- 
ance of their innervation, and since these veins drain the spinal column, 
cord, thoracic wall and muscles of the back, disturbances of these parts 
are common. 

The trophic effects of a rib lesion are noted in muscles, bones and 



408 APPLIED ANATOMY. 

other tissues supplied by the sixth intercostal, the recurrent meningeal, 
and the sixth thoracic sympathetic ganglion. All nerves are more or 
less trophic to the parts supplied, hence any disturbance of the above 
named nerves will produce some trophic effect. The muscles suffer 
most and soon the median furrow becomes widened, the ribs begin to 
prolapse, the antero-posterior diameter of the chest decreases and res- 
piration becomes shallow. Necrosis of the rib is sometimes a sequel to 
the lesion. Weakness of the walls of the stomach is also a trophic effect 
of the lesion. 

*McConnell states in experiments on dogs: "Two weeks after 
operation dissection showed the fourth, fifth and sixth ribs on the right 
side dislocated upward at the vertebral ends. 

The usual muscular tension and rigidity of the spinal ligaments in 
the area affected. 

Marked inflammation and hemorrhage of the sympathetic chain, 
the rami, posterior spinal nerves, the intercostal, the posterior and an- 
terior nerve roots, the meninges of the cord for a diameter of a quarter 
of an inch surrounding the exit of the fifth spinal nerve on the right side, ' 
and along the anterior commissure. The pathological condition here was 
exceptionally marked. The dog was sick and inactive for a week fol- 
lowing the first forty-eight hours after the operation. 

Enlargement of spleen to over twice the normal size. " 

THE SEVENTH RIB. 

The seventh rib is the lowest of the true ribs. Its costal cartilage 
is longer than that of the ribs above. Its relations, lesions and effects 
of lesions, are similar to those of the sixth rib. When subluxated, the 
muscles attached to it are either relaxed or contractured. Those affected 
are the levator costse, serratus magnus, intercostals, the abdominal mus- 
cles and the diaphragm. All of these muscles have to do with respira- 
tion, therefore in a lesion of the seventh rib, respiration is disturbed. 

In relaxation of these muscles, prolapsus of the ribs results. In 
contractures of the muscles, normal movements of the ribs are impaired, 
while in some cases the rib is drawn out of place. A lesion of the seventh 
rib will, in some cases, produce relaxation of these muscles; in others, 
contracture, on account of (1) attachment of these muscles to the rib, 
and (2) through disturbance of the seventh pair of thoracic nerves. 

♦Journal A. O. A., Vol. V, p. 16. 



APPLIED ANATOMY. 409 

The blood-vessels affected by this lesion are the intercostal vessels 
with their spinal and muscular branches, the gastric and hepatic vessels. 
Clinically, it seems that the veins are affected more often and more 
readily than the arteries. As a result there may be anemia or conges- 
tion of the muscles of the back, seventh intercostal space, pleura, spinal 
cord, stomach and liver. The explanation is that the lesion exerts 
pressure on some of these vessels, while others are affected through their 
innervation which is hv way of the seventh thoracic ganglion and great 
splanchnic. 

The nerves affected by a lesion of the seventh rib are the seventh 
thoracic spinal nerve with its posterior and anterior, or intercostal 
branches, the recurrent meningeal nerve, the gangliated cord and the 
seventh thoracic sympathetic ganglion with its branches, viz., the great 
splanchnic, aortic, and filaments to the vertebra and ligaments. The 
lesion may stimulate or inhibit the passing of impulses over these nerves. 
There may be relaxation of contracture of the muscles supplied by the 
seventh dorsal segment or sensory disturbances in the integument of the 
back and the seventh interspace. The pleura is usually involved, partly 
through its nerve supply and partly on account of its attachment to the 
rib. The passing of impulses over the great splanchnic is disturbed, 
hence vaso-motor, secretory, motor, sensory and trophic disturbances, 
most commonly found in the stomach and liver. All of these nerves 
are in relation with the seventh rib, or the impulses passing over them 
pass over nerves that are in direct relation; that is, the impulses passing 
over the great splanchnic, also pass over the rami, gangliated cord, and 
common nerve trunk of the seventh thoracic pair of nerves and are in 
relation with the head of the seventh rib. 

The viscera affected by a lesion of the seventh rib are the stomach 
and liver, the seventh rib on the left affecting the stomach, while a le- 
sion of the corresponding rib affects the liver. This may be explained in 
two ways: (1), relation of the rib to the viscera, and (2), relation of rib 
to the nerve supply to them. These effects vary in that the lesion in one 
case is irritative, while in another it is inhibitive. Thus it may produce 
excessive peristalsis, activity and pain; or lessened peristalsis, lessened 
activity and a general paralytic condition of the viscera. 

The spina] cord, spinal column, ligaments and muscles are also af- 
fected by the lesion. Indigestion, biliousness, pleurisy with respiratory 
disorders complicate acute cases. The diaphragm is also disturbed in 



410 APPLIED ANATOMi'. 

that its position is changed, its openings altered in size and its contrac- 
tions hampered. The author has had some experience with cases of 
hiccough in which the trouble was caused by a lesion of the lower ribs, 
the seventh being at fault. The lesion seemed to irritate the diaphragm, 
and as a result the attack came near terminating fatally. By lifting 
the rib, that is by correcting the rib lesion, the irritation was relieved and 
the hiccough ceased immediately. The importance of this sort of lesion 
in the persistent types of hiccough is underestimated, since in many of 
them the ribs that give attachment to the diaphragm are often found to 
be in a state of descent, or more commonly a single rib is twisted in such 
a way that it has an irritative effect. The explanation is based (l),on 
attachment of the muscle (diaphragm) to the rib, and (2), irritation of 
the intercostal nerves which help to innervate the diaphragm. Thermic 
changes, the interspace becoming cold, and localized perspiration are 
often associated with the lesion of the corresponding rib. I' have often 
found a lowering of the surface temperature along the seventh and eighth 
interspaces on the left side in chronic catarrh of the stomach. 

The sternal end of the rib is subject to irregularities in that the 
cartilage is often forced upward or outward. In rickets and adenoids of 
the throat, there is often found a depression or shallow, wide groove cor- 
responding to the upper attachments of the diaphragm to the chest wall. 

THE EIGHTH RIB. 

The eighth rib belongs to the false ribs, so-called because it does not 
articulate directly with the sternum, but with the cartilage of the seventh 
rib. The false ribs have a greater range of mobility and are more elas- 
tic than are the true ribs. The obliquity is greater and this is often de- 
cidedly increased in cases of general weakness and from tight or im- 
properly worn clothing. 

The movements of this rib are upward and outward in inspiration 
and downward and inward in expiration. In all lesions of this rib these 
are impaired, in acute cases made painful, while in the chronic they are 
lessened, this resulting in descent or prolapsus. The lesions of this rib 
are similar in character to those above, torsion and depression of the 
sternal with elevation of the vertebral end, being the most common. 
In this sort of displacement the lower edge is turned outward to such an 
extent that it can be readily palpated. The interspace below at the 
sternal end is decreased in size, while that above is increased. 



APPLIED ANATOMY. 



411 



CERVICAL 




Fig. 124. — Drawn from a dissection at the A. S. 0. to show the thickness of the 
skin of the back and points of emergence of the cutaneous nerves. Note the arrange- 
ment of the muscle fibers. 



41'2 APPLIED ANATOMY. 

The effects of a lesion of this rib, vary with the degree and length of 
standing of it. The sensory effects are most common and important 
from a clinic point of view and will be considered first. The sensory 
nerves involved directly are the eighth thoracic with their branches, the 
anterior and posterior divisions. The gangliated cord in relation con- 
tains some afferent fibers that convey impulses from the abdominal 
viscera to the spinal cord, thence by it on to the sensorium. This af- 
ferent tract is impaired by a lesion of this rib and on this account, the sen- 
sibility of the viscera is increased or decreased by it. Pain from vis- 
ceral irritation is often referred to the cerebro-spinal nerves branching 
from the segment that supplies the viscus, as in hepatic colic. The con- 
verse is also true that is, pain in the viscus is produced by the irritation 
caused by the subluxated rib. 

Painful affections of the liver, are caused in some cases by this lesion. 
Pain in the pleura, in the eighth interspace and in the intercostal mus- 
cles in relation, is the result of this lesion irritating the eighth inter- 
costal nerve, since it supplies these structures. These sensory disturb- 
ances cause respiration to be imperfect, jerky and shallow. There may 
be a perversion of function of these sensory nerves, this producing ting- 
ling sensations or, what is technically called, formication. There may be 
numbness of the parts or other sensory disturbances that commonly 
result from inhibition of a sensory nerve. All these sensory effects are 
explained by the relation of the sympathetic cord, eighth thoracic nerve 
and their branches, to the eighth rib. 

The motor effects of this lesion are characterized by contracture or 
relaxation of the muscles supplied by the nerves in relation, and by lessen- 
ed or increased peristalsis of the viscera supplied by the part of the great 
splanchnic nerve which is in relation with this rib, viz., the liver, bile 
ducts, stomach, and small intestine, upper part. The diaphragm is 
affected, this interfering with respiration and the return of the blood from 
parts below the muscle. 

The vaso-motor effects are manifest by dilatation or constriction of 
the vessels of the muscles of the back, the thoracic wall, pleura, cord, 
stomach, liver, pancreas, and duodenum. The vaso-motor impiilses 
to these parts pass over the splanchnic, recurrent meningeal, and eighth 
thoracic nerves and they are in relation with the eighth rib. 

The secretory effects are localized sweating along the eighth inter- 
space and altered secretion in the viscera supplied with secretory im- 



APPLIED ANATOMY. 413 

pulses by the great splanchnic nerve, viz., the liver, pancreas and stomach. 
The principal effects of a subluxation of this rib are, pain along the 
course of the rib, pleurisy, shallow and painful respiration, and liver dis- 
turbances such as biliary colic. 

*McConnell states in experiments on dogs in which the ribs were 
displaced: "Three weeks after the production of the lesions, dissection 
showed the eighth rib on the right side and the seventh rib on the left 
displaced upward as the vertebral ends. 

The muscles, superficial and deep, contiguous to the lesions, were 
rigid. 

There was marked inflammation of the corresponding sympathetics 
and rami (macroscopic ally and microscopically). 

Enlargement of the spleen to twice normal size." 

THE NINTH RIB. 

The ninth rib furnishes a landmark for the location of the gall-bladder 
and the spleen. The upper edge of the spleen is in relation with the 
left ninth rib, while the costal cartilage of the right ninth rib is in rela- 
tion with the gall-bladder. The costal cartilage of the rib is often in- 
jured by falls on the side, and sometimes by injudicious treatment. Its 
lesions are similar in character to lesions of the ribs above and the effects 
are about the same as those of the eighth rib. A lesion of this rib will 
affect the innervation of the small intestine, liver, spleen, pleura, gall- 
bladder, a portion of the peritoneum and the muscles in relation, espec- 
ially the diaphragm. These effects occur because of the relation of the 
rib to the nerves mentioned, on account of which the displaced rib exerts 
pressure directly on one or more of them. 

The disorders associated with this lesion are biliary colic, congestion 
of the liver, affections of the small intestines, intercostal neuralgia, 
girdle pain, herpes zoster, pleurisy and other respiratory disorders caused 
by effects on the diaphragm. 

This rib is subject to downward displacements on account of the at- 
tachment of muscles, such as the serratus posticus inferior and dia- 
phragm, and on account of the obliquity of the rib and the shape of the 
articular facets. The facets on the transverse processes of the lower 
thoracic vertebra? face slightly downward, while those of the vertebra? 
above face slightly upward. This is, in the case of the upper ribs, for 
*Journal A. O. A., Vol. V, p. 14. 



414 APPLIED ANATOMY. 

the better support of the chest as in the carrying of weights, while in the 
case of the lower ribs, it gives greater freedom to the movements of the 
diaphragm. Perhaps this accounts for the frequency of prolapsus or 
downward displacement of the lower ribs. 

It is claimed that pressure applied to the vertebral end of the right 
ninth rib will relieve hepatic colic. This is explained by the fact that the 
afferent impulses from the gall-bladder and bile ducts pass over that 
portion of the great splanchnic and gangliated cord, that are in relation 
with the head of the right ninth rib and most if not all, the impulses to 
and from the liver and gall-bladder pass over the right side. Perhaps a 
better explanation is that the inhibition lessens the number and inten- 
sity of the motor impulses hence dilatation of the duct follows. 

THE TENTH BIB. 

The tenth rib is classed with the peculiar ribs because it has a single 
facet for articulation with the body of the tenth thoracic vertebra. It 
is long, curved and has the usual groove, tuberosity, and angle. The 
distance between the angle and the tuberosity is greater than in the ribs 
above, also the obliquity is greater. 

The mobility is greater than that of the ribs above, and it is more 
subject to displacement from contraction of the muscles attached to it. 

It is in relation with the spleen, liver, and suprarenal capsule; the 
pleura and diaphragm; and the lesser splanchnic and tenth thoracic 
nerves and their branches and connections. 

The lesions of this rib cause disturbances of function in a way sim- 
ilar to those of other ribs, that is, by direct pressure on structures or 
indirectly, through effects on nerves and the spinal cord. The costal 
cartilage of this rib is often broken off but causes little trouble, other than 
a local weakening of the part. 

Pain in the abdominal wall near the umbilicus is one of the most 
common of effects of a lesion of this rib. It is explained by the fact that 
the tenth intercostal nerve is in relation with the rib and is impinged on 
by the subluxated rib. The pain is usually referred to the periphery 
of the nerve, hence the pain is felt at the umbilicus. This pain may be 
one referred from disease of the small intestine as in intestinal indiges- 
tion, or from kidney disorders as in acute inflammation. 

A relaxed abdominal wall is due, in many cases, to a dropping of the 
lower ribs, and the tenth, takes part is the general descent: In some 



APPLIED ANATOMY. 415 

cases the lesions of the ninth and tenth ribs seem to be the primary 
causes. In anemia, this rib is usually displaced downward but it may 
be an effect instead of a cause. In irritative lesions of this rib, the ab- 
dominal wall is tender and contractured. This is explained by the stim- 
ulation of the tenth .intercostal nerve. The abdominal muscles in re- 
lation with this rib, connect with their spinal center, by way of the 
tenth intercostal nerve. If this connection is broken, relaxation of the 
muscles takes place, but if the nerve or its communicating branches are 
stimulated, contraction or contracture of the abdominal muscles is the 
result. The nerve connections existing between the spinal cord and 
small intestine are often interfered with by this lesion, and some dis- 
order of these parts is the result. This is also true of the kidney, and 
ovary and consequently any disease of these parts may be the result of a 
lesion of this rib. Respiration is affected through the disturbance of 
the diaphragm, this muscle being attached to the rib. 

The principal diseases caused or predisposed to, by this lesion are 
Bright 's disease, intestinal indigestion, ovarian colic and in fact any dis- 
order of the ovary. The most common effect in recent cases is pain in 
the abdomen at or near the umbilicus, which is often mistaken for peri- 
tonitis, appendicitis, ovaritis or some disease of the intestines. 

THE ELEVENTH RIB, 

The eleventh rib is peculiar in several respects. It has a single facet 
for articulation with the body of the eleventh thoracic vertebra, a poorly 
developed angle, no tubercle and no neck. It does not articulate with 
the transverse process of the vertebra, is short, twisted but little, and the 
anterior end is pointed. The subcostal groove is shallow and the end of 
the rib is tipped with cartilage which is pointed and occasionally broken 
off by trauma or by injudicious treatment as in the ninth and tenth ribs. 

On account of- the marked mobility of this rib, it is called a floating 
rib. This free mobility is due to the fact that the sternal end is free, 
while the vertebral end has only a single articulation. The position of 
this rib is then controlled to a great extent, by the condition of the mus- 
cles and other tissues attached to it. This ought to be taken into consid- 
eration when we attempt to reduce a dislocation of it since it will do little 
if any good to correct the subluxation unless the muscles attached to it 
are restored to a normal condition. 

This rib acts as a stay or support for the muscles attached to it as 



416 APPLIED ANATOMY. 

do the ribs of an umbrella. It is fixed by the muscles attached below 
and thus furnishes a fulcrum for the action of the respiratory mus'cles 
and especially the diaphragm. These muscles are the external oblique, 
transversalis, serratus posticus inferior, accessorius, ilio-costalis, levator 
cos'tae, and the intercostals. The pleura, parietal layer, lines the inner 
aspect of the rib. The left one is in relation with the spleen while on the 
right side the liver is in relation. The upper part of the kidney is some- 
times in relation with the rib. 

The lesions of this rib are usually of two kinds, the one in which the 
anterior end is turned downward, thereby increasing the eleventh inter- 
costal space, the other in which the rib is rotated forward and upward and 
the point carried up under the tenth rib. In this case the rib seems to 
be forced directly inward as well as rotated. The first is diagnosed by 
finding the lower edge of the rib prominent, the point turned downward 
and outward^ the intercostal space widened at the anterior end and lessen- 
ed at the vertebral end and by finding tenderness along the vertebral end 
of the rib. The position as it is determined by palpation, is typical in 
the second case. The point of the rib is felt with difficulty if 'at all. 

The effects of a lesion of this rib vary with the degree, the way in 
which it occurred, the length of standing and the condition of the tissues 
attached to it. The pleura and muscles are affected since they are at- 
tached to the rib. The spleen and liver are affected because they are 
in close relation. If the rib is dislocated inward as is often the case from 
improperly worn clothes, it presses directly on these viscera. I 
have made dissections in which I found grooves in the liver caused by 
tight lacing, by which the ribs were forced into the substance of the 
liver. 

The intercostal vessels in relation, will in some way be affected by 
the lesion, and as a result, the circulation of that part of the spinal cord 
will be disturbed. These blood-vessels are in relation with the head of 
the rib and when a subluxation occurs, pressure is exerted directly on 
the vessels. 

The nerves in relation that would in ordinary cases be affected by 
a displacement of the rib, are the eleventh thoracic with its anterior and 
posterior divisions, the sympathetic cord and the eleventh ganglion and 
its branches which connect it with the cerebro-spinal nerves in relation, 
and the nervi efferentes of this ganglion. 

Pseudo-appendicitis is one of the most common of results of a lesion 



APPLIED ANATOMY. 417 

of this rib. The patient describes a pain that is in the right iliac fossa, 
which is similar to if not identical with that of true appendicitis, of the 
chronic form. There is tenderness on pressure, on extension of the body, 
and usually some indications of bowel disorder. These symptoms re- 
sult from the lesion irritating or otherwise affecting the eleventh inter- 
costal nerve, which is distributed to the iliac fossa. The point of greatest 
pain is at McBurney's point, that is midway between the umbilicus and 
the anterior superior spine of the ilium. In true appendicitis, the pain 
is referred over this same nerve hence the error in diagnosis. The nerve 
also supplies the muscles of the abdominal wall in relation, hence when 
it is irritated as it is in most cases of subluxation, the muscles contract, 
become tender and the patient with difficulty can extend the limbs or 
bend the body backward. 

In many cases of supposed ovarian disease, the eleventh rib is sub- 
luxated and presses on the eleventh intercostal nerve, which produces 
pain in the same area as is found in organic disease of the ovary. In 
true ovarian disease, the pain is referred to the areas innervated by the 
eleventh intercostal, since this segment of the spinal cord supplies the 
ovary. Head's law very nicely explains these referred pains and espec- 
ially those from ovarian and bowel disorders. A "stitch" in the side 
is so often caused by a lesion of this rib. On account of its free mobil- 
ity, extreme lateral flexion of the body or sudden twists will often cause 
the rib to be pulled from its normal position by muscular action. This 
produces an irritation of the nerve so that any movement of the part 
produces a pain of such a character that it is familiarly called a "catch." 

Kidney, ovarian and bowel disorders often result from a lesion of 
the eleventh rib since the connection existing between the spinal cord and 
these organs is interfered with by the lesion. The explanation is that 
this connection is by way of the lesser splanchnic nerves, the white rami 
and the gangliated cord. These nerves are in relation with the head of 
the eleventh rib and will beyond doubt, be impinged on by a subluxation 
of the rib; or the blood-vessels going to and from the spinal cord 
through the eleventh intervertebral foramen will be pressed on and thus 
the nutrition of the cells located in this segment which give rise to 
the impulses passing out over the above named nerves will be in- 
terfereed with. Clinically, it is a demonstrated fact that a lesion of 
this rib will produce disease of the kidney, ovary and bowel. 

The condition of the abdominal muscles is, to a certain extent, con- 



418 APPLIED ANATOMY. 

trolled by the condition of this rib. The explanation is that the motor 
and trophic impulses to these muscles pass out over the eleventh inter- 
costal nerve and it is in relation with this riband would be affected by a 
lesion of it. The lesion may be an irritative one and contracture would 
be the result or it may be a paralytic one, in which case relaxation would 
be the sequel. In other cases, the effects are the result of traction or 
pressure on these muscles since most of them are attached to this rib. 
I will mention the diaphragm as a special example. Its position and 
function are always more or less disturbed by a lesion of the eleventh rib. 
As a result, the openings in it are lessened in size this in turn causing 
congestion of parts below and a greater strain is thrown on the heart. 
Dr. Still has often mentioned this fact in connection with heart disturb- 
ances such as palpitation, arrhythmia and even regurgitation and hyper- 
trophy. 

Hiccough is the best example of disturbance of function of the dia- 
phragm as a result of a rib lesion. The traction on or irritation of, this 
muscle, causes it to contract spasmodically ,which condition is called 
hiccough. This is especially true of the worst types of this disease 
which ofttimes proves fatal. 

THE TWELFTH RIB. 

The twelfth rib has a single facet for articulation with the pedicle 
of the twefth thoracic vertebra. The rib is but little twisted, short, 
pointed at the anterior extremity, and the shaft is narrow, rounded and 
smooth above, and rough and sharp on its inferior aspect. It has no 
angle, neck, tubercle, nor subcostal groove. It has a greater range 
of movement than any of the ribs and is in reality, a floating rib. Like 
the eleventh rib, its position is determined by the condition of the tissues 
attached to it. It acts as a stay and support of the sides of the abdominal 
parietes. As in the case of the eleventh rib, it, when fixed by contrac- 
tion of the muscles below, acts as a fulcrum for the respiratory muscles. 
It is fixed from below by the quadratus lumborum muscle, some of the 
abdominal muscles and the ligamentum arcuatum externum. 

This rib is in relation with the kidney and usually the large bowel. 
The attachment of muscles is the same as for the eleventh rib except that 
the quadratus lumborum is only attached to the twelfth. In addition, 
it gives attachment to some of the ligaments of the diaphragm. 

The rib is subject to displacements similar in character to those of 



APPLIED ANATOMY. 419 

the eleventh, that is the anterior end may be forced downward, or up 
under the eleventh rib. The normal obliquity is less than that of the 
rib above, yet it is often found in such a state of descent, that it almost 
or actually touches the crest of the ilium. This is the result of a general 
weakening of the abdominal walls. The rib may be pulled down by the 
contraction of the quadratus lumborum muscle which is attached to the 
lower border of the rib. 

On account of its position, it is subject to displacement from the 
wearing of improperly fitted clothing and especially from the wearing 
of belts or tight bands. Other lesions result from muscular contraction, 
and forced lateral flexion or extension of the body. These lesions produce 
disease by pressure on adjacent tissues, traction on muscles and liga- 
ments attached, pressure on viscera in relation and by pressure on the 
nerves and blood-vessels in the twelfth thoracic intervertebral foramen. 

The motor effects are characterized by contracture or relaxation of 
the abdominal muscles, and by increased or decreased activity of the 
ureters, tubes and intestines. The muscular effects are explained by 
the fact that the nerve supply of the abdominal wall comes in part from 
the twelfth thoracic, and this nerve is either stimulated or inhibited by a 
lesion of this rib, because it is in relation. If stimulated, there will be 
contracture of the lower abdominal muscles but if the subluxation in- 
hibits the passing of motor impulses along the nerve, there will be a 
relaxation of these muscles. In many cases, the contractured or relaxed 
condition of these muscles is due to other causes and the rib lesion is sec- 
ondary. The principal sensory effect is pain in the iliac fossa. Pain or 
some sensory disturbance is referred to the back, crest of the ilium, and over 
the hip as low as the great trochanter, that is, in the areas supplied by the 
twelfth intercostal nerve. Visceral pain and sensory disturbances of 
the peritoneum sometimes result from this lesion on account of the re- 
lation of the rami communicantes to the head of the rib. Usually the 
pain is referred to the cerebro-spinal nerves in relation, instead of the 
sympathetic. On this account, irritation of visceral nerves having their 
course in the twelfth thoracic segment, either peripherally or along their 
course as at the head of the rib, will result in the pain being referred to the 
cerebro-spinal nerves in relation, that is the twelfth thoracic. This ex- 
plains the fact that in most cases of ovarian, kidney and intestinal dis- 
orders, the pain or ache is felt in the back or along the course and distri- 
bution of the twelfth thoracic. The secretory and vaso-motor disorders 



420 APPLIED ANATOMY. 

resulting from this lesion, are explained through the above mentioned 
nerves, that is the rami, lesser and least splanchnics and the sympathetic 
ganglia, since these nerves carry vaso-motor and secretory impulses to the 
above mentioned organs. Disorders of the integument of the lower 
part of the back are sometimes the result of a lesion of this rib, since 
the nerves carrying trophic, vaso-motor, sensory and secretory impulses, 
are in relation with the rib and are involved in many cases. A localized 
eruption as in herpes zoster and excessive secretion of sweat in this region, 
are the most common of these disturbances. 

THE THORAX. 

The thorax is formed by the ribs, the sternum and costal cartilages 
in front, the shafts of the ribs on the side, the bodies of the thoracic or 
dorsal vertebras and their discs behind. In shape it resembles a trun- 
cated cone, -flattened antero-posteriorly, and rounded laterally. These 
structures are so arranged that they form a movable frame work to which 
are attached the muscles of respiration and which protects the heart and 
lungs. 

The sternum, which is composed, in the adult, of three flat spongy 
bones, is of interest to us in that the lower end, the ziphoid appendix, is 
often depressed as in certain occupations in which the patient assumes a 
stooping posture, or in certain diseased conditions of the bones, as rickets. 
The costal cartilages connect the sternum with the true ribs. They 
vary in length and obliquity. The upper cartilages are short, the lower 
large and oblique. The right side of the chest is usually larger than the 
left, possibly on account of the fact that most people are right handed. 
According to Holden, the diameters of the chest at different levels in the 
average male skeleton are as follows: "The antero-posterior diameter, at 
the inlet, is two and one-fourth inches; at the junction of the manubrium 
and gladiolus, four and one-half inches; and at the outlet, five and three- 
eighths inches. The transverse diameter at the inlet measures four and 
three-eighths inches, between the second ribs, seven inches; between the 
third ribs, eight and one-eighth inches; gradually increasing between the 
succeeding ribs, it attains its maximum between the ninth ribs, where it 
measures ten and five-eighths inches; and gradually diminishes below that 
level." The vertical diameter in increased in inspiration. 

The female thorax differs from the male in that its capacity is smaller, 
the sternum shorter, and the lower opening smaller in proportion than 



APPLIED ANATOMY. 



421 



is that in the male. The mobility of the upper part is greater. This is 
possibly due to the compression, of the lower ribs from the wearing of 
certain kinds of clothing. The ribs are smaller and more oblique. The 
free mobility of the upper ribs permits of greater enlargement of the 
thoracic cavity in adaptation to the requirements of pregnancy. If this 




Fig. 125. — Showing a subluxation of the eighth rib on the left side. IT. upward 
displacement at the vertebral end; A. widening of the interspace below; D. down- 
ward displacement at anterior end; B. widening of the ninth interspace in the mid- 
axillary line. Compare the interspaces on the two sides. (From photo of dissec- 
tion made at the A. S. O.). 



422 APPLIED ANATOMY. 

were not true, pregnancy would interfere to a considerable extent, with 
respiration on account of the pressure on the diaphragm. 

In most cases it: is easy to locate or count the ribs, but in obese people, 
the landmarks are obliterated and on this account we quote Holden's 
rule for counting the ribs:* 

"(a) The finger passed clown from the top of the sternum soon comes 
to a transverse projection, slight, but always to be felt, at the junction of 
the first with the second bone of the sternum. This corresponds with 
the middle of the cartilage of the second rib. 

(b) The nipple of the male is placed, in a great majority of cases, 
between the fourth and fifth ribs, about three quarters of an inch ex- 
ternal to their cartilages. 

(c) The lower external border of the pectoralis major, corresponds 
with the direction of the fifth rib. 

(d) A line drawn horizontally from the nipple round the chest cuts 
the sixth intercostal space mid-way between the sternum and the spine. 
This is a useful rule in tapping the chest. 

(e) When the arm is raised, the highest visible digitation of the 
serratus magnus corresponds with the sixth rib. The digitations below 
this correspond respectively with the seventh and eighth ribs. 

(f) The scapula lies on the ribs from the second to the seventh, in- 
clusive. 

(g) The eleventh and twelfth ribs can be felt even in corpulent per- 
sons, outside the erector spinas, sloping downward. 

(h) One should remember the fact that the sternal end of each rib 
lies on a lower level than its corresponding vertebra. For instance, a 
line drawn horizontally backward from the middle of the third costal 
cartilage at its junction with the sternum, to the spine, would touch the 
body, not of the third dorsal vertebra, but of the sixth. Again, the end 
of the sternum would be about the level of the tenth dorsal vertebra. 
Much latitude must be allowed here for a variation in the length of the 
sternum, especially in women." 

Movements of the Kibs. 

In inspiration, all the diameters of the chest are increased, which is 
accomplished by the action of certain muscles which draw the anterior 
ends of the ribs up, and on account of the shape of the ribs, this increases 

♦Landmarks Med. and Surg. Holden, p. 22. 



APPLIED ANATOMY. 



423 




Fig. 126. — The right side of the thorax. The lines denote the position of the right 
lung. 



424 APPLIED ANATOMY. 

both the anteroposterior and lateral diameters of the chest. The lower 
ribs are drawn downward and the upper ones are fixed by the scaleni 
muscles, therefore the vertical diameter is possibly increased. The 
' uscles of inspiration are the diaphragm, by the contraction of which, 
the vertical diameter is increased, the scaleni, levatofes costarum, serratus 
posticus superior and the external intercostals. The movements. of the 
chest are hampered by abnormal conditions of these muscles or dis- 
placements of the ribs. The movements should be symmetrical, quite 
free and without pain. In cases of lung disease, the movement is found 
unilateral, decidedly lessened and painful, particularly in cases of pleu- 
risy and adhesions. 

The surface markings of the chest are of importance to the practi- 
tioner, since there are so many changes of contour from diseases of the 
lungs or heart or the great blood-vessels, which can be diagnosed by 
noting their relation to certain of the landmarks of the thorax. 

The heart is placed obliquely in the chest cavity, with its base at the 
junction of the second costal cartilage with the sternum and its apex at 
the junction of the fifth rib with its costal cartilage. To locate its base, 
draw a transverse line across the sternum a little above the level of the 
third costal cartilage. The base extends to about one-half inch to the 
right of the sternum and one inch to the left. The apex is, in the normal 
heart, located at a point about two inches below the left nipple and one 
inch toward the medium line. This corresponds to the fifth interspace. 
Holden says a neeedle introduced in the third, fourth or fifth right inter- 
costal space close to the sternum, would penetrate the lung and the right 
auricle. A needle passed through the second intercostal space close to 
the right side of the sternum would, after passing through the lung, enter 
the pericardium and the most prominent part of the bulge of the aorta. 
To locate the pericardial region in which there is cardiac dullness, accord- 
ing to Latham, make a circle of two inches in diameter around a point 
mid-way between the nipple and the end of the sternum. This region 
will indicate sufficiently for all practical purposes, that part of the heart 
which lies immediately behind the wall of the chest and is not covered 
by lung nor pleura. The aortic valves are behind the third intercostal 
space on the left side. The pulmonary valves are behind the junction of 
the third costal cartilage and the sternum on the left side. The tri- 
cuspid valves are right behind the sternum at about the level of the fourth 
costal cartilage. The mitral valves are behind the third ' intercostal 



APPLIED ANATOMY. 425 

space just to the left of the sternum. Therefore, in organic heart dis- 
ease, the murmur is heard over these spaces, the location depending on 
the valve affected. 

The upper border of the pericardium corresponds to the junction of 
the first and second portions of the sternum, that is, the sternal end of 
the second rib. It is somewhat elliptical in shape and extends to the 
right as far as the para-sternal line, to the left, to the mid-clavicular line 
and downward to the diaphragm, with which it is united. It is attached 
to the sternum in front and the fifth costal cartilage on the left side. In 
effusions the operation called paracentesis is performed through the 
fifth or sixth interspace of the left side, this depending upon the degree 
of distension. 

The pleura extends upward to a line drawn from each sterno-clav- 
icular joint to the prominence at the junction of the first and second 
parts of the sternum. Eisendrath says: "The two pleurae run parallel 
to each other, the right passing a little beyond the median line. The 
space between them corresponds to the location of the anterior mediasti- 
num. At the fourth rib, the left pleura leaves the sternum and passes 
outward in an oblique manner, following the left border of the sternum 
to the sixth cartilage. The space thus left between it and the sternum, 
corresponds to that portion of the pericardium which is in contact with 
the chest wall. On the right side the pleura continues almost to the 
ensiform process, and then passes gradually outward, crossing the lower 
border of the seventh rib in the mammary line, the ninth rib in the axillary 
line, and the eleventh near the spine. " 

The highest point of the pleura is about one and one-half inches 
above the clavicle, which corresponds to the apex of the lung. The 
lowest point is the twelfth rib. It extends almost to the tip of this rib. 

The surface markings of the lungs are almost identical with those of 
the pleurae except that they do not extend so low. The only difference 
is that the lower portions of both lungs are at the sixth rib in the mam- 
mary line, the eighth rib in the axillary and the tenth rib behind. Dur- 
ing inspiration the lower border of the lung moves downward through 
the space of one rib. The position of the lungs as well as their condi- 
tion is determined by percussion, which is best done with the patient in 
the sitting or erect posture. 

The arch of the aorta corresponds to a line drawn from the junction 
of the costal cartilage of the left side and the sternum, to the upper border 
of the second rib on the right side. 



426 APPLIED ANATOMY. 

The trachea and bronchi are in the median line and correspond to a. 
line drawn from the upper margin of the sternum to the level of the sec- 
ond rib. Bifurcation takes place at the second rib. 

The surface markings of the attachments of the diaphragm corres- 
pond to a line drawn around the body passing through the ensiform 
cartilage and bony ends of the sixth ribs to the body of the first lumbar 
vertebra. During the contraction of the diaphragm, the position of the 
ribs is changed. In cases in which the ribs are softened, the diaphragm, 
by its contraction, often produces a groove, called Harrison's groove. 
This is the result of rickets or attacks of asthma or other obstructive 
respiratory disorders. 

The spleen corresponds to the ninth, tenth and eleventh ribs and is 
slightly anterior to the axillary line. In enlargements of this organ it is 
displaced forward and downward and produces a marked change in 
contour of the left side. 

The kidneys are in relation with the twelfth rib,hence have little 
to do with the contour of the chest, although in enlargements 
of the organ, a fullness at the vertebral end under the twelfth rib, is found. 

The stomach lies almost entirely on the left side under the true 
ribs, but is often prolapsed on account of relaxation or distension. In 
distension, it is displaced downward and to the right. It extends slightly 
across the median line of the body. 

The nerves of the chest wall are the intercostal, which are in rela- 
tion with the under surface of the ribs. At the points at which the per- 
forating branches emerge, that is, at the angle of the rib and the axillary 
and parasternal lines, there is marked tenderness in cases of displace- 
ments of the ribs, pleurisy and intercostal neuralgia. 

The arteries are the intercostal, which are derived from the thoracic 
aorta. The veins of the chest wall correspond to the arteries and most 
of them empty into the azygi. The lymphatics of the upper part empty 
into the axillary glands. The deep lymphatic vessels of the chest wall 
are the intercostal and diaphragmatic, which eventually empty into the 
internal mammary lymphatic glands. The superficial, as stated above, 
empty into the axillary glands, therefore diseases of the breasts will 
produce enlargements of the axillary glands, as in cancer. The super- 
ficial glands of the chest wall are the pectoral and the epigastric. The 
pectoral drain some of the lymphatic vessels of the mammary gland. 
The deep lymphatic glands of the chest wall are the intercostal (exter- 




l2TJi RIB 



Fig. 127. — Posterior view of the thorax. (After Cunningham). Note the re- 
lation of the kidneys to the twelfth rib and the pleura. 



428 APPLIED ANATOMY. 

nal, anterior and posterior) and internal mammary. The posterior 
intercostal glands are of interest to us in that they lie opposite the heads 
of the ribs and therefore would be affected by rib lesions. They drain 
a part of the intercostal spaces, the spinal canal, the muscles of the back 
and the diaphragm. 

The contour of the chest is determined more by the size and condi- 
tion of the viscera, that is, the heart and lungs, than by any other thing. 
It is conical in form, the broader part of the cone being the upper part. 
The walls are convex but this varies considerably in different patients 
on account of the difference in muscular development, the amount of fat 
deposited and the condition of the bony parts. Change of contour re- 
sults from change in size of the viscera, from certain occupations, dis- 
eases of the air passages, abnormalities or diseases of the spinal column, 
and the general condition of the patient. 

In spinal -diseases, the contour of the chest is usually changed. In 
diseases in which the mineral matter of the bone is decreased, as in rick- 
ets, the contour of the chest is also altered. These changes of contour 
are of vast importance to the physician, because they are indicative, if 
not diagnostic of the condition of the vital organs and particularly the 
heart and lungs. If the chest is flat, that is if the antero-posterior dia- 
meter is lessened and the lateral diameter apparently increased, the ribs 
more oblique, the sternum depressed, we call it a tubercular chest. These 
seem to be hereditary cases, especially those predisposed to pulmonary 
tuberculosis, although it does not necessarily follow that tuberculosis 
is present in a person who has a flat chest. In such cases the ribs are 
very flexible, expansion is lessened and the pectoral and other muscles 
are not well developed. This can be remedied partly by deep breathing 
exercises on the part of the patient to develop the lungs, and partly by 
the correction of lesions which interfere with the innervation of the mus- 
cles which hold the ribs in normal position. This muscular atrophy or 
non-development, may be partly the result of non-use of the muscles, or 
the result of rib or thoracic lesions which interfere with the trophic 
nerves to them. By advising the patient to take exercise, these muscles 
will be developed because of the increased rate of inspiration. The res- 
piratory muscles lift and thereby produce a pressure vacuum in the 
thoracic cavity and the air rushes in to fill this. Therefore, if the pa- 
tient does not exercise, these muscles are not used and do not develop, 
and even atrophy, if they have once been developed. 



APPLIED ANATOMY. 



429 



The barrel-shaped chest is short and round, that is, its anteropos- 
terior diameter is nearly as long as its transverse and is indicative of 
emphysema. In such cases the ribs are almost horizontal and the inter- 
spaces increased, and respiration is carried on almost entirely by the 




Fig. 128. — Showing the deltoid and pectoralis major muscles. The movements of 
the arm are dependent to a great extent on the normal activity of these muscles 



430 APPLIED ANATOMY. 

diaphragm. The chest wall moves but little during respiration and the 
ribs seem to have become fixed in this abnormal position. 

The chest is found to be deformed in rickets, there being a beady 
condition along the junction of the ribs with their costal cartilages and 
immediately below this there is a groove, called Harrison's groove. If 
asthma occurs in such a case, the deformity called "Pigeon" or "funnel 
breast, " may result. In Pigeon breast, the sternum and costal cartilages 
project beyond the ends of the ribs. The transverse diameter is shortened 
while the antero-posterior diameter is lengthened. The beaded condition 
to which has been applied the term "rachitic rosary, " is due to the thick- 
ening of tissues at the junction of the ribs with their cartilages. Deaver 
quotes Treves saying, that the explanation of this deformity is: 
"When an inspiration is taken, a threatened vacuum is created within 
the chest, air rushes in by atmospheric pressure, and at the end of the 
inspiration the balance of pressure without the chest and within it are 
equalized. If in inspiration there is an impairment to the entrance of 
air, the atmospheric pressure upon the external wall of the chest must 
produce some effect, being unbalanced by a light pressure upon the inner 
chest wall. In children, and especially in rickety children, the thorax 
is very pliable and elastic, and if a constant impediment exists to -the 
entrance of air, as afforded, for example, by greatly enlarged tonsils, the 
thoracic walls may yield in time to the unbalanced pressure brought to 
bear upon them at each inspiration. The weakest part of the thorax 
is along the.costo-chondral line on either side, and it is here that the pari- 
eties yield most conspicuously in such cases, and by this yielding the de- 
formity is produced." 

The funnel breast is characterized by a deep depression at the lower 
part of the sternum. It is believed to be the result of obstructed breath- 
ing as in hypertrophied tonsils, and adenoid growths in the throat. 
These obstructions interfere with respiration so that during inspiration 
the lower part of the sternum is forcibly retracted. The patient often 
assumes a bent posture, the ribs are soft and the development of the 
lungs seems to be interfered with. Sometimes it attacks only one side 
and in some of the author's cases a depression was found as wide and 
deep as the hand, which corresponded with the sixth and seventh ribs. 

Scoliosis produces a unilateral enlargement of the chest. This is 
the result of rotation of the vertebrae which invariably complicates a 
case of lateral curvature. The ribs are carried with the transverse pro- 



APPLIED ANATOMY. 



431 



cesses so that in a right lateral curvature the left side of the chest would 
be prominent and the left side would be depressed. The contour of the 
chest will be changed in kyphosis, it becoming more nearly round, that 
is, barrel-shaped. In lordosis the antero-posterior diameter of the chest 
is lessened and this is one of the most common of conditions in which 




Fig. 129. — Showing an extreme case of progressive muscular atrophy, resulting 
from injury by fall from bicycle. The lesions were at the second and third thoracic 
articulations. Death resulted from pneumonia. There was little thoracic respira- 
tion. (From photo). 

the chest and spine are affected. It seems to be a general rule that in 
posterior deviations, the antero-posterior diameter of the thorax is in- 
creased and the obliquity of the ribs lessened, while in anterior condi- 
tions the opposite effects occur. 



4H2 APPLIED ANATOMY. 

Unilateral enlargement is due to cardiac hypertrophy. This can be 
determined by locating the heart by percussion and noting the location 
of the enlargement. A shrinking of one lung has the effect of making 
the opposite side appear to be enlarged. In old pleural adhesions, the 
chest is flattened and movements are lessened in the affected area. On 
account of this, the opposite side is developed to such an extent that 
there is really enlargement. In collapse of one lung due to destruction of 
tissue as in tuberculosis, the chest wall becomes depressed over that area 
and the opposite side becomes enlarged. Unilateral enlargements may 
also be due to hypertrophy of the spleen, or if on the lower right ride, 
to hypertrophy of the liver. The usual cause of slight unilateral en- 
largement is scoliosis. A displacement of two or more ribs may also 
cause a slight change in contour on the affected side. 

It is important to be able to ascertain the cause of a change of con- 
tour as well as the degree of enlargement. To do this accurately, in- 
spection as well as palpation should be made. In some cases there is 
bi-lateral shrinking of the chest due to diseases of the lungs, principally 
old adhesions. By causing the patient to take a deep inspiration, the 
degree of movement can be ascertained and by this to a certain extent 
•the extent of the adhesion. 

In certain occupations the contour of the chest may be changed as 
in miners, shoe-makers or those whose occupation requires a stooping 
or bent posture. This is accompanied by a posterior condition of the 
thoracic spine and is usually not pathological. 

In the weak and anemic, the ribs often get down, sometimes as the 
cause of the condition, but more commonly as the result. The ribs are 
held in normal position by the tonicity and contraction of the thoracic mus- 
cles and if these muscles are not well nourished and if there are lesions 
which interfere with their innervation or nutrition, relaxation results and 
the ribs become more oblique and closer together. In such cases the 
lower edges of the rib evert, so that in extreme cases they even overlap. 
This obliquity may be due to tight lacing. All the diameters of the 
lower part of the chest are decreased and the ribs are often forced as 
low as the crest of the ilium and the ilio-costal space is almost obliter- 
ated, the great muscles of the back are atrophied and the movements 
of the body impaired. The viscera in relation are compressed and the 
writer has seen cadavers in which the liver was furrowed by the ribs in 
relation having been forced into it. 



APPLIED ANATOMY. 



433 



The muscles which have to do with the contour of the thorax are the 
pectoral, intercostal, serratus magnus and the muscles of the back. The 
muscles on the front and side of the thorax all stand out prominently 
in the normal case, but in so many diseases they are atrophied. Deep 
breathing is to be advocated, partly on account of the development of 
the lung which follows, and partly on account of the development of the 




Fig. 130. — Showing the change in contour of the chest in a marked case of angu- 
lar curvature (Pott's disease). 



IB 



434 APPLIED ANATOMY. 

muscles of the thorax. The contour of the thorax is partly governed 
by these muscles, therefore in cases in which they are atrophied, the 
contour is abnormal. 

The contour of the chest may be changed by pleural or pericardial 
effusions. Ordinarily, the interspaces are only enlarged and appear 
puffed, but in some, there is marked swelling of the wall. The charac- 
ter and location of the swelling with the presence of disease of the heart 
or lung, and the tenderness elicted on pressure over the area, make the 
diagnosis of the cause of the change of contour fairly easy. 

The general contour differs very materially in different people. In 
some the character of the clothing, Occupation and the degree of muscu- 
lar development so change the contour that there is a wide deviation 
from the normal. The effects are measured by the amount of pressure 
exerted on the viscera and the changes in the individual ribs which 
affect the gangliated cord and other important structures in relation 
with the head of the rib. If the changes come on very slowly, the vis- 
cera may become adapted to their changed relations as rapidly as the 
changes occur, while in most cases of deformity of the thorax, it is the 
result not the cause of the visceral disease. 

Tenderness of the chest is suggestive of a diseased condition of the 
lung, heart or pleura or of a subluxated rib. In pneumonia, the tissues 
over the diseased area, become thickened and tender. In chronic dis- 
ease of the lung there is tenderness on pressure over the interspaces. 
Such tenderness is, in all probability, due either directly to the rib lesions 
that are the primary cause of the disorder, or to the changes in the spinal 
cord which are the result of the disease; these affecting the intercostal 
nerves that supply the chest wall. Pleurisy and pericarditis are accom- 
panied by tenderness in the chest wall in relation with the diseased area. 

A localized lowering of the surface temperature, is suggestive of a 
lesion of the rib in relation or of disease of the viscus innervated by the 
segment that supplies the affected part. This is true of chronic dis- 
eases and especially of chronic gastritis. Localized sweating has a sim- 
ilar significance. The anatomical explanation lies in the fact that the 
vitality of the affected part is lowered either by the rib lesion directly or 
else by the effects of the disease on the spinal cord or the blood-vessels 
supplying the nerve tissues. 



APPLIED ANATOMY. 435 

THE ABDOMEN. 

The condition of the abdominal wall is of great importance because it 
is a fairly reliable sign of the condition of the viscera of the pelvic, as well 
as of the abdominal cavity. The various abdominal diseases as well as 
pelvic disturbances are depicted in the abdominal wall. It may be an 
enlargement or simply a tenderness. The abdominal wall extends from 
the costal arches to the crests of the ilia. It is elastic, changes its form 
readily and adapts itself to changes without injury to itself. A blow, 
such as a kick or a fall upon some sharp object will often cause no injtiry 
to the wall, but will produce a serious laceration of the abdominal con- 
tents. It is composed of integument, fascia, fat, muscles, peritoneum and 
fibrous tissue. 

The contour of the abdomen, that is, its prominences and depressions, 
is governed by the size of the viscera, the amount of fat, or the presence 
of tumors or visceral enlargements in the abdominal cavity. The ac- 
cumulation of fat in this place is very marked and McClellan cites a case 
in which it was four and one-half inches thick. 

The enlargements of the abdomen are due to many things. Ascites 
produces a symmetrical enlargement, which is diagnosed by a change of 
contour with change of position, coupled with this, is usually a history of 
liver disorder. On percussion or palpation, it is usually easy to determine 
that the enlargement is due to the presence of fluid. Pregnancy pro- 
duces a change in the contour of the abdomen after the third month. 
This is determined by the signs and symptoms of pregnancy. The en- 
largement is at first symmetrical and later on becomes somewhat un- 
ilateral. Pelvic tumors, if large enough to be forced out of the pelvic 
cavity, produce a change of contour of the abdomen. The enlargement 
is not symmetrical, but usually there are irregularities which can be clearly 
palpated. In enlargement of the spleen, the contour of the abdomen is 
changed. Sometimes the tumor extends past the median line in which 
case, the abdomen is quite large. 

In congestion and hypertrophy of the liver, there is a unilateral en- 
largement of the abdomen. The diagnosis as to the cause of the enlarge- 
ment, is based on the palpation and percussion of the liver, and the loca- 
tion of the enlargement. Peritonitis will produce a symmetrical enlarge- 
ment. The accumulation of gas in the bowels will produce some change 
in the contour, which is most pronounced in the retention of menses. 




Fig. 131. — Anterior view of the areas of distribution of the sensory nerves of the 
skin (shown on the left side of the body), and distribution of sensation according to 
segments of the spinal cord (shown on the right side of the body). (After Eisendrath). 



APPLIED ANATOMY. 437 

The accumulation of fat in the abdominal wall produces a prominence 
which is often mistaken for tumors. Occasionally a unilateral ventral 
hernia is found, in which case the contour of the abdomen is changed in 
proportion to the degree of protrusion. Enteroptosis, gastroptosis, ab- 
dominal tumors and distension of the urinary bladder from retention 
of urine are other causes of enlargement of the abdomen. 

Retraction of the abdomen is most frequently due to emaciation, or 
due to constitutional disease, as cancer or "to any other disease in which 
the nutrition of the body is affected. In chronic intestinal indigestion 
the abdominal wall is shrunken and the patient assumes a stooping pos- 
ture. In such cases the abdominal wall is contracted and the patient 
assumes this position on this account, it being the position in which 
there is the greatest rest to these muscles. In injury of the knee or elbow 
we have an analogous condition, in which there is a partial flexion of the 
joint. 

There are certain lines which are fairly constant. In the female 
the lineae striae are present as the result of stretching of the abdominal 
wall from pregnancy. These lines are also found in cases where the 
walls have been stretched from any other cause, such as ascites or other 
enlargement. The recti muscles can be seen and the slight transverse 
depressions between the different parts of these muscles can usually be 
outlined. These are called the lineae transversa?. In some cases the 
recti muscles become separated and a vertical groove results which cor- 
responds to the point of separation. The umbilicus is a landmark which 
is used for certain measurements and for locating some of the abdominal 
viscera. It is on a level with the disc between the third and fourth lum- 
bar vertebra, or in some cases, of the body of the fourth. It is a de- 
pressed cicatrix, which varies in depth in different individuals. In the 
young, it is often everted and in the aged, it is retracted. In pregnane y, 
accumulation of gas or other enlargements, it is usually everted. In 
chronic intestinal diseases it is found retracted. Its depth is probably 
due to the degree of shortening of the urachus, which is attached to the 
scar. In some cases the scar fails to close properly and an umbilical 
fistula is formed through which urine passes. 

The anterior superior spines of the ilia are,in an average sized person, 
prominent and are used as landmarks for the location of other parts and 
measurements of the lower limbs. The substernal angle furnishes the 
landmark for the location of the pyloric end of the stomach, which is a 



438 



APPLIED ANATOMY. 




Fig. 132. — Surface markings (on the left side) of the thoracic and abdominal 
viscera. (After Eisendrath). C. C, costoclavicular line; U. L., upper lobe of lung; 
L. L., lower lobe of lung; C. A., costal arch; S., spleen; 1, transverse colon; 2, descend- 
ing colon; 3, sigmoid.; A., anterior superior spine of the ilium; T., trochanter. 



APPLIED ANATOMY. 439 

few inches directly below. This angle or interchondral space, is formed 
by the divergence of the cartilages of the false ribs. The depth and width 
of this angle varies with the shape of the thorax. It is narrow in women 
who wear tight clothing and in cases of the dropping of the lower ribs or 
a lessening of the antero-posterior diameter of the thorax from any cause. 

The abdomen is arbitrarily divided into regions by the passing of 
vertical lines from the cartilage of the tenth rib and superior spines of 
the ilia, and transverse lines through the cartilage of the eighth rib and 
the spines of the pubes. These regions thus formed are called the right 
hypochondriac, epigastric, left hypochondriac* right lumbar, umbili- 
cal, left lumbar, right inguinal, hypogastric and the left inguinal. It 
is thus divided for the purpose of describing the position of the viscera 
and that of the better describing the location of abdominal enlargements 
or disease of the abdominal viscera. 

The abdominal aorta corresponds to a line drawn from a point 
slightly to the left of the ensiform cartilage to another point on a level 
with and immediately to the left of the umbilicus. In all organic dis- 
eases of the stomach and intestines such as gastritis and enteritis, the 
pulsation of the aorta is markedly increased, sometimes to such an ex- 
tent that they can be seen. In thin people the artery can be palpated 
quite distinctly and in the above mentioned diseases, its walls seem to be 
thickened. The celiac axis is given off about five inches above the um- 
bilicus, the renal artery is about four inches above. The iliac arteries 
radiate from the umbilicus downward and outward to a point which is 
about mid-way between the anterior superior spine of the ilium and the 
symphysis of the pubis. The internal iliac, is given off at a point about 
two inches below the umbilicus. 

The liver lies in the hypochondriac and epigastric regions and some- 
times extends across to the left hypochondriac region. Its anterior 
margin extends about an inch below the costal cartilages and can be pal- 
pated in the average case, during respiration. In congestion or hyper- 
trophy of the liver, this margin can be readily palpated. It is tender to 
the touch and often feels hardened. The upper border of the liver reaches 
as high as the dome of the diaphragm, the right fourth interspace in the 
mammary line, the eighth rib in the mid-axillary line and the tenth rib 
in the scapular line. Posteriorly, it extends to the tenth and eleventh 
thoracic spine and the bodies of the vertebras. It extends across the 
median line about one and one-half inches, and in unusual cases, it reaches 



440 



APPLIED ANATOMY. 




Fig. 133. — The regions of the abdomen. 



APPLIED ANATOMY. 441 

the left mammary line. Deaver says: "The liver reaches as high 
as the transverse line drawn through the lower end of the meso-sternum; 
in the mammary line this transverse line passes over the fifth intercostal 
space or lower border of the fifth rib. The upper surface of the left lobe 
of the liver is opposite a transverse line drawn through the lower end of 
the meso-sternum. The upper surface of the right lobe is opposite the 
lower border of the fifth rib in the right mammary line; in the right mid- 
axillary line, opposite the seventh rib; and in the mid-scapular line, 
opposite the ninth rib; and at the side of the spinal column, opposite the 
tenth thoracic spinous process." These lines are determined by per- 
cussion and are only approximate, since the liver varies greatly in posi- 
tion. The gall-bladder is almost entirely covered by the liver, but the 
fundus projects slightly below the anterior margin and is in relation with 
the costal cartilage of the ninth rib. The gall-duct passes obliquely 
downward and empties at a point slightly to the right and above the 
umbilicus. Clinically, there is often found a thickening of the tissues 
around the lower end of the duct and the localized hardness can be 
plainly felt. There is some tenderness in these cases and the condition 
is almost diagnostic of liver disease. 

The stomach lies in the left hypochondriac and epigastric regions 
and its position is more variable than that of the liver. Its cardiac end 
corresponds to a point over the left costal cartilage of the seventh rib 
which is about an inch from the sternum. The pyloric end lies about an 
inch to the right of the median line and usually beneath the liver and 
about three inches from the sterno-xiphoid articulation. Addison says 
that the pyloric portion of the stomach is practically bisected by a hori- 
zontal plane which passes through the abdomen mid-way between the 
supra-sternal notch and the pubic symphysis. The lesser curvature of 
the stomach corresponds to a curved line connecting the cardiac and 
pyloric ends. The greater curvature corresponds to a line drawn up- 
ward from the cardiac orifice to the fifth rib and thence to the pyloric 
orifice. When the stomach is empty it lies quite obliquely in the ab- 
dominal cavity and is almost entirety covered by the ribs and cartilages 
on the left side. When distended, it descends, becomes more nearly 
transverse and crosses the median line to a distance of two or three inches. 

The small intestines lie in a frame formed by the large intestine. The 
duodenum is the part which is of most interest to us in that it is quite 
frequently diseased and because it receives the gall-duct. Eisendrath 



442 APPLIED ANATOMY. 

says: "The duodenum corresponds on the surface, to the right half of 
the epigastric region behind the eighth costal cartilage (horizontal por- 
tion); the second or vertical portion lies mid-way between the median 
line of the body and the vertical line which separates the right hypo- 
chondriac from the epigastric region. The third or ascending portion 
passes obliquely upward across the body, from the right half of the um- 
bilical region to the left half of the same, where it joins with the jejunum 
at a point one inch to the right of the median line (duodeno-jejunal 
flexure) , at a point about mid-way between the ensiform process and the 
umbilicus." 

The large intestine is divided into the cecum, ascending colon,, 
hepatic flexure, transverse colon, splenic flexure, descending colon, sig- 
moid flexure and rectum. 

The cecum corresponds to the right iliac and right lumbar region. 
The base is slightly below McBurney's point. Its position is variable, 
since it is subject to displacement downward. In constipation and in 
enteroptosis it often gets into the true pelvic cavity. 

The ascending colon extends upward to the liver, at which place it 
makes quite a sharp bend to the median line. The transverse colon sags 
in the middle and reaches almost to the umbilicus. Its position is also 
variable and it is found almost as often below the umbilicus as above it, 
especially in cases of intestinal indigestion, constipation and enteroptosis. 
The writer examined a case in which the transverse colon was found 
partly in the true pelvic cavity. The splenic flexure is in relation with 
the spleen, at which point it makes a sharp bend forward and downward. 
The descending colon passes almost vertically downward and when near 
the pelvic brim makes a turn which is called the sigmoid flexure and 
crosses the left sacro-iliac synchondrosis. As it passes into the true 
pelvic cavity, it becomes smaller. The large intestine is accessible to 
palpation with the possible exception of the hepatic and splenic flex- 
ures, and on this account fecal impaction can ordinarily be easily diag- 
nosed. 

The vermiform appendix corresponds to the middle of the line con- 
necting the umbilicus and the anterior superior spine on the right side. 
This is called McBurney's point. 

The pancreas lies immediately below and behind the stomach. It 
crosses the inferior vena cava, aorta and the body of the first lumbar 
vertebra. It corresponds to a horizontal line drawn about three inches 
above the umbilicus. 



APPLIED ANATOMY. 443 

The kidneys are in relation with the eleventh and twelfth thoracic 
and first and second lumbar vertebrae, and the right is lower than the 
left. The surface markings on the abdominal wall are as follows: the 
lowest point extends to the lower border of the tenth costal cartilage, 
while the upper borders reach to within two inches of a line drawn hori- 
zontally through the xiphoid appendix. On account of their depth 
and the amount of adipose tissue surrounding them, they cannot in the 
ordinary person be palpated from the front. Deaver says: "a trans- 
verse plane through the umbilicus passes just below the lower border 
of the kidneys, and they are cut in half by a line drawn vertically up- 
ward in the middle of Poupart's ligament. " 

The external abdominal ring is in the lower part of the aponeurosis 
of the external oblique muscle and is in relation with the spine of the 
pubis. It is of interest in that it consitutes a weak place in the abdom- 
inal wall and hernia often takes place at this point. It is called a ring 
because it gives passage to the spermatic cord, the genital branches of 
the genito crural nerve and the ilio-inguinal nerve in the male, and in 
the female the round ligament of the uterus and the above named nerves. 
In hernia, there is to be found a tumor which increases in size whenever 
the intra-abdominal pressure is increased, as in coughing and lifting. 
The opening can ordinarily be palpated and the diagnosis in doubtful 
cases is based on this. The tests for hernia should be made while the 
patient is in the erect posture, since the tumor is larger and the impulses 
more marked with the patient in this position. 

The skin of the abdominal wall is quite closely adherent to the ab- 
dominal fascia, especially around the umbilicus. It is broken in cases 
of abnormal enlargements as ascites and pregnancy and the lineae albi- 
cantes are thus formed. The deeper layer is continuous with the apon- 
eurosis of the external oblique muscle at Poupart's ligament, the crest of 
the ilium and the lineae alba. 

The superficial vessels are the anterior ends of the lower intercostal 
and the lumbar arteries and veins. In addition to this are the super- 
ficial epigastric, the circumflex iliac, and branches of the internal mammary 
artery. The superficial veins of the front of the abdomen are quite num- 
erous and are subject to varicosities during pregnancy and other en- 
largements. Deaver quotes Schiff as saying that small veins connect 
the portal vein with the epigastric veins at the umbilicus. This ac- 
counts for the dilatation of them in hypertrophic cirrhosis of the liver. 



444 APPLIED ANATOMY. 

The lymphatic vessels of the abdominal wall accompany the blood-ves- 
sels, those above the umbilicus emptying into the axillary glands and 
those below, into the inguinal. The nerves of the abdominal wall are 
the lower five or six intercostal and branches of the ilio-hypogastric and 
ilio-inguinal, which are from the anterior division of the first lumbar 
nerve. The nerve supply to the abdominal wall is of great importance 
to the physician in that nearly all abdominal and pelvic visceral dis- 
eases cause pain to be referred to these nerves. Eisendrathsays:* "The 
spinal segments with which they are connected are also in communica- 
tion with the viscera of the abdomen and thorax through the sympa- 
thetic system. Hence diseased conditions of the abdominal viscera give 
rise to disturbance in the spinal segments with which they are connected, 
and the brain, being accustomed to localize pain along the spinal nerves, 
makes a mistake and refers the pain along the spinal nerve of the seg- 
ment disturbed. Not only is pain referred, but the skin supplied by the 
disturbed spinal segments becomes tender, and through a study of these, 
Head has been able to localize the visceral centers, thus affording the sur- 
geon a means for increased accuracy of location of pain as a symptom in 
abdominal diagnosis. " These nerves supply both the integument and the 
muscles, therefore a stimulation of them, as in examining the abdomen 
with cold hands, will cause the muscles to contract and thus make it 
difficult to palpate the viscera beneath. These nerves are connected 
with the gangliated cord by means of the rami communicantes. On 
this account in irritative disease of the viscera as in appendicitis, the 
abdominal wall becomes tender and rigid. These nerves run obliquely 
forward and downward, which thing should be remembered in the making 
of incisions in the abdominal wall. 

The condition of the abdominal wall is of importance in that it is 
a fair indication of the condition of the viscera of the abdominal cavity. 
Diseases of the abdominal or pelvic viscera are in some way indicated by 
changes in the abdominal wall or of the structures immediately beneath. 
A contractured abdominal wall is most frequently the result of a chronic 
peritonitis. In the cases of chronic intestinal indigestion, the wall is 
quite rigid and the abdomen retracted. It is sometimes suggestive of 
asthma or other conditions in which the respiration is of the abdominal 
or diaphragmatic type. If the tightened or contractured condition is 
accompanied by tenderness, it is probably a case of an intestinal indi- 
gestion or chronic peritonitis from other causes. In acute peritonitis, 

*Clinical Anatomy, Eisendrath, p. 220. 



APPLIED ANATOMY. 445 

and in cases of distention from accumulation of gas, the abdominal wall 
is often very tense. The percussion note is tympanitic and from this 
the differential diagnosis is made between these conditions and solid 
tumors and cysts in which condition the note is dull. 

A relaxed abdominal wall may be the result of over distension or 
stretching of it, the accumulation of fat or general weakness. The most 
common form is the result of pregnancy in which the walls are in a sub- 
involuted condition in which cases, they fail to regain their former tone. 
In nulliparae, the relaxed abdominal wall is diagnostic of enteroptosis. The 
degree of relaxation of the wall is indicative of the degree of relaxation 
of the supports of the intestines. Often the accumulation of fat in the 
abdominal wall causes it to relax and gives the patient a pendulous ap- 
pearance, and in such cases there is usually a great deal of fat in the 
omentum and the intestines. In a general way then, a fat abdominal 
wall is indicative of the accumulation of fat around the intestines; a re- 
laxed abdominal wall, of a relaxed condition of the supports of the in- 
testines; while a contractured abdominal wall is indicative of an 
irritation of the peritoneum caused most frequently by chronic catarrh 
of the bowel. A localized contracture or hardening of the wall is sug- 
gestive of an irritative disease of the part in relation, or a contracture of 
the abdominal, or if deep, of the psoas muscles. If the thickening of the 
tissues or tumefaction is not superficial, it is indicative most frequently 
of an impacted bowel or a congested viscus or in some cases, an enterolith. 
The localized relaxation is suggestive of a thinning of the abdominal wall 
at that point and predisposes to hernia, particularly if it is near the um- 
bilicus or abdominal ring. 

The temperature of the abdominal wall should be taken into consid- 
eration in the examination of a patient. If the temperature is above 
normal, it is indicative of peritonitis, the degree of temperature deter- 
mining the degree of inflammation. If this occurs in the lower part of 
the abdominal wall, it is indicative of inflammation of the pelvic perito- 
neum caused by ovarian or uterine disease. If localized in the right iliac 
fossa, it suggests peritonitis from appendicitis. If in the neighborhood of 
the umbilicus, it is probably a case of inflammation of the bowels. Only 
in incipient peritonitis, is the increase of temperature localized, while a 
general rise of temperature is indicative of a diffuse peritonitis. In 
children suffering with indigestion, the surface temperature is often in- 
creased to a greater degree than that of any other part of the body. By 



446 APPLIED ANATOMY. 

manipulation of the intestines by which they are lifted or changed as to 
position, this temperature can be reduced, often at a single treatment. In 
the treatment of children for such a disorder, the abdominal manipula- 
tion is the most important of all treatments. A coldness of the abdom- 
inal wall, is, according to Dr. Still, the result of a displacement upward 
or to one side, of the omentum, which is an apron like flap which sep- 
arates the abdominal wall from the intestines, thereby protecting them 
against injury and perhaps against change of temperature. In many 
cadavers examined by the writer, the omentum was found rolled up and 
displaced upward or to one side. The coldness of the abdominal wall is 
found in cases in which the vitality, that is, the activity of the intestines 
and other abdominal viscera is lessened. In subinvolution of the ab- 
dominal wall and pelvic organs, the jtarts feel cold to the touch and often 
there is a cold perspiration on the surface. 

The areas of tenderness in the abdominal wall are suggestive of a con- 
gestion or inflammation of the viscera in relation. This painful condi- 
tion is often reflex, but in many cases it is the result of the inflammation 
extending by contiguity of tissue, from the visceral to the parietal layer 
of the peritoneum. It is practically impossible for tenderness or in- 
flammation of a viscus to occur without the abdominal wall becoming 
affected, that is, it becoming tender also. A general tenderness of the 
abdominal wall is indicative of a diffuse peritonitis, or a general disease 
of the intestines as in cases of sudden cessation of the menses or chronic 
catarrh of the bowel. A localized tenderness over the pit of the stomach, 
that is over the sub-sternal angle, is about as good a diagnostic indica- 
tion of gastritis or some other organic disease of the stomach as there is. 
In mild cases the tenderness is most marked in the deep structures, while 
in acute cases, the integument over this area becomes so tender that the 
patient can scarcely bear the weight of the clothing on the part. Tender- 
ness between the pit of the stomach and umbilicus, that is, about mid- 
way between, is suggestive of an organic disease of the small intestine. 
If this tenderness seems to follow a horizontal course, it is in the trans- 
verse colon. A tenderness in the right hypochondriac region is sugges- 
tive of congestion of the liver or of gall stones. Often there is a localized 
area of tenderness just above and to the right of the umbilicus, at which 
point the gall-duct empties into the duodenum; this is suggestive of 
catarrh of the gall bladder, or of gall stones. In appendicitis, the tender- 
ness is over McBurney's point. This may be confused with that from 



APPLIED ANATOMY. 447 

ovarian disorders, which usually is at a point somewhat lower than this. 
Tenderness in the iliac fossae occurs in congestion, inflammation or or- 
ganic disease of the peritoneum, tubes, and ovaries. Supra-pubic tender- 
ness is suggestive of congestion or inflammation of the uterus or organic 



Fig. 134. — Surface markings of the thoracic and abdominal viscera (right side) . 
U. L., upper lobe of right lung. L. L., lower lobe. M. L., middle lobe. P., lower 
boundary of the lung. 7., lower border of liver. A. C, ascending colon. T. C, 
transverse colon. (After Eisendrath). 



448 APPLIED ANATOMY. 

disease of the bladder. Tenderness of the abdominal wall may occur in 
cases of strain of the muscles, hernia, Pott's disease involving the thoracic 
vertebra? and fracture or dislocation of the lower thoracic vertebra?. In 
the examination for abdominal tenderness, ascertain whether it is super- 
ficial or deep, also the degree of it, location and length of standing. 

In lesions of the lower ribs, often the pain is referred to the abdom- 
inal wall, but in these cases, pressure will not ordinarily increase the 
pain. Pseudo-appendicitis is a very good example of this type of dis- 
ease and in many cases of supposed ovarian and gastric disorders, the 
pain is a referred one. 

In many disorders of the abdominal and pelvic viscera, there is a 
marked pulsation of the arteries which supply the parts. This pulsa- 
tion is due to a constriction of the vessel from a thickening of the walls 
or else to a stimulation of the vaso-constrictor nerves supplying the part. 
Pulsation at 'the pit of the stomach, is indicative of congestion or inflam- 
mation of the stomach, if immediately above the umbilicus, of disorders 
of the small intestine. In chronic ovarian disorders, there is pulsation 
and thickening of the iliac arteries, which things can be determined in 
an average case by palpation over them. The writer has examined many 
cases in which the artery could be distinctly palpated, being hard and 
large and considerably larger than the corresponding one. In thin people, 
care should be taken not to mistake the normal pulsation of the abdom- 
inal aorta for an aneurysm or other pathological conditions. 

The function of the abdominal wall is to support the abdominal 
viscera as well as protect them against injury. If the wall is relaxed it 
does not well support or protect, hence displacement of the viscera is the 
result. Its function is also disturbed by contracture of the wall whether 
from lesions or visceral disease, and the contour of the abdomen is thus 
altered. Lesions along the lower thoracic region involving the vertebra? 
and ribs, disturb the function of the abdominal wall in that they inter- 
fere with the innervation of its muscles. On this account the muscles 
will become contractured or relaxed, both of which disturb function. 

THE TEMPORO-MAXILLARY ARTICULATION. 

The temporo-maxillary articulation is formed by the glenoid fossa 
and the edge of the temporal bone or eminentia articularis, and the 
condyle of the lower jaw. This articulation is of importance on account 



APPLIED ANATOMY. 



449 



of the frequency of dislocation or injury and the effects on the fifth cranial 
nerve. The ligaments are the capsular, which is divided into several 
portions such as the external lateral and internal lateral ; the interarticu- 
lar cartilage; the spheno-maxillary and the stylo-maxillary. The two 
lateral ligaments in addition to holding the bone in place, protect the 
internal maxillary vessels and the auriculo-temporal nerve, during move- 
ments of the lower jaw. The interarticular fibro-cartilage acts as a 
buffer and prevents shocks to the brain, as in the violent closing of the 
jaw or blows on the chin, which would otherwise injure the brain through 




Fig. 135 — Showing the temporo-maxillary articulation. 

the thin bony plate of the glenoid cavity which is in relation with the 
middle fossa of the skull. This joint is innervated by branches of the 
fifth nerve, and on this account the effects of a lesion would be most 
pronounced in the area supplied by this nerve. The movements of the 
joint consist of a hinge-like movement with a slight gliding action and 
some rotation. These movements are necessary for the proper triturat- 



450 APPLIED ANATOMY. 

ing of the food. The muscles concerned in the movements of the jaw 
are: 

Depressors. The platysma myoides, the mylo-hyoid, the genio- 
hyoid, the anterior belly of the digastric and the genio-hyo-glossus. 

Elevators. The masseter, the temporal and the internal pterygoid. 
The lower jaw may be protruded or retracted by the fibro-cartilage and 
the condyles gliding forward and backward in a horizontal direction. 
The forward movement is produced by the contraction of the external 
pterygoid assisted by the masseter and the internal pterygoid. Retrac- 
tion is effected by the posterior part of the temporal and a part of the 
masseter. The grinding movements are accomplished by the alternate 
contractions of the internal and external pterygoid muscles on each side. 

In all ordinary movements of the jaw the fibro-cartilage is held in 
relation with the condyle, but if the depression of the jaw is marked as in 
yawning, the condyle may be dislocated forward. The external pterygoid 
muscle has to do with holding the bone out of place, thus the jaw is 
locked in its abnormal position. McClellan says: "A proper under- 
standing of the mechanism of this displacement is necessary for its 
reduction, which demands that the lower jaw be drawn forward, 
forcibly depressed and then pushed backward and upward. The dis- 
location of the jaw comes most frequently from force applied to the 
jaw when the mouth is open, but perhaps more frequently from the spas- 
modic action of the external pterygoid muscle in yawning. " The signs 
of the dislocation are a widely opened mouth, which cannot be closed, 
pain and swelling of the joint and dribbling away of the saliva. A sub- 
luxation of the jaw is more common than a complete displacement. It 
consists of a slipping forward of the interarticular cartilage upon the 
eminentia articularis as a result of rupture or relaxation of the ligaments. 
This occurs most frequently in young and delicate people in which the 
ligaments are relaxed. In this case the condyles catch and temporarily 
lock the jaw, which after loosening cause the jaw to be closed with a 
snap. In most cases the two sides of the jaw are not depressed sym- 
metrically, that is the symphysis is drawn out of the median line. These 
partial dislocations can be diagnosed by noting the character of the 
movement, which is best done by placing the hands over both articula- 
tions while the patient opens the mouth. 

As a result of these lesions, not only is the function of the joint im- 
paired but the structures in relation are injured or in 801116 way affected. 



APPLIED ANATOMY. 451 

These structures are the parotid gland, the fifth nerve and the temporo- 
maxillary artery. Often facial neuralgia is the result of a subluxation 
at this joint which irritates the fifth cranial nerve. The pain is often 
referred to the teeth, or the points on the face at which the nerve is super- 
ficial. Some disorders of the parotid gland result from a lesion of the 
lower jaw by which the gland is directly injured or affected through its 
innervation, and becomes tender and congested and gives rise to symp- 
toms similar to those in mumps. The writer has seen many cases of 
erysipelas of the face in which the trouble was undoubtedly due to sub- 
luxation of the inferior maxilla, since in nearly all of them the condition 
was relieved within a short time by correcting this lesion. The possible 
explanation is that the vaso-motor nerves to the superficial blood-ves- 
sels of the face are in some way affected by a subluxated condition of the 
bone, hence the marked congestion which is the first sign of the disease. 
In addition to this we should consider the micro-organism which is 
supposed to be responsible for the disease in that it is the exciting 
cause. 

In reducing this lesion it may be necessary to introduce a cork or 
the finger wrapped with a towel, between the last molar teeth and then 
by using this as a fulcrum and the jaw as a lever, the head of the bone can 
be pried back and down into its socket. In cases of subluxation, the 
lesion can be reduced by using the angle of the jaw as a lever and pro- 
ducing some pressure on the articulation as the mouth is opened. 

THE HYOID BONE. 

The hyoid bone acts as a stay for the support of the numerous mus- 
cles attached to it, therefore its position is dependent on the condition 
of the muscles attached to it. It consists of a body and four cornua. 
The greater cornua can be palpated just above and to the side of the 
thyroid cartilage. Each projects upward and backward and termin- 
nates in a round tubercle to which is attached the thyro-hyoid ligament. 
This bone is of interest in that injuries to the throat as in choking, dis- 
turb its position and consequently disorders of the voice and difficult 
deglutition result. In contracture of the hyoid muscles, for example the 
omo-hyoid, aphonia often results. Therefore in cases of huskiness of 
the voice, loss of voice, chronic hacking cough or even painful condi- 
tions of the throat, this bone should be examined, because in these dis- 
orders it is often found to be displaced. These effects are explained by 



452 APPLIED ANATOMY. 

the fact that the muscles attached to it are contractured and that the 
nerves in relation are affected, particularly the superior and recurrent 
laryngeal. Contractures of these muscles put a tension on the voice- 
box, thereby interfering with its function, while in other cases they pull 
the bone backward against the nerves in posterior relation, thereby 
setting up an irritation of them. In whooping cough, this bone is often 
found displaced upward and backward and the severity of the paroxysms 
can be lessened to a marked extent by drawing it down into its normal 
position. By grasping the cornua and pulling them downward and for- 
ward thereby stretching and overcoming the contracture of the tissues 
above the bone, the irritation can be relieved or at least lessened in in- 
tensity. In some cases the two ends of the bone may not be of the same 
length, this giving rise to an irregularity that may be mistaken for a lesion. 

. THE STERXO-CLAVICULAR ARTICULATION. 

The sterno-clavicular articulation is quite shallow and on this ac- 
count the clavicle is subject to displacement. The ligaments permit of 
considerable movement when the shoulder and arm are used. It is 
frequently slightly displaced and coupled with this is often found hyper- 
mobility, so that it is possible, by grasping the middle third of the clav- 
icle, to move the sternal end of the bone through a space of half 
an inch. The most common lesion of this articulation is a backward 
displacement of the sternal end of the clavicle. This is diagnosed by 
feeling it in its abnormal position, and noting that it is less prominent 
than the opposite side. This sort of displacement may produce dyspnea, 
dysphagia or congestion of the head and face from pressure on the 
trachea, esophagus or the veins of the neck. Goitre is supposed to be 
produced, or made worse by a downward or backward displacement of 
this end of the clavicle. In some of these cases, the upward displacement 
of the first rib is the real condition rather than a displacement of the 
clavicle. The distance between the clavicle and rib is lessened in either 
case and would lead to an obstruction of the vessels located between the 
two. The effects of this lesion are most pronounced in the veins which 
leads to congestion of the throat, thyroid gland and arm. In all cases 
of sore throat, exophthalmic goitre or enlargements of the neck whether 
from lymphatic disturbances or due to venous congestion, the clavicle 
should be examined, because in many of these, it is subluxated back- 
ward and downward and thus obstructs the drainage of these parts. 



APPLIED ANATOMY. 453 

The effects of a lesion of this end of the clavicle are then determined almost 
entirely by the degree of pressure on the adjacent blood-vessels. A 
displacement of this end of the clavicle will weaken the shoulder in that 
the bone acts as a brace to the shoulder. On this account it is torn loose 
by strong muscular exertions in which the shoulder and arm are used. 

THE ACROMIOCLAVICULAR. 

The acromio-clavicular joint is shallow and has a peculiar obliquity. 
It is of greater importance to the physician partly on account of the fre- 
quency of the subluxation and partly on account of the severity of the 
effects. It has the usual capsular ligament and the interarticular fibro- 
cartilage which is often imperfect. In all movements of the shoulder 
girdle, this articulation is involved. In movements of the arm, forward 
and backward and upward past the horizontal plane, this articulation is 
involved. The acromial end of the clavicle is most frequently dislocated 
upward and backward. As the result of such a lesion, the movements 
of the shoulder girdle are imperfect and many movements of the arm 
painful or impossible. The arm can be raised to a level of the shoulder 
without the movement of this joint, but whenever it is carried forward 
or backward as in combing the hair or putting on a coat, this joint is in- 
volved. If a lesion exists, these movements are practically impossible, 
but in the average case they are only painful so that the patient has 
difficulty in backward or upward movements of the arm. This lesion 
is often the cause of pain along the groove of the biceps and at the in- 
sertion of the deltoid, in which cases, the trouble is usually attributed to 
a slipping of the bicipital tendon in its groove. In cases treated by the 
writer it was found that in most of them in which a diagnosis of dislo- 
cation of the bicipital tendon was made, there was found to be a lesion at 
the acromio-clavicular articulation. This lesion not only disturbs the 
function of the joint, that is, movements in which this joint is used, but 
it seems to affect the circumflex and other nerves in relation. This 
gives rise to a referred pain which is felt at the insertion of the deltoid 
along the tendon of the biceps and over the top of the shoulder. The 
patient often describes it as "rheumatism" of the shoulder on account 
of the stiffness and pain. In all cases in which a patient cannot get the 
hand to the back of the head or the spine, or cannot extend the arm above 
the head, it is well to examine this articulation, since in most of them there 
will be found a tenderness and irregularity at the acromio-clavicular 



454 APPLIED ANATOMY. 

joint. Reduction is as a rule, easily effected by drawing the shoulder 
and arm up and back and at the same time applying some pressure over 
the acromial end of the clavicle. In cases in which it does not stay in 
place, it is well to bandage the joint and strap the arm to the side. 

THE SHOULDER-JOINT. 

The shoulder-joint is formed by the head of the humerus and the 
glenoid fossa of the scapula. It is an enarthrodial or ball-and-socket 
joint, and the movements are freer than those of any other articulation. 
The glenoid fossa is deepened by the glenoid ligament and even in this 
condition, is much smaller than the head of the humerus, which accounts 
for the great freedom of movement. The capsular ligament is attached 
to the circumference of the glenoid cavity and to the anatomical neck 
of the humerus below. It is very loose and large and in fact is large 
enough to accommodate the head of the femur. In dislocations of the 
humerus, this ligament is ruptured at the lower part, which is the weakest 
portion. The coraco-humeral or accessory ligament, seems to be a thick- 
ening of the inner part of the capsular ligament which extends from the 
coracoid process to the tuberosity of the humerus. The glenoid liga- 
ment is a fibro-cartilaginous rim which surrounds the edge of and deepens 
the glenoid cavity. It is continuous above with the long head of the 
biceps tendon and below with the long head of the triceps. These lig- 
aments do not securely hold the head of the bone in position, but the 
tendons of the muscles in relation, so reinforce them that the head of 
the bone is thoroughly well held in place. The important tendons are 
those of the supra-spinatus, infra-spinatus, and teres minor muscles, pos- 
teriorly ; the broad tendon of the subscapularis strengthens it on the inner 
part; the long head of the triceps below and the long tendon of the biceps 
strengthens the upper anterior part of the joint. In addition to these, 
the deltoid covers over the entire joint and strengthens and protects 
it. 

The synovial membrane lines the ligaments of the joint and sends 
a reflexion around the long tendon of the biceps and communicates with 
the bursal sacs around the tendons in relation. In injury to the shoulder- 
joint, the synovial sac often becomes distended with fluid and thus pro- 
duces a fluctuating swelling around the joint. This is often followed 
by adhesions or dryness of the joints in which there is crepitus. Care 
should be taken in the treatment of chronic synovitis of the shoulder- 



APPLIED ANATOMY. 



455 



joint because of the danger of making it worse by the breaking of ad- 
hesions. 

The blood-supply of the joint is derived from the suprascapular, 
anterior and posterior circumflex and subscapular arteries. It is inner- 
vated by the suprascapular, circumflex and a few filaments from the 
subscapular nerve. McClellan says: "The shoulder-joint is practically 
a universal joint and as it depends upon the arrangement and power of 
the surrounding tendons rather than upon the mechanical adjustment of 
the opposing bony surfaces, the grouping of the muscles in effecting the 
various movements should be understood. Extension is effected by the 
teres major, latissimus dorsi and the posterior third of the deltoid. These 



ACROMIOCLAVICULAR CORACO-ACROMIAL /TRAPEZOID LIST. 




1 mm * 



Fig 136. — The glenoid fossa, scapula.clavicle, and acromio-elavicular articulation. 

are assisted in raising the arm by the teres minor and infraspinatus mus- 
cles. Flexion is produced by the coraco-brachialis and the anterior 
portion of the deltoid aided by the pectoralis major; abduction by the 
deltoid and supraspinatus ; adduction by the pectoralis major, teres 
minor, latissimus dorsi and coraco-brachialis." 



456 APPLIED ANATOMY. 

On account of the shallowness of the glenoid cavity, the powerful 
leverage exerted on the joint by the arm as in protecting the body in 
falls, the large size and rounded shape of the head and the looseness of 
the ligaments, dislocation of this joint is comparatively very common. 
It is caused most frequently by forcible extension as in falls on the hand 
or elbow and twists of the arm. Sometimes a direct blow on the shoul- 
der will dislocate the humerus. The form of the dislocation is deter- 
mined by the position of the head of the bone in relation to the glenoid 
cavity. Thus, there may be four forms of dislocation; the subcoracoid, 
in which the head is forward and slightly downward; the subglenoid, 
in which it is directly under the cavity; the subspinous, in which it is 
back and the subclavicular, in which it is anterior. The other disloca- 
tions are only modifications of these. 

The signs of dislocation of the shoulder, depend upon the length of 
standing of the case and the character of the injury. In all recent cases 
there is swelling, lessened mobility, pain in the joint and along the course 
of the arm and no crepitus. There is prominence of the acromian pro- 
cess with a depression immediately beneath, a flattening of the shoulder, 
a change in the direction of the humerus and on palpation, the head of 
the bone is found to be at a place elsewhere than in the glenoid cavity. 
The usual tests for dislocation of the shoulder are, the strait edge test 
in which a straight edge applied to the shoulder will touch the arm and 
acromian process; increased circumference of the joint and limitation of 
the movements of the arm, so that when the hand is placed on the op- 
posite shoulder the elbow will not touch the chest; and palpation of the 
bone in its abnormal. position. 

The subcoracoid, is the most common of the displacements of the 
shoulder. In this dislocation, the head of the bone is anterior to the 
glenoid cavity and under the coracoid process. It is diagnosed by feel- 
ing the head of the bone in this position and by noting the prominence 
of the tissues caused by the abnormal position. The limb may be short- 
ened, but it is in many cases not affected at all as to length. There seems 
to be all grades between the subcoracoid and subglenoid displacements, 
the latter being the next most common form. The diagnostic points 
of this form are, the presence of the head of the bone under the glenoid 
cavity, that is, in the axilla, marked depression over the anterior part 
of the axilla, lengthening of the arm and quite a large depression be- 
tween the head of the bone and the coracoid process. 



APPLIED ANATOMY. 



457 



The other forms of dislocation of the shoulder are very rare. The 
most important of the diagnostic signs, is the abnormal position of the 
head of the bone, which can be palpated and seen in its changed position. 

Most important as well as most constant of the effects of a displaced 
shoulder is the interference with the function of the joint, that is, loss or 




Fig. 137. — Dislocation of the shoulder with atrophy, paralysis and deformity. 
The fingers were stiff, flexion of the wrist impossible and pain in the shoulder-joint, 
very great. Under treatment, the pain was relieved but reduction was found impos- 
sible on account of the great amount of inflammatory tissue around the joint. (From 
photo). 

restriction of movement. In order that a joint may have normal move- 
ment, the articular surfaces must be in contact and if they are changed, 
the disturbance of movement is usually in proportion to the degree of 



458 APPLIED ANATOMY. 

change. In dislocation of the shoulder the articular surfaces are of course 
separated and otherwise changed, hence the limited movement of the 
arm. Adhesions occur in many cases as a result of the irritation and in- 
flammation, which so commonly accompany a displacement of the hu- 
merus. These adhesive bands still further restrict the movements of 
the shoulder and often have to be broken up before reduction is possible. 
Probably the best way to do this is by repeated stretching and manipu- 
lation of them, by which they are gradually torn and absorption hastened. 

Atrophy of the muscles of the shoulder occurs in every chronic case, 
partly on account of the impairment of the vessels and nerves to these 
muscles and partly on account of non-use. The muscles first affected 
and in which the atrophy is greatest, is the deltoid. This is on account 
of its innervation more than anything else, since it is supplied by the 
circumflex nerve, which is the main supply of the shoulder-joint and its 
ligaments. In dislocation of the shoulder, the shoulder-joint is injured 
and consequently the circumflex nerve, and the above atrophy is one of 
the effects. If other nerves of the brachial plexus are involved or if 
the arm and hand are held in a fixed position for too great a length of 
time, contractures producing deformities will result. In some cases 
bandaging of a shoulder or arm will lead to these contractures and de- 
formities. These deformities can be prevented in most instances by 
proper care, that is, passive movements being resorted to in cases in which 
the patient is unable to use the arm. Another effect which is chronic, is 
that of repeated dislocations. One dislocation makes it easier for an- 
other to occur on account of the relaxation of the ligaments and injury 
to the tissues of the joint. This weakness or relaxation may be in part 
the result of lesions of the upper thoracic area that interfere with the 
nutrition of the joint. 

Partial dislocation of the shoulder is a condition in which the lig- 
aments that hold the head of the bone in place are so relaxed that they 
permit the bone to drop away from its socket or else the bone has been 
forcibly twisted in the socket, thereby injuring the ligaments. The first 
is the result of a general weakness or local disorder due to lesions of the 
upper thoracic area affecting the trophic nerves to the joint, or to a re- 
peated dislocation or injury of the shoulder. In recent cases, the head 
of the bone may be pulled to one side of the socket, or it may become 
twisted, either of which constitutes a partial dislocation. As in the case 
of the hip, it seems that the head of the humerus is either in or out of the 



APPLIED ANATOMY. 459 

socket, but clinically, it is a fact that the head may become twisted in 
the glenoid cavity, this interfering with the function of the joint. In 
these cases of partial dislocation of the shoulder-joint, only some of the 
movements are impaired. The ordinary movements of the arm may be 
normal, but if the patient should attempt an exaggeration of any of 
these normal movements there will be restriction and pain. The pain 
in these cases may be a continuous ache referred to the area of distribution 
of one of the brachial nerves, or it may be a sharp pain on certain at- 
tempted movements. The sensory disturbance may be confined to the 
shoulder-joint in which case it is often called rheumatism of the shoulder. 
Some of the trophic disorders of the arm can be attributed to a partial 
dislocation of the head of the humerus. 

THE ELBOW. 

The principal disorder of the elbow consists of a partial dislocation 
of the head of the radius. This is characterized by pain along the course 
of the nerve in relation, numbness or perverted sensation in the part and 
in many cases, by some trophic disorder, such as caries of the bone, or 
some eruptive disorder of the skin covering the forearm. It is diagnosed 
by locating the head of the bone in an abnormal position, pain over the 
part and by restriction of movement. In complete dislocations of the 
elbow, both the bones of the forearm are dislocated backward on the 
humerus so that the coronoid process of "the ulna is in the olecranon 
fossa and the neck of the radius on the eapitellum of the humerus. In 
such a dislocation the joint locks whenever extension is attempted and 
the olecranon process, that is the elbow, becomes very prominent. An- 
other form of lesion of the bones of the forearm consists of an approxi- 
mation of the upper ends of the bones. This condition is diagnosed by 
palpation by which the distance between them is ascertained, and by 
pain and tenderness along the tissues between the bones. In many cases 
in which the symptoms and conditions are obscure, it is well to examine 
either for a partial dislocation of the radius or an approximation of 
these two bones. 

THE WRIST. 

The principal disorder of the wrist-joint is a sprain, or in some cases 
a partial or complete dislocation of the joint is found. This occurs on 
account of falls in which the patient attempts to protect the body by 



460 



APPLIED ANATOMY. 



catching himself on the hand. By doing this the movement is carried 
beyond the physiological range, therefore the ligaments are either torn 
or over-stretched. This results in a thickening and an exudation. In 



TROCHLEA 



OBLIQUE 




ULNA 



Fig. 138. — Showing longitudinal section of the elbow-joint. 



APPLIED ANATOMY. 461 

such cases it is advisable to examine for a fracture of the radius, since 
such is accompanied by swelling of the joint, which is identical with that 
of a sprain. In partial dislocations of the wrist there will be found slight 
irregularity, some restriction of movement and tenderness. The effects 
of an injury to this joint are stiffness, or weakness of the articulation, 
pain and swelling. 

THE HAND. 

The carpal bones are seldom misplaced, but the os magnum occasion- 
ally is forced backward in extreme flexion of the hand. It is character- 
ized by prominence of the bone which may be mistaken for a weeping 
sinew, or a ruptured tendon. It seldom produces any trouble further 
than that of weakening the hand or producing pain at certain movements 
or when a strain is thrown on that part. 

The phalanges of the hand are quite often sprained or dislocated, 
particularly the thumb. This is the result of direct violence or from 
hyperextension. The diagnosis is comparatively easy on account of the 
signs, they being abnormal position, swelling, pain and limitation of 
movement. The thumb is subject to sprains which result from blows 
on the end of it or hyperextension. The principal articulation involved 
is the one between the first phalanx and the metacarpal bone. The 
effects are hard to overcome, they consisting in the main of a thickening, 
congestion and extreme tenderness of the ligaments. 

THE UPPER EXTREMITY AS A REGION. 

The upper extremity as a region. The skin of the arm is quite thin 
and freely movable. On this account the veins stand out in prominence 
and cutaneous eruptions are rare. The surface markings of the prin- 
cipal arteries and veins and nerves is important, since compression of 
the vessels and inhibition of the nerve, can be done to better advantage 
if the external markings are well known. The brachial artery is indi- 
cated by a line drawn from the inner border of the biceps or posterior 
axillary fold, to the center of the elbow. A line from this point to the 
scaphoid bone represents the radial, while one drawn to the pisiform, 
the ulnar artery. The course of the median nerve is the same as that 
of the brachial artery. The posterior circumflex nerve and artery are 
in relation with the insertion of the deltoid muscle. 

The ulnar nerve corresponds to a line drawn from the lower part of 



462 APPLIED ANATOMY. 

the axilla or apex, to the internal condyle, thence along the under side 
of the arm in relation to the flexor carpi ulnaris tendon. The musculo- 
spiral, corresponds to a line drawn obliquely around the upper part of the 
arm, it crossing the humerus at the junction of the middle and lower 
thirds. 

The lymphatics accompany the veins, those from the forearm empty- 
ing into the glands at the angle of the elbow, while those of the upper 
arm, empty into the axillary glands. The superficial veins form quite 
a net work in the integument of the arm and in some people in whom 
the skin is thin, the veins are very prominent. In infections of the 
hand and forearm, the superficial lymphatic vessels and sometimes the 
veins become inflamed and are characterized by red lines that lead up- 
ward from the point of infection. 

The contour or external configuration of the arm depends on the 
age, sex and occupation of the individual. In children and females, it is 
about cylindrical on account of the lack of development of the muscles 
and the deposit of subcutaneous fat, while in adults in whom the mus- 
cles are developed, the arm is flattened from side to side. The devel- 
opment of the supinator longus, pronator radii teres, triceps and the biceps 
muscles, changes the contour of the arm to a marked degree. The tendon 
of the biceps makes a triangular depression in front of the elbow called 
the antecubital fossa and is of interest in that the brachial artery and 
median nerve are in relation. At the insertion of the deltoid muscle is 
another depression at which place pain is usually referred in disorders of 
the shoulder- joint or brachial plexus. At the back of the elbow is a 
slight depression when the arm is extended, which marks the articula- 
tion of the radius with the ulna, and furnishes a landmark in the exami- 
nation of this articulation. The prominence of the elbow is formed by 
the olecranon process of the ulna. On the inner and posterior side of 
of the ulno-carpal articulation is a prominence formed by the styloid 
process of the ulna. In dislocations and fractures at or near this joint, 
this prominence serves as a landmark in locating the joint and in the 
differential diagnosis. 

The upper extremity is subject to change in contour from many 
diseases. If the nails are abnormally convex, both transversely and 
longitudinally, it is symptomatic of tuberculosis. In such cases if the 
nails were allowed to grow they would become clawed. If they are 
brittle and have white spots in them it is indicative of malnutrition. If 



APPLIED ANATOMY. 



463 



they are very short, it is suggestive of nervousness, since nervous people 
often bite the nails, to the quick. If the fingers are clubbed and the nails 
short, it is suggestive of organic heart disease. This applies particularly 
to children in which the nail is broad and short, and is found especially 
in the congenital types of valvular diseases of the heart. A dactylitis is 
almost diagnostic of hereditary syphilis or tuberculosis. A dactylitis 




Fig. 139. — Showing the condition of the hands and forearms in a marked case of 
progressive muscular atrophy. (From photo). 

consists of an inflammation of the finger or toe and is characterized by an 
enlargement of the joint and often by the formation of a small ulcer. 
In the hereditary form, the development of the finger is interfered with 
when it appears to be short and stumpy. 

If the joints of the fingers are enlarged and the hand everted.it is 
suggestive of arthritis deformans. In this disease the deformity very 
often reaches a marked degree so that all the fingers are drawn out of 
shape. In certain injuries to the palmar fascia, contraction may result 



464 APPLIED ANATOMY. 

which draws the little and ring fingers into the position of extreme flexion. 
This produces a deformity which is quite characteristic and easily diag- 
nosed on account of the thickening of the fascia of the palm of the hand. 
This is called Dupuytren's contraction. A flattening of the thenar and 
hypothenar eminences, is almost diagnostic of progressive muscular 
atrophy. If this is accompanied by a softening of the tissues of the hand 
and atrophy of the adductor muscles of the thumb, and the hand be- 
comes very thin, it is diagnostic of chronic anterior polio-myelitis. The 
swelling of one or more joints of the hand occurs in chronic rheumatism 
and in gout. The diagnosis is based on the other symptoms. 

There are certain motor disorders which are common and fairly diag- 
nostic of nervous and other diseases. Spasmodic or convulsive move- 
ment of the hand and arm occurs in chorea. This is usually accompanied 
by some movement of the head, neck and shoulders. It is usually unilat- 
eral but may* -affect both arms. A constant movement of the forefinger 
and thumb is suggestive of paralysis agitans. This occurs in the aged. 
Athetoid movements of the hand and wrist occur in hysteria and in cer- 
tain nervous diseases. They may be the result of infantile cerebral palsy 
or of lesions which affect the muscles of the hand. The effects are pecu- 
liar in that the fingers assume curious and unusual positions such as 
extreme flexion, pronation, extension, tortion and supination. 

Intentional tremor is indicative of spinal cord disease especially 
disseminated sclerosis. Tremor of the hands and arms is found in Graves 
disease, often during senility and in patients suffering from hemiplegia. 
Certain forms of nervousness are characterized by tremor of the hand. 
Hare says: "There are two sets of movements associated with the 
movements of the muscles of the wrist and hand which possess grave 
prognostic and diagnostic importance. The first of these is twitch- 
ing of the muscles of the forearm (subsultus tendinum). It indicates 
severe exhausting disease. The second is picking at the bed clothes. 
This is called carphologia. It is a grave symptom and usually is indi- 
cative of approaching death." Inco-ordination of the movements of the 
hand and arm occurs in some cases of locomotor ataxia. It may result 
from a neuritis or upper thoracic lesions, the differential diagnosis being 
based on the other symptoms of tabes dorsalis. 

Contractures of the muscles and tendons of the hand and wrist and 
those of the elbow, result from dislocations of the shoulder and from 
trauma. In some cases these are the result of hysteria. Rigidity of the 



APPLIED ANATOMY. 



465 



parts occur in some cases of chronic hydrocephalus. In epileptic spasms, 
the clonic contractions peculiar to this disease. Monoplegia or paralysis of 
one arm or hand, results from hemiplegia, injury to the brachial plexus or 
in certain spinal cord disturbances. The writer has had cases of mono- 




Fig. 140. — Showing a lesion at the articulation between the second and third 
thoraciCjVertebra. The patient fell from a bicycle, striking on the back of the neck. 
In about one year, symptoms of progressive muscular atrophy set in and at the time 
of the taking of the photo, the disease was well under way. Note the lateral devia- 
tion and break at the point of the arrow. (From photo). 



466 APPLIED ANATOMY. 

plegia in an upper extremity that were due to upper thoracic lesions. 
In other cases, there is found a dislocated shoulder or injury to the 
brachial plexus as in obstetric paralysis. Pressure of growths in the 
axilla, will also lead to paralysis of the upper arm type which is some- 
times called Erb's paralysis. Ordinarily complete motor and sensory 
paralysis of one upper extremity, is indicative of injury to the brachial 
plexus. If other parts of the body are involved it is suggestive of hem- 
iplegia while in some cases, it is the result of upper thoracic lesions. Im- 
pairment of movement and weakness of the arm, most frequently result 
from upper thoracic lesions and from repeated dislocation of the shoul- 
der. If it affects only one side it is probably a shoulder disorder, but 
if both sides are involved, it is most probably the result of a disorder of 
the spine. 

The cutaneous nerves of the upper extremity are the supra-clavicu- 
lar, circumflex and intercosto-humeral, internal cutaneous, nerve of 
Wrisberg, musculo-spiral, musculo-cutaneous, median, ulnar and small 
branches from the principal divisions of the brachial plexus. The deep in- 
nervation comes principally from the main trunks of the- brachial plexus, 
as the circumflex, musculo-spiral, musculo-cutaneous, ulnar and median. 
The upper extremity is subject to many sensory disturbances, some of 
which are local and some reflex. Certain visceral diseases tend to pro- 
duce pain in the arm, as is the case of cardiac disease in which pain is 
referred to the area supplied by the left ulnar nerve. Pain is also re- 
ferred to the arm in cases of dislocation of the shoulder, of the acromial 
end of the clavicle and from subluxations of the upper thoracic verte- 
brae. A lesion of the upper ribs will produce pain or an ache in the 
shoulder, this sometimes extending down the arm. The explanation of 
most of these referred pains lies in the fact that the sensorium is often 
mistaken as to the origin of the sensory impulses carried to it and they 
are referred to the periphery of the nerve. In the case of a lesion of the 
upper thoracic vertebras, the sensory impulses that arise from it are 
carried to the sensorium and the pain is referred to the periphery of 
the nerves in relation, that is, to the brachial nerves. Pain along the 
tract of any of the brachial nerves may be due to a tumor on the nerve, 
or irritation from other causes, as infection, inflammation, or displace- 
ment of the shoulder or vertebra with which it is in relation. Neuralgic 
conditions, or aches in the nerve, are ordinarily due to congestion of the 
nerve trunk and the pain is increased by pressure along the nerve. A 



APPLIED ANATOMY. 



467 



throbbing pain indicates an acute congestion of an area in which the 
elasticity of the tissues is lessened. Each beat of the heart forces more 
blood into the already congested vessels and thereby the pain is increased 
with each heart beat. 





Fig. 141 — Showing a subluxation of the third dorsal vertebra. Note the " break' ' 
at the point of the arrow. The lesion was produced by trauma and in a short time, 
symptoms of progressive muscular atrophy began to develop. At the time of the 
taking of the photo, three years after the accident, the disease was well developed. 
(From photo) . 



468 APPLIED ANATOMY. 

Parasthesia of the arm, that is perverted sensation in which there 
is tingling and numbness, is most frequently due to direct pressure on 
the nerve trunk. This comes from a displacement of some of the bones 
with which the brachial nerves are in relation, as in the case of the hu- 
merus, clavicle, radius and ulna. The writer has treated a few cases 
of parasthesia of the arm due to lower cervical and upper thoracic le- 
sions. The explanation of the effect is that the displaced bone presses 
directly on the nerve trunk or vessels supplying it or else interfere with 
the sensory cells of the ganglion on the posterior root. In some forms of 
heart trouble there is numbness of the ring and little fingers on the left 
side. In hemiplegia, especially in the early stages, the fingers become 
numb. In the aged, often there is found a tingling sensation or numbness 
of the hand and fingers. This may be due to a change in the arteries or 
to trophic disorders of the brain. 

The arm is subject to trophic disorders as the result of spinal and 
peripheral lesions. The vaso-motor disorders will be considered along 
with the trophic since they are related. The trophic and vaso-motor 
centers for the upper extremity are located in the upper thoracic spinal 
cord. This is determined partly by clinical observation and partly by 
physiological experiments on animals. A lesion of the upper thoracic 
vertebral articulations and particularly the second and third,will produce 
vaso-motor and trophic changes in the arm. The explanation is that the 
lesion breaks the line of nerve connection existing between the spinal 
cord and the arm or else interferes with the nutrition of the cells con- 
stituting these centers. The peripheral lesions consist of dislocations 
of the shoulder and elbow. In other cases the nerve may be tornjor 
otherwise injured by trauma so that its functions are impaired. Atrophy 
of one arm is most frequently the result of a neuritis of traumatic origin 
or dislocation of the shoulder. Inflammation and swelling of the arm 
are sometimes due to a spinal lesion. In ulcers and eruptions of the 
integument and in caries of the bone, examine carefully for subluxations 
of the bones with which the various brachial nerves are in relation. 
The writer has seen cases of what appeared to be eczema cured by cor- 
recting a displacement of the radius. 

There are certain secretory disturbances of the upper extremity 
that are of diagnostic importance. Hypersecretion of sweat of the palms 
of the hands is fairly diagnostic of nervousness, which sometimes occurs 
in cases of constipation and the early stages of progressive muscular 



APPLIED ANATOMY. 469 

atrophy. A localized dryness of the skin is suggestive of a local lesion 
such as a lower cervical or upper thoracic subluxation or displacement 
of the shoulder. Chaffing of the hands is due in part to disturbance of 
sebaceous secretion, that is, it is lessened. This may be a part of a gen- 
eral disturbance but often is a local one. These secretory disorders are 
dependent to a great extent, upon the amount and character of the blood 
circulating through the part. 




Fig. 142. — Showing a specimen of dermography. The letters were made by 
stroking the skin with a dull pencil. At first, there was a bright, red line followed 
by a welt, as shown in the picture. The condition was the result of an attack of 
measles in which the rash "went in." (From photo). 

THE HIP-JOINT. 

The hip-joint is formed by the acetabulum and the head of the femur. 
The acetabulum is a circular depression formed by the junction of three 
bones, the ilium, the ischium and the pubis. The ilium forms about two- 
fifths, the ischium a little more than two-fifths and the pubis the re- 
maining one-fifth. It is directed downward, outward and forward but 
this varies somewhat in different cases. In the female and in "pigeon- 
toed" people, the acetabulum faces somewhat forward thus throwing the 
trochanters anterior. The margin formed by the cotyloid ligaments, in- 
creases the depth of the socket. The lower side is broken by a notch or 
depression called the cotyloid notch. On this account dislocations of 
the hip, occur at this point more frequently than at any other. Ossifi- 
cation of the bones forming the acetabulum begins quite early but is not 
completed until some time after birth. At the age of sixteen, ossification 
is usually completed. Anything interfering with this process during 
fetal life will often lead to the congenital form of dislocation of the hip. 



470 APPLIED ANATOMY. 

The head of the femur is hemispherical in shape, quite smooth and 
glistening, being covered with cartilage except the part to which is at- 
tached the ligamentum teres. The ligaments of the hip-joint are the 
capsular and the ilio-femoral which is a part of the capsular, the cotyloid, 
the ligamentum teres and the transverse. The capsular ligament com- 
pletely invests the joint, being attached above to the edge of the acetabu- 
lum and to the neck of the femur below. It is thickest and strongest over 
the anterior and external parts of the joint, since the strain on these parts 
is greatest, while below it is quite thin and loose. The ilio-femoral lig- 
ament, sometimes called Bigelow's or the Y-ligament, consists of a 
thickening of the anterior portion of the capsular ligament. It is at- 
tached above to the anterior superior spine and passing downward, it 
divides into two parts, on which account it is called the Y-ligament, it 
having the appearance of an inverted Y. One of these bands, the outer 
one, is attached to the anterior inter-trochanteric line near the tro- 
chanter, the inner one, to the lower end of this line. This ligament 
is seldom broken in the average dislocation and is of importance in that 
it acts as a fulcrum around which the movements of the head of the bone 
occur, and thus the different displacements are determined. The action 
and course of this ligament must be considered in the reduction of hip 
lesions. 

The cotyloid ligament consists of strong bands of fibro-cartilaginous 
tissue which are attached to the edge of the acetabulum. It deepens 
and protects the cotyloid cavity and thus tends to prevent dislocation. 
The transverse ligament is really a portion of the cotyloid. It passes 
across the cotyloid notch and thus converts it into a foramen through 
which the vessels to the hip-joint pass. The ligamentum teres extends 
from the head of the bone to about the center of the acetabulum. It is 
not always present, but when it is, it is broken in dislocation. These 
ligaments of the hip-joint are subject to relaxation and contracture as 
are the ligaments of other joints. They may so relax that the bone will 
drop part way out of the socket, thus lengthening the limb, but this is 
not so common as in the case of the shoulder-joint. They do not have 
so much to do with holding the head of the femur in the socket as with 
limiting the movement of the joint. After section of these ligaments, 
air pressure will hold the head of the bone in place. The ligaments of 
the hip-joint help to economize the muscular effort in balancing the 
trunk. 



APPLIED ANATOMY. 



471 



The muscles in relation with the joint are: in front, the ilio-psoas; 
externally, the gluteus minimus and rectus femoris; internally, the ob- 
turator externus and pectineus, while the pyriformis, the two gemelli 
and the quadratus femoris are in posterior relation. A synovial mem- 
brane lines the entire capsule and the cotyloid ligament, and is reflected 



ANT INF ILIAC SPINE 



ILIO-FEMORAL 
LIGT 




Fig. 143. — Showing the ligaments of the hip-joint Note the ilio-femoral. 

over the articular surface of the head of the femur. In synovitis of the 
hip, the capsule becomes distended in cases in which there is much ef- 
fusion and thus causes bulging in Scarpa's triangle and backward into 



472 APPLIED ANATOMY. 

the tissues, thus obliterating the gluteal fold. Movement of the joint is 
limited and the thigh tends to assume a position of flexion, inward rota- 
tion and adduction, this being the position of rest for the joint. 

The arteries that supply the joint are derived from the obturator, 
gluteal, sciatic and internal circumflex. These are innervated princi- 
pally from the lumbar spinal cord by way of the aortic plexus, which 
surrounds the abdominal aorta and sends off filaments with each branch 
of the iliac arteries. 

The nerves supplying the joint are derived from the sacral plexus, 
the obturator, great sciatic and the accessory obturator nerve. The 
joint is an enarthrodial one and is capable of all forms of movement, 
although they are not so marked as in the case of the shoulder. Flexion, 
extension and circumduction are the principal movements. Flexion is 
limited by the contact of the neck of the femur with the upper edge of 
the acetabuhuri; extension, by the ilio-femoral ligament and circumduc- 
tion, by the ligaments and muscles attached. Abduction and adduc- 
tion are limited principally by the capsular ligament. Movement is 
also governed to a certain extent by the depth of the hip socket and the 
condition of the muscles and synovial membrane of the joint. The 
pathological conditions which interfere with the movement of the hip- 
joint are, dislocation, caries of the joint, non- or imperfect development 
of the socket, partial dislocation and painful conditions due to other 
causes, such as inflammation or sprain of the joint. 

Dislocation of the hip may be either acquired or congenital, that is, 
taking place after birth, or incomplete formation of the acetabulum. 
The dislocations of the hip are usually classified under four forms: up- 
ward and backward or dorsum iliac, sciatic, thyroid and pubic. These 
dislocations result from exaggeration of the movements of the hip, that 
is, the femur is carried beyond the normal range of movement. In most 
cases the thigh is flexed and abducted when the dislocation occurs, thus 
forcing the heavier bone against the lower or weaker part of the capsular 
ligament. In the iliac form of dislocation, the head of the bone rests 
above and behind the acetabulum upon the posterior surface of the ilium. 
The lower and posterior part of the capsular ligament is usually ruptured 
and the round ligament broken. The glutei muscles and other external 
rotators, are usually torn or put on a stretch. These contractures in- 
terfere with reduction. The diagnosis of this form of dislocation is 
based on the position of the head and trochanter, length of the limb and 



APPLIED ANATOMY. 473 

the disturbance of mobility. The head of the bone can often be palpated 
up and behind the acetabulum and the trochanter is abnormally prom- 
inent. The limb is slightly flexed, adducted and the toe turned inward 
so with the shortening which accompanies this dislocation the sole of the 
foot will rest on the arch of the other foot. The trochanter is usually 
above Nelaton's line, but this is not diagnostic of the displacement on 
account of the degrees of relaxation of the ligaments of the joint. Ex- 
ternal rotation of the thigh is limited or impossible, this depending, 
however, on whether or not the Y-ligament is torn. If this ligament is 
ruptured the toes are not necessarily inverted nor is external rotation 
impossible. 

The sciatic form of dislocation is one in which the head of the bone 
rests in or just in front of, the sciatic notch. The head of the bone after 
being forced backward through the capsule, comes in contact with the 
tendon of the obturator internus muscle, which deflects the head into 
the sciatic notch, this tendon offering a great obstacle to the reduction 
of the dislocation. In this dislocation there is flexion, adduction and 
inward rotation, but all less pronounced than in the iliac form. There 
is some shortening of the limb, but not so much as in the dorsum iliac 
form, except when the patient is in the sitting posture and then the 
shortening is quite pronounced. The reason for this is that the head of 
the bone is displaced backward more than it is upward, therefore in 
flexion of the thigh, the shortening of the limb is exaggerated. Some- 
times the head of the bone gets locked in the sciatic notch, thus making 
reduction impossible. This form of dislocation is very painful. 

In the thyroid dislocation, the head of the bone is displaced down- 
ward into the thyroid foramen, it resting upon the obturator externus 
muscle. The glutei, ilio-psoas, adductor brevis, pyriformis, obturator 
externus and pectineus muscles are either torn or stretched by this form 
of displacement. There is eversion of the foot, lengthening of the limb 
and internal rotation is limited, or is impossible in some cases. The 
head of the bone can be palpated in its abnormal position and the tro- 
chanter is turned backward. The peculiar jjosture of the patient is the 
result of an attempt to relax the ilio-psoas muscle. 

The pubic form of dislocation is rare and it is one in which the head 
of the bone rests in relation with the pubic bone. The limb is slightly 
shortened, abducted and rotated outward and the head of the bone can 
be readily palpated in its abnormal position. 



474 APLLIED ANATOMY. 

The change in length of the limb in these dislocations is determined 
by the position of the head of the bone whether it is below, above or 
behind the acetabulum. The degree of eversion and inversion is reg- 
ulated by the Y-ligament, it holding the trochanter in position while the 
head is displaced forward and downward, or upward. If the head of 
the bone is displaced forward and downward, the muscles and Y-liga- 
ment hold the trochanten in position thus producing eversion of the 
foot. If dislocated upward and backward, this ligament holds the tro- 
chanter in place and thus prevents eversion. The pain in dislocations 
of the hip is determined by the amount of damage to the tissues, the 
degree of inflammation, amount of exudate and the nerves that are im- 
pinged upon. Pain is usually present over the sciatic nerve, that is, in 
its upper part, partly on account of the traction or pressure exerted upon 
it, or through injury to the pyriformis muscle. Pain in the knee is the 
result of injury to the obturator or anterior crural nerve. The promi- 
nence of the hip is regulated by the position of the trochanter and the 
condition of the muscles. Ordinarily there is atrophy of the muscles, this 
producing a depression or flattening of the hip. The two sides should 
in all cases be compared not only by palpation but by inspection. The 
various creases of the hip are changed as to depth and direction, par- 
ticularly the crease formed by the buttocks. The flexion lines just below 
the buttock are usually obliterated. 

Congenital dislocation of the hip is a form in which the acetabulum 
is so shallow that the hip-bone is forced out of place from pressure dur- 
ing intra-uterine life, or else is forced out of the socket when the child 
begins to use the limb. The essential point of difference between con- 
genital and acquired forms of dislocation is the degree of development or 
depth of the socket, that is, it is always shallow in the typical congenital 
form. The hip is usually displaced upward directly across the rim of the 
acetabulum, while in the .acquired form it is ordinarily displaced downward 
through the cotyloid notch. In the congenital dislocation there is ordi- 
narily shortening of the limb and the child walks with a rocking move- 
ment. Mobility is usually increased rather than restricted and on in- 
spection with the parts exposed, the bone can be seen to pla}' up and 
down in the muscles, as the child walks. There is no tenderness and the 
limb can be drawn down almost to the length of the sound side on account 
of the relaxed condition of the ligaments. Not alone is the acetabulum 
imperfectly developed but the head of the bone is often mal-developed 



APPLIED ANATOMY. 475 

on account of interference with its nutrition, while the angle that the neck 
forms with the shaft is greater than in a normal case. Perhaps the 
'earliest indication of this type of dislocation is that the child does not 
crawl naturally and is backward in walking. The two buttocks are not 
the same size, the limb on the affected side is malnourished and the 
tissues flabby and the child walks with a distinct limp, and if the condi- 
tion is bi-lateral, the gait is a distinctly waddling one. The diagnosis 
and prognosis are best made after taking a skiagraph of the hip. The 
principal involved in the treating of congenital dislocation is to over- 
come the adductor muscles force the head of the bone into the socket, 
set up an irritation which would cause an exudate to form, thus holding 
the head in place and then abducting the limb and putting on a cast, to 
hold it in this position. The object of this abduction is to place the head 
of the bone in such a position that the muscles cannot draw it over the 
poorly developed rim of the acetabulum. In addition to .this, passive 
movement should be begun quite soon after the reduction, that is, the 
parts should be treated to better the nutrition of the bone, ligaments 
and muscles concerned. 

Articular osteitis of the hip, or hip-joint disease, is a lesion of the 
joint characterized by inflammation and degeneration of the head of 
the femur and the acetabulum. It is usually regarded as tubercular in 
character although, as Hilton points out, it is not necessarily the case. It 
is associated with traumatism of the hip and sometimes there is a co-ex- 
isting displacement, that is, the injury causes a lessening of resistance 
which permits the tubercle bacilli to propagate. About the first indica- 
tion of this sort of disorder of the hip-joint, is a slight limp. This is more 
marked in the morning and it gradually wears off as the day advances. 
This limp is due in part to the stiffening of the muscles and to the in- 
flammation of the joint. Deformity soon appears which consists usually 
of a flexion with abduction and appa.rent lengthening. This is due to 
the fact that the child attempts to place the hip in the position of greatest 
ease. Atrophy of the glutei muscles takes place so that the contour is 
changed, also the gluteal lines are obliterated. Pain or tenderness in 
the hip or in the inner side of the knee, are present in most cases. The 
child refers the pain to the knee and on pressure the pain is greatest over 
the head of the bone. The limitation of motion is perhaps the best 
symptom upon which to diagnose this condition. This is the result of 
contracture of the muscles and change in the form of the bones that 



476 APPLIED ANATOMY. 

form the joint. The child often cries out in its sleep. The general 
health is often impaired and the child is pale and anemic and usually 
has the tubercular diathesis. These symptoms increase in intensity 
until an abscess forms which usually appears in front of the joint. The 
disease most frequently starts in the head of the femur and then extends 
to the acetabulum, and finally there is degeneration of all the parts, 
unless the progress of the disease is arrested. 

In making an examination for this disorder, the child should be 
stripped of all clothing and caused to walk back and forth in order that the 
amount of disturbance of function may be the better estimated. If the 
limp is due to the disease of the hip-joint, the child will not move the articu- 
lation very much in making the step. It tries to protect that side by 
throwing most of the weight on the sound hip. The thigh on the af- 
fected side is usually considerably smaller, than on the sound side. By 
placing the chi'ld in the dorsal posture on the table, it will be found that 
in attempting to force the popliteal space to- the table that the lumbar 
spine will be arched, it being found impossible to force the popliteal 
space and the lumbar spine to the table at the same time if the case is 
one of tuberculosis of the hip. By attempted movements of the hip, 
it will be found that they are limited on the affected side, which is due to 
the condition of the muscles and ligaments of the hip as much as it is 
due to the pain. All these passive movements should be given with the 
greatest care, especially if the disease has reached the stage of pus forma- 
tion, or if the head of the bone is honey-combed, since fracture of the 
neck of the femur may be produced if the parts are handled roughly. 

Partial dislocation of the hip is a condition in which the head of the 
femur is twisted in the socket, or else drawn up against one side of the 
acetabulum and held there by muscular and ligamentous contraction. 
It is usually the result of abduction of the limb in which the movement 
is carried beyond the physiological range, this throwing the head of the 
bone against the weak part of the joint. This sort of lesion is more nearly 
analogous to spinal lesions than are the dislocations of the hip. Partial 
dislocation is characterized by restriction of movement of the hip, lame- 
ness and pain at, and swelling of the knee. This swelling assumes the 
form of a synovitis of the knee and a puffy enlargement soon forms on 
the inner side of the joint soon after the injury. The length of the limb 
may be affected and if it is, it is most frequentty slightly lengthened. 
The toe is often everted and the limb slightly flexed. The measurement 



APPLIED ANATOMY. 477 

of the hip, that is, Nelaton's and Bryant's lines, do not show any dis- 
placement. However, these lines are unreliable even in the diagnosis 
of a dislocation of the hip. It is a well know fact, clinically, that many 
cases of lameness characterized by the above symptoms, are due to a twist 
of the head of the femur in its socket and that the symptoms can be re- 
lieved by treatment directed to restoring normal relations between the 
head of the bone and its socket. The pain in the knee as in other lesions 
of the hip-joint, is the result of a disturbance of the anterior crural or 
obturator nerves. The painful affections, of the hip-joint are the result 
of dislocation, sprain, caries and certain sjDinal lesions that affect the 
sciatic and other nerves that supply the joint, but especially the sciatic. 
The pain may be a referred one, but this is not so common as in the case 
of the knee-joint. If it is a referred one, the trouble is most commonly 
in the pelvic organs, such as an enlargement of the uterus or other vis- 
cus which produces pressure directly on the nerve supplying the hip. 
The trophic condition of the hip-joint, especially its degree of develop- 
ment, is controlled by the condition of the lumbar spine. If lesions ex- 
ist in this area, the nutrition of the hip will suffer, this causing a dis- 
eased or shallow socket, weakness of the ligaments of the joint and tend- 
ency to tubercular affections. In all trophic and vaso-motor disorders 
of the hip, the lumbar spine should be carefully examined since a lesion 
in this region will affect the anterior crural, the obturator, the sciatic and 
the vaso-motor nerves that supply the hip-joint. These vaso-motor 
nerves reach the joint by way of the arteries and are derived from the 
gangliated cord. In all tubercular affections of the hip-joint, this part 
of the spine should be especially treated, since by so doing the vitality of 
the hip is increased. 

THE KNEE-JOINT. 

The knee-joint is formed by the lower end of the femur, the upper 
end of the tibia and by the patella, and is described as consisting of three 
articulations: one between each of the condyles of the femur and the 
tuberosity of the tibia and one between the femur and the patella. It 
is a very large, complicated joint and the surfaces are nearly fiat. It is 
classed as a ginglymoid or hinge-joint, but it is not so typical as is the 
elbow, since it is much more complicated. On account of the size and 
shape, it is regarded as one of the weakest joints in the body, but the 
number, size and arrangement of its ligaments, and the strong muscles 



478 



APPLIED ANATOMY. 



POST. 
CRUCIAL 



/NT.CRUCIAL^. 




Fig. 144. — The ligaments of the back of the knee-joint. 

with their tendinous expansions around the joint, make it quite strong. 

There are many ligaments around this joint but only a few will be 
considered here, namely, the patellar and the semi-lunar cartilages. 

The ligameiitum patellae or anterior ligament, is the lower end of the 
quadriceps extensor tendon. It is very strong, broad and flat. It is of 
interest principally in that fracture of the patella results from the 



APPLIED ANATOMY. 479 

sudden and strong contraction of the quadriceps extensor muscle. This 
also has to do with the dislocation of the patella, which condition is not 
unusual. 

The semi-lunar cartilages are two crescent-shaped cartilages placed 
on the top of the tibia. They are wedge-shaped and thus deepen the 
cavity. They are of interest in that they are subject to displacement 
which results in the locking of the joint. The knee-joint has a very 
large synovial membrane which lines the surfaces of the bone except 
those covered by the articular cartilage. It also covers the semi-lunar 
fibro-cartilages and extends upward several inches under the quadriceps 
extensor muscle and laterally to the vasti muscles and is separated from 
the patella by a cushion of fat. It is reflected from the patella and thus 
forms some of the internal ligaments of the joint. It also assists in form- 
ing some of the bursa? in relation to the tendons of the knee-joint. On 
account of some of these communicating with the cavity of the joint, 
care should be taken in the opening of them when they are distended 
with fluid. On account of the extension upward of this synovial mem- 
brane, synovitis of the knee is characterized by considerable swelling 
above the patella, and often the patella itself is lifted away from the 
lower end of the femur. 

The arteries of the knee-joint are derived from the anastomotica 
magna of the femoral, an- articular branch from the popliteal and the 
recurrent from the anterior tibial. The nerve supply is derived from the 
popliteal, anterior crural and obturator nerves. The importance of this is 
brought out best in cases of dislocation or disease of the hip. 

The movements of the joint consist principally of flexion and ex- 
tension and some internal and external rotation. Flexion is limited by 
contact of the leg and femur. In slight flexion of the leg, all the liga- 
ments are relaxed, with the exception of the ligamentum patella?, and on 
this account in injuries of the knee, the limb assumes a semi-flexed posi- 
tion. The posterior crural and common ligaments, prevent over ex- 
tension, hence are injured in all cases in which the knee is forcibly bent 
backward. The anterior and posterior crucial ligaments when normal, 
prevent the bones from slipping forward or backward, while the lateral, 
prevent lateral displacements. The movements of the knee are re- 
stricted by disorders of these ligaments of the synovial membranes and 
changes of the bone itself. The knee-joint is seldom displaced on ac- 
count of the number and size of the ligaments surrounding it. but sprains 



480 



APPLIED ANATOMY. 



of it are not rare and do not readily yield to treatment. The number 
of ligaments involved and the extent of the injury, account for this. 
When force is applied to the joint, the effect is in the ligament rather than 
the articular surfaces and a sprain is the result. In dislocation ofjthe 
knee-joint, there will be prominence on the side to which it is displaced 



POST CRUCIAL 




TRANSVERSE 



Fig. 145. — Showing the inferior articular surface of the tibia, and ligaments. 
Note the size and shape of the articular surfaces. 

while a depression exists on the opposite side. In recent cases there will 
be swelling and congestion of the joint. Movement is impaired and 
painful. It is differentiated from a sprain by the change in contour of 



APPLIED ANATOMY. 481 

the bones forming the joint since in sprains, change in contour is due to 
the thickening of the ligaments and the effusion around the joint. 

The patella quite frequently becomes displaced; the outward dis- 
location being the most common. It is the result of muscular action or 
trauma applied to the edge of the bone. The contraction of the quad- 
riceps extensor is the principal cause. The partial form of dislocation 
of the patella, it is due to relaxation of the ligamentum patellae. 
When this condition exists, the patella has too great a play and then from 
muscular action, it will suddenly slip over one or the other of the con- 
dyles, thus causing a locking of the knee-joint. Ordinarily the patient 
can press the bone into place and it causes no further trouble until it 
becomes displaced a second time. 

The dislocation of one or a part of the semi-lunar cartilage is, per- 
haps, the most important of all these displacements. The condition is 
the result of a sudden twist or wrench of the knee, especially during partial 
flexion. This accident is accompanied by a locking of the joint, severe 
and sudden pain, swelling and the formation of a prominence on the 
side to which the cartilage is displaced. One displacement predisposes 
to another so that the cartilage may slip out on the least strain of the 
joint. This condition can best be reduced by grasping the cartilage and 
exerting pressure on it, while the limb is moved to-and-fro. If the frac- 
tured cartilage becomes loosened, it may lock the joint at almost any 
time. The patient may be walking along with no impairment when all 
of a sudden, the floating piece of cartilage works into the joint and 
suddenly locks it. 

Swelling of the knee is suggestive of a synovitis or an effusion from 
injury to one of the bursa?. If the patella is raised, or if it floats, in which 
case it is termed "riding of the patella," it is due to synovitis. If it is 
not raised by the effusion, it is in the bursa. Most cases of swelling of 
the knee are due to effusions, which, in quite a number of cases, are due 
to disorder of the hip-joint. This consists of a slight puffiness on the 
inner aspect of the knee, which fluctuates in size and is not particularly 
painful. In other cases, it is due to a sprain of the joint or to over ex- 
ertion. 

In some cases, the enlargement of the knee is due to tuberculosis of 
the bone, either the lower end of the femur or the upper end of the tibia, 
in which it becomes honey-combed. Usually an abscess forms in such 
cases. This breaks above on the inner side of the knee-cap or below and 
to the inner side of the joint. 



482 



APPLIED ANATOMY. 



Stiffness of the knee-joint may be due to deposits, synovitis, dislo- 
cation or to tenderness due to a sprain. The particular form of stiff- 
ness can be diagnosed by noting the contour, degree and form of move- 
ment and by getting a history of the case. Pain of the knee-joint is 



QUAD EXTENSOR K. 



NOVIAL SAC 



/PATELLA 




POST 
CRUCIAL LIGT 



Fig. 146. — The right knee-joint from the lateral surface. (The joint cavity and 
several bursa? have been injected with a stiffening medium and then dissected out. 
(After Spalteholz). 



APPLIED ANATOMY. 483 

usually the result of hip-joint disease, or some form of dislocation of the 
hip. In other cases it is due to direct injury of the knee, as in sprains, 
dislocations and synovitis. Crepitus in the knee-joint is very common 
but usually causes no trouble further than a creaky sound whenever the 
joint is moved. It is usually the result of an old synovitis in which there 
were adhesions formed, or it may be the result of fever, over use of the 
joint or other conditions in which the synovial membrane becomes af- 
fected. There is a lessened amount of secretion of synovia, hence insuf- 
ficient lubrication of the joint and particularly that part between the 
patella and the femur. Sometimes a portion of the cartilage gets into 
the knee-joint, or perhaps some foreign body gets into it, which condi- 
tions cause a locking of the joint. Little can be done with such a con- 
dition. 

A lesion of the tibiofibular articulation is sometimes present, a par- 
tial dislocation of the fibula being the most frequent of the pathological 
conditions. Normal movements of this joint are slight, consisting of a 
slight up-and-down gliding movement. Sometimes the fibula is forced 
upward and outward, this not only producing interference with the move- 
ment, but affecting the external popliteal nerve, which is in relation. In 
addition to the tenderness at the joint, there is usually irregularity, and 
if both are found the diagnosis is fairly conclusive. The principal ef- 
fects of this lesion are pain along the course of the musculo-cutaneous 
and anterior tibial nerves, and a burning sensation at the bottom of the 
foot. 

THE AXKLE-JOIXT. 

The ankle-joint is formed by the lower ends of the tibia and fibula 
and the astragulus. The movements of this joint are extension and flex- 
ion, which combined reach about seventy degrees. The ligaments of the 
joint and the tendo Achillis, restrict these movements. The ligaments 
in the front of the joint are weakest of all and on this account, swelling 
from injury of the joint occurs first at this point. 

The most common lesion of the joint is a sprain which consists of a 
rupture to a greater or lesser extent, of these ligaments. In all sprains 
there is a partial dislocation of the bones forming the joint. On this 
account manipulation, by which this partial dislocation is reduced, is to 
be advised immediately after the accident. As a result of this injury 
there is pain, swelling and inflammation of the parts, particularly the 



484 



APPLIED ANATOMY. 



synovial membrane and ligaments. The effects of this lesion are re- 
striction of movement, swelling and pain. The disturbance of movement 
is the result of the effect on the ligament and of the change in position of 




NAVICULO-CUNE.IFORM 



LONG PLANTAR 'SHORT PLANTAR 



Fig 147. — The ligaments of the ankle and a part of the foot. The internal lat- 
eral are Involved in sprains of the ankle-joint. 

the bones forming the joint. The pain is due to the rupture of, or pres- 
sure on, the nerves in relation. 

In Pott's fracture, dislocation quite frequently occurs at this joint, 
or at least there is a partial dislocation and a sprain which tend to con- 



APPLIED ANATOMY. 



485 




Fig. 148. — The joints of the right foot. 



486 APPLIED ANATOMY. 

fuse the diagnosis. In elderly people, a fracture should be suspected 
in cases of injury to this joint and the examination made accordingly. 
Sometimes the astragulus is displaced on its articulations above and 
below. 

The other bones of the ankle and foot are occasionally displaced. 
The first metatarsal bone and the first phalanx are quite frequently 
displaced in cases of bunions. In displacements of these small bones 
of the foot, there will be pain and disturbance of movement. In one 
case seen by the writer, there was a displacement of one of the cuneiform 
bones that gave rise to symptoms which simulated hip-joint disease, 
at least it was so diagnosed by some physicians. There was a limp and 
pain at the bottom of the foot. In most cases, pain in this area is due 
to a lesion higher up, but occasionally it is the result of a local lesion. 
In many cases of pain in the bottom of the foot, it is due to the displace- 
ment of a sesamoid bone. These bones are formed in the flexor tendons 
and reach a remarkable size in some instances. In forcible contraction 
of the muscles of the foot these bones may be forced out of their grooves 
or articular facets and thus give rise to considerable pain on movement 
of the foot. Such disorders can usually be diagnosed by palpating the 
irregularity and noting the location of the pain. 

THE LOWER EXTREMITY AS A REGION. 

The skin of this region is thickened at points of pressure as in front 
of the knee and the gluteal region. On the inner sides of the knee and 
leg it is quite thin and very freely movable. The mobility of the skin 
over these parts tends to protect the joint in cuts and contusions in that 
the force is directed away from the underlying parts. 

The femoral artery and vein correspond to a line drawn from a point 
about midway between the anterior superior spine and the symphysis, 
to the internal condyle. The popliteal artery lies in the popliteal space 
and is subject to pressure at this point in sitting with the legs hanging. 
The posterior tibial artery corresponds to a line drawn from the center 
of the lower part of the popliteal space to a point just behind the internal 
malleolus. The perineal artery lies behind the fibula and is possibly 
affected by subluxations and fractures of this bone. 

The long saphenous vein corresponds to a line drawn from the internal 
malleolus along the inner aspect of the leg and thigh to Scarpa's triangle. 
The short saphenous vein corresponds to a line drawn from the outer 



APPLIED ANATOMY. 487 

side of the tendon of Achilles, to a point immediately behind the knee. 

The great sciatic nerve corresponds to a line drawn from a point 
midway between the tuberosity of the ischium and the great trochanter, 
along the back part of the thigh to the center of the popliteal space, at 
which place it usually divides. The peroneal nerve extends from this 
point down the leg in company with the peroneal artery. The anterior 
tibial corresponds to a line drawn from near the head of the fibula diag- 
onally across to a point about an inch anterior to the external malleolus. 

The bony prominences which serve as landmarks for the lower ex- 
tremity also have to do with the contour of the part. The great tro- 
chanter forms a prominence on the side of the upper part of the thigh 
and is of importance in locating the head of the femur. The patella is 
the principal eminence of the knee. The "shin bone," or the anterior 
edge of the tibia, determines the contour of this part of the leg and is 
subject to injuries and fractures. A blow at this place is particularly 
painful on account of its nearness to the integument, hence has no soft 
parts to protect it. The malleoli are the great landmarks of the ankle, and 
from them measurements are taken for determining certain forms of 
injuries of the lower extremity, such as fractures and dislocations. 

The glutei muscles determine the contour of the hip. The vasti 
and recti determine the contour of the anterior part of the thigh. The 
course of the sartorius muscle is brought into prominence whenever 
the thigh is flexed and adducted. The hamstring tendons have to do 
with the contour of the back part of the knee, while on the inner side, 
those of the sartorius and vasti and pectineus can be palpated. The 
calf muscles, that is the soleus and gastrocnemius, determine the contour 
of the back of the leg. 

The changes of contour of the lower extremity should be carefully 
noted in making up a physical diagnosis, since nearly if not all disorders 
of the lower extremities are characterized by some change of contour. 
Of the hip and thigh, a dislocation of the femur is the most common cause 
of change of contour. The change is brought about from displacement 
of the trochanter, contracture of some muscles and atrophy of others. In 
all cases in which the contour is abnormal, the diseased side should be 
compared by inspection, with the sound side. Hip-joint disease will 
also change the contour of the hip, principally on account of atrophy of 
the glutei muscles. The trochanter in these cases may be also displaced 
or the neck destroyed, this altering the contour. Fracture of the 



4SS APPLIED ANATOMY. 

femur will change the contour of that part on account of change in the 
bone and the effect on muscles attached. Fracture of the neck of the 
femur often results in an upward displacement of the trochanter which 
may be mistaken for a dislocation of the hip. In all such cases in 
the aged, an intracapsular fracture of the hip should be suspected. 
Change of form of this part results from atrophy or hypertrophy of the 
muscles or from edema of the thigh. In athletes, often the rectus muscle 
is ruptured, this causing some change in contour. In the various spinal 
cord diseases in which the lower limbs are involved, there is a change of 
contour from atrophy or occasionally from hypertrophy of the muscles 
of the thigh. Change of contour of the knee and leg is more common 
than in the thigh. 

It is important to understand the surface anatomy of the knee, since 
there are so many changes of contour of the part. McClellan says: 
"A knowledge of the construction of the joint may serve to interpret 
many symptoms and to explain the production of various movements, 
but what has been aptly called the language of form appeals to the 
judgment and, if properly applied, often determines the diagnosis and 
the result of treatment. " Synovitis of the knee invariably produces 
enlargement which is most marked on the anterior and inner aspect. 
There may be an effusion into the different bursse around the joint, this 
producing a unilateral enlargement. Most of these enlargements due 
to effusion are the result of disorder of the hip-joint, but in some instances 
they are due to direct injury of the knee. Tuberculosis of the knee-joint 
produces an enlargement, hence change in contour. The upper end of 
the tibia is most frequently involved and often the bone becomes honey- 
combed and doubled in size. In cases of emaciation, the knee-joints are 
often apparently enlarged on account of atrophy and shrinkage of the 
muscles above and below it. Paralysis of the leg leads to atrophy, hence 
change in form. In neuritis and progressive muscular atrophy, the calf 
muscles are more or less atrophied. In diseases of the hip, such as 
fractures, dislocations or hip-joint disease, the muscles of the leg are 
atrophied, partly from non-use and partly, from an interference with 
nutrition. Fractures of the tibia or fibula change the contour of the 
leg, Pott's fracture being the most typical. Edema of the leg is sug- 
gestive of heart or kidney disease if symmetrical, but if of only one leg, is 
suggestive of a spinal or innominate lesion, which interferes with the 
lymphatic circulation from the limb. Usually the edema is worse to- 



V 



■ lllh.THORACIC 



,12th 



IL 



-->\ 



MUSCULO ■ 

CUTANEOUS 

4S5 L. 



HYPOGASTRIC 

IsLLUMBAR 

GENITO CRURAL 

UIO INGUINAL 

I ij SACRAL 

SM.SCIATIG2.3.& 

EXTCUTANEOUS 
2S.iL. 

2.5S4 L 
OBTURATOR 

-INTCUTANEOUS 
245 L 



-MID CUTANEOUS 

StS L. 

-PATELLA PLEX. 

-PATELLA BRA. Of 
USAPHENOUS 

-INT.ORLONG 
SAPHENOUS 
3&4L 

SURAL BRA.OF 
L. SAPHENOUS 

LAT.CUTANEOUS 

OR PERONEAL 

51. SI. 2. S. 

, EXT. SAPHENOUS 
I 12. S. 

EXT. PLANTAR 
U2S 

INT.CALCANEAN 
IS2 b 

-ANT.TIBIAL 
4S5L 

>INT.PLANTAR4 5LX15> 



Fig. 149. The segmental sensory innervation of the lower extremity. 



490 APPLIED ANATOMY. 

ward evening and especially so, if the patient is on the feet very much. 
In chronic cases the swelling pits on pressure and if there is an injury to 
the part, it heals slowly. Edema may be the result of milk-leg which in 
turn is, I believe, a sequel to innominate lesions which occur during 
child-birth, although it is popularly believed to be due to infection. 
The edema may also be a sequel to typhoid fever especially if on the 
right side. If the entire lower extremity and the external genitalia are 
involved it is called elephantiasis. In most of these disorders of the leg 
characterized by edema, the trouble is either in the hip-joint or else 
there is a subluxation of the innominate. Ordinarily if there is no dis- 
coloration the trouble is due to lymphatic obstruction, but if the veins 
are involved, there is in all probability some discoloration. 

Rheumatoid arthritis often produces a change in contour of the 
knees and feet on account of the deposit around the joints. There are 
certain nervous disorders called arthropathies, which produce enlarge- 
ment of the joints, particularly those of the lower limb. 

A sprain of the ankle may result in a deformity which may last for 
months on account of the edema and swelling of the injured ligaments. 
In those chronic cases a dislocation or fracture should be thought of. 
If it occurs in an aged person or one who is mal-nourished, it is possibly 
a fracture, but in the young a dislocation is more common than a fracture. 

The arch of the foot may be broken down, this producing a condi- 
tion called "flat foot." This weakens the ankle and leads to a peculiar 
gait. The various forms of talipes, result from contracture of tendons, 
alteration in the shape of the bones, partial displacements and from 
shortening of ligaments and fascia attached to the foot. If the patient 
walks on the toes, which condition is called talipes equinus, it is gener- 
ally the result of infantile paralysis, the deformity being the result of a 
contraction of the tendo Achillis. Talipes varus is the most common of 
the congenital forms on account of the attitude of the fetus in utero. 
In the acquired form the os calcis is drawn up by the tendon of Achilles 
thus partially displacing the astragulus. Talipes valgus, or flat foot is 
the result of breaking down of the arch and occurs in those who are un- 
derfed and in people who have to stand on their feet a great deal. It 
occurs in some cas.es of improperly cared .for Pott's fracture. In these 
various deformities of the foot, the tendinous contractures are prominent 
and sometimes they reach such a degree that tenotomy has to be per- 
formed before the deformity can be overcome. 



APPLIED ANATOMY. 491 

The various movements of the limbs, that is the gait of a patient, are 
very suggestive of the disease with which the patient is afflicted. 
Although the gait varies in normal individuals, yet ordinarily the ap- 
pearance of the legs and feet and the peculiarity of the gait, reveal the 
fact that there is something wrong with the movements of the limb . If t he 
patient has a "heel and toe" walk and has to look where he steps, and 
if the arch of the foot is flattened, it is quite suggestive of locomotor 
ataxia. This disturbance of movement is due to an impairment of the 
muscular sense more than to a weakness of the muscles. There is also 
some weakening of the ankle and the patient is unable to stand on his 
heels although the muscles of the lower extremities seem to be in a thor- 
oughly good condition. In multiple neuritis, there is a peculiar gait 
called the "steppage" gait. (The foot is drawn forward and the toe is 
raised so that the heel first strikes the ground in much the manner adopt- 
ed when one attempts to step over an obstacle). In spastic paraplegia, 
the toes seem glued to the floor and the patient has to lean forward in 
order to be able to advance the limbs. This gait is explained by the 
fact that the flexors of the thigh are weakened, while the flexors of the 
leg are shortened. The toes are inverted, the knees adducted and the 
patient has what is commonly called a "cross legged progression." 

In atonic paraplegia, both feet are dragged, the toes trailing on the 
ground. The patient necessarily has to walk with crutches and the 
limbs are dragged along. In infantile paralysis in which one limb is 
involved, the foot is usually everted and the patient drags it in such a 
fashion that the inner side scrapes the floor. Hemiplegia is character- 
ized by a dragging of the foot on the paralyzed side in such a way that 
the end of the toe and inner side of the sole is worn. This coupled with 
paralysis of the upper extremity on the same side makes the diagnosis clear. 
This peculiarity of gait is the result of weakness, that is, inability to ad- 
vance the limb, hence it is dragged. In children a "waddling gait" is 
suggestive of a double displacement of the hip. It is present in congen- 
ital dislocation of one hip but less marked. In iliac displacements of 
the hip, the toe is turned in and the limb shortened, the body is inclined 
toward the affected side. In a thyroid displacement of the hip, the toe is 
turned outward and the limb is lengthened and the patient's body is 
inclined to the opposite side in order to tilt the pelvis so that the limb 
may be shortened. A propulsive gait is indicative of paralysis agitans. 
A drunken gait occurs in patients suffering with cerebellar ataxia and in 



492 APPLIED ANATOMY. 

certain forms of chorea. In cerebellar ataxia there is the intentional 
tremor. The patient may, in reaching for an article, stab all around it 
and finally gets his hands on it in a manner similar to that of a drunken 
person. A stiff gait is often found in disseminated sclerosis, this closely 
resembling the gait of spastic paraplegia. In Friedreich's ataxia the 
gait is uncertain and if the patient is told to stand with his feet together 
there will be swaying of the body. This is due to inco-ordination and 
loss of muscular sense. 

The various limps are due to painful conditions of the hip, knee or 
foot , or possibly of the spine. By examination, the cause is usually very 
easily ascertained, and by knowing the different forms of disorder of the 
gait and movements of the limbs, the cause can more easily be located. 

Pain in the hip-joint is suggestive of displacement, caries, sciatica, 
or lesions of the various bones with which the sensory nerves to this 
part are in relation. Pain in the knee-joint comes most frequently from 
partial displacement of the hip, or other disorder of this joint. It may be 
due to a synovitis of the knee, a loose cartilage, or a displacement of the 
bones forming the joint. Ache or pain along the femur, comes most 
frequently from an inflammation or congestion of the sciatic nerve. 
This, in turn, comes from pelvic disorders, spinal cord diseases or a lesion 
of the spine or innominate bones. Pain in the leg is the result of pressure 
on the nerve supply at some point or it may be referred from visceral 
disease such as inflammation of the pelvic organs. Pain in the foot may 
be the result of the displacing of any of the joints with which the sciatic 
nerve or its branches are in relation, or it also may be the result of a vis- 
ceral disorder from which the pain is referred. 

In most painful disturbances of the leg not due to inflammation or 
trauma, there is some lesion of the joints in relation with the sciatic 
nerve which has most to do with supplying sensation to the lower limbs. 
It is a good plan to examine first the joints in relation with the pain and 
then successively all the joints between the point of pain and the spinal 
cord. Perversion of sensation, such as numbness or tingling of the 
nerves of the lower extremity, is most frequently due to pressure on the 
trunk of the nerve. This is illustrated by the fact that by sitting 
on a high chair and suspending the legs, they will go to sleep. Numb- 
ness may also be due to cerebral disorders. In all these affections the 
spinal column should be examined, since a lesion of any of the lumbar 
vertebras will in all likelihood, intercept the passing of sensory impulses 



APPLIED ANATOMY. 493 

from the lower extremity to the spinal cord, thus the perversion of sen- 
sation. 

The most common vascular disorder of the lower limb is a varicos- 
ity of some of the superficial veins. The vein most frequently affected 
is the long saphenous and especially that part, in relation with the ankle. 
The superficial veins are affected because their walls are not reinforced 
by muscular contraction, and the part farthest away from the heart and 
subject to greatest pressure would be affected most, hence the varicosi- 
ties are found on the inner side of the ankle. The vaso-motor centers 
for the lower limbs are located in the lumbar spinal cord. The impulses 
from these centers pass out over the nervi efferentes into the aortic 
plexus, thence along the plexuses around the arteries which go to the 
lower limbs. This line of communication between the spinal cord and 
the gangliatecl cord and the various vessels of the lower extremities, must 
be kept open or else there will be some effect in the parts supplied. A 
lesion of the lumbar vertebral articulations, will in some way interfere 
with this communication, because the displaced bone produces pressure 
on the nerves over which these impulses pass. On this account in all 
vascular disorders of the lower extremity such as congestion, inflamma- 
tion, varicosity or coldness, the spinal column should be examined. In 
other cases, a dislocated hip or diseased condition of the pelvic viscera 
will produce vascular disorders of the lower limb. All the blood from 
the limb passes up through the pelvis and any pelvic enlargement would 
tend to interfere with the drainage of the limb. In fibroid tumors, 
congestive hypertrophy of the uterus and in pregnancy, the lower limb 
is affected as to its circulation. The trophic impulses seem to go hand 
in hand with the vaso-motor. In non-development of the acetabulum, 
lack of development of the femur, or other bones of the lower extremity, 
in atrophic conditions of the limb or even in caries, the spinal column 
should be examined since lesions of the lumbar portion, interfere with the 
passing of vaso-motor and trophic impulses from the spinal cord to the 
parts below. 

In tuberculosis of the hip and knee, the principal treatment is 
directed to improve the nutrition of the part. This is accomplished by 
spinal treatment, in addition to the constitutional. Therefore in trophic 
and vascular disorders of the lower extremity, examine especially the 
lumbar vertebra, innominate bones and the hip-joint. The secretory 
disorders of the lower extremity consist of excessive or lessened perspira- 



494 APPLIED ANATOMY. 

tion. Sweating of the feet is the most common. In some cases this 
perspiration is markedly acid and the writer has known of cases in which 
the patient would rot out a pair of shoes in a month or so as the result 
of this disturbance of the secretion of sweat. This may be the result 
of a constitutional disorder, yet in some cases, at least, it is due to af- 
fections of the sweat centers on account of lesions in the lower thoracic 
and lumbar area. Dryness of the lower extremities is more suggestive 
of kidney disorder than of anything else. However, if it is a local one, 
the cause is along the course of the nerves that have to do with connecting 
the sweat centers with the periphery. 

THE CRANIAL NERVES. 
THE OLFACTORY. 

The olfactory nerves consist of roots, tract, bulb and about twenty 
fine non-medullated nerve fibers that are distributed to the mucous 
membrane of the nasal cavity. This nerve is the special nerve of smell 
and is stimulated by volatile, odorous substances. It acts as a sentinel 
to warn the body against bad air and the ingestion of improper foods. 
The stimulation of this nerve seems to reflexly affect the secretion of 
saliva. On this account food that has a pleasant odor is more palatable 
and more easily digested than that which has an unpleasant odor. 

This nerve is seldom affected directly, but may be disturbed through 
fracture of the cribiform plate or tumors of the brain. In most cases of 
disorders of the sense of smell, anosmia being the most important, the 
fifth cranial nerve is involved and consequently there is a lessened or 
hyper-secretion of mucous from the membrane lining the cavity. Le- 
sions of the cervical articulations, especially those of the axis and the 
third, and of the upper thoracic vertebrse, disturb the functions of this 
nerve by affecting the fifth cranial and the vaso-motor nerves supply- 
ing the nasal mucous membrane. The explanation is that the lesion 
affects the vaso-motor nerves at their origin or along their pathway and 
thus interferes with the circulation through the mucous membrane lining 
the nasal cavity, that is, it produces a catarrhal condition of the nose. 
In other cases the turbinated bones become diseased or polypi form in 
the nose. These disorders affect the sense of smell by interfering with 
the normal secretions rather than by directly affecting the olfactory 
nerve, In hysterical individuals there may be hyperosmi-a, while in 
epileptics, aura often start in the nose. 



APPLIED ANATOMY. 495 



THE OPTIC NERVE. 



The optic nerve rises from the quadrigeminal body and the optic 
thalamus and is connected with the occipital lobe. The two tracts con- 
verge to form the optic chiasma or commissure, from which the optic 
nerves are formed. The nerve is directed forward and outward, pierces 
the dura mater and escapes from the cranial cavity through the optic 
foramen and it spreads out to form the principal part of the retina. It 
is in relation with the ophthalmic artery and is pierced by the central 
artery of the retina. 

The function of the nerve is that of vision. This function may be 
disturbed by disorders of the blood, pressure from hemorrhage or intra- 
cranial tumors, fractures of the skull and in certain spinal cord diseases 
and spinal lesions. The most common lesions affecting the optic nerve 
are in the upper cervical and upper dorsal regions. These lesions dis- 
turb the circulation and nutrition of the nerve since the vaso-motor 
centers for the ophthalmic arter}' are as low as the third thoracic seg- 
ment of the spinal cord. The impulses pass out over the anterior nerve 
roots into the gangliated cord, thence upward and into the superior cerv- 
ical ganglion. Then they are conveyed by the cavernous plexus directly 
to the optic nerve with the central artery of the retina. It is a clinic 
fact that spinal injuries produce atrophy of the optic nerve. Writers 
on the subject do not agree as to the explanation of this effect, some lean- 
ing to the view that they are the result of a trophic disturbance, while 
others assume that they result from an ascending meningitis, while others 
contend that these injuries produce a fracture of the base of the brain. 
From an osteopathic viewpoint, the effect, that is, that of optic atrophy, 
is explained on the theory of vaso-motor disturbance which is the re- 
sult of spinal injury, in cases in which the injury is above the fourth 
thoracic vertebra. Gifford, in the American Text-Book of Diseases of 
the Eye, states "that the numberless cases of optic nerve atrophy in 
various forms of spinal disease also led to the belief at one time preva- 
lent, of a trophic connection between the spinal column and the optic 
nerve; and because the disc in many of these cases (though by no means 
in all) was of a grayish hue, it was common to speak of gray or spinal 
atrophy. The spinal affection in which atrophy is most commonly 
observed is tabes. " The explanation of this connection as given is 
that the vaso-motor and possibly the trophic impulses to the optic nerve, 



496 APPLIED ANATOMY. 

arise as low in the spinal cord as the third thoracic segment. Spinal 
cord diseases or lesions of the vertebral articulations at or above this 
point will affect the function of the optic nerve. 

In kidney disorders particularly the interstitial form of nephritis, 
the optic nerve is usually affected, thus producing some form of blind- 
ness. In artero-sclerosis, the central artery of the retina or the opthal- 
mic artery, may be involved and consequently disturbance of function 
of the optic nerve occurs. In the condition known as "choked disc," 
there is usually present a brain tumor producing pressure on the chiasma. 
The nature of this condition is not well understood, but according to 
some it is clue to the cerebro-spinal fluid, under increased pressure, 
forcing its way into the optic sheath and so compressing the veins as to 
produce a true congestion or edema, which may be accompanied by in- 
flammation. 

Most of'the causes of disorders of the optic nerve are extra-cranial 
and are especially found in the upper part of the neck and back. They 
produee disturbances of the nerve principally through vaso-motor af- 
fects on the brain, such as congestion, tumefactions and malnutrition of 
the centers of vision or the optic tract. 

The blood supply for the center of vision, that is, the central lobe, 
comes principally from the vertebral artery. Possibly the best explana- 
tion of the connection existing between the lesion and the optic nerve 
is through the disturbance of the vertebral artery and plexus. 

THE THIRD. 

The third cranial nerve has its origin in the gray matter underneath 
the fissure of Sylvius. Brubaker says that this nerve "consists of about 
fifteen thousand peripherally coursing nerve fibers which serve to bring 
the nerve cells from which they arise into relation with a large portion 
of the general musculature of the eye." It passes through the caver- 
nous sinus and enters the orbit through the sphenoidal fissure. As it 
enters the orbit it divides into two branches, the superior and inferior, 
the superior supplying the superior rectus and the levator palpebrse 
superioris muscles, while the inferior supplies the internal and inferior 
recti and ends in the inferior oblique muscle. This nerve communi- 
cates with the cavernous plexus, the ophthalmic division of the fifth 
and sends a branch to the ciliary ganglion which is called its motor or 
short root. 



APPLIED ANATOMY. 497 

The function of this nerve is to transmit nerve impulses to all the 
muscles of the eye except the external rectus and the superior oblique. 
As the result of a lesion paralyzing or inhibiting the action of this nerve, 
there will be ptosis, strabismus, double vision, some dilatation of the 
pupil, loss of power of accommodation and sometimes vertigo and 
photophobia. These effects may be produced by intra-cranial disorders, 
such as cerebral tumors or hemorrhage, or by extra-cranial affections, 
such as lesions in the upper cervical region. It is a well known fact 
that lesions of the upper cervical vertebra; will produce disturbance of 
the third nerve. The writer has seen and treated cases of this sort in 
which there was no doubt but that the lesion produced the effect, ptosis 
being the most common and pronounced. It is difficult to explain why 
such a lesion will affect the third cranial nerve, unless we do it through 
the vaso-motor connections. So far as we can ascertain from the liter- 
ature, writers in general, claim that no motor impulses from the spinal 
cord pass upward into this nerve, but one author states that some pass 
from the medulla upward into it and are distributed to parts supplied 
by the nerve. 

Vaso-motor impulses for the vessels which supply the part of the 
brain from which this nerve arises, apparently come from the upper 
thoracic area and pass by way of the gangliated cord and its branches 
around the carotid artery through to the blood-vessels of this part of the 
brain. This is disputed by some, but it appears to be the most reason- 
able explanation of the relation between the cause and effect. The 
lesion interferes with the nutrition of the cells, or perhaps the nerve 
itself, since nutrition is governed to a great extent, by the vaso-motor 
nerves. 

The lesions that are most commonly found in affections of the third 
cranial nerve are: subluxations of the second and third cervical ver- 
tebra. These act as predisposing causes, while the exciting causes that 
are usually given, act the more readily. If the effect on the nerve ap- 
pears to be the result of intra-cranial disorder, such as a hemorrhage, 
the cause of this is extra-cranial, that is, in the neck. The condition of 
the cranial viscera is controlled by the spinal cord and therefore the 
communication between the two parts should be free. 



498 APPLIED ANATOMY. 

THE FOURTH. 

The trochlear or pathetic us nerve arises below the grey matter sur- 
rounding the aqueduct of Sylvius. It has a long course before it makes 
its exit from the cranial cavity and is distributed to the superior oblique 
muscle. It receives a branch from the cavernous plexus and from the 
ophthalmic division of the fifth nerve. The sympathetic carries to it 
vaso-motor fibers, while the fifth cranial, gives to it the muscle sense 
fibers. It is motor and trophic in function. In cases in which this 
nerve is involved often the patient holds one side of the head slightly 
elevated. Lesions of the neck may affect this nerve through the vaso- 
motor connections. The disturbances of it are rare. 

THE FIFTH. 

The fifth cranial nerve is similar to a spinal nerve in that it arises 
from two roots, a motor and a sensory, and has a ganglion. The motor 
root is derived from the floor of the fourth ventricle. The large sensory 
posterior root, according to Landois, receives fibers " (1) from the gray 
matter of the sensory nucleus of the trigeminus, situated to the side of 
the motor nucleus, and the analogue of the posterior horn. (2) From 
the gray matter of the posterior horn of the spinal cord down to the 
second cervical vertebra. (3) From the cerebellum, fibers passing through 
the crus." The origin of the sensory root, is connected with the motor 
nuclei of all of the nerves arising in the medulla oblongata, with the ex- 
ception of the abducent. This fact explains the various reflex effects. 

The trigeminus divides into three principal divisions, the ophthalmic, 
superior and inferior maxillary. These nerves through their ganglia, 
connect with most of the other cranial nerves. The ophthalmic divi- 
sion communicates with the third, fourth and sixth cranial nerves in the 
cavernous sinus. Through the spheno-palatine and otic ganglia, the 
fifth nerve communicates with the seventh cranial nerve, and with the 
ninth nerve through the otic ganglion. It also has a very free connec- 
tion with the cavernous and carotid plexuses and receives from them 
most of its vaso-motor impulses. This nerve is principally sensory in 
function although it transmits motor, vaso-motor, secretory and trophic 
impulses. On account of the wide area of distribution and the import- 
ance of the parts supplied, as well as the character of the impulses, this 
nerve is very important and is connected with nearly all diseases of the 
head and face. 



APPLIED ANATOMY. 499 

This nerve, like the other cranial nerves, is subject to disturbance 
from intra-cranial growths, congestion of the head, while it is particularly 
liable to disturbance from caries of the teeth and various disorders of 
the nasal cavity, mouth, ear and throat. In addition to these, this 
nerve is affected by lesions in the cervical and upper dorsal regions and 
subluxations of the lower jaw. A lesion of a cervical vertebral articu- 
lation will affect this nerve in one of two ways. First, this lesion will 
intercept the passage of impulses from the spinal cord to the nerve and 
second, it will interfere with the nutrition of the descending root of the 
nerve by pressure on the veins and arteries that drain and supply the 
segments of the cord in which this root is found. Lesions of the upper 
thoracic area will affect the fifth cranial nerve by intercepting the 
passing of vaso-motor and other impulses from the upper thoracic spinal 
segments into the gangliated cord, or it will interfere with the nutrition 
of the nerve cells that give rise to the vaso-motor impulses that pass 
to the head and face and are distributed by means of the fifth 
nerve. These lesions also interfere with the circulation, that is, nutri- 
tion of the fifth nerve and its cells, since they disturb the circulation to 
the brain. A lesion of the lower jaw will affect the nerve by direct 
pressure or injury, since it sends a filament to the temporo-maxillary 
articulation. One or all of the functions of the fifth nerve may be af- 
fected by these lesions and in our clinic work, it is very common to find 
the cervical lesion responsible for most of these disturbances. 

The fifth cranial nerve is motor to the azygos uvula muscle through 
the posterior palatine nerve, to the tensor palati and tympanum muscles, 
the digastric, mylo-hyoid and the muscles of mastication, which consist 
of the temporal, the two pterygoid and the masseter. 

The motor impulses for the dilators of the pupil come immediately 
from the ophthalmic division of the fifth and indirectly from the cervical 
sympathetic. Although it has not been definitely demonstrated that 
motor impulses pass from the spinal cord to the head and face, yet it is 
to be presumed that they do, this presumption being based on clinic 
results. Cervical and upper thoracic lesions, affect the muscles of the 
eye, this having been demonstrated in many cases treated by the writer. 
Assuming that no motor impulses pass from the spinal cord to these 
muscles, the effects can be explained through the vaso-motor and trophic 
connections that undoubtedly exist between the spinal cord and parts 
supplied with motor impulses by way of the fifth cranial. These im- 



500 APPLIED ANATOMY. 

pulses arise in the upper part of the thoracic spinal cord and pass by way 
of the gangliated cord and its ascending branches to the ophthalmic 
division of the fifth. Lesions along the course of these fibers inter- 
cept or otherwise interfere with this connection and consequently there 
is an effect in the parts supplied. 

Landois says: "Anastomotic fibers pass from the second cervical 
nerve downward through the lateral columns of the spinal cord to the 
cilio-spinal region and thence through the three or four uppermost 

thoracic nerves into the cervical sympathetic In the dog and 

in the cat, at least, these fibers do not pass through the ciliary ganglion, 
but directly along the optic nerve to the eye, all passing through the 
Gasserian ganglion, the first division and finally through the long ciliary 
nerves. " 

The fifth cranial nerve is sensory to nearly all the dura mater, the 
eye-ball and its appendages, the mucous membrane lining the cavities 
of the head and face, the integument of the face and side of the head, 
the teeth, tonsils, two-thirds of the tongue, mastoid cells, the various 
glands and articulations of the lower jaw. Pain in any of these parts is 
due to an irritation of this nerve either at its periphery, along its course 
or in the cranium. Since neither the nerve cells nor the course of the 
nerve is in relation with the spinal cord, it is somewhat difficult to ex- 
plain why lesions of the cervical vertebrae affect the sensory function of 
this nerve. That such lesions do affect the functions of this nerve is a 
well demonstrated clinic fact. There are two ways of explaining the 
effects of a cervical lesion on this nerve. First, the long or sensory root 
comes from as low in the spinal cord as the second or even the third 
cervical segments, while second, the nerve, and the parts to which it is 
distributed, receive their trophic and vaso-motor impulses from the spinal 
cord and these are affected by -the lesion, since they come from the spinal 
cord. Pain is defined by Baruch as "the prayer of the nerve for pure 
blood. " There may be anemia of the nerve or other vascular disturb- 
ances, in which there is either abnormal pressure on, as in contracture of 
muscles or stimulation of the nerve filament, from the toxic products 
of the stagnated blood, which things affect the nutrition of the nerve. 
These, according to the above definition of pain, produce pain. 

The fifth cranial nerve supplies about three-fourths of the dura 
mater with sensory impulses, the vagus being the other important nerve 
to this part. In most cases of headaches the dura mater is affected 



APPLIED ANATOMY. 501 

through the disturbance of the fifth nerve. A lesion in the neck will 
produce headache by causing a congestion of the brain and this in turn 
produces pressure on the meninges, probably the most sensitive struc- 
ture in the cranial cavity, hence the ache is actually due to pressure on 
the branches of the fifth cranial nerve from increased amount of blood 
in the unyielding cranial cavity. The throbbing type of headache is 
the result of this pressure being increased with each pulsation of the 
heart, hence the pain is synchronous with the heart beat. Stooping, 
increases the blood pressure in the cranial cavity and thus increases the 
intensity of the ache. Exercise of any sort which causes an increased 
rate in the heart beat, will cause the pain to become more severe and the 
throbbing is harder and more frequent. In such a case, exercise increases 
the heart rate and as a result, the blood pressure in the brain is propor- 
tionately increased and since there is a pathological congestion already 
existing, the increased pressure produces pain in the meninges. In the 
other types of headache, the fifth cranial nerve is irritated by the toxic 
material in the blood. This may come from retention of the menses, 
liver or gastric disorders, kidney disease, cystic degeneration of the ovary 
and from cervical lesions that impair the quality of the blood circulating 
through the brain by lessening the rate of flow. So soon as the current 
slows, the blood deteriorates in quality, and in passive congestion, toxic 
products are formed which, in turn, stimulate the sensory nerves. The 
most common lesions that affect the sensory innervation of the dura 
mater and thus have to do with the production of headache, are at the 
second and third cervical, fourth, fifth, seventh, eighth and ninth dorsal 
and the fourth and fifth lumbar, that is, the headache may be due to 
disturbances of the vaso-motor supply to the brain, affection of the heart, 
disturbances of the quality of the blood through diseases of the liver and 
kidneys and reflexly, through diseases of the uterus. 

Pain in the eye-ball is the result of some disorder of the fifth cranial 
nerve which supplies it. This is explained through the vaso-motor and 
trophic nerves, which receive their impulses from points below, and on 
account of which a cervical lesion will affect the eye. The aching of 
the eye-ball is most frequently the result of a congestion of it either from 
overuse, catching of cold, or neck lesions affecting the vaso-motor sup- 
ply to it. 

Pain in the various cavities lined with mucous membrane, is usually 
the result of congestion of these mucous membranes, the pain being the 



502 APPLIED ANATOMY. 

result of pressure on the nerve as a mechanical stimulation, or chemical 
stimulation, as in the case of toxic matter in the blood. 

Pain in the different parts of the face at which points the fifth cranial 
nerve becomes superficial, is ordinarily the result of congestion of the 
nerve itself, as is demonstrated by the pain on pressure over the supra- 
orbital nerve when the patient has a cold in the head. Toothache is most 
commonly the result of irritation of the fifth nerve from decay of the 
tooth. A lesion of the lower jaw may cause the pain to be referred to a 
tooth that is apparently sound, while a neck lesion may interfere with 
the nutrition of the nerve, on which account pain will be referred to its 
area of distribution, that is, the teeth. 

The soft palate, the uvula, tonsil, salivary glands and two-thirds of 
the tongue receive their sensory innervation by way of the fifth cranial, 
hence, in pain in these areas the fifth nerve is at fault. The trouble 
m y be a peripheral one, or it may be a referred pain, since it is a well 
known fact that an irritation of one part of the fifth nerve often produces 
a pain in another part, which is ordinarily called a sympathetic pain. 
A good illustration of this is that a decayed tooth will produce earache. 

Facial neuralgia, one of the most painful affections, is the result of 
congestion or inflammation of the fifth cranial nerve. This comes most 
frequently from a neck lesion, which disturbs the vaso-motor supply of 
the blood-vessels of this nerve. Some palliative effect can be obtained 
by the application of heat to the affected part or from pressure along the 
course of the nerve. 

The fifth cranial nerve is more closely connected with the sympa- 
thetic nervous system than any other cranial nerve, perhaps on account 
of the numerous ganglia in relation with it. On this account, many 
visceral disorders cause pain to be referred to the area supplied by the 
fifth nerve, and particularly the coverings of the brain and the eye. 
Often in uterine displacements or inflammation, pain is referred to one 
eye or to other parts supplied by the fifth nerve. In nearly all those 
cases in which the pain is a referred one, there are local lesions that dis- 
turb the nutrition and circulation of the nerve and are in the main, re- 
sponsible for the referred pain. Thus in the various types of reflex 
headaches, there are ordinarily, lesions of the upper cervical vertebral 
articulations. 

The fifth cranial nerve receives its vaso-motor impulses from the 
superior cervical ganglion, that is, they pass through this ganglion. 



APPLIED ANATOMY. 503 

They pass upward over the plexuses around the carotid arteries and 
through the Gasserian ganglion, thence over the divisions of the nerve 
and especially the ophthalmic or first division of the nerve. Although 
parts of the head and face receive their vaso-motor impulses directly 
from the superior cervical ganglion, yet most of them pass through the 
fifth nerve. 

Nearly, if not all, the vaso-motor impulses to the blood-vessels of 
the eye and its appendages, pass through the ophthalmic division of the 
fifth, the parts to be especially mentioned are the iris, choroid and the 
retina. Since the vaso-motor impulses to the parts supplied by the 
cranial nerve are derived from the spinal cord, especially the upper 
thoracic segments, it is readily seen why lesions of the cervical and 
upper thoracic vertebra?, would produce vascular disturbances of the 
above areas. 

The secretory impulses that pass through to the lachrymal, mucous, 
salivary and sweat glands, come from the spinal cord by way of the cer- 
vical sympathetic and the fifth cranial nerves. The lesions of the cer- 
vical region will increase or decrease the secretion of the lachrymal 
gland. This is explained through either the secretory or vaso-motor 
nerves, since secretion seems to depend to a great extent, upon the 
amount and quality of blood. The condition in which there is an ex- 
cess of secretion, is called the "weeping eye'" and in cases seen by the 
author, there were lesions in the neck that were responsible. 

The mucous glands lining the nasal and oral cavities, the throat, and 
those covering the tongue, receive their secretory impulses from the 
spinal cord by way of the fifth nerve. As in secretion in other parts of 
the body, the vaso-motor nerves are to be considered. The best example 
of a neck lesion producing secretory disturbances of the mucous mem- 
brane, is an ordinary cold. Invariably in these cases some sort of neck 
lesion is present such as contracture of muscles, and congestion of the 
deep tissues, due primarily, in the average case, to subluxations of one 
or more of the cervical vertebra. Pressure over the articular processes 
is productive of pain or at least soreness. Sitting with the back of the 
neck in a draft will cause these muscular lesions to form and within a 
few minutes the coryza will develop. The lesions affect in some way, 
the passing of vaso-motor and secretory impulses to the mucous glands 
located in the nose and thus the effect. 

The salivary glands receive their impulses from the upper thoracic 



504 APPLIED ANATOMY. 

segments of the spinal cord, they passing by way of the cervical sympa- 
thetic cord, superior cervical ganglion, cavernous plexus and the max- 
illary divisions of the fifth nerve. A lesion of any vertebral articulation, 
at the origin or along the course of these nerve fillers, will stimulate or 
inhibit the passing of impulses over them, thus an increase or decrease 
in the amount of saliva secreted. Most, if not all, the secretory nerves 
of the sweat glands of the head and face come from the spinal cord by 
way of the cervical sympathetic and the fifth cranial. There may be 
excessive sweating of the head, dryness of the parts or localized disturb- 
ances. The writer has treated cases of hemidrosis in which the cause 
was located at the articulation between the second and third cervical 
vertebrae. A cure was effected in these cases by the correction of the 
lesion, which is at least indicative of the fact that secretory impulses pass 
from some point below in relation with this articulation, and were af- 
fected by the lesion. 

An oily condition of the skin of the face is most frequently the re- 
sult of impairment of the sweat, as well as the sebaceous glands. The 
amount of sweat is lessened, hence the sebaceous secretion is not dis- 
solved, diluted or washed away by the sweat, therefore remains in the 
pores of the skin. In such cases the affected parts of the face never 
sweat. The lesion is sometimes found in the neck and is the possible 
cause of this disorder. There is an increased secretion of sebaceous 
matter when the patient becomes heated from exertion and the face 
becomes quite oily but no perspiration is visible. This condition is worst 
in warm weather. 

It is as yet a disputed point as to whether trophic impulses pass over 
the trigeminus or whether certain effects in parts innervated by the fifth, 
are not due to vaso-motor disturbances. If the nerve is divided, there 
will be, within a few days, inflammation and finally necrosis of the eye- 
ball, and trophic disorders of the other parts supplied by the fifth cranial 
nerve. In such experiments the eye becomes anesthetic and thus is 
unable to expel dust or any irritant that may get into the eye. The 
organ is not conscious of an injury and makes no effort to remove the ir- 
ritant. The reflex secretion of tears is wanting and thus the foreign body 
remains in the eye and finally sets up an inflammation which is the re- 
sult of loss of sensation, rather than an interference with the trophic 
nerves. At any rate there are trophic disorders that are of importance 
as a result of affections of the fifth cranial nerve. Among these disturb- 



APPLIED ANATOMY. 505 

ances are falling of the hair, grayness and splitting of the hair, eruption 
on the face, dryness of the skin and keratitis and other disorders of the 
eye characterized by malnutrition. 

The fifth cranial nerve furnishes to the muscles of the face what is 
called by Landois "muscle sense." In lesions impairing this nerve, the 
delicacy of movement of the muscles of the face is impaired in conse- 
quence of the absence of the muscle sense. 

THE SIXTH. 

The abducens nerve arises from a nucleus with large cells that cor- 
responds to the anterior horns of the spinal cord. This nucleus is located 
in the floor of the fourth ventricle in relation with the deep origin of the 
oculo-motor. Landois says: "Probably some oculo-motor fibers arise 
from the abducens nucleus and from the left, those fibers of the right 
oculo-motor that rotate the right eye inward. (This explains the syner- 
gistic action of the two eyes in lateral movement)." This nerve passes 
out of the cranial cavity through the sphenoidal fissure and supplies the 
external rectus muscle. While in the cavernous sinus it receives branches 
from the cavernous plexus that convey to it vaso-motor impulses and 
branches from the ophthalmic division of the fifth nerve. The sympa- 
thetic communicating branches in all probability, carry motor impulses 
to the nerve from the spinal cord. Landois says, that in the cat, the motor 
fibers for the external rectus pass in part through the dorsal nerves, 
from the first to the fifth. In man, according to Klumpke and Oppen- 
heim, the communicating branch of the first dorsal nerve is the path for 
the motor impulses to the unstriated muscles of the eye and the external 
rectus muscle. A lesion at the origin of or along the course of these 
nerve impulses to the external rectus muscle, will affect the activity of 
this muscle, hence strabismus. If the lesion is irritative, there will be 
external strabismus but if it is paralytic, internal strabismus will result. 
Again, cervical and upper thoracic lesions, disturb the vaso-motor in- 
nervation of this nerve which is followed by weakness and a resultant 
squint. Clinically, these lesions seem to be responsible for the acquired 
cases of strabismus, while in the congenital form there is some disturb- 
ance of the muscle itself such as contracture or shortening. Perhaps the 
best explanation of why spinal lesions produce disturbances of the ab- 
ducens nerve is that it, according to Landois, receives motor impulses 
by way of the cervical sympathetic, and the above mentioned lesions 
affect the cervical sympathetic nerves. 



506 APPLIED ANATOMY. 

THE SEVENTH. 

The facial nerve has its deep origin in the pons under the floor of 
the fourth ventricle. It is described by Morris as a mixed nerve having 
a sensory and motor root, the former consisting of the pars intermedia. 
This intermediate part arises from the medulla in connection with the 
nucleus of the glosso-pharyngeal, and sends most of its fibers to the facial 
and the remainder to the auditory. In company with the auditory 
nerve, the facial enters the internal auditory canal and the aqueduct of 
Fallopius. It then makes a sharp bend at which is located the genicu- 
late ganglion, which is supposed to be analogous to the ganglion on the 
posterior nerve roots of the spinal nerves. While in the internal audi- 
tory meatus, the seventh, gives filaments to the eighth nerve, the 
auditory artery and perhaps the temporal bone. It gives off along 
its course, the -great superficial petrosal, the chorda tympani, motor nerve 
to the stapedius muscle, branch of communication to the small super- 
ficial petrosal nerve, a filament to the vagus and the external superficial 
petrosal, which connects the geniculate ganglion with the sympathetic 
plexus surrounding the middle meningeal artery. After it escapes from 
the skull through the mastoid foramen, it divides into the posterior 
auricular, lingual, muscular to the posterior belly of the digastric and the 
stylo-hyoid. In the substance of the parotid gland it divides into the 
two terminal divisions, the temporo-facial and the cervico-facial, branches 
from which form a plexus called the pes anserinus. This nerve com- 
municates with the fifth, eighth, ninth, tenth cranial, great auricular 
from the cervical plexus and with the sympathetic plexus around the 
middle meningeal artery. 

The principal function of this nerve is that of supplying motor im- 
pulses to the muscles of the face. It also transmits vaso-motor, secre- 
tory and gustatory impulses. Langley considers the seventh and ninth 
nerves together and states that the two together probably supply with 
autonomic fibers the whole of the mucous membrane of the nose and 
mouth. *"The fibers run in the several branches of the fifth nerve sup- 
plying the respective glands for stimulation of these branches causes 
secretion and after section of any one branch, stimulation of the seventh 
and ninth nerves has no longer an effect in the region to which the cut 
branch runs." It has been shown that the seventh nerve sends vaso- 

*Schafer's Phys. Vol. II. p. 660. 



APPLIED ANATOMY. 507 

motor impulses to the salivary glands, to the tongue, mucous membrane 
of the floor of the mouth and to the soft part of the palate. These im- 
pulses pass into the seventh nerve by way of the sympathetic plexus 
around the middle meningeal artery, which in turn receives its vaso- 
motor impulses by way of the superior cervical ganglion. This furnishes 
an explanation of why a cervical lesion will affect the parts supplied by 
the seventh nerve. 

The chorda tympani nerve contains secretory and vaso-dilator fibers 
for the sublingual and submaxillary glands and also gustatory fibers for 
the margin and tip of the tongue. The gustatory fibers of this nerve 
probably originate in the glosso-pharyngeal and enter the facial through 
the pars intermedia. This nerve also contains fibers to the anterior 
lateral portion and tip of the tongue. It is possible that the facial also 
receives sensory impulses from the vagus. Muscle sense fibers are 
furnished to the facial by the trigeminus. 

The principal lesions affecting the seventh cranial nerve are growths, 
fracture of the base of the brain, diseases of the ear, forceps pressure, 
and bony and muscular lesions of the neck. The most important dis- 
ease of this nerve is Bell's paralysis, which consists of a paralysis of the 
lateral half of the face. This is usually a motor paralysis, although in 
some cases there may be pain. The eye on the affected side cannot be 
entirely closed, food gets in between the teeth and the cheek, patient 
cannot pucker the lips as in whistling or expectorating, and the voice is 
muffled. The wrinkles are smoothed out on the affected side, the mouth 
is drawn toward the sound side and the tongue cannot be pro- 
truded in the median line. The extent and degree of the paralysis is 
best brought out in attempted movements of the muscles of the face as 
in laughing or crying. In some cases there is tightening of the ear- 
drum which produces some disorder of the sense of hearing, while in other 
cases the chorda tympani branch of the facial is affected and is followed 
by some loss of taste. In the author's practice, most of the cases of 
Bell's paralysis resulted from cervical lesions such as contracture of 
muscles and displacement of vertebrae. Exposure to a draft, the catch- 
ing of cold and injury from any cause will bring on an attack in some 
cases. Perhaps the best explanation of why a cervical lesion produces 
a paralysis is, that the vaso-motor supply to the cells of origin of the 
seventh nerve and the nerve itself and the parts supplied b) r the nerve, are 
impaired by the lesion, since the impulses pass up by way of the gang- 



508 APPLIED ANATOMY. 

liated cord and on this account are subject to disorders. A contrac- 
tured condition of the muscles of the neck in a similar way produces the 
effect. 

As stated above the vaso-motor nerves from the superior cervical 
ganglion pass into the seventh nerve by way of the plexus around the 
middle meningeal artery. It has not been demonstrated as yet that motor 
impulses pass from the spinal cord up through this nerve, but judging 
from the short interval of time existing between the production of the 
neck lesion and the paralysis, one would infer that there is a direct motor 
connection which is broken by the lesion. 

There are other disorders of the seventh nerve such as blepharo- 
spasm. It may be due to direct irritation of the facial nerve, or as Bru- 
baker states, it may be caused by stimulation of the ' ' sensory nerve of 
the eye principally in connection with scrofulous inflammation of the 
eye, or in consequence of excessive irritability of the retina. " Often 
one unconsciously blinks when brought into a strong light. In path- 
ological conditions in which there is photophobia, there often results a 
clonic spasm of the eye-lids. There may be other forms of spasm of the 
muscle supplied by this nerve in which there is fibrillary twitching, ab- 
normal winking or histrionic spasms. As stated in connection with 
Bell's paralysis, these motor effects may result from a direct disturbance 
of the motor impulses, but since this is not definitely proven, it is better 
to explain the effects through vaso-motor and trophic disorders. In 
addition to these neck lesions it is recognized that intra-cranial disorders 
such as hemorrhages and tumors and injury of the periphery of the nerve, 
will produce disorders of the seventh, but back of these exciting causes 
there will be found in most instances, a neck lesion which is primary to 
the disorder, the exciting cause then acting the more readily. The 
writer has treated cases of facial paralysis due to mastoid abscess, in- 
flammation of the middle ear and to polypi of the ear. 

THE EIGHTH. 

The auditory nerve is the nerve of the special sense of hearing. 
Gowers says that the deep origin is still involved in uncertainty. Its 
attachment to the medulla, (at the junction of this with the pons) is by 
two roots, one of which winds around the restiform body, (inferior cere- 
bellar peduncle) while the other passes into the substance of the medulla. 
The nerve thus formed by the junction of these roots, is directed outward 



APPLIED ANATOMY. 509 

to the internal auditory meatus in company with the facial nerve. The 
pars intermedia sends some filaments to the auditory nerve, but as to 
the kind of impulses carried by them, we are in doubt. It is supposedly 
trophic and vaso-motor. 

The auditory nerve while in the meatus, divides into an upper or 
vestibular branch and a lower or cochlear nerve. The vestibular nerve, 
according to Landois, is essentially connected with the gray matter that 
is in relation with the cerebellum and probably subserves the purpose of 
maintaining the equilibrium. The cochlear nerve supplies the saccule, 
the posterior semicircular canal and is continued through the labyrinth 
as the cochlear nerve and is distributed to the organ of Corti. The 
auditory nerve then has two functions, namely, that of hearing and that 
of maintaining the equilibrium of the body. From this there may arise 
two sets of diseases one characterized by loss of, or interference with, 
the sense of hearing, and the other characterized by vertigo or disturb- 
ances of equilibrium. 

The sense of hearing may be increased, decreased or lost. Stimu- 
lation of the nerve whether from a local condition or the result of a general 
nervous disorder as in hysteria, will produce a condition called hyper- 
acusis. Tinnitus aurium, or ringing in the ears, is quite often due to a 
hypersensitive condition of the auditory nerve. In other cases, it is 
due to derangement of the mechanism that transmits the sound, which 
has been described before. The roaring in the ears from the taking of 
quinine is the result of congestion of the labyrinthine arteries, "which 
may increase to the degree of causing rupture of the vessel." It is also 
due to the poisonous effect of the drug. Deafness is more commonly due 
to a disturbance of the mechanism conveying the sounds than to a dis- 
order of the apparatus that receives the impulses, that is, the auditory 
nerve. Deafness due to paralysis of the nerve, is diagnosed by inability 
of the patient to hear when the vibration is applied to the mastoid pro- 
cess, or other parts in which the medium is bone or other tissue. The 
other forms of disorder of the auditory nerve are characterized by ver- 
tigo, staggering gait, vomiting, roaring in the ears which symptoms 
make up the so-called Menieres' disease. The nerve in this disease may 
be affected reflexly, or it may be affected as the result of increased at- 
mospheric pressure. Menieres' disease has been produced by forcible 
injections into the ears of rabbits and in addition to the vertigo, there 
was nystagmus and rotation of the head toward the affected side. 



510 APPLIED ANATOMY. 

Some have attempted to prove that seasickness was due to a de- 
rangement of this nerve, but as yet no definite proof has been presented. 

The lesions that involve the auditory nerve are those which pro- 
.duce direct pressure on it or those that interfere with its nutrition or 
circulation. Abscesses and diseases of the bone with which it is in re- 
lation, will produce a direct effect on it, while cervical lesions will affect 
its nutrition and vaso-motor supply. 

The vaso-motor supply to the blood-vessels that supply the cells of 
origin of the nerve, seem to follow up the vertebral artery from the upper 
thoracic and lower cervical regions. Other vaso-motor impulses pass 
by way of the superior cervical ganglion and over the cavernous plexus 
either by way of the facial or glosso-pharyngeal nerves, the former by 
way of the pars intermedia, the latter by way of the tympanic plexus. 
Deafness is often caused by a subluxation of some of the upper cervical 
vertebrae. In 'most of those cases the tympanum and middle ear are 
involved. Occasionally a case is found in which the auditory nerve is 
involved as the result of a cervical lesion, but I believe it is an excep- 
tional condition. 

That the auditory nerve bears a close connection to vertigo, is indi- 
cated by the fact that it cannot be induced in deaf mutes, or in animals 
in which the labyrinths have been destroyed. The heart also has some- 
thing to do with vertigo, and this tends to prove that the circulation of 
blood also has something to do with the production of the disorder, be- 
cause in cases of weakness of the heart, or anemia of the brain, there is 
at least a tendency toward vertigo. 

THE NINTH. 

The glosso-pharyngeal nerve arises from nerve cells situated below 
the floor of the fourth ventricle. The filaments unite to form the nerve 
which emerges from the medulla between the olive and restiform bodies. 
The ninth is a mixed nerve but the afferent fibers predominate. The 
sensory descending root is from the fasiculus solitaris. Cunningham 
says: "It begins at the upper limit of the medulla, and can be traced 
downwards through its whole length. Its precise point of termination 
is not known but it is believed that it is carried for some distance down- 
ward into the upper part of the cord, viz., to the level of the fourth cer- 
vical nerve according to Kolliker. " This tract is formed principally 
by the glosso-pharyngeal, while a few of the afferent fibers of the tenth 
enter it. 



APPLIED ANATOMY. 511 

The nerve thus formed, passes out of the cranial cavity through the 
jugular foramen in company with the pneumogastric and spinal ac- 
cessory nerves, but in a separate sheath of dura mater. It then passes 
downward between the hyoid bone and the lower jaw, is in relation with 
the carotid artery and ends in the tongue. 

In the jugular foramen there are two enlargements or ganglia, the 
jugular and petrous. The petrous ganglion gives off the tympanic branch 
which with branches from the sympathetic filaments around the carotid 
artery, form the tympanic plexus. This plexus supplies the mucous 
membrane of the tympanum, the mastoid cells and the Eustachian 
tube. It in addition, communicates with the superior cervical ganglion, 
the auricular branch of the pneumogastric and sometimes with the 
ganglion on the root of the vagus. In the neck it gives off a branch that 
supplies the stylo-pharyngeus muscle and pharyngeal branches that 
innervate the muous membrane of the pharynx. There is a tonsillitic 
and a lingual branch. 

Functionally, the ninth nerve is the gustatory nerve of the posterior 
third of the tongue and a part of the soft palate; the motor nerve for the 
stylo-p