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CLINICAL APPLIED ANATOMY

OR

THE ANATOMY OF MEDICINE AND SURGERY

CLINICAL APPLIED ANATOMY

OK

THE ANATOMY OF MEDICINE AND SURGERY

BY

CHARLES R. gOX

M.D., B.S., B.Sc.LoND., M.R.C.P.LoND., F.R.C.S.Eng.,

PHYSICIAN TO OLT-PATIENTS ST. THOMAS's HOSPITAL, AND ASSISTANT PHYSICIAN TO THK LONDON

FEVER HOSPITAL, LECTURER ON APPLIED ANATOMY AND DEMONSTRATOR

OF MORBID ANATOMY ST. THOMAS'S HOSPITAL,

AND

W. McADAM ECCLES

M.S.LoND., F.R.C.S.Eng., ■

ASSISTANT SURGEON, JOINT LECTURER ON ANATOMY AND DEMONSTRATOR OF OPERATIVE SURGERY

ST. Bartholomew's hospital, examiner in anatomy for the fellowship of

THE ROYAL COLLEGE OF SURGEONS, ENGLAND, AND EXAMINER
IN SURGERY FOR THE SOCIETY OF APOTHECARIKS.

ILLUSTRATED BY 45 PLATES, OF WHICH 12 ARE COLOURED,
A.XD 6 FIGURES IX THE TEXT.

PHILADELPHIA

P. BLAKISTON'S SON & CO.

1012 WALNUT STPtEET

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COMPUMtNTS
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QrA53»

BIS
1 90^

PREFACE

In 1862 there appeared a work which is now classical, " Best
and Pain," by John Hilton. In the preparation of the present
volume we have endeavoured to follow, in some degree, the lines
suggested by that author, and to indicate the important influence
of Anatomy on the incidence and progress of disease, disorder,
and injury of the human body.

We are fully conscious that we have but inadequately fulfilled
the task we have imposed upon ourselves. There are many
omissions ; and explanations are not always so complete or
convincing as we could desire. We have aimed throughout at
keeping the book within reasonable limits, and have avoided the
inclusion of highly controversial points. So many excellent
treatises on Applied Anatomy have made their appearance of
recent years that it might be thought that there was neither
room nor necessity for another. The present work, however,
differs from these in that it deals with the purely clinical side of
the subject, and is written from a practitioner's rather than an
anatomist's point of view. Hence all anatomical points which
are not essential are omitted. The anatomy of surgical pro-
cedures, which is already amply detailed in various manuals of
operative surgery, is purposely passed over.

We trust that the book will prove of service to the senior
student and to the practitioner, and show that Systematic
Anatomy has not yet said its last word in the education of the
clinician.

W f A n >vi

vi PEEFACE.

We desire to express our great indebtedness to the various
authors who have given us permission to reproduce their
diagrams and illustrations. Our requests have in every case
been met with the greatest courtesy and consideration. The
source of these illustrations is, we believe, acknowledged in each
instance. Our thanks are also due to Mr. Lapidge and Mr. C.
Douglas for the care they have bestowed upon the preparation of
the drawings from which many of the other illustrations have
been made.

C. E. B.

W. McA. E.
Loj^DON, W.
January, 1906.

CONTENTS.

♦

CHAPTER PAGE

I. INFLAMMATION 3

II. TUBERCULOSIS AND SYPHILIS 15

III. GANGRENE, BURNS AND SCALDS ..... 33

IV. SPECIFIC FEVERS 39

V. INTERNAL PARASITES . 58

VI. TUMOURS ... 66

VII. FRACTURES 79

VIII. DISLOCATIONS 113

I IX. DISEASES OF BONES AND JOINTS 126

X. DISEASES OF MUSCLES, TENDONS, FASCIA, AND BURS^.

TALIPES 134

XI. DISEASES OF THE NERVOUS SYSTEM .... 156

XII. DISEASES OF THE VASCULAR SYSTEM .... 244

XIII. DISEASES OF THE LYMPHATIC SYSTEM .... 284

XIV. DISEASES OF THE DUCTLESS GLANDS .... 289
XV. DISEASES OF THE RESPIRATORY SYSTEM . . . 303

XVI. DISEASES OF THE ALIMENTARY TRACT, PERITONEUM, AND

DIGESTIVE GLANDS 341

XVII. DISEASES OF THE URINARY SYSTEM .... 421

XVIII. DISEASES OF THE GENITAL SYSTEM .... 440

XIX. DISEASES OF THE EYE 455

XX. DISEASES OF THE EAR 461

C.A.A.

CLINICAL APPLIED ANATOMY.

GENEKAL DISEASES AND INJUKIES

CHAPTER I.
INFLAMMATION.

Inflammation may be aseptic or septic. A very large propor-
tion of inflammatory conditions are septic, that is, due to the
invasion of bacteria.

The entrance of bacteria into the tissues may be through the
skin or mucous membranes, usually with more or less loss of
surface epithelium. When once the blood stream 'is infected,
there is a possibility for remote parts of the body to become
inflamed, because the bacteria may be carried to them in the
circulation.

Exposed surfaces of skin are liable to injury, and thus an
entrance for micro-organisms is obtained. Hence it is that
septic inflammation of the head, of the upper part of the neck,
and of the hands and fingers is so common.

Inflammation of the cornea or conjunctiva is frequent,
and is due to the irritation caused by minute foreign bodies
entrapped between the eyelids and the external surface of the
eyeball. The rhythmical contraction of the orbicularis palpe-
brarum is intended to prevent this inflammatory process by the
removal of extraneous matter, but it is not always successful.

Other parts which, though usually covered by clothing, are

1—2

4 CLINICAL APPLIED ANATOMY.

open to receive blows are apt to become the seat of inflammation,
a good example being the shin.

Sometimes the damage done to the tissues by subcutaneous
injuries prevents their being able to resist the onslaught of
bacteria reaching them in the blood. Hence it is that
inflammation, and possibly subsequent suppuration, may occur
in the part injured.

Again, portions of skin liable to friction, as, for instance, where
the back of the neck is rubbed by the collar, are frequently the
site of inflammation, due to bacteria being rubbed from the
surface into the hair follicles and glands. Furuncles or boils
are thus induced. A " sore heel" from the friction of the boot
in walking is another common example of the same kind.

Intermittent pressure, such as happens over the metatarso-
phalangeal joint of the great toe, will lead first of all to the
formation of an adventitious bursa, or bunion, and often subse-
quently to inflammation of the same.

Parts subject to strains, particularly joints, are peculiarly
liable to become inflamed. Of all the joints of the body the
knee-joint would seem to be the most susceptible.

The more exposed mucous membranes are those which most
frequently suffer from attacks of inflammation. Thus it is that
catarrh of the nasal mucous membrane is met with every day,
and that tonsillitis is so prevalent. The mucous membrane
of the alimentary tract is readily irritated, and consequently
inflamed, by material brought to it through ingestion of improper
food, and peculiarly so by bacteria.

SUPPUKATION.

When pus is formed in the tissues it has a tendency to find
its way along the lines of least resistance to the skin surface,
or into one of the cavities of the body. Therefore it is that
the structures within which suppuration occurs have a marked
bearing from their anatomical peculiarities and relations upon
the actual course taken by the pus in its passage to an exit.

Axillary Fascije.

Pr3tracheal layer
of cervical
fascia.

Brachial plexus.

Scalenus antlcus
nuiscle.

Axillary artery,

Pectoralis minor
muscle.

Pectoralis major
muscle.

Fig 1. — Diagram to illustrate the arrangement of the cervical fascia in the
supra-clavicular region, its connection with the clavi-pectoral fascia, and
the connection of the latter with the axillary fascia. (After Edward
Taylor.)

[To face page 5.

AXILLAEY ABSCESS. 5

Certain abscesses, from their anatomical position, are likely
to do grievous harm if allowed to progress unopened by the
surgeon. Thus pus in the neighbourhood of joints, which
themselves are not inflamed, may track into the articular cavity,
and bring about irreparable mischief by setting up suppurative
arthritis. Again, a focus of suppuration in the ischio-rectal
fossa will most easily find its exit through the bowel wall, causing
a troublesome persistent rectal sinus. Pus confined by firm
resistent fascia may so press upon important structures as to
become a menace to life, as in the case of an abscess beneath
the deep fascia of the neck, where it may narrow the trachea
and cause urgent dyspnoea. So further, pus within the sheath
of a muscle may track widely, and may present at a point very
remote from its original starting point, and sinuses extremely
difficult to eradicate may be the consequence. Puriform fluid
formed deep to the periosteum of a long bone tends rapidly to
strip the membrane from the outer surface of the shaft, leading
to necrosis.

The track of pus in certain regions is dealt with on other pages,
but its particular course in some may be alluded to in this
chapter.

Axillary Abscess. — Superficial axillary abscesses are due to
septic inflammation of the large sebaceous glands in the skin.
Most commonly the deep ones are dependent upon suppurative
lymphadenitis ; sometimes they are due to disease of the ribs or
of the shoulder- joint.

When sufficient pus has been allowed to collect in the axillary
space, its presence will cause the hollow of the axilla to become
obliterated, and the concavity of its floor to be even converted
into a convexity. Further, the anterior wall of the space
formed by the pectoralis major will bulge. The abscess will
increase also in an upward direction behind the clavi-pectoral
fascia, sometimes passing deep to the clavicle into the posterior
triangle of the neck. The pus will be hemmed in at the back of
the space, because of the attachment of the serratus magnus to
the vertebral border of the scapula. (See Fig. 1.)

6 CLINICAL APPLIED ANATOMY.

In opening an axillary abscess, the line of the incision is
usually made vertically along the inner wall, and half-way between
the anterior and the posterior folds of the axilla. In this way the
chief blood-vessels will be avoided, namely the axillary, lying
along the outer wall, the long thoracic, under cover of the
anterior fold, and the subscapular, close to the posterior fold. In
addition, this incision will give the best drainage when the
patient is sitting up, a position which will be frequently assumed
after the evacuation of the pus.

Healing may be delayed unless the arm is kept at rest by the
side, and sometimes the cicatricial tissue formed may by its con-
traction afterwards limit the perfect movements of the scapula
over the thoracic wall, and even interfere with those of the
shoulder-joint itself.

Inguinal Abscess, or Bubo. — Suppurative lymphadenitis is
the usual cause of this form of abscess. The lymphatic glands
lying above Poupart's ligament are frequently infected in
gonorrhoea, and an abscess often has to be dealt with. As the
glands lie superficial to the aponeurosis of the external oblique
muscle, there is not much difficulty for the pus to find its way to
the surface ; hence burrowing is not common.

An incision to evacuate the pus may be made either obliquely,
parallel with Poupart's ligament, or vertically over the summit of
the swelling. Two anatomical objections may be urged against
the former : every movement of the thigh will tend to draw the
lower edge of the incision away from the upper, and thus retard
healing, and there will be a tendency for the inferior part of the
wound to form a trough or pocket in which pus may collect. To
the vertical incision, especially if made freely, neither of these
objections can be brought. It is, however, best to make an oblique
incision over the whole length of the swelling, and to dissect out
the offending glands and the bulk of the surrounding inflamed
tissues by a planned operation under a general anaesthetic.

Psoas Abscess. — An abscess within the fascial sheath of the
psoas muscle is nearly always the outcome of a tuberculous
deposit in the bodies of the lower dorsal or the lumbar vertebrae.

PSOAS ABSCESS. 7

The psoas magnus muscle arises from the lower border of the body
of the last dorsal and the sides of the bodies of the lumbar vertebrae
and the corresponding transverse processes. It is covered with
the iliac fascia, the part over the psoas being thinner than that
over the iliacus. Above, this fascia becomes attached to the
internal arcuate ligament ; on the outer side, to the ventral layer
of the lumbar fascia ; on the inner side and below, it is attached
to the margin of the sacrum and the brim of the true pelvis.

Tuberculous material formed in connection with disease of the
lower dorsal vertebrae cannot easily pass forwards, owing to the
presence of the anterior common ligament, and it cannot readily
pass backwards into the spinal canal, owing to the posterior
common ligament ; hence it is forced to take a lateral course and
gravitate downward in the posterior mediastinum until it reaches
the lowest confines of this space. Here it will be directed by the
last rib and the twelfth dorsal vertebra behind, and the arcuate
ligament in front, into the sheath of the psoas muscle, this being
the line of least resistance.

Tuberculous material formed in connection with the lumbar
vertebrae can pass directly outwards into the substance of the
psoas along the line of its origin from these bones.

Whichever way the caseous material finds its entrance into the
sheath of the psoas, once there it will tend to invade the whole
length of the muscle, and passing behind Poupart's ligament, will
enter the thigh. Here it will be at first posterior to the femoral
vessels, and subsequently internal to them. The matter as a rule
passes to the surface either to the outer side of the femoral
vessels immediately below Poupart's ligament, or to the inner
side of the upper part of the thigh, below and internal to the
position in which a femoral hernia is seen.

In some cases fluctuation can be readily obtained between the
abdominal and thigh portions of the swelling, though commonly
the communication is so small that this definite sign is unobtain-
able. Moreover, the cavity, in addition to fluid, may contain a con-
siderable proportion of solid contents in the form of caseous masses,
which greatly tend against the ready production of fluctuation.

8 CLINICAL APPLIED ANATOMY.

In the treatment of these collections of tuberculous material,
it is important to recollect the above anatomical bearings.
Effective treatment must be thorough, and to be thorough both
the intra-abdominal as well as the crural compartments, if they
exist, must be attacked. An incision into the thigh portion from
the front is a comparatively easy procedure, due attention being
paid to the vessels of the groin. A vertical lumbar incision just
external to the outer margin of the erector spinse is necessary to
open that portion of the abscess which occupies the sheath of
the psoas. This incision should be the first that is made. After
division of the skin a dense aponeurosis is met with, and requires
division in the whole length of the wound. The actual sheath
of the erector spinas is best left unopened. The lumbar trans-
verse processes are now felt for round the outer margin of the
erector muscle, the quadratus lumborum intervening. This also
will require vertical division, care being exercised not to wound
the lumbar arteries. As soon as the quadratus is cut through
the psoas, which slightly overlaps it, is exposed, and the cavity
of its sheath, containing the caseous material, can be readily
reached. Stretching across the interior of the abscess cavity
there can often be felt the lumbar plexus of nerves, which has
been dissected out where it lies in the substance of the muscle.
Care must be taken not to perforate extra-peritoneal tissue,
and still more so the posterior layer of the parietal peritoneum,
which covers the anterior surface of the psoas. The actual seat
of the tuberculous disease in the centre of the vertebrae may
often be reached and dealt with through this incision.

Retro-pharyngeal Abscess. — A collection of pus may occur in
the loose cellular tissue between the prevertebral layer of deep
cervical fascia and the posterior wall of the pharynx.

An acute abscess in this region may be induced by punctured
wounds of the pharyngeal wall, by septic processes tracking from
the surrounding parts, and by acute suppurative lymphadenitis
of the retro-pharyngeal gland.

As a rule the suppuration takes place about the level of the
mouth, and the swelling caused by the pushing forwards of the

Retro-pharyngeal Abscess.

X

Z , Posterior
wall of
pharynx.

Upper part

of larynx.

Fig. 2. — A retro-pharyngeal abscess. (St. Bartholomew's Hospital Museum.)

[To face page 8.

EETEO-PHAEYNGEAL ABSCESS. 9

posterior wall of the pharynx can be readily seen on oral inspec-
tion. The pus here will have a tendency to induce dyspnoea,
from its close proximity to the upper opening of the larynx, and
also dysphagia, from its obstructing the passage into the lower
part of the pharynx. (See Fig. 2.)

The symptoms in these cases are often so urgent as to
require prompt surgical intervention in the way of evacuation
of the pus, or the performance of tracheotomy, to relieve the
dyspnoea.

There is not time for the pus to track any distance before
serious symptoms arise ; hence its release by an incision made
through the mouth is the most speedy and satisfactory. If the
incision is made in or near the middle line of the posterior wall
of the pharynx, there are no structures of importance that can be
exposed to injury. As soon as the pus is liberated the patient
should be turned over on to the face, so that the fluid may be less
likely to enter the larynx by easily running out of the mouth.

In chronic retro-pharyngeal abscess the collection is usually
dependent upon tuberculous disease of the cervical vertebrae, or
a tuberculous deposit in the retro-pharyngeal lymphatic gland.
In these cases the symptoms are, as a rule, much less urgent, and
consequently time is given for the tuberculous material to track
somewhat extensively. It will thus tend to spread laterally, and
may then present in the neck behind or even in front of the
sterno-mastoid, or it may [)ass downwards into the posterior
mediastinum. The anterior common ligament of the spine lies
in front of the bone abscess, and the latter may bulge on each
side of the ligament.

The evacuation of the material may be carried out through the
tissues of the neck by an incision made along the posterior
border of the sterno-mastoid. The deeper part of the dissection
will lie behind the carotid sheath, and must be carried out with
the utmost care. By this method of opening these tuberculous
collections no chance of contamination through the mouth will
occur, and the actual site of disease in the bodies of the cervical
vertebrae may even be explored.

10 CLINICAL APPLIED ANATOMY.

Submandibular Abscess.— Abscess in the region beneath the
mandible is by no means rare, and is generally induced by septic
lymphadenitis of the submandibular glands caused by infection
from the mouth.

Suppuration may be late, but extensive infiltration and oedema
is often early, and may induce dyspnoea by involving the loose
cellular tissue around the upper opening of the larynx. Incision
and free evacuation of the pus is necessary.

SEPTICAEMIA AND PYEMIA.

Any focus of micro-organisms is a source from which bacteria
or their toxins may pass into the blood or lymph circulation.

When pyogenic cocci enter the blood stream of the systemic
circulation it is generally into the capillaries and venous radicles
that they pass. If they are not rapidly killed or their toxins
neutralised, they are carried to the right side of the heart. Here
endocarditis may occasionally occur. The bacteria, however,
are usually swept into the lung capillaries, possibly to set
up pulmonic and pleural disease. If they traverse these
capillaries, which are large and allow ready passage, the left side
of the heart is next invaded, and again endocarditis may
supervene.

Passing into the arterial system from the left ventricle, the
bacteria may travel to any part of the system, and may lodge in
any capillaries, but particularly those of the kidneys and the
synovial membranes of joints, in the former because the renal
organs are excretory, in the latter because there is always some
liability to slight degrees of trauma.

If at the seat of infection thrombosis of small venules occurs,
there is a probability of infected emboli being detached and
carried in the blood to distant parts. These from their nature
are more apt to plug capillaries either of the pulmonary or
systemic circulation than are bacteria alone.

When pyogenic bacteria enter the radicles of the portal circu-
lation, they are carried direct to the capillaries of the liver, there
to excite portal pyaemia or pylephlebitis. If they are not caught

PYiEMIA. 11

in these capillaries, they pass on through the hepatic veins to
the right side of the heart.

When pyogenic bacteria enter the lymph stream, they are
carried to the lymph glands, there to be filtered off and killed in
a large proportion of cases, with or without evident inflammation
of the glands and their surroundings. If the cocci escape the
meshes of the filter, they may pass by the efferent vessels to the
larger lymphatic channels, and so on into the general venous
circulation at the entrance of the thoracic duct into the junction
of the left subclavian and left internal jugular veins, or that of
the right lymphatic duct into the junction of the right subclavian
and the right internal jugular veins.

Although pyaemia may ensue from infection in any region of
the body, it is perhaps peculiarly prone to follow infection in
certain definite spots. Thus in the head, the middle ear is a
common seat of origin. Further the skin of the cheek and the
red surface of the lip are dangerous positions should inoculation
occur. The facial vein communicates by its radicles with those
of the ophthalmic vein, particularly about the inner canthus,
and through it with the cavernous sinus, and further the deep
facial vein has connections with the pterygoid plexus, which
again communicates with the same intra-cranial sinus by small
venous channels traversing the foramen ovale and foramen
lacerum medius. Moreover, the facial vein tends to remain
patent when incised, and has no valves, so that septic material
may easily pass from it to the internal jugular.

The uterine veins are a frequent source of septic emboli. So
also are the veins of the periosteum of bone, and particularly
those bones which are much exposed to injury, such as the tibia.

WOUND INFECTIONS.
Cellulitis and Erysipelas. — These two acute inflammatory
conditions are probably both of them dependent upon one and
the same specific virus — a streptococcus, the species of which
may slightly differ in the two infections, so as to cause some
modification of the signs and symptoms.

12 CLINICAL APPLIED ANATOMY.

In cellulitis the infection seems to originate and to spread
chiefly in the subcutaneous tissues; in erysipelas the infection
occurs and spreads chiefly in the skin. In cellulitis the skin
becomes rapidly cut off from its blood supply, so that it has a
tendency to slough, while at the same time death of the
subcutaneous tissues is the rule ; in erysipelas, even if the
inflammation is sufficiently severe to induce the formation of
bullae, no loss of tissue occurs except of the most superficial
layers of epithelium. In cellulitis the streptococcus travels by
means of both lymphatic and venous channels, and red lines of
inflamed lymphatic vessels extending to the first chain of glands
are not infrequent ; in erysipelas the streptococcus wanders in
the fine cutaneous lymphatic capillaries, and there is no
lymphangitis, although always lymphadenitis of the first chain
of glands.

Tetanus. — Tetanus is due to the entrance of tetanus bacilli
into the tissues and the action of their toxins upon the central
nervous system. Owing to the anaerobic nature of the organism,
the bacilli are unable to grow upon small and superficial wounds ;
hence punctured wounds which lodge bacteria deep in the tissues
place them in a soil well-fitted for their vital activity. Since
garden mould, road refuse, and similar materials form the chief
habitat of the bacilli, punctured wounds of the hands and feet
from sharp pointed metallic bodies and lacerated wounds of the
head, caused chiefly by falls from vehicles, are those which are
not infrequently followed by the development of tetanus.

It is perhaps needless to say that wounds in the web between
the thumb and the index finger are not more liable to give origin
to tetanus than are wounds elsewhere, except from the fact that
the hands so often come into contact with the material
containing the specific virus. The bacilli remain localised at
the point of infection : it is very rare indeed for them to wander
into the blood stream and be disseminated by this means, their
anaerobic nature being again an obstacle to their migration.

There is little doubt that the toxin gains access to the central
nervous system by way of the trunks of the peripheral nerves.

ANTHEAX. 13

probably by means of the protoplasm of the axis cylinders.
Experimentally the incubation period, other things being equal,
is directly proportional to the length of these nerves.

When large doses of toxin are produced, the poison may be
also carried to the central nervous system by the blood stream.

A very characteristic symptom in tetanus is the painful
spasmodic contraction of the diaphragm, which gives rise to
severe epigastric pain radiating to the back.

The antitoxin of tetanus may be administered by injection into
the theca of the spinal cord, by subdural injection, or by injection
into the brain itself, these methods affording the most direct
route to the central nervous system in which the toxin becomes
locked up.

A peculiar form of the disease known as cephalic tetanus
occurs when the focus of infection is in the facial nerve area.
In this form the facial nerve becomes paralysed, possibly from
compression of the swollen trunk by its bony canal.

Anthrax. — Anthrax is a specific disease dependent upon
inoculation with the bacillus anthracis, usually derived from
the bodies or skins of infected animals. It is possible that
inhalation of infected dust or ingestion of infected foods may
give rise to the disease. Wool-sorters, butchers, farmers,
veterinary surgeons, tanners, and pathologists are all liable to
have abrasions of the fingers, hands, forearms, or face infected
with the characteristic bacillus ; hence it comes about that the
malignant pustule, the evidence of the site of inoculation, most
commonly occurs on these parts. The bacteria are rapidly
carried over the whole body by the blood stream.

Glanders. — Almost always glanders in the human subject
arises by infection from diseased animals, most frequently
horses, by the virus being blown from the nostrils of the
affected animal into the eyes, nose, or mouth of the horsekeeper,
ostler, farrier, veterinary surgeon, or slaughterer. The disease is
spread from the primarily infected mucous membrane by the
lymphatics, and lymphangitis and lymphadenitis are common
occurrences. The vascular system also transmits the virus,

14 CLINICAL APPLIED ANATOMY.

and so secondary foci, resembling in the chronic form of the
disease those of syphilis and tubercle, may be found in the
internal organs, muscles, and subcutaneous tissues.

Actinomycosis. — Actinomycosis may occur in the human
subject ; it is an infection by the actinomyces, or ray fungus.
The fungus most commonly gains entrance through the mucous
membrane of the alimentary tract, particularly of the mouth and
the appendix vermiformis, from the chewing and ingestion of
infected grain.

In the human subject the disease is not infrequently seen in
the cheek or subcutaneous tissue of the neck. When the infec-
tion occurs lower in the alimentary tract it seldom show^s itself
until the liver or spleen becomes involved, when these organs
frequently become attached to the surrounding tissues by in-
flammation, and the characteristic actinomycotic pus is discharged
externally. The fungus will then have a great tendency to
burrow in the superficial fascia and to give rise to a considerable
number of tortuous sinuses.

Infection may also occur through the respiratory tract, from
which it spreads extensively, not only in the lung tissue, but over
the pleura and into the neighbouring bones, and again a large
number of sinuses opening in all directions is likely to be seen.

CHAPTER II.
TUBEKCULOSIS AND SYPHILIS.

Local Tuberculosis. — The site of primary invasion in tuber-
culosis is largely determined by anatomical factors. The
uninjured epidermis affords an eJBficient protection, so when
infection through the skin does occur it is in parts exposed to
free contact and to mechanical injury, such as the margin of the
nostril, the lip, and the angle of the eye. Tuberculosis of the
skin may follow trivial injuries, such as tattooing, hypodermic
injections, or scratches received during post-mortem examina-
tions. Another example of wound infection is the local tuber-
culosis which sometimes follows ritual circumcision. When
tuberculosis attacks the skin it is not always by direct
inoculation ; the primary focus of infection may be in a mucous
membrane close by, as occurs in some cases of facial lupus.
The skin may also be infected through the medium of its blood-
vessels, but for some reason this is rare, possibly because the
comparatively low temperature of the surface does not much
favour the growth of the bacillus.

The digestive tract, like the skin, is exposed to direct infection,
and the parts most likely to suffer are those which are most
richly supplied with lymphoid tissue. The tonsils and the lower
part of the small intestine are peculiarly vulnerable on this
account. The tonsil, with its crypt-like structure, is not only
exposed to primary infection, but is often secondarily infected by
tuberculous sputum, and the same applies to the small intestine.

The soft palate, which during swallowing and coughing serves
to shut off the posterior nares, is liable to primary infection by
the passage of tuberculous food and to se«eondary infection by the
forcible impact of phthisical sputum.

The mouth, pharynx, and oesophagus are well protected by

16 CLINICAL APPLIED ANATOMY.

squamous epithelium. Moreover, neither food nor sputum tarry
long in these situations. When tuberculosis attacks the tongue
the ulcers are usually on the margins, near the tip, positions
presumably liable to slight injury.

The stomach and upper part of the small intestine usually
escape, the former on account of its motor activity and acid
contents and the latter because of the scantiness of its lymphoid
tissue and the rapid passage of its contents. The discharge of
the bile and pancreatic juice into the second part of the duodenum
also conduces to the immunity of the upper part of the small
bowel. There are certain positions in which the digestive tract
may become locally involved by extensions of the tuberculous
process from lymphatic glands. The upper part of the pharynx
may be infected from retro-pharyngeal glands which drain the
nasal fossae, and the oesophagus may be invaded by tuberculous
glands of the mediastinum.

The respiratory Iract is likewise exposed to direct infection.
The nose is particularly well guarded against invasion. Q'he
vestibule is lined by thick skin as far back as the limen nasi, and,
moreover, is armed with thick recurved vibrissae. The
Schneiderian membrane is thick, erectile, endowed with very
high reflex excitability, and freely provided with a mucoid
secretion inimical to bacterial growth. The ciliated epithelium
of the respiratory portion of the nose is an additional protection.
Notwithstanding all this, tuberculosis does at times invade the
nasal cavities. The infection may be introduced on the finger,
and slight injury at the same time inflicted ; tuberculous sputum
may lodge in the nasal cavity as the result of imperfect cough, or
invasion may occur by continuity of tissue.

The complicated structure of the larynx, its exposure to cough
pressure, and the absence of ciliated epithelium on its cords,
render it very liable to infection by tuberculous sputum during
cough. By virtue of its position it may also become primarily
infected, but this is exceptional.

In pulmonary phthisis it is said that the larynx is often
involved on the same side as the diseased lung. The accuracy of

PULMONAEY TUBEECULOSIS. 17

this statement is disputed. The unilateral infection is attributed
to a weakening of the corresponding half of the larynx due to
pressure on the recurrent laryngeal nerve. The nerve is supposed
to be involved by the tuberculous process at the lung apex or
pressed upon by tuberculous glands in its neighbourhood. The
larynx, thus weakened, cannot properly clear itself. The exposed
position of the crico-arytenoid joint often leads to its invasion in
laryngeal tuberculosis, with consequent fixation of the vocal cord.

The trachea and main bronchi are protected internally by their
smoothness, their ciliated epithelium, and their impermeable
basement membranes, but may be invaded from without through
the lymphatic glands of the tracheo-bronchial group.

The lungs are the commonest site of tuberculous infection.
The virus is probably air-borne. The terminal air-passages — i.e.,
/ the terminal bronchioles and the alveoli — are forced to rid them-
selves of inhaled particles by the slow process of lymphatic
drainage, whilst similar particles on the upper parts of the
respiratory tract are rapidly removed by the upward current of
mucus produced by the ciliated epithelium and fail to pass
inwards through the basement membranes. In children the bacilli
easily traverse the lung and lodge in the bronchial glands, but
in adults, in whom absorption is hindered by the greater firmness
of the mucous membrane and possibly also by partial choking of
the lymphatics, broncho-pneumonic lesions result, commencing
in the terminal bronchioles and extending to the alveoli in
connection with them.

The anatomical causes of the vulnerability of the apices are
much disputed. Imperfect blood and lymph circulation, deficient
expansion, and deficient expiratory power have all been alleged as
causal factors.

Once established in the lung, the tuberculous focus can spread
by various paths. Infection may be carried from the apex of an
upper lobe to the apex of a lower or to the opposite lung by
aspiration, the infected sputa being inhaled along the short wide
bronchus which leads to the apex of the lower lobe, or across the
bifurcation of the trachea to the opposite lung. From all

C.A.A. . 2

18 CLINICAL APPLIED ANATOMY.

established foci local extension may occur radially by means of
lymphatics and also by direct continuity of tissue. During the
progress of a tuberculous lesion an incompletely thrombosed
artery may be opened, and localised embolic miliary tuberculosis
be set up in the part of the lung to which the invaded vessel is
distributed.

A distinctive feature of lung tuberculosis in childhood is the
direct infection of lung tissue by adjacent tuberculous lymphatic
glands. Since glands can be traced into the lungs as far as the
fourth subdivision of the bronchi, they are apt to appear as
embedded caseous masses, and may be confused with true
pulmonary deposits.

It is also possible for the lungs to be invaded through the
blood stream as part of a disseminated miliary tuberculosis, and
some authorities believe that phthisis is of embolic origin.

The serous memhraiies are frequently the sites of tuberculosis.

Invasion of the pleura is often secondary to that of the lung
and the bronchial glands. The intimate relation of the visceral
pleura to the lung, the subpleural course of many efferent
pulmonary lymphatics, the termination of these lymphatics in
the bronchial glands, and the close relation of the glands
themselves to the pleura, all facilitate invasion of the latter,
which may either occur by direct continuity or possibly by
lymphatic backflow. The pleura may also be invaded by the
medium of the blood stream, but its vessels are comparatively
unimportant. Yet another path for pleural invasion is from the
peritoneum through the lymphatics of the diaphragm. Carious
ribs or vertebrae may infect the pleura by contact.

Very similar considerations apply to pericardial infection.
This sac is adjacent to the lungs and pleurae, also to the sternum,
ribs, and dorsal vertebrae ; the bronchial and other mediastinal
glands are in close apposition to it. From any of these sources
tuberculosis may spread. It is also open to infection from below
through the diaphragm and by the blood stream.

The peritoneum maybe invaded by means of the blood stream,
but, as is the case with the pleurae, its vessels are small and

GENITAL TUBERCULOSIS. 19

unimportant. It is, however, exposed to infection from the
digestive and the urinary tracts and from the genital organs.
Caseous mesenteric or retroperitoneal glands may involve the
peritoneum by continuity or actually burst into the sac.
Tuberculous ulceration of the intestine almost invariably gives
rise to local peritoneal tuberculosis, and may originate a more
widely spreading infection. Tuberculous infiltration of the
Fallopian tubes is very favourably situated for direct extension
to the peritoneum through their ostia or coverings. Of the male
genital organs the seminal vesicles are in close contact with the
lower part of the great sac, and the tunica vaginalis of the testis
may communicate with the peritoneal cavity through an
unobliterated funicular process. A pleural tuberculosis may
extend to the abdominal cavity either by means of the lymphatics
of the diaphragm or by actual continuity when a defect exists
in the posterior part of the diaphragm. Such a defect is not
uncommon between the costal and vertebral attachments of the
muscle. Diffusion of tuberculosis in the peritoneum is aided
by the constant movements of the abdominal walls and the
peristaltic action of the intestines.

The genital system, like other systems, may be invaded through
the blood stream, and the localisation of tuberculosis in the
epididymis is explained on this hypothesis as being due to
the sluggish blood and lymph circulation in that part of
the gland which lies at the junction of the blood supply of
the testicle proper and the blood supply of the vas deferens.
However, it is believed by some authorities that genital tuber-
culosis, although usually secondary to pulmonary phthisis,
even in these instances is due to an ascending infection
along the urethra. The mucous membrane of the prostatic
portion is bored like a sieve, and so affords a ready lodgment to
bacilli. Excretion of living tubercle bacilli by the kidney may
also infect the parts below. Whether the prostatic deposit of
tubercle be brought by the blood stream, or ascend the urethra, or
descend the ureter, it lies at the junction of the urinary and
genital systems, and may serve as a focus of infection for both,

2—2

20 CLINICAL APPLIED ANATOMY.

the process spreading on the one hand to the seminal vesicles
and along the vas to the epididymis, and on the other to the
urinary bladder.

Of the female genital organs, the Fallopian tube most commonly
suffers. As is the case with gonorrhoea, the infection may ascend,
but the vagina is well protected by its squamous epithelium, and
the cervical canal by its cylindrical epithelial coat and its narrow-
ness. Infection may be carried to the uterus, tubes, or ovaries by
the blood stream. Intestinal tuberculosis may directly infect the
tubes, ovaries, uterus, or bladder when infected coils of gut are
in contact with the viscera mentioned.

Tuberculosis of the urinary system may originate in the kidney
as a blood-borne infection, the bacilli settling in the vascular
tufts or in the tubes during the process of excretion. The
infection may ascend from the genital system in the male, for
the trigone of the bladder is easily invaded from the prostate, and
since the mucous membrane of this region is here most fixed, it is
less likely to free itself during the processes of distension and
evacuation of the bladder. The kidney may be infected from the
bladder by an extension along the ureter, or by way of the lympha-
tics of that tube, or by regurgitation of urine. The kidney is
sometimes invaded in genital tuberculosis without the inter-
vention of" bladder tuberculosis ; in such cases it is suggested
that the infection spreads from the epididymis by way of the
lymphatics of the vas deferens, thence to the lymphatics of the
ureter, and so to the kidney. The bladder is thus excluded from
the track of infection. The fact that the bladder in the female is
less likely to become tuberculous than the bladder in the male is
accounted for by the absence of prostate, which is a common
focus of infection.

The hrain and its membranes are usually infected as part of an
acute miliary tuberculosis derived from a caseous focus elsewhere
in the body. Direct infection from the ear sometimes occurs, and
in some cases an infection from the lymphatics outside the skull
appears to be possible. The continuity of the lymphatic sheaths
of the cranial nerves with the lymphatics outside the skull suppHes

TUBBECULOSIS OF BONES. 21

a pathway in the latter form of invasion. The sheath of the
optic nerve is connected with the lymphatics of the orbit and eye ;
the sheath of the auditory nerve is in communication with the
perilymph spaces of the internal ear. The olfactory nerve sheaths
are intimately connected with the lymphatics of the olfactory
mucous membrane.

The spinal meninges usually suffer in company with the
meninges of the brain, but may be involved alone as the result of
the invasion by a tuberculous focus in the body of a vertebra, and
in the same way the spinal cord may become locally tuberculous.

Of the organs of the senses the ear is open to direct infection
along the Eustachian tube or to invasion from the meatus or
invasion by means of the blood stream.

The posterior part of the eye usually suffers in a blood-borne
tuberculosis, the richly vascular choroid affording a nidus. The
affection is then bilateral. Unilateral affection of the anterior
parts of the eye points rather to local infection from without. The
conjunctiva and lachrymal apparatus may be similarly infected.
The preauricular, submandibular, and cervical lymphatic glands
are enlarged in these cases of anterior local infection. The vascular
iris is liable to suffer in common with the back of the eye in
general infection, also may be invaded from the front in local
infection. The rarity of local tuberculous infection is due to
the efficiency of the lachrymal apparatus and the protection
afforded by the squamous epithelium of the conjunctivae.

Tuberculosis of the hones and joints is generally secondary to
a focus elsewhere. Infection is conveyed to the bone or joint
involved by the lymphatic or vascular systems, usually by the
latter. As a rule the primary focus is in the bronchial glands
or in the lung. The petrous bone and mastoid may be
directly infected by way of the Eustachian tube or the external
auditory meatus. The carpal and tarsal joints may, in some
instances, be invaded directly from contiguous tendon sheaths.
Cancellous bone, from its richer blood supply, is more likely to
suffer than bone which is compact ; vascular, rapidly growing
epiphyses are especially liable to infection, particularly where

22 CLINICAL APPLIED ANATOMY.

their situation exposes them to risk of injury. The numerous
articular vessels which ^supply an epiphysis in active growth
render it more vulnerable than the diaphysis with its solitary
artery. The vessels which supply an epiphysis also supply the
adjacent joint ; hence disease of the two is often associated, but
the joint may also be invaded by direct extension from the
epiphysis. In adults after the period of rapid epiphysial growth
has passed the synovial membrane rather than the bone is likely
to be the part attacked.

The vascular cancellous tissue of the bodies of the vertebrae,
the head of the tibia, the condyles of the femur, the neck of the
femur, the lower end of the humerus and of the olecranon, is
favourable to a tuberculous deposit. The bones of the tarsus, in
which cancellous tissue is abundant, and which are peculiarly
exposed to slight strains and injuries during locomotion, are often
the site of tuberculosis. Those exposed to the greatest strain
are said to be most frequently attacked, the order of liability
being os calcis, first metatarsal, astragalus, cuboid, scaphoid,
and cuneiform. The proclivity of the inner longitudinal arch
is very obvious. The relation of the tarsal bones to the synovial
cavities of the foot determines the subsequent direction of the
tuberculous process. In this respect disease of the scaphoid bone
is serious, since it may extend to both the anterior and posterior
segments of the tarsus. When the carpus is attacked the fact
that the synovial sac between the bones of the first row and the
radius is shut off from the second row of joints is important.
The joints of the second row communicate with the carpo-meta-
carpal joint by a channel between the trapezoid and os magnum.

The cancellous tissue of the flat bones of the skull, of the
finger bones, of the acetabulum, and of the glenoid fossa of the
scapula affords a good nidus for the tubercle bacillus.

Necrosis is a natural result of inflammation in an unyielding
tissue like bone. In very acute tuberculous inflammation of
the ends of the long bones a wedge-shaped sequestrum may
form, pointing to embolism of an artery as the origin of the
process.

LYMPHATIC TUBERCULOSIS. 23

The secondary results of bone tuberculosis depend on the
anatomical relations of the bone involved. Increased epiphysial
growth is sometimes seen ; joint tuberculosis is a common
sequel. When a diseased bone is in intimate relation with a
serous sac the latter may be involved by extension ; tuberculous
peritonitis, pleurisy, and meningitis at times arise in this way.
Disease of the bodies or laminae of the vertebrae may give rise to
paraplegia by causing pressure on the spinal cord or by directly
invading it. The intimate relation of the psoas muscle to the
vertebrae explains the frequency of psoas abscess in tuberculous
caries. Destruction of bone gives rise to various deformities of
the spine and joints.

Tendon sheaths are liable to tuberculous infection, which
manifests itself as a chronic teno-synovitis. Primary infection
of these structures is probably blood-borne, but the intimate
relation of tendon sheaths to certain joints allows direct infection
from the joints themselves. Thus the flexor and extensor sheaths
may suffer in disease of the carpus, and the sheaths of the
peroneal and tibial muscles in disease of the tarsus. Conversely
disease of a tendon sheath may infect a joint over which the
tendon passes ; the tendon sheaths around the wrist are peculiarly
liable to invade the wrist-joint in this way.

The mawinaru gland may be invaded by way of the milk
ducts, and then the inflammation is primarily parenchymatous
or through fissures o£ the nipple, when interstitial mastitis may
be expected. Secondary lymphatic glandular enlargement
follows.

The lymphatic glands are often the site of localised tuberculosis.
The drainage area of the group of glands first involved must be
assumed to be the place of primary infection. The glands which
most frequently suffer are the tracheo- bronchial group, the
cervical chains, and the mesenteric group, corresponding respec-
tively to infections of the lung (or possibly of the trachea and
oesophagus), of the nose and throat, and of the small intestine.
The primary lesion may be insignificant, and there is good
reason for the belief that the bacilli may even penetrate

24 CLINICAL APPLIED ANATOMY.

mucous membranes without producing any lesion at their
point of entry.

The bronchial glands are remarkably liable to infection in
childhood. In early years the afferent lymphatics are more
permeable, and the pulmonary lymphatics in particular have not
yet been choked with dust and carbon particles. Moreover, the
occurrence of lung inflammations connected with whooping
cough, measles, and other infectious diseases to which children
are prone, renders the adjacent glands susceptible. By some it
is believed that these glands may be directly infected from the
trachea or oesophagus.

The invasion of cervical glands is partly explained by the
frequency of trivial lesions of the mouth, fauces, and scalp, the
presence of enlarged tonsils and carious tooth sockets, and the
exposure of these parts to infection by food or air. If a deep
gland of the neck is primarily infected, the deeper lymphatics
following the great vessels constitute the track of infection ; if
the primary infection is of a superficial gland, the glands in
immediate relation with this are next involved.

Primary involvement of the mesenteric glands naturally sug-
gests food infection.

Tuberculosis of the inguinal glands is rare. When it does
occur it is usually the result of tuberculous affection of the
external genital organs.

Widely disseminated glandular tuberculosis is sometimes due
to infections brought to the glands by the blood stream.

The firm capsules of lymphatic glands for a long time protect
the surrounding tissues from invasion ; when the capsule is
perforated local extension follows.

Disseminated Miliary Tuberculosis. — Disseminated tubercu-
losis results when the blood-vessels or the lymphatic channels
are invaded by the bacilli. In the former case the secondary
deposits are widespread, in the latter more or less localised. The
direct invasion of the large blood-vessels by numerous tubercle
bacilli is the usual basis of widespread miliary tuberculosis ; for
small vessels tend to become thrombosed during invasion, and so

MILIAEY TUBEECULOSIS. 25

general dissemination may be prevented. An old caseous deposit
is generally the starting-point of the blood infection. Tuberculosis
of the vessel walls ensues, not only at the site of invasion, but
also in other parts of the vascular system by direct settlement
of the organisms or by penetration of the vasa vasorum. General
dissemination throughout the body soon results. Bacilli which
have entered an artery are carried as emboli into the tissues
supplied by that vessel only ; but bacilli which enter a vein or
the thoracic duct may be carried into the general circulation and
reach all parts of the body. Unfortunately veins and the
thoracic duct are more likely to be perforated than are arteries,
since the walls of the latter are thicker. When the walls of the
thoracic duct are penetrated the general circulation is Foon
invaded by way of the great veins into which the contents of
the duct are poured. It is noteworthy that the afferent lym-
phatics of the pleural and peritoneal membranes are not inter-
rupted by protective lymph-glands on their way to the thoracic
duct.

There are several localities in the body where veins are
especially lia))le to become infected from tuberculous foci. The
pulmonary veins are involved more frequently than any other, the
infection spreading from tuberculous glands around the bifurca-
tion of the trachea or from the lung itself. The mesenteric veins
are liable to suffer by reason of their intimate relations to the
mesenteric glands. The lower part of the vena azygos major is
sometimes infected by tuberculous retroperitoneal glands, the
jugular veins by cervical glands, and the innominate veins by
glands in the superior mediastinum.

Branches of the pulmonary artery may be directly invaded
in tlie lung, and even the main trunks of the aorta and pul-
monary artery have been infected from tuberculous mediastinal
glands.

When bacilli enter the circulation by way of the systemic veins
or thoracic duct, they traverse the right cavities of the heart, and
are chiefly deposited in the lungs, the capillaries of which form
the first filter tliey meet; hence tlie most copious miliary deposit

26 CLINICAL APPLIED ANATOMY.

may be expected in this situation. Others will pass on through
the left side of the heart and he generally distributed by the
arterial system.

If a pulmonary vein he the place of entrance the infection will
sweep on directly to the general arterial system and be dis-
tributed to the organs this supplies. Generally the brunt of the
infection will be borne by those organs which are most richly
vascular, such as the spleen, liver, and kidney. The lung will be
invaded along the bronchial arteries, and so to a comparatively
slight extent.

A focus of infection in the portal vein area will chiefly infect the
liver, and any bacilli which find their way through this barrier
will emerge by the hepatic veins and find a resting-place in
the lungs. It is well to remember that the liver may be
infected through the hepatic artery when bacilli are in the
arterial blood stream.

When the endocardium or the aorta are involved the route of
infection is by all the systemic arteries, but when a small arterial
trunk is invaded, which may occur when tuberculosis is active
in such organs as the lungs and kidneys, the micro-organisms
will settle as infarcts in the terminal distribution of the vessel
involved.

The great serous sacs are but scantily supplied with blood-
vessels, so the peritoneum, pleurae, and pericardium do not show
a profuse depo.sit of tubercles in blood infections. The choroid,
although small, is very vascular, and tubercles deposited in it
may sometimes be seen with the ophthalmoscope. The actively
growing tissues of children, with their free blood supply, afford a
good nidus for bacilli when the latter have once entered the blood
stream.

In disseminated blood tuberculosis the bacilli are in the vessels,
and therefore, despite the copious deposits in the lung mentioned
above, they will not be found in the expectoration unless there
be an old pulmonary focus, or, as sometimes happens, the disse-
minated foci are of different ages, and some of the older deposits
have gained access to the air-passages. Deposits of different

SYPHILIS. 27

ages point to successive blood infections. Similar considerations
apply to the serous sacs; but few bacilli are found in the effusions
they contain when they have been infected by the blood stream.
When meningeal symptoms are present, bacilli are sometimes
to be found in the arachnoid fluid.

The difficulty in obtaining bacilli from the blood stream in
general tuberculosis may be explained by the consideration that
the bacilli do not continuously circulate, but are soon entangled
and settle down.

Disseminated tuberculosis may also spread by means of lym-
phatic vessels. The lymphatic stream is sluggish, and the
obstructions are numerous, so the miliary tubercles are mostly
seen near the original focus and have not the wide distribution
which is met with when the blood stream carries the infection.
Lymphatic dissemination may be seen when tuberculosis is
spreading from foci in the lung. It may also be observed when
tuberculosis is invading the lung from a bronchial gland, the
spread in this instance being retrogressive. It is possible that
the nodular forms of tuberculosis of serous membranes and
spleen are the result of lypaphatic infection, and that this form of
infection may precede and originate a general blood tuberculosis.

SYPHILIS.

Syphilitic infection is favoured by damage to the surface
epithelium, for it is probable that the virus of syphilis invades
the intra-epithelial lymphatics at the point of inoculation.
A surface lesion may be absolutely necessary before the
lymphatics of the thick skin covering such parts as the finger or
cheek become infected, but in parts where the epithelial
covering is more delicate, as, for instance, the conjunctivae,
abrasion may not be a necessary antecedent. Tattooing affords
an easy method of inoculation, and the readiness with which a
cracked lip or a bite may become infected alao bears witness to the
vulnerability of the tissues w^hen their epithelial covering has
been damaged. During the period of lactation the nipple often

28 CLINICAL APPLIED ANATOMY.

presents small excoriations, and in wet-nurses these may become
infected ; sometimes both nipples are invaded simultaneously in
this manner. A finger chancre is usually found by the side of
the nail, a spot very liable to slight laceration. The proclivity to
infection of the groove between the prepuce and the corona is
probably an example of the same natural tendency.

It appears that the poison is carried from the point of infection
by the perivascular lymphatics, and so invades the nearest group
of lymphatic glands. These glands undergo a slow and painless
enlargement. Indurated lymphatics can sometimes be traced
from the chancre towards the glands involved. The glands
which first enlarge are those in direct anatomical continuity with
the part infected. With a genital chancre the horizontal set of
inguinal glands is usually affected first, with a central chancre
of the lower lip the supra-hyoid glands, and with a chancre
situated laterally the submandibular group. A finger chancre is
followed by swelling of the outer group of axillary glands, or, if
on one of the inner fingers, the epicondylar gland may first sufier.
An eyelid chancre will first infect the preauricular glands. The
occurrence of '' crossed bubo," where the chancre is on one side
of the prepuce, and the bubo in the opposite groin, admits of an
anatomical explanation, for although the lymphatics of the skin of
the penis and of the prepuce, after following the course of the
superficial dorsal vein, pass mainly to the groin of the same side,
yet a decussation may occur, and as a rarity one trunk only
may be present, so that all the lymphatics converge to the same
groin.

The lymphatics of the glans penis run with the deep dorsal
vein of the organ within the aponeurosis. Some of them pass
into the abdomen through the crural canal, having traversed the
row of lymph-glands round the femoral vein, whilst the rest
enter by the inguinal canal, and join the same vertical set of
lymph-glands at a higher level where it surrounds the external
iliac vein.

When syphilis enters on its secondary stage, the phenomena
become generalised. The symmetrical distribution and wide

SECONDARY SYPHILIS. 29

extent of the skin lesions point to a blood infection, and the
sHght general enlargement of the lymphatic glands throughout
the body as contrasted with the localised glandular swellings
dependent upon the primary inoculation is also to be regarded as
an indication of systemic infection.

The occasional manifestations of jaundice, albuminuria, and
swelling of the liver and spleen are also evidences of general
blood infection, as also are the later affections of the eyes,
middle ears, and testicles. In congenital syphilis, large paren-
chymatous organs like the liver and spleen, which have a free
blood and lymph supply, may suffer severely.

The characters of the eruptions in the secondary stage are
modified by the position of the lesion. On ordinary skin
suppuration rarely occurs. Where two skin surfaces come into
contact, and there is warmth, dirt, and moisture, condylomata
result ; on mucous membranes, which are naturally moist,
mucous patches occur. Hence mucous patches may be
expected in the mouth or on the fauces, condylomata in the
creases below the breasts, in the groins, in the axillae, between
the toes, between the auricle and the mastoid, at the anal margin,
rarely at the umbilicus and in other positions.

The tongue, which, from its position and functions, is
constantly liable to slight injuries, and is covered by a thick layer
of moist epithelium, may become the seat of refractory secondary
manifestations. Laryngeal lesions are more protected, and not
so liable to ulcerate as are lesions nearer the mouth.

The involvement of epiphyses and joints admits similar
anatomical explanations to those advanced in connection with
tuberculosis.

It is not surprising that the arterial system, which forms the
tract by which general distribution occurs, should suffer severely.
The actual evidence of vascular disease is rather late in making
its appearance. Endarteritis occurs, and may end in thrombosis,
which causes irretrievable damage to important nervous struc-
tures. The virus, by affecting the vasa vasorum of the larger
vessels, may lay the foundation of aneurysm, or give rise to a

30 CLINICAL APPLIED ANATOMY.

localised ulceration of the interior of the ascending aorta, or
cause a widespread arteriosclerosis.

The manifestations of the tertiary stage of syphilis differ from
those of the secondary stage in their asymmetry. The original
symmetrical distrihution by the blood stream may be said to
have left residual proclivities or possibly infected foci, which in
many instances are stirred up to activity by local accidents or
peculiarities.

When these local inflammations attack tubular structures
the results may be very serious. The posterior surface of the
palate may become adherent to the pharyngeal wall at the level
of the Eustachian tubes ; strictures of the larynx, trachea,
bronchi, or oesophagus may be induced ; the small intestine,
the ileo-caecal valve, and, more particularly, the rectum, may
be similarly affected. .Cerebral arteries may be occluded by a
like process, and strictures of the common bile duct and of
the nasal duct have been met with. The nasal duct, from its
proximity to the nasal bones, may become involved as the result
of disease of the latter.

The irregular areas of caseation, so characteristic of the
gummatous inflammations of the tertiary stage, are the result
of vascular obliteration. At the periphery of a gumma, where
the blood supply is less interfered with, organised fibrous tissue
will be found. A gumma, which by situation is exposed to
injury or to the access of septic organisms, is liable to soften
and to ulcerate. Gummata in the subcutaneous tissues, in
the mouth and in the pharynx may be given as examples of this
tendency. In the deeper and more protected viscera such
changes are rare. Tertiary visceral syphilis is commonest in
the liver and the spleen. The liver suffers more frequently
than other organs, possibly because its greater size increases the
possibility of infection. It is also liable to slight injury by the
overlying ribs. Liver gummata tend to result in depressed
cicatrices, and these are often met with on the surface of the
organ.

The tendency of subcutaneous gummata to ulcerate has been

TEETIAEY SYPHILIS. 31

mentioned. Gummatous ulcerations are common in parts exposed
to injury and pressure, such as the tissues around the lower
part of the knee, on the buttocks, and over the sacrum.

With regard to bones, the most vascular and cancellous
and those which are exposed to injury from their position are
liable to suffer. The proclivity to inflammation of the spongy
vascular bones of the nasal cavity, of the palate, of the vertex
of the skull, and even of the spinal column, is well known. The
tibiae and the clavicles, which are bones especially exposed to
injury, are [)rone to gummata. It is possible that the attach-
ment of powerful muscles to bone and periosteum may determine
the incidence of syphilitic nodes, for example the clavicular
origin of the greater pectoral, the attachment of the calf muscles
to the lower end of the femur, and the insertion of the masseter
into the mandible. The persistency of the bone pains in gum-
matous periostitis may be explained by the tension of the
resisting periosteum, whilst the pains which accompany bone
sclerosis are due to increasing pressure on the nerves which lie
in the contracting Haversian canals. Syphilitic necrosis is
brought about by vascular occlusion, due to pressure and to endar-
teritis. The nasal deformities of syphilis are explained by the
destruction of the supporting bone and cartilage of the septum,
and in child ]*en also by retarded growth of the inflamed
structures.

Bursae, by virtue of their functions, are exposed to pressure,
and those which are most exposed are most likely to show
syphilitic manifestations. In persons who kneel much the
prepatellar bursae may become gummatous ; in those who sit
much the bursae over the ischial tuberosities may become
similarly diseased. Other bursae likely to suffer are those about
the insertions of the muscles on the inner side of the leg below
the knee, those over the great trochanter, and the bursae between
the ilio-psoas muscle and the hip-joint.

Syphilis may affect the central nervous system in various

ways. Arterial disease, gummatous and sclerosing inflamma-

ions of the interstitial tissues, and primary degenerations of

32 CLINICAL APPLIED ANATOMY.

nerve elements all occur. Arterial disease leads to softening of
the parts supplied ; the arteries most affected are the large
trunks at the base of the brain, and it is possible that their
relation to the bony base of the skull has some bearing on their
liability to suffer. Gummatous inflammation of the meninges
will cause various and erratic forms of cranial nerve paralysis.

CHAPTEE III.
GANGEENE, BUKNS AND SCALDS.

Gangrene may in general be said to be due to (1) obstruction
to veins alone, (2) obstruction to arteries alone, (3) obstruction
to both veins and arteries, and (4) obstruction to capillaries.

Gangrene occurs much more commonly in the lower extremity
than in the upper, this being due to the fact that the farther
removed a part; is from the heart, the less vis a tergo there is to
drive blood to it, and the greater the difficulty of return of blood
from it. The least vascular structures, such as fascial and areolar
tissue, slough most readily.

Obstruction to Veins alone is not often seen in the extremities,
but a typical example is the death of a loop of intestine in
strangulated hernia. Here the pressure from without, while not
sufficient to cut off the entrance of blood through the arteries, is
ample to prevent the proper return through the veins : hence
the tissue of the bowel becomes more and more congested and
deprived of its proper nutrition in consequence of the inter-
ference with the circulation through its vessels, and gangrene
will inevitably result if the pressure is not removed early
enough.

Septic thrombosis of the main venous channel of a limb, as,
for instance, of the common femoral or of the subclavian vein, may
lead to rapid moist gangrene, but slowly formed aseptic clotting
within the vessel may merely tend to passing or perhaps
permanent venous congestion.

Obstruction to Arteries alone is perhaps most commonly due to
emboli which, becoming detached from the heart, block the vessel
at certain points. Should the occluded artery be a terminal or
end vessel, with no collateral anastomosis, gangrene is almost
inevitable. A good example is that of embolic obstruction of

C.A.A. 3

34 CLINICAL APPLIED ANATOMY.

the superior mesenteric artery, as a result of which the blood
supply of a portion of the small intestine is suddenly arrested,
often leading to symptoms simulating mechanical intestinal
obstruction.

Embolism in main arteries with anastomoses most usually
occurs at points where the vessels bifurcate : for instance, the
common femoral may be blocked at the spot where the deep
femoral arises, or the brachial may be occluded where it divides
into the radial and ulnar. The embolus may also be arrested by
the curvature of an artery opposite the flexure of a joint, as, for
instance, in the popliteal trunk behind the knee. The greater
the anatomical difficulties in the way of opening up a collateral
circulation, the greater is the likelihood of the supervention
of gangrene. Main arteries may also be temporarily or per-
manently obstructed by external pressure, particularly in the
case of unreduced fractures and dislocations. This is well seen
in the instance of pressure upon the popliteal artery by the lower
posteriorly flexed fragment in transverse fracture above the
condyles of the femur.

Atheroma of an artery may lead to its obstruction, owing to
thrombosis being induced by the roughening of its internal coat.
This, however, is unlikely except in the case of the medium sized
vessels of the lower limb. Arteritis obliterans may further be
the cause of the onset of gangrene in both the lower and the
upper extremity.

The line of demarcation in gangrene which has resulted from
arterial embolism, or from occluding arterial disease, is deter-
mined by the anatomical arrangement of the arterial tree. An
embolus, being likely to lodge at a point of bifurcation, will, if
the vessel be completely occluded and no collateral circulation
be possible, give rise to death of the tissues thus deprived of
their blood supply. Therefore the line of demarcation may
be expected at the lower limit of the last branches derived
from the trunk above the obstruction. For instance, if the
popliteal artery be occluded at its point of division, a line of
demarcation may form in the upper third of the leg. If an

GANGEENE. 35

embolus be small enough to pass into one of the tibial vessels
the collateral circulation is usually sufficient to preserve the
vitality of the leg. When arterial disease is present the smaller
branches are likely to be occluded first, hence in the lower limb
gangrene of toes may occur, or the line of demarcation may
form just below the ankle joint, or, if the disease be more exten-
sive, both tibial arteries may be occluded and the popliteal still
patent owing to its greater calibre. The conditions will then
approximate to those present in embolism mentioned above.

Besides the toes and the feet the skin of the middle third of
the front of the leg, being exposed to slight injuries, is liable to
become gangrenous in old people in whom the circulation is
feeble and the arteries are narrowed.

Obstruction to both Veins and Arteries. — This is by no means
an infrequent cause of death in the periphery. It is perhaps most
typically seen in the instance of gangrene following upon liga-
ture of the superficial femoral artery for the cure of a popliteal
aneurysm. The aneurysmal sac itself has pressed upon the accom-
panying vein, and has thus given rise to more or less congestion
of the parts below. The blood flow through the main artery is
then suddenly arrested, and the vis a tergo, which before the
ligation of the artery was only barely sufficient to return the
blood past the obstruction in the vein, now completely fails to do
so. In consequence, the distal portion of the limb becomes
greatly congested and nutrition interfered with, and moist
gangrene may result. It is possible also for the aneurysmal sac
to so press upon the surrounding articular arteries as to interfere
very seriously with the anastomotic circulation.

Obstruction to Capillaries. — The cessation of the flow of blood
in the capillaries is most commonly brought about as a result of
certain anatomical dispositions.

The first of these is the distance of the capillaries from the
central pump, the heart. The flow of blood through the minute
vessels in a weakened state of the force of the heart's systole may
become slower and slower till at last stasis ensues, and if this is
prolonged, gangrene sets in. Such a condition is seen in certain

3—2

36 CLINICAL APPLIED ANATOMY.

instances of so-called senile gangrene, where, however, arterial
disease is usually present, and perhaps more typically in
that symmetrical peripheral gangrene known as Eaynaud's
disease, in both cases the smaller arterioles and capillaries are
obstructed by clot following stasis. Senile gangrene begins
almost always at the extreme periphery of the lower extremity,
namely, in the toes. These are the farthest off of any part from
the heart, and a slight traumatism, such as the cutting of a corn
or the pressure of an ill-fitting boot, determines a lessening
of resistance which, with the poor circulation, induces death of
the area.

Eaynaud's disease is most frequently seen at the end of the
upper extremity in the fingers^ parts which, although nearer the
heart than the toes, are perhaps more frequently exposed from
their uncovered condition to the effects of cold. So also are the
tips of the ears and the nose, which may likewise suffer in this
disease.

The gangrene induced by frost-bite is due to the cessation of
circulation in the terminal vessels, and again is seen almost
entirely in the extreme peripheral parts, and particularly those
subjected to most exposure — the toes, fingers, ears and nose.

The loss of large quantities of blood may so retard the circula-
tion that gangrene may result in the extremities, and for the same
reason, when the carotid artery is tied after severe haemor-
rhage hemiplegia from anaemia of brain tissue is to be expected.

The second anatomical consideration is that parts exposed to
pressure, especially if that pressure be long continued, are
extremely liable to necrosis. Inflammatory exudations under
firm fasciae and under the periosteum of bones may give rise to
sufficient pressure to induce gangrenous or necrotic processes.
It is from pressure that bedsores occur over bony points in patients
who have to remain in one position for some length of time.
Pressure sores may also be caused by the application of a splint
not sufficiently padded, where it comes in contact with bony
points. In association with this may be mentioned the not very
infrequent occurrence of a sore at the posterior part of the heel

BUENS AND SCALDS. 37

during the splint treatment of fracture of the bones of the leg.
In this instance the thin amount of soft tissue covering the heel
is compressed between the os calcis and the splint, and therefore
dies. The same process may occur on the back of the forearm or
wrist from splint pressure.

The spreading gangrene due to infectious processes may be
classified with that due to capillary obstruction, although the direct
action of toxins on the tissues also plays a part in its production.
Such gangrene tends to spread by virtue of its cause, and does
not show halting places determined by vascular arrangements
such as have already been described when dealing with gangrene
due to occlusion of arterial trunks.

In states of obstructed or much enfeebled circulation, microbic
invasion of tissues may occur and lead to necrotic or gangrenous
processes. These processes are common in strangulated gut,
and may also be seen in the mucous membrane of the mouth, and
as the result of slight injuries of the integument of the extremities
in old people.

BUENS AND SCALDS.

In burns of the third degree where there is partial destruction
of the true skin, the nerve endings are exposed, and consequently
great pain is induced.

Burns involving the surface of the trunk are more dangerous
than those of the limbs, possibly because of the irritation of
nerve terminations which are in close connection with important
centres.

Parts which are insensitive from lesions of the sensory nerves,
or in a patient still unconscious from the administration of an
anaesthetic, are very liable to be burnt from the too close applica-
tion of hot water bottles, and this is peculiarly prone to happen
in the lower extremity.

It is doubtful whether ulceration of the first part of the
duodenum is at all a frequent complication of extensive burns,
even those of the trunk, when the case is kept free from septic

38 CLINICAL APPLIED ANATOMY.

infection. Absorption of toxic products from septic regions after
the destruction of skin by heat, and their excretion with the
bile into the duodenum, embohsm of an artery of the mucous
membrane of the duodenum and subsequent action of the gastric
secretion on the bloodless part, and over-activity of Brunner's
glands after destruction of many of the sebaceous glands of the
skin, have all been put forward as explanations of the origin of
the ulcer.

It is important to bear in mind that scalds of the mouth and
fauces may be followed by oedema of the aryteno-epiglottidean
folds surrounding the superior opening of the larynx, causing
severe dyspnoea necessitating tracheotomy.

All burns or scalds which have involved the true skin or deeper
structures are apt to be followed by contraction, which in certain
positions may lead to very marked deformity and disorganisation
of the functions of the part. This is particularly so in the
flexure of joints, as for instance when the sleeve of a dress has
caught on fire, and the skin of the bend of the elbow is destroyed ;
the resulting contraction will then effectually prevent proper
extension of the elbow. A burn involving the front of the upper
part of the neck may induce such contraction as to draw down
the chin and the mandible together with the lower lip towards
the sternum, and thus seriously interfere with the closure of the
mouth and with mastication.

CHAPTEE IV.

SPECIFIC FEVEES.

Typhoid Fever.

The bacilli of typhoid fever usually gain access to the body by
way of the digestive tract, and find their first nidus in the
aggregations of lymphoid tissue which are situated in the lower
part of the small intestine. Since the ileum occupies the lower
and right divisions of the belly cavity, it is in the right iliac
fossa that gurgling and tenderness are most) apt to occur during
the course of typhoid fever. The shape of a typhoid ulcer
is determined by the distribution of the lymphoid patch in
which it arises ; hence, when it is situated, as is commonly the
case, in an agminate gland (Peyer's patch) the ulcer is elongated
in the direction of the long axis of the gut, and situated at that
part of the circumference of the bowel which is most remote
from the attachment to it of the mesentery. Ulcers originating
in the solitary glands of the bowel may have a rounded outline
and occur at any part of the bowel circumference. Ulcers of
irregular shape may result from the fusion of smaller ulcers or
the partial necrosis of an agminate gland. Although for some
reason, possibly the stagnation of intestinal contents above the
ileo-csecal valve, ulcers are usually more or less limited to the
lower part of the ileum, yet the lymphoid nodules in other parts
of the bowel may become involved. Thus ulcers have rarely
been discovered in the duodenum, sometimes in the jejunum,
more frequently in the appendix vermiformis and the large
bowel, the whole extent of which may be involved in exceptional
cases.

The great quantity of lymphoid tissue at the point of entrance
of the ileum into the colon accounts for the widespread ulceration

40 CLINICAL APPLIED ANATOMY.

often found at the termination of the small bowel, and a similar
explanation holds for the extensive involvement of the caecum
in some cases. Owing to the longitudinal axis of the ulcers,
stricture rarely results as a sequel of typhoid ulceration.

The fact that the lymphoid aggregations of the bowel have their
bases set in large lymph sinuses accounts for the readiness with
which the mesenteric glands and retroperitoneal glands become
swollen during the progress of the disease.

The lower part of the ileum is the common site of perforation
in typhoid fever. The richness of the lymphoid collections, the
free mobility, and the peristalsis necessary to overcome the
resistance of the ileo-csecal valve, sufficiently explain the
frequency of perforation here. The large bowel has thicker
coats, less lymphoid tissue, and is less likely to be ulcerated ;
consequently perforation is uncommon. Although the accident
has been known to occur in the ascending and in the transverse
colon, yet it appears to have been found more frequently in
the pelvic segment. This portion of the colon has a full
mesentery, is constantly varying in position with alterations in
distension of the urinary bladder, and is in close proximity to
the sphincters guarding the anus. The conditions therefore are
similar to those which obtain at the lower part of the ileum.

Haemorrhage from the bowel in typhoid fever is usually the
result of the erosion of small vessels derived from the terminal
branches of the superior mesenteric artery. The terminal
arteries of the small bowel encircle the gut, reaching the bowel
in the mesentery ; at first they run for a short distance imme-
diately beneath the serous coat, then they perforate the muscular
layers and run in a deeper plane. It is obvious then that ulcera-
tion of Peyer's patches will sooner open an arteriole than
would ulceration nearer the mesenteric border of the intestine.

The specific organism readily gains access to the blood stream,
and thus not only becomes widely distributed in the body, having
been found in the gall bladder, bones and cerebral meninges, but
also produces special vascular lesions. Typhoid phlebitis with
thrombosis is the most important immediate lesion. Thrombosis

TYPHOID FEVER 41

is more common in the lower limbs and in the left femoral vein or
its popliteal and saphenous tributaries than elsewhere. This
proclivity of the left side is partly explained by the fact that the
left common iliac vein, which receives the blood from the left
lower extremity, is crossed near its termination by the right
common iliac artery, and thus the circulation may be impeded.
Clot extending along one common iliac vein may ultimately block
the veins of both lower limbs.

When arterial thrombosis occurs it is usually in the femoral or
popliteal arteries, both of which may be considered liable to slight
injury where they cross the joint flexures. From obstruction
in smaller vessels peripheral gangrene may occur. Parts liable
from their anatomical situation to suffer in this way are the feet,
ears, nose, penis, labia, cornese, etc.

Clots detached from the veins may be carried through the right
heart and produce pulmonary embolism, and the same accident
may occur when a thrombus in the right heart is detached by
some undue exertion and becomes impacted in the pulmonary
artery in a coiled-up form.

Difi'use arteriosclerosis may show itself in later life as the
result of the vascular infection which occurs in typhoid fever.

The lenticular rose spots are of vascular origin. They probably
depend upon capillary infections and paralysis. The bacilh can
be obtained from the spots and the eruption is not seen after
death.

Typhoid osteitis and periostitis is said to occur by preference
in the regions of the epiphyses in young people in whom these
parts have an extraordinarily free blood supply. In adults, the
tibiae, femora, sternum and ribs are most frequently attacked
because the tibiae in particular are exposed to injury, and the
sternum and ribs are very vascular. The spine is sometimes
invaded.

Laryngeal ulceration in typhoid fever is found in those parts
of the larynx which are said to be freely supplied with lymphoid
tissue. The ulcers are apt to occur at the base of the epiglottis,
on the posterior wall of the larynx, on the false cords, between

42 CLINICAL APPLIED ANATOMY.

the arytenoid cartilages and at the posterior extremities of the
true vocal cords. The ulceration at the base of the arytenoid
cartilages from its position may invade the perichondrium of the
cricoid and lead to the exfoliation of this cartilage.

Peritonitis in typhoid fever is an invasion by contiguity. It
usually arises in consequence of the perforation of the bowel, but
may possibly arise from bowel without actual perforation in some
cases. Infarction and abscess of the spleen, suppuration in
mesenteric glands, ulceration and perforation of the gall-bladder,
and abscesses in other parts such as the ovary, rectus abdominis,
the sheath of which is deficient posteriorly in its lower part, and
the urinary bladder may all be the cause of peritoneal infection.

From the relation of the ulcerated bowel to the portal tribu-
taries it is easy to see how portal pyaemia and liver abscesses may
arise as complications. The cholecystitis of typhoid fever is
probably due to blood infection, but it is conceivable that an
ascending infection along the bile duct might occur.

Otitis media as a result of typhoid fever is more common in
children than in adults. The reasons for this are given below
when dealing with scarlet fever. Extension of infection from the
mouth along the parotid ducts gives rise to parotitis. Ulcerations
of the palate and pharynx are also secondary infections from the
mouth.

Certain muscles are apt to rupture in the course of the
fever. Muscular degeneration is the basis for this, but no doubt
mechanical factors come into play. The muscles which are most
likely to give way are the rectus abdominis, the adductors of
the thigh, the psoas or the pectorals.

Bed-sores, being due to continued pressure on debilitated
tissues, are likely to occur where bony prominences have a
scanty tissue covering ; hence they may occur over the sacrum,
the trochanters, the points of the heels, front and outer side of
the knees, elbows, shoulders, malleoli, scapulae, and the anterior
superior spines of the ilia.

The bacilli may be eliminated in large numbers through the
kidney, and thus involve the renal pelves, the ureters, and the

SCAELET FEVEE. 43

urinary bladder. Urethritis and orchitis, which occasionally occur
in typhoid fever, are possibly to be explained as direct secondary
infection, via the urethra, and vas deferens, or as descending
typhoid infections from the kidney ; but the orchitis is possibly
a blood-borne infection.

Scarlet Fever.

Although the virus of scarlet fever may obtain access to the
body through wounds, burns, or the raw surfaces left as the
result of recent childbirth, yet the common portal of entry is the
lymphoid tissue of the faucial and naso-pharyngeal tonsils.
When the resulting inflammation is considerable, the swollen
pharyngeal tonsil tends to block up the posterior nares, and to
obstruct nasal breathing. The secretions escaping by the nose
appear in the form of an irritating rhinorrhoea, which excoriates the
skin of the upper lip. At the same time the swollen faucial tonsils
interfere with deglutition and mouth breathing. Intense inflam-
mation may culminate in widespread local destruction of tissue.

Early enlargement of the lymphatic glands in connection with
the fauces and nasopharynx may be expected. This primary
adenitis is due to infection, conveyed by lymphatics, and appears
in the form of tender submandibular swellings. The glandular
infection may be of mixed character, since the buccal, nasal and
pharyngeal cavities are liable to become centres of secondary
infection by reason of their exposure. The virulence of the
infection from the throat may be such that a periadenitis, and
even diffuse suppuration in the connective tissue planes of the
neck may result. When such extension occurs thin-walled veins
may be opened by ulceration, but the arteries, protected by their
thickness, usually escape. The oedema of the eyelids, which
often accompanies the adenitis, is explained by the fact that
their lymphatics traverse glands of the affected groups.

The scarlatinal rash is a manifestation of vascular infection,
and is due to distension of small blood-vessels in the true skin.
The rash is at first minutely papular and discrete. This punctate
arrangement does not appear to be determined by the presence

44 CLINICAL APPLIED ANATOMY.

of hair follicles, but is probably due to some anatomical arrange-
ment of the vessels of the skin. The well-known area of
circum-oral pallor, bounded laterally by the naso-labial folds
and below by the point of the chin, corresponds to a definite
thickening of the skin around the mouth, the transition from the
thin skin of the cheeks to the thick skin of the circum-oral zone
taking place at the naso-labial lines. A more marked thickening of
integument is found in the palms and soles, localities where the
rash is also wanting. It seems reasonable to believe that the
uniform diffuse character of the eruption on the face, in contrast
to its punctate appearance elsewhere, has some relation to the more
superficial distribution of the free vascular supply to the '' flush-
area." The arteries of this area are mainly unnamed branches of
the posterior aspect of the facial trunk, and lie more superficial
than the named facial branches. The scarlatinal rash is most
intense in the regions where flexures of the skin naturally
occur, such as the axillge, elbows, wrists, groins and knees. In
these situations small linear hgemorrhages may often be seen.

On the outer aspects of the upper arms, and on the outer sides
of the thighs and legs, the skin normally presents coarse papules;
these are brought into prominence by scarlatinal injection, and
do not fade so readily as the rash elsewhere. A certain amount
of exudation accompanies the fully developed rash, and it is
this exudation which lays the foundation of the subsequent
desquamation. The peeling roughly follows the order of
appearance of the rash, but occurs earlier where the cuticle is
very thin, especially in those parts which from their situation
are subject to friction. The tongue being exposed to friction
and moisture begins to peel at its tip and edges within twenty-
four hours, bringing its vascular papillae into greater prominence ;
friction of the night-dress determines early peeling about the
lower part of the neck and adjacent parts of the chest ; the lobules
of the ears and the cheeks coming into contact with the pillow,
early show a fine powdering. The thick skin of the palms and
soles, and particularly that of the heels, is the last to be shed,
and comes off in larger flakes.

SCAELET FEVEK. 45

Certain anatomical points are worth noting as bearing on the
compHcations of scarlet fever.

The possibility of the buccal, nasal and pharyngeal cavities
acting as foci of secondary infection has already been alluded to.

The secondary adenitis involves that group of glands which is
in anatomical connection with the fauces and nasopharynx.
Swelling of these glands sometimes immediately precedes the
onset of acute nephritis, and there appears to be some connection
between the two phenomena.

The otitis media is due, like that which occurs in measles, to
extension of infection along the Eustachian tube. The remark-
able limitation of this complication to childhood is explained by
the shortness of the tubes in early years, by their nearer
proximity to the tonsil at this age (they open at the level of the
hard palate) and to the greater liability of the nasopharynx to be
blocked by adenoid tissue. Under these adverse circumstances
the cilise of the tubes fail to protect them. The parotid lymph
glands, which receive lymphatics from the tympanum, may
become swollen as the result of otitis media.

In childhood the air spaces of the mastoid are very superficial,
and may actually communicate with the surface, so pus may
make its way outwards below the periosteum. Pus superficial to
the periosteum may be derived from a suppurating mastoid
lymph gland.

The broncho-pneumonia of severe scarlet fever is explained by
the nearness of the glottic aperture to the faucial inflammation,
and the consequent aspiration of infective discharges from the
nasopharynx.

The distribution of scarlatinal inflammation in the kidneys
is mainly influenced by vascular arrangements. The typical
nephritis is chiefly, but not exclusively, glomerular.

The localisation of what is known as the " septic rash " appear-
ing in scarlet fever is largely determined by pressure ; it is found
on the extensor aspects of the elbows and knees, but is also seen
on the cheeks and buttocks.

Irritating discharges from the nares, angles of the mouth and

46 CLINICAL APPLIED ANATOMY.

eyes, and the external auditory meatus, account for the distribu-
tion of the eczematous areas found in these locaHties. The
difficulty in cleansing the recesses of the ear, nose, fauces and
accessory air sinuses explains the long-continued infectivity of
discharges from these places.

Diphtheria.

This disease is one which attacks mucous surfaces, and, being
due to infection from without, it infects the nose, naso-pharynx,
fauces, pharynx, or larynx primarily. The subsequent extension
of its membranous manifestations is usually determined by the
continuity of parts. Thus, in bad cases membrane may spread
through the larynx, along the trachea, bronchi, and bronchioles ;
the ear may be invaded through the medium of the Eustachian
tube, and the conjunctiva by way of the nasal duct. In excep-
tional cases false membrane may spread down the oesophagus
and even be present on the mucous coat of the stomach. The
lachrymal secretion and protective muscular mechanisms of the
eyelids no doubt largely account for the general immunity of the
conjunctiva, whilst the mechanism of deglutition and motor
activity of the stomach may be held responsible for the common
escape of the oesophageal and gastric mucous membranes.

The mucous surfaces of the vulva, vagina and anus are some-
times, though rarely, the site of primary invasion. The same
parts may become involved during the progress of faucial diph-
theria, probably by infection conveyed by the fingers. In addition
to spread by continuity, the tissues of the body are invaded by the
toxin of diphtheria by the medium of the blood-vessels and lym-
phatics. The characteristic bacilli may be conveyed by lymphatics
to the glands, which drain the area primarily involved, or gaining
access to the blood-vessels, may become deposited in such
viscera as the spleen, liver and kidneys. As a general rule,
however, the bacilli remain localised at the point of infection
and parts contiguous to this, and it is the toxin alone which
circulates. The bacilli which are occasionally found in the lung
alveoli have passed along the respiratory passages.

DIPHTHEEIA. 47

Skin is an effectual barrier to diphtheritic infection, but
wounds or raw surfaces may be attacked.

When diphtheria attacks tissues which are naturally lax, con-
siderable oedema may accompany the formation of false membrane.
(Edematous swelling may therefore occur in the fauces, soft
palate, uvula, and superior opening of larynx. Occasionally
destructive ulceration of the same parts is met with.

Diphtheria may prove dangerous either from the mechanical
suffocative effects, which depend upon the localisation of the
membranous exudation, or from toxaemia, which is dependent
upon absorption.

Suffocative symptoms are produced when the larynx, trachea,
bronchi or bronchioles are involved. Of these the larynx is the
first affected by virtue of its position, and its involvement
produces urgent symptoms on account of the ease with which
the upper laryngeal aperture is occluded by membrane and
oedema. Even after tracheotomy it is often possible to observe
the deadly effect of occlusion of the lower air passages.

Toxic symptoms in diphtheria are determined by two factors :
first, the extent of the membranous exudation, and, secondly,
the facility with which absorption can take place. The
comparative harmlessness of membrane limited to the nasal
cavities may possibly be due to lack of facilities for absorption.
There are abundant indications that free absorption takes place
in the regions of the nasopharynx and fauces.

The arrangement of the lymphatics of the air tubes renders it
probable that but little lymphatic absorption takes place in the
trachea and bronchi, where the basement membrane completely
cuts off the deep lymphatics from the surface lining of the tubes.

The local lymphatic glandular swelling in diphtheria has
already been alluded to ; the inflammation when it spreads
outside the glandular capsules may give rise to a brawny infiltra-
tion of the connective tissues of the neck. It is stated that the
parotid and submandibular salivary glands may become inflamed
in diphtheria ; when this really occurs it is presumably due to
an extension of infection from the mouth along the ducts of the

48 CLINICAL APPLIED ANATOMY.

glands in question. It is well to bear in mind that lymphatic
glands are so intimately related to the parotid and submandibular
salivary glands that they may almost be said to be embedded in
them, and clinically it may be very difficult to distinguish
lymphatic glandular from salivary glandular swellings.

The albuminuria and neuritis of diphtheria are probably both
the results of toxins, carried by the blood stream.

Measles.

This highly infectious disease chiefly manifests itself in the
respiratory tract and the skin. The appearance of Koplik's spots
on the buccal mucous membrane affords the earliest evidence of
the infection. The distribution of these spots is in some way
influenced by position, for they usually occur on that part of the
buccal mucous membrane which is in contact with the teeth, and
so are best seen by drawing the cheek away from the molar teeth
and by everting the lips.

Catarrh of the mucous membrane of the nose inducing sneezing,
and of the eyes causing photophobia, appears quite early. This
catarrhal condition rapidly extends locally ; by invasion of the
frontal sinuses it causes frontal headache, by spreading to the
fauces and mouth it gives rise to a patchy redness, which is
followed by congestion and swelling of the tonsils, soft palate,
uvula and pharynx. Further extension involves the larynx,
trachea, bronchi, bronchioles and even the alveoli of the lung.
In some cases the brunt of the catarrhal affection falls upon the
larynx in the early stages, and coryza is insignificant. Laryngeal
diphtheria is then closely simulated.

The Eustachian tube being in direct continuity with the naso-
pharynx provides a path for the extension of the catarrh to the
tympanum. Deafness, earache and suppuration may result, and
the foundation thus laid for more serious complications such as
mastoid disease, sinus thrombosis, pyaemia, meningitis or
intracranial abscess.

The primary involvement of the respiratory mucous membrane
explains the great infectivity of measles in its early stages.

MEASLES. 49

The occurrence of diarrhoea, and sometimes of an ileo-colitis
with passage of blood and mucus, points to an affection of the
mucous membrane of the digestive tract.

It appears probable that the virus is disseminated in the body
by means of the blood stream. This conjecture is strengthened
by the fact that the children of mothers suffering from measles
are sometimes born with the rash fully out. Moreover, the
eruption is itself produced by vascular congestion and small cell
infiltration. The congestion and infiltration are best marked in
the neighbourhood of the vascular papillae of the skin, and the
resulting infiltration of the subcutaneous connective tissue is a
very characteristic phenomenon of the disease. Subcutaneous
haemorrhages are not of very serious import in measles. There
is evidence that the supporting vascular stroma of the lung is
affected in a manner similar to the skin, giving rise to a special
form of interstitial pneumonic infiltration.

Further evidence of the circulatory spread of the disease is
occasionally forthcoming in the form of various nervous affections.
Convulsions, delirium, coma, hemiplegia, myelitis, lateral column
symptoms, peripheral neuritis and transitory insanity have all
been known to occur. The myelitis has been found definitely
associated with vascular lesions.

The lymphatic glands undergo a moderate enlargement in
measles, the submandibular, occipital, tracheo-bronchial, and
sometimes the axillary and inguinal groups being involved. The
glandular enlargement occurs early, and is usually slight and
transitory, but the bronchial glands in particular appear to be
rendered prone to tuberculous infection as a result. Often,
slight splenic enlargement accompanies the enlargement of the
glands. The enlargement of spleen and glands is probably the
consequence of blood infection.

Those parts of the body which are liable to bacterial infection
from without are prone to suffer severely from secondary infec-
tions following measles. Thus the gangrenous process known as
noma occurs as a sequel, both in the cheek and on the vulva ;
secondary laryngeal and pulmonary affections constitute the

C.A.A. 4

50 CLINICAL APPLIED ANATOMY.

great danger of the disease, and the production of otitis media
has ah'eady been alluded to.

German Measles.

Most of what has been already stated about measles also
applies to German measles, but it must be remembered that the
latter is almost always a much milder and usually uncomplicated
disease. Two points of difference stand out : Koplik's spots do
not occur in German measles, and the lymphatic glandular
swelling is usually more marked. The glands chiefly involved
are the occipital, the mastoid and the concatenate groups, but the
submandibular, the axillary and the inguinal glands may also be
enlarged. In exceptional cases the glandular enlargement may
precede the general symptoms for several days.

Mumps.

It is highly probable that the infection of mumps gains access
to the salivary glands by way of their ducts, the parotid glands
being invaded along Stenson's ducts, and the submandibular
along Wharton's ducts. The fact that swelling of the second
parotid gland often occurs a few days after that of the first is in
favour of ascending duct infection.

The only anatomical connection of the salivary glands with
the pancreas, testicles, ovaries and breasts is that effected by the
blood stream, so it is assumed that it is by this channel that
inflammation of these organs arises as a complication.

The parotid swelling in parotitis corresponds exactly to the
position of the gland, and so may be distinguished from inflam-
matory swelling of the small lymphatic glands which lie close to
or are actually imbedded in the parotid. The inflammatory swell-
ing obliterates the sulcus between the mandible and the sterno-
mastoid muscle ; extends forwards on the masseter towards the
face corresponding to the anterior part of the gland and its socia,
and pushes the lower part of the auricle outwards from the head
so that the lower part of the ear lies over the central part of the

ACUTE EHEUMATISM. 51

swelling. The raising of the auricle from the side of the head is
very characteristic of parotid swellings. The denseness of the
facial envelope which the gland receives from the deep cervical
fascia accounts for the great pain and for the absence of inflam-
matory redness from the skin over the surface. The close
proximity of the gland and of its glenoid lobe to the posterior
aspect of the mandible, the wedging of the swollen pterygoid lobe
between the pterygoid muscles, and the continuity of the parotid
fascia with that over the masseter, account for the pain which
accompanies all masticatory movements. The relation of the
gland to the under wall of the auditory meatus, and the frequent
presence of defects in this bony lamina, explain perhaps the
occasional extension of inflammation to the tympanum, but the
Eustachian tube always offers a direct route for infection of the
ear from the mouth. It is said that the so-called " carotid lobe "
of the gland, whic his prolonged inwards towards the great vessels,
may give rise to pressure on the jugular vein, and so produce
circulatory disturbance within the skull. The intimate relation
of the swollen gland to the sterno-mastoid muscle causes stiffness
of the neck, that part being rigidly fixed to avoid pain. The
inflammation occasionally extends to the facial nerve which is
embedded in the gland, and produces some degree of facial
paralysis.

Acute Eheumatism.

Inflammation of the fibrous structures of the body is very
characteristic of rheumatism, and, although in adults the cap-
sules of the joints chiefly suffer, rheumatic manifestations are
common in the tendons of muscles, in fasciae and other structures
consisting chiefly of connective tissue, such as the pericardium
and pleura.

Articular rheumatism chiefly attacks the larger joints, the
wrists, elbows, ankles, and knees being particularly liable to
suffer, but no joint is immune. The resulting swelling and the
accompanying erythema of the skin are most apparent in those
joints which are superficial and thinly covered. Consequently

4—2

52 CLINICAL APPLIED ANATOMY.

joint swelling and surface redness are best seen in rheumatism of
the hands and feet, of the ankles and wrists, and of the elbows
and knees. By examining superficial joints it may be obvious
that the swelling is not strictly limited to the joint cavity, but
also involves the periarticular structures, and sometimes the
surrounding tendon sheaths. In joints, such as the hip and
shoulder, which are deeply seated and surrounded by muscles,
the objective signs of rheumatism may be limited to muscular
rigidity.

The attitude assumed by a patient suffering from articular
rheumatism is determined in great degree by the joint effusion
and consequent joint tension. The position of greatest joint
capacity and least joint tension is assumed. Hence the knees
and elbows are flexed when inflamed, whilst the ankles and
wrists are extended, and there is some tendency for the hand to
be deviated towards the ulnar side.

Rheumatism may influence the gait quite apart from articular
affection. In children a peculiar form of progression on tip-
toe with flexed knees may sometimes be met with, and is attri-
buted to rheumatic inflammation of the tendons of the hamstrings
and their surrounding structures. A transitory limp, at first
closely resembling that of tuberculous hip disease, may be seen
when the fibrous structures around the hip-joint are involved.
Wry-neck is the expression of the inflammation of the fibrous
structures of the cervical region, and occasionally retraction of
the head results from the same cause. The broad lumbar fascia,
which gives origin to the erector spinse, the gluteus maximus,
the latissimus dorsi, and other muscles, when inflamed by rheu-
matism may be the seat of agonising pain readily provoked by
movements of the trunk, thigh, or arm.

The subcutaneous nodules of rheumatism have a great tendency
to form over thinly covered bony points, and so may at times
be found in the following situations : about the olecranon process,
the margins of the patellae, and the malleoli of the ankle ; along
the vertebral spines, the clavicles, the iliac crests, the temporal
ridges, and the superior curved line of the occipital bone.

GOUT. 53

Forms of interstitial neuritis and of interstitial myositis are
also described in connection with rheumatism. Inflammation of
the sclerotic coat of the eye and of the iris may occur.

Not only are the fibrous structures of the heart, such as the
valves and pericardium, liable to rheumatic inflammation, but
the myocardium may also be affected, and here it is said the
inflammation is not necessarily of interstitial or fibrous origin.

Gout.

Clinically the likeness of acute polyarticular gout to acute
rheumatism is striking, and the lesions of chronic gout are
distributed in the body in a manner similar to those of the more
chronic forms of rheumatism.

Gout not only manifests itself as an arthritis, but also invades
the cartilages and fibrous tissues of other parts of the body.
Such structures as ligaments, tendons, bursse, and the fibro-
cartilaginous helix of the ear, frequently suffer. More rarely
the sclerotic coat of the eye, the fasciae of the palms and soles,
the fibrous basis of the aortic and the mitral valves, the pericar-
dium, the laryngeal cartilages and the vocal cords, the tarsal
cartilages of the eyelids, the cartilages of the nose, the fibrous
sheaths of nerves, and even the cerebral and spinal membranes
are known to become the seats of uratic deposits.

The gouty deposit in a joint first occurs a little beneath the free
surface of the cartilage and at a point near the centre ; it may be
inferred that in this position both the blood and lymph streams
are sluggish. The presence of synovia and of the fluid of tendon
sheaths, both of which contain an excess of sodium salts, is
believed by some to be an important factor in determining the
local deposit of urate of soda.

As a rule gout first attacks the metatarso-phalangeal joint of
the great toe. T^is joint is subjected to considerable strain in
walking, entering as it does into the formation of the inner part
of the longitudinal arch of the foot ; in addition, it is near the
periphery of the circulation, and the arteries in gouty subjects

54 CLINICAL APPLIED ANATOMY.

are frequently diseased. It may be that all these factors conspire
in determining the localisation of gout in the joint in question.
The first manifestation of gout may, however, occur in some
other joint than that of the great toe ; the knee, the ankle, and
the metacarpo-phalangeal joint of the thumb are sometimes first
attacked. These joints are exposed to slight injuries which may
appear to determine the incidence of the inflammation.

After the great toe joints, the articulations most commonly
affected are the joints of the instep, the ankles, the knees, the
joints of the fingers, and the wrists. Less commonly the elbows,
shoulders and hips may suffer. When the joints are superficial,
and thinly covered, as for instance is the case with the great toe
joints, the ankles, wrists, and joints of the thumb and fingers,
the accompanying infiltration and dusky erythema may simulate
an ordinary cellulitis.

The tendency of fasciae, ligaments, and tendons to become the
seats of uratic deposit may be explained by the poor blood supply
afforded to these structures. The tophi are very likely to ulcerate
through the skin if they are exposed to slight injury or constant
irritation. This tendency may be noticed in connection with
gouty deposits in the olecranon bursa, whilst tophi around the
great toe joint may, by ulceration, actually lay open the joint
cavity. Uratic deposit in important bursse and in the tendons
and ligaments of a joint may cripple a limb as effectually as
actual articular gout would.

The deformities produced in the hands by affection of the finger
joints are characteristically irregular, the fingers appearing knotted
and bent like the gnarled roots of an old tree. The great toe
joint becomes deformed and often ankylosed ; the knee and elbow
may become fixed in a flexed position and some degree of rigid
talipes may be also induced.

KiCKETS.

Although bone changes are not the sole lesions in rickets,
they form the most striking feature of the disease, and it is with

EICKETS. 55

them that applied anatomy has mostly to deal. The disease
chiefly manifests itself in the epiphyses. Here the normal pro-
cess of intra-cartilaginous bone formation becomes perverted ;
the layer of proliferating cartilage becomes increased in breadth
and thickness, and the progress of ossification in it is imperfect
arid irregular. The characteristic thickening of the bones is due
to the presence of the imperfectly consolidated cartilage, and so
is found near, but not absolutely at the ends of the bones. In the
long bones the medullary canal also becomes enlarged, the hard
bone is absorbed, and soft spongy bone lying under thickened
periosteum takes its place. In estimating the evidence of rickets
it is well to bear in mind that the ends of the ribs, where they
join their cartilages, are normally slightly enlarged.

The deformities of rickets are produced in various ways. Many
are the results of attitude and pressure, some are due to muscular
action, and others are caused by atmospheric pressure acting in
conjunction with impeded inspiration.

Deformities due to attitude may often be seen in the lower ends
of the tibiae and in the chest. They may also occur at the lower end
of the femur. Children who have not learned to walk often lie or
sit with the lower ends of the tibiae crossing each other ; the ends
of these bones then become bent by mutual pressure, and the
curve of one bone fits accurately the curve in the other. The
tendency of young children with rickets to lie with the forearms
flexed over the front of the chest accounts for the presence of a
longitudinal sulcus at the side of the thorax into which the upper
arm fits, and which at its lower end is often prolonged obliquely
forwards and upwards, corresponding to the position of the fore-
arm. It is believed that a bending inwards of the lower end of
the femur produced by sitting or lying with the knees crossed is
the basis of some cases of knock-knee, whilst in other cases the
lower end of the femur may become so twisted on the shaft that
the knee points outwards.

In children who have learned to walk, an exaggeration of the
normal forward bend of the tibia in its lower parts may be pro-
duced ; the weak point of the bone is at the junction of the

66 CLINICAL APPLIED ANATOMY.

middle and lower thirds of its shaft, and it is here that the
tension of the calf muscles and the weight of the body conspire
to produce the maximum deformity. Similarly the natural
forward and outward curve of the femur may become exaggerated
and softening of the upper part of the shaft, near the trochan-
ters, or of the neck may cause the latter to sink under the
weight of the body, and produce the condition known as coxa
vara.

The mechanism of production of knock knee is disputed, and
possibly not always the same. It may, as already mentioned, be
caused by faulty posture which allows the end of the femur to
bend inwards, or it may be due to laxity of the internal lateral
ligament of the knee joint, which allows the bone to become
separated on the inner side. The deformity is perpetuated by
the unrestrained growth of the adjacent inner parts of the femur
or tibia or of both. This growth is usually supposed to occur
at the epiphysis, but some believe that the diaphysis is at fault.
As a result, instead of the weight of the body being transmitted
through the knee joint and shaft of the tibia to the centre of the
ankle, it falls outside the knee joint, aggravating the deformity
and also inducing flat foot.

The pelvis, when deformed by rickets, usually undergoes antero-
posterior compression ; the weight of the trunk transmitted from
above causes projection of the sacral promontory and flattening
of the cavity. A reniform outline is thus produced. Sometimes,
however, especially if the rickety softening occur after the acquire-
ment of walking, a trefoil pelvis similar to that of osteomalachia
results. This is due to the additional pressure caused by the
indriving of the heads of the femora against the acetabula.

The epiphyses of the upper limb are enlarged first because the
child crawls before learning to walk. The bones of the forearms
may become bent with convexity outwards if the child is in the
habit of supporting the weight of the body with the hands, or of
crawling on hands and knees. The humerus also becomes curved
outwards, the curve corresponding to the point of attachment of
the deltoid muscle.

EICKETS. 57

Atmospheric pressure, acting during inspiration, may drive in
the softened ribs in the neighbourhood of the costal cartilages
causing a lateral sulcus with curved projection of the sternum and
pigeon breast. The action of the diaphragm on the lower six
costal cartilages, to which it is attached, is believed to produce
constriction of the lower thoracic zone, and at the same time the
costal margin is everted by the mass of the enlarged liver, and
also by the enlarged spleen.

An accumulation of imperfectly ossified spongy membrane
bone at the centres of ossification of the parietal and frontal
bones causes an exaggeration of the frontal and parietal emi-
nences. In the parietal bones, and the vertical plate of the
occipital bone, a process of atrophy known as cranio-tabes may
occur, so that the skull in these regions becomes thin and flexible
or is even perforated. The weight of the head, resting on the
pillow, may produce flattening and deformity of the bone thus
softened. The process of dentition is delayed by rickets, the
proper development of the teeth being interfered with. In
addition certain deformities of the jaws are induced. The
mandible is stunted in its growth, and the alveolar margins of
the jaws may become inverted by pressure of the masseters and
muscles which surround the oral aperture. In infants the gentle
continuous curve of the spine becomes exaggerated, so that it is
much more convex backwards than is normal. This is the result
of the weight of the head and the relaxation of the supporting
muscles and ligaments. The curve usually rights itself when the
child is supported by the arms, but occasionally there appears to
be some rigidity in the lumbar region. Later on lateral curvature
may also show itself.

Greenstick fractures are common in the long bones and
especially in the clavicles. The softened bones yield readily to
slight violence, but the pulpy periosteum retains the ends in
apposition.

CHAPTEK V.
INTERNAL PAEASITES.

Parasites of the fluke family, as a rule, enter the body by way
of the alimentary tract, and pass thence to the liver by means of
the bile duct. They may produce symptoms of biliary obstruction
with jaundice and sometimes liver abscess. Occasionally ascites
and hsematemesis also occur, indicating portal obstruction. One
member of the family, Distoma Eingeri, is parasitic in the lungs
of man, being found in small cavities which communicate with
the bronchi ; it is the cause of endemic haemoptysis in Japan.
Unlike the common flukes, it may be more widely disseminated
in the body of its host, and has been found in the brain, the
connective tissues of the orbit and the peritoneum. It probably
finds access to the pulmonary veins, and so is carried to the right
heart, and ultimately into the arterial stream. It is obvious
that the liver flukes are not thus favourably situated for
dissemination.

The parasite Bilharzia hcematohm also belongs to the fluke
family, but differs from others in the fact that the sexes are
separate. Its mode of entry into the body is not, as yet, accurately
determined; the mouth, urethra, anus, and skin have all been
suggested as portals. Sexually mature worms are usually found
in the submucous tissues of the bladder and rectum, and in the
large venous sinuses of the latter. In the female they may occur
in the walls of the vagina. Young worms may be discovered in
the portal system and sometimes in the general venous system, as
might be expected from the location of the adult worms at the point
of union of the two. The spiked ova may be found infiltrating the
tissues of the urethra, bladder, ureters, rectum, and even the
liver. Urethral fistulae, vesical calculi and growths, cystitis,
dilated ureters, secondary renal inflammations, and sometimes a

WOEMS. 59

characteristic form of cirrhosis of the liver result. Hsematuria
may be present, chiefly at the end of micturition, owing to
pressure exerted by the contracting bladder.

Worms. — The common round worms are practically confined to
the intestinal tract, being inhabitants of the small gut ; the bowel
is sometimes obstructed by tangled masses of these worms. The
parasites have a tendency to wander, and are especially prone to
insinuate themselves into small openings and canals. They have
been found impacted in the biliary and pancreatic ducts, have
wandered through holes in the bases of ulcers of the bowel, and
escaped also through a perforated vermiform appendix. They
have crawled into the oesophagus, or been ejected from the
stomach and so made their way into the larynx, trachea and
bronchi, into the accessory sinuses of the nose, and even into the
Eustachian tube and middle ear, escaping through a ruptured
tympanic membrane. By passing through adherent perforated
bowel they may reach cavities with which the latter has no
normal communication, such as the urinary bladder. The worms
are sometimes found in abdominal abscesses, having reached
them from the bowel, or possibly, in those which point at the
umbilicus, along a patent Meckel's diverticulum. Wandering
from the anus they have been known to find their way into the
neighbouring vagina.

Thread worms are said mostly to congregate in the caecum
and ascending colon ; they have been found in numbers in the
vermiform appendix. The females, migrating towards the anus
to deposit their eggs, set up intolerable itching, and by wandering
to the vulva irritate that part. They may even enter the
bladder by the urethra. As the result of the irritation and
consequent scratching, auto-infection occurs, the ova being
unconsciously conveyed to the mouth by the fingers and
swallowed.

Whip 2vorms, like thread worms, favour the caecum and bowel
in its immediate neighbourhood.

The parasites of anJdyostomiasis gain access to the body by the
mouth and possibly through the hair follicles of the skin in those

60 CLINICAL APPLIED ANATOMY.

parts of the body exposed to friction and contamination with
damp, infected soil.

Infection with Trichina spiralis occurs as the result of eating
measly pork. The investing capsule having been dissolved by
the gastric juice, the worms mature and breed in the upper part
of the small intestine. It is said the adult female may partially
penetrate the intestinal wall, and actually deposit her ova in the
lymphatic sinuses of the bowel. Whether the lancet-shaped
embryos thus reach the spaces or penetrate the bowel from its
interior by their own endeavours is immaterial, they become
widely disseminated. Two views are held as to the anatomical
route by which this dissemination occurs. One idea is that
the embryos, entering the lymph spaces, are carried along the
thoracic duct to the veins, traverse the heart and lungs, and
are ultimately carried to the muscles by the arterial blood stream ;
the other view is that, after penetrating the wall of the bowel,
they gain access to the root of the mesentery, or cross the
peritoneal cavity, and having thus reached the subperitoneal
connective tissue, migrate along its planes to the interstitial tissue
of the muscles, and in smaller numbers to the subcutaneous
tissues of the body. The muscles most ajffected are, in order,
the diaphragm, especially its crura ; the intercostals ; the cervical
and laryngeal muscles ; the muscles of the eye ; the biceps and
triceps. In the larger muscles the parasites are most numerous
near the tendinorfs ends, possibly the lateral pressure during
contraction is less at these points. The parasites lie between the
individual muscle fibres, and are not actually within the sarco-
lemma as was formerly supposed.

The muscles infected become swollen, tender and hard.
Implication of the diaphragm and intercostals interferes with
respiratory movements, whilst infection of the masticatory
muscles, the tongue, pharynx and larynx causes the actions of
chewing, talking and swallowing to be excessively painful. The
patient is quite crippled by the inflammation of the muscles of
the limbs and trunk, and assumes a semiflexed attitude to
relieve muscular tension as far as possible. The oedema which

TAPE WOEMS. 61

accompanies the disease may possibly be due to lymphatic
obstruction or inflammation.

Tape Worms are confined to the intestine, the head being
adherent to the mucous membrane. The spaces beneath the
valvulae conniventes afford a particularly secure and protected
point of attachment.

The cysticercus stage of Tcenia solium occasionally occurs in
man, the eggs having been swallowed or possibly having even
reached the stomach by regurgitation when the intestine is
inhabited by the mature worm. The hexacanth embryos
penetrate the blood-vessels and are carried to the brain, heart,
eye, and other parts. The rarity with which they are found in
the liver throws doubt upon the carriage by the portal vein.
When found free in the chambers of the eye they have probably
escaped from the vessels of the choroid or iris. The presence of
the vesicles in the eye, where they can be seen with the ophthal-
moscope, and in the skin whence they can be excised for examina-
tion, is of assistance in diagnosis. Pressure largely influences the
size and form of the vesicles. In the cerebral ventricles where
they are free to grow they attain a larger size than elsewhere,
attaining the diameter of nearly an inch in some cases. In the
subarachnoid space they may assume a flattened dendritic form.

When the ova of Tcenia echinococcus are ingested by man the
six-hooked embryos are set free in the stomach by digestion of
their chitinous envelopes, and work their way through the
mucous membrane of the stomach into the blood-vessels of its
walls. The embryos having been found in the portal vein, it is
reasonable to infer that their distribution is mainly effected by
this vessel. This would account for the great frequency of
hydatid cysts in the liver, and also account for the fact that,
next to the liver, the lungs are the commonest site of the disease,
for if the embryos succeed in traversing the liver, the normal
course of the circulation would carry them through the hepatic
veins to the right side of the heart, and thence to the pulmonary
capillaries. The parasites which have succeeded in traversing
both the hepatic and the pulmonary filters are carried on by the

62 CLINICAL APPLIED ANATOMY.

blood stream and may settle in connective tissue elsewhere.
Possibly embryos may also reach the liver directly by penetrating
that part which is moulded on the anterior wall of the stomach,
and may also directly infect the peritoneum by entering it after
passing through the stomach walls. The peritoneum may be
infected by the direct rupture into it of a cyst of the liver or
other peritoneal-covered viscus. There is no evidence that the
parasites travel by way of the lymphatic trunks, but it is suspected
that they may travel along the connective tissue planes in the
body ; subserous areolar tissue is a favourite nidus.

Hydatid cysts may rupture into various passages and cavities
in the body. If these passages or cavities are in free communica-
tion with the external air or the digestive tract, as occurs when
the cysts rupture into the bronchi or bowel, septic organisms may
gain access to the cyst and suppuration ensue.

The severity of the symptoms induced by the growth of
hydatid cysts is influenced to a considerable degree by their
situation, which determines the amount of expansion possible.
Hydatids of the liver and spleen may attain a great size without
producing urgent symptoms ; in the thorax the unyielding walls
and retractile lungs cause dyspnoea to be a comparatively early
sign; cysts impacted in the pelvis cause marked symptoms of
compression of bowel and bladder ; cysts in the cranial cavity
and spinal canal soon produce pressure symptoms, which how-
ever, are sometimes modified by perforation of the bony coverings.

In the lung the smaller bronchi may freely communicate with
the space which is filled by the cyst, and when the latter ruptures,
or is torn by the insertion of an exploring needle, the lung may
be deluged by the contents of the cyst, with a fatal result.

In the heart, cysts favour the connective tissue of the auriculo-
ventricular septum. By rupture into the cavities of the heart
pulmonary or systemic embolisms may occur.

Cysts of the liver may grow from its upper surface in the form
of dome-shaped projections which encroach on the lung base ;
such cysts usually project into the right half of the chest, since
this is in more immediate relation with the liver. When

HYDATIDS. 63

examining for such projections the anatomical limits of the lower
edge of the lung must be accurately known. The pleural sac
intervenes, and irritation of this may induce an effusion which
obliterates the domed outline of dulness projecting from the liver.

The relations of the liver determine to some extent in what
directions hydatids of this organ may rupture. Cysts near the
upper surface may open into the pleural sac or the base of the
adherent lung; bile-stained cysts may then be expectorated.
The pericardial sac has also been invaded. In some cases the
liver cyst presents through the lateral thoracic wall or in the
epigastrium. Cysts which project from the under surface of the
liver are liable to rupture into the greater sac of the peritoneum
or more rarely into the lesser sac. Some such cysts open
directly into the duodenum or into the stomach, where that is
closely applied to the under surface of the liver. Eupture into
the pelvis of the right kidney may also take place.

Splenic and renal cysts are uncommon. The former may bear
similar relations to the left lung and pleural sac that liver cysts
hold to the right ; or they may encroach on the abdominal cavity.
Kenal cysts may open into either the large or small intestines, or
the peritoneal sac or even the lung, but most commonly tend to
discharge into the ureters, inducing renal colic with the passage
of cyst fragments, scolices or booklets.

The omenta, the mesenteries, the subperitoneal tissue of the
abdomen and the pelvic connective tissue, including that which
forms the basis of the broad ligaments, and that which lies
between the bladder and the rectum form favourite sites for
hydatids. Cysts may also be found in the connective tissue of
the ischio-rectal fossae, of the neck, trunk, and even of the limbs.

An interesting fact is noticeable in connection with hydatids
of the brain. The cysts are mostly in the cerebrum, and are
twice as common in the right hemisphere as in the left ; they are
rare in the cerebellum. Tbis distribution points to an embolic
origin, and conforms to the ordinary distribution of cerebral
embolisms. Hydatid cysts of the brain give rise to little or no
surrounding inflammation, and are said never to suppurate

64 CLINICAL APPLIED ANATOMY.

spontaneously ; both these facts are explained by the protection
from external infection afforded by their position. The cysts
often communicate with the lateral ventricles, and serious loss
of cerebrospinal fluid may follow operations for their removal.

Hydatid cysts in the spinal canal may be extradural or intra-
dural. The former may have extended from the vertebral bodies
or be primary, and in such cases should be very favourably
situated for operative interference.

Hydatids of bones favour the cancellous tissue and medullary
cavities. In bone, possibly as the result of pressure, the cysts
usually, although not invariably, assume the exogenous form.

As would be expected, by virtue of the blood-borne infection,
hydatid cysts are occasionally met with in situations other than
those described above. The orbit, pancreas, and the vermiform
appendix may be mentioned in this connection.

Filarise. — Embryo filarial parasities are to be found in the
circulating blood, but the mature parasites of this group, so far
as they infect man, are found in the subcutaneous, interstitial,
subperitoneal or mesenteric connective tissue planes, with slight
variations according to species ; they also occur in the lymphatics.
Indications of the presence of the mature worm are forthcoming
when it is located in the subcutaneous or subconjunctival con-
nective tissue, or happens to block the thoracic duct or some of
the larger lymphatic trunks. The female of one species, the
guinea-worm, actually perforates the integument to discharge
her ova ; the perforation occurring at a spot in the foot or leg
likely to come into contact with water, since the young parasites
need an intermediate aquatic host. The embryos of other species
of filariae, circulating as they do in the blood stream, are able to
be extracted from it by certain blood-sucking insects.

The Filaria Bancrofti, which is the parent form of the well-
known Filaria nocturna, particularly favours the lymphatics of
the trunk and extremities, and the complications induced by the
presence of this worm can be explained on anatomical grounds.
The occlusion of lymphatics, which is caused by the presence of
the parasite or the inflammation it has induced, is followed by

FILAEI^. 66

lymphatic distension below the obstruction. When the thoracic
duct itself is the site of this obstruction its tributaries become
varicose, and a collateral lymph circulation is attempted; the
chyle stream becomes actually reversed in the lower part of the
duct and passes by way of the pelvic lymphatic trunks to the
femoral and inguinal regions and scrotum, and thence upwards
in the abdominal walls to reach the lymphatic system of the upper
part of the body. The varicose lymphatics of the collateral
circulation tend to give way and discharge the chyle they convey
under these altered circumstances. They may weep on the
surface of the skin, fill up the tunica vaginalis testis with
chylous fluid or rupture on the surface of some part of the
urinary mucous membrane and give rise to chyluria. The
inguinal and femoral groups of lymphatic glands which are
interposed in the course of the reflux stream become swollen
from varicosity of their lymph spaces, and the lymphatic tissues
of the scrotum are swollen by a similar mechanism. The enlarged
lymphatics are in situations exposed to slight injury, and may
become acutely inflamed.

In some cases the lymphatics are thought to be blocked in
another way, i.e., by the discharge of immature ova from the
filaria nocUirna, practically an abortion, for the worm is normally
viviparous. The ova, on account of their breadth, are not
capable of traversing the lymphatic trunks, and consequently
become impacted in the efferent lymphatics of the part of the
body in which the worm is ensconced. Elephantiasis results in
the part thus deprived of free lymphatic drainage. Under such
circumstances it is easy to see that filarial embryos may be
absent from the general circulation and yet found in the lymph
of the diseased member. The presence of filariae in other parts
of the body will probably explain those instances where the
embryos are found in both situations.

C.A.A.

CHAPTEE VI.
TUMOUKS.

The genesis, incidence, growth, and spread of tumours is much
influenced by anatomical considerations.

Tumours may be classified into four groups : Tumours having
their origin in connective tissue, tumours having their origin
in epithelium, tumours designated dermoids, and tumours termed
cysts.

Connective-Tissue Tumours.

The fact that every tissue of which an organ is composed can
give rise to a tumour implies that a knowledge of the anatomy of
the organ, and therefore of its histology, is an excellent guide to
an enumeration of the primary tumours which may arise in it.

A growing bone in a young subject affords a typical example.
Composing it will be found bone, both cancellous and com-
pact, cartilage, both articular and epiphyseal, periosteum,
red medullary marrow and fat. Thus an osteoma, chondroma,
sarcoma, myeloma, fibroma, or lipoma may be found in
connection with a growing bone.

Osteomata, or bony tumours.

There are two varieties of osteomata, the cancellous and the
compact. Speaking generally, developmental and anatomical
considerations account in great measure for the special position
and growth of the two forms. Cancellous osteomata are nearly
always associated with epiphyseal lines, and particularly with
that epiphysis from which the bone chiefly increases in length.
Thus the lower end of the femur, the upper end of the tibia, the
upper end of the humerus, and the lower end of the radius are
frequent sites of such bony growths. In their early stages they

Enchondroma of Fingek.

Articular
cartilage.

Enchon-
d roma.

— Enchondioina.

Epii)hyseal ^ \V^- 1,.
cartilage. \ v. ■

Articular cartilage.

Fig. 3.— Section of the three phalanges of a finger affected with an enchondroma, showing
position of varieties of cartilage.

[2o pxe. page 60.

CHONDEOMATA. 67

are capped by cartilage, and continue to increase in size so long
as there is cartilage left to ossify. They are not uncommonly
multiple. They are painless as a rule, but if they increase in
size to such an extent as to lie close under the skin of a part sub-
jected to pressure, an over-lying bursa may form, and inflamma-
tion and pain result. This may be typically present over an
osteoma at the lower end of the tibia, projecting so as to cause
friction of the skin against the boot. Again, local or referred
pain may be in evidence when an osteoma presses upon a nerve.
Earely actual paralysis may result from such pressure as when
an osteoma of the lower end of the femur implicates one or
other of the popliteal nerves.

Compact or ivory osteomata are nearly always found upon
bones which have been developed in membrane. Hence they
are generally associated with the flat bones of the skull, and
with the mandible. They occur at times in the osseous wall of
the external auditory meatus, and from their position may lead
to annoying deafness by filling up the canal. The air spaces of
the frontal bone form another site for their incidence, as also
does the angle of the mandible.

Exostoses, or bony out-growths, occur chiefly at the attach-
ments of certain muscles, as, for instance, the lowest part of the
insertion of the adductor magnus, causing an elongated adductor
tubercle. Also they are met with frequently on the terminal or
ungual phalanx of the great toe, probably induced by the inter-
mittent pressure to which this part is so subject.

Chondromata, or cartilaginous tumours.

Tumours composed of cartilage generally arise from the
cartilage in connection with growing bones, but they are also
formed in organs which at one period of development contained
cartilage.

Associated with bones they will naturally be seen as out-
growths from epiphyseal cartilages, or more rarely as endosteal
tumours derived from islets of diaphyseal cartilage left behind
unossified. In the latter case they are usually found expanding
metacarpals or phalanges, and are in most instances multiple.

5—2

68 CLINICAL APPLIED ANATOMY.

Associated with such organs as the parotid and submandibular
glands, they most probably originate in remnants of develop-
mental cartilage. In the case of the parotid, it is possible that
remains of the cartilage of the first branchial arch may account
for the cartilaginous portion of the mixed tumours. When
cartilaginous elements occur in the testis or ovary they can
only be explained on the ground that they belong to teratomata.

Lipomata, or fatty tumours.

Wherever adipose tissue is found in the body, there lipomata
may develop. There are, however, certain positions where they
are more commonly seen than elsewhere, and generally there is
an anatomical explanation of their existence in these areas.

Subcutaneous lipomata are very frequent. The subcutaneous
tissue contains much fat in well-nourished individuals, and in
particular regions, often where there is a likelihood of pressure,
as for instance about the shoulders and the buttocks, encapsuled
lipomata are prone to develop. Diffuse lipomata, on the other
hand, affect their own characteristic situations, such as the neck,
the axillae and the groins.

Extra-peritoneal lipomata arise from any part of the fatty
tissue lying in contact with the peritoneum. Appendices
epiploicse are natural sub-serous lipomata. Sessile extra-
peritoneal fatty tumours may grow to a large size, and may
excite injurious pressure on surrounding organs.

Not infrequently small lipomata grow in the extra-peritoneal
tissue beneath and protrude through adventitious openings in the
linea alba, or through the deep inguinal or the femoral rings, and
after a while, by dragging upon the peritoneum, cause a finger-
like process of that membrane to be formed. Lipomata of the
spermatic cord may be explained by the cord drawing down with
it some of the extra-peritoneal adipose tissue. This is further
shown by the fact that occasionally such a lipoma contains
cells which are closely allied to adrenal elements, derived from
the lumbar region in which the testis was originally developed.

The fatty tissue found external to synovial membranes, particu-
larly that of the knee, outside the spinal dura mater, in the

FIBEOMATA. 69

submucosa, and in connection with periosteum, gives rise to
sub-synovial, extradural, sub-mucous, and periosteal lipomata.

Lastly intermuscular planes, especially of the abdominal wall,
often give lodging to considerable quantities of fat which
may form intermuscular lipomata. Occasionally also lipomata
are seen within the sheaths of the biceps, deltoid, rectus
abdominis and other muscles, constituting intramuscular
lipomata.
Fibromata, or fibrous tumours.

Fibromata may grow from connective tissue anywhere, but
they are peculiarly liable to occur in connection with periosteum,
and particularly that periosteum which is associated with
mucous membrane, as for instance the muco-periosteum cover-
ing the gums, from which an epulis, innocent in character,
is derived. Frequently these small tumours are attached to
the membrane lining the tooth socket, and are therefore in a
way pedunculated.

Again, the fibrous tissue of the connective tissue sheath of a
nerve is a frequent starting-place of fibromata, the swelling then
being called a false neuroma. On the termination of some of
the sensory nerves small fibrous growths occur, extremely painful
to the touch and frequently spoken of as painful subcutaneous
tubercles. It is somewhat questionable whether these two
varieties of swellings should be classified under fibromata or
neuromata.

Most of the polypi growing from mucous membranes are
fibromata which have undergone a certain amount of myxomatous
degeneration ; hence nasal polypi and the firmer naso-pharyngeal
outgrowths are primarily fibromata.

In some instances pedunculated fibromata appear attached to
the skin, particularly about the scrotum and labium. Although
in some cases such tumours are thought to have their origin
in connection with nerve terminations, the amount of fibrous
tissue in the actual growth rather leads to their being classified
under fibromata than under neuromata. When very numerous
the nodules constitute a disease spoken of as neuro-fibromatosis.

70 CLINICAL APPLIED ANATOMY.

Angiomata, or blood tumours.

Angiomata are tumours composed of an abnormal formation
of blood vessels. As a rule they are spoken of as nsevi.

One form of the subcutaneous capillary naevus — the '' port-
wine stain " — is most often found upon the face, but it may be
seen upon the trunk or even a limb. Its frequency upon the
face and its actual distribution in particular regions of the
cheek may be dependent upon nerve distribution, the influence
of the nerve during development possibly having some obscure
bearing upon the excessive formation of capillaries.

The other, circumscribed, form is very common, and may be
found in almost any part of the skin, but it is peculiarly
liable to be seen on the face or head, on the trunk, and on the
external genital organs.

The more deeply placed naevi — the cavernous angiomata —
which are often in structure extremely like the vascular portions
of the corpus spongiosum, may be found in the same regions as
the capillary form, or beneath the deep fascia, in muscles, or
even in the viscera, as for instance in the liver.

The last form of angioma, frequently termed plexiform, is
rare, and almost entirely confined to the scalp and upper limb,
and consists for the most part of vessels which should rank as
arteries.

Lymphangiomata, or lymphatic tumours.

A lymphangioma bears the same relation to lymphatic vessels
as an angioma bears to blood vessels.

A lymphatic naevus is generally seen in the condition known as
macroglossia, in which there is congenital enlargement of the
tongue. Occasionally it may occur in the skin, and particularly
in regions where lymphatic glands are collected.

Another form of lymphangioma occurs as the so - called
" hydrocele of the neck," which is in reality a lymphatic cyst.
Cysts may also arise in the axillae and the adjacent part of the
thoracic walls. They are usually present at birth, and bear some
resemblance to the large subcutaneous lymph spaces of frogs.

Myomata, or muscle tumours.

SAECOMATA. 71

Myomata are generally described as being tumours composed
of unstriped muscle fibre, and may be associated with any of the
organs in which involuntary muscle may be present. They are
peculiarly liable to occur in connection with the uterus, and may
in these situations be mixed with a considerable quantity of
fibromatous tissue. In connection with the alimentary tract
myomata have been most frequently seen in the oesophagus, the
stomach and the duodenum — in other words, in the proximal
portions of the tract.

Myelomata, or red marrow tumours.

These tumours are composed of tissue very similar to the
red marrow of growing bone, and were formerly spoken of as
myeloid sarcomata. They are nearly always found at the
cancellous ends of long bones, and most frequently at that end
which is the epiphysis from which the bone chiefly grows in
length, as for instance the lower end of the femur, the upper
end of the tibia, and the lower end of the radius. Another
common place for a myeloma to originate is in the cancellous
tissue of the mandible, the growth expanding the bone so as to
produce the characteristic thinning of its compact outer layer.

Sarcomata. — This is the only truly malignant connective-
tissue tumour. It may occur in any mesoblastic tissue, and
therefore in almost every organ of the body. While this is true,
the growths are found much more commonly in certain regions
than in others ; periosteum, fascia and subcutaneous tissue
are peculiarly liable to be the seat of round- or spindle-celled
sarcomata.

Again, all composite glands, such as the kidney, testis, parotid,
etc., are prone to the incidence of sarcomata.

The pigmented form of the neoplasm — melano-sarcoma —
arises in the skin, in the uveal tract, and sometimes in mucous
membranes.

The spread of sarcomata is governed to a great extent by
anatomical considerations. All tumours of this nature are
extremely vascular, and the blood vessels connected with them
are ever prone to carry the elements of the growth to distant

72 CLINICAL APPLIED ANATOMY.

parts ; hence, organs far removed from the primary seat of
disease rapidly hecome infected with secondary deposits. While,
however, it is true that sarcomata are chiefly disseminated by
the blood stream, it is also true that a considerable number are
also spread by the lymphatic system, for sarcomata of periosteum,
bone, tonsil, testis, ovary, parotid and skin, as well as all
melanomata, frequently give rise to secondary deposits in
lymphatic glands.

Epithelial Tumours.

Epithelium occurs on the surface of the body, covering the
skin and the appendages thereto, and lining mucous mem-
branes, or, deeply, as a lining to the secreting portion and ducts
of glands.

Tumours arising from Surface Epithelium.

Papillomata, or warts. — These, the common, innocent epi-
thelial tumours — occur on the skin, but particularly on those
parts which are liable to be irritated or infected ; therefore they
are common about the hands, the glans penis, prepuce, vulva, and
surrounding skin. The crops of warts so frequent on the fingers
are due to the exposed position of these organs, and therefore
their constant liability to be irritated and infected.

There are two surfaces covered by stratified epithelium other
than the skin which may give origin to warts. The first is the
dorsum of the tongue, on which papillomatous tumours are by
no means infrequently seen, and are again as a rule the outcome
of irritation and infection. The second is the true vocal cord,
where again papillomata, sometimes multiple, are frequent.
Their occasional disappearance after tracheotomy in children may
be in j)art due to the rest given to the larynx.

Epitheliomata. — An epithelioma is a squamous-celled carci-
noma, and therefore may arise on any surface covered by a
stratified epithelium. It is undoubtedly true that epithelioma

PITHELIOMATA. 73

occurs where there is long-continued irritation, consequently
epithelioma is most often seen on those spots where irritation
(and it must be remembered possibly also infection) is most
likely to occur. Hence any exposed portions of skin, such as
the hands and lips, are frequently the sites of epitheliomatous
deposits.

Other common sites are those in which two skin surfaces tend
to come in contact, as for instance about the anus and vulva
where there is great liability to irritation, to small wounds and
possibly to infection. Also, where the skin is thrown into
rugae there is again the liability for squamous- celled carcinoma
to make its appearance, as on the scrotum, forming the so-called
" chimney-sweep's cancer." It is often said that the line of
junction of skin and mucous membrane — that is, where tran-
sition from one kind of epithelium to another takes place — is a
region in which epithelioma commonly originates. While this is
undoubtedly true, there is no clear evidence that it is due to the
change from one form of epithelium to another, but it is of every-
day observance that these same spots, if on the surface, are those
commonly the site of slight injuries.

Again, as in connection with warts, so the epithelium covering
the tongue, and also that forming the superficial layer of the true
vocal cord, may give rise to squamous-celled carcinoma. Hence
the connection between the simple papillomata and epitheliomata
is self-evident : both originate from epithelium, and both are
found frequently where irritation, and particularly prolonged
irritation, is common, and slight injuries such as a crack or a
fissure often occur.

Epitheliomata, like other malignant growths, spread in one or
more of three ways. First, by direct extension into the surround-
ing tissues, which extension is termed infiltration. It is inter-
esting to note however that this infiltration by no means occurs
only in the line of least resistance, and so differs from the
extension of innocent tumours, which merely push the parts
aside, or of abcesses finding their way to the surface. Secondly,
epitheliomata spread to distant parts by means of the lymphatic

74 CLINICAL APPLIED ANATOMY.

system. In most cases the nearest chain of lymphatic glands
rapidly becomes the site of secondary deposits, but it is
comparatively rare for the afferent lymphatic vessels and the
tissues around them to become early involved. It is possible,
however, that when the nearest lymphatic glands have been
removed by operation or have become greatly implicated by the
new growth, the afferent lymphatic vessels have great difficulty
in conveying the lymph stream, with the result that the lymph
as it were is dammed back and any virus it may contain affects
the walls of the vessels and may escape into the surrounding
tissues. It is conceivable that so-called cancer en cidrasse is
thus occasioned. The third way of dissemination, which is
decidedly rare in epithelioma, is by the blood stream.

Tumours arising from the Epithelium of the secreting

PORTION OR DUCTS OF GlANDS.

Adenomata. — The secreting epithelium of glands occasionally
gives rise to a tumour constructed upon the type of the gland but
without the function of producing its secretion. Such a tumour
is called an adenoma, and is innocent in nature. While all glands
are theoretically capable of producing adenomata, certain organs
are the most common sites of the new growth. Thus the mammary
gland, sebaceous glands, the prostate, the parotid, the thyroid
and the ovary are not so very infrequently the birthplaces of
adenomata.

Carcinomata. — The epithelium lining the acini of glands is an
extremely frequent starting-place of carcinoma ; hence occurs the
increasingly common origin of carcinoma in the female mamma,
and in the glands of the cervical canal of the uterus. Other
favourite situations, common to both sexes, are the glands at the
pyloric orifice of the stomach, and those in the rectum and other
parts of the large intestine.

Such carcinomata rapidly infiltrate the surrounding tissues,
usually extending beyond the gland in which they originate,
and later involve the skin or mucous membrane and so induce

DEEMOIDS. 75

ulceration and fungation. Further, they disseminate rapidly
to the lymphatic glands near by, by the lymph stream, and to
distant organs by the vascular system.

Dermoids and Teratomata.

In the vast majority of dermoids, skin or dermal tissue forms
the basis of the tumour. They may be classified in four
varieties : — sequestration dermoids, tubulo-dermoids, ovarian or
testicular dermoids, and dermoid patches. A knowledge of
developmental anatomy explains many of the points observable
concerning dermoids.

Sequestration Dermoids. — If the surface epithelium becomes
included in the deeper tissues a dermoid is likely to be formed.
Hence it will be readily seen that such dermoids occur where
there is the greatest chance for portions of epithelium to become
sequestrated. The middle line of the body is therefore a common
situation, seeing that there is here a junction of the two halves
of the foetus. In the process of fusion, small portions of epithelium
may be cut off by mesoblastic tissue from the surface and thus
become buried, and therefore middle line sequestration dermoids
are easily explained. On the dorsal aspect they are most often seen
in the region of the sacrum and coccyx, where also dimples and
pits may be observed and may be considered as abortive attempts
to sequestrate surface epithelium. Dermoid cysts in this region
which have suppurated and discharged explain at least one form
of persistent sacral sinus. In the median line on the ventral
aspect dermoids are more common. Occasionally they are found
within the thorax, epithelium having been caught by the closing
sternum, and thus deeply buried. In addition, those facial and
branchial fissures which are found in the face and neck
frequently and easily become the sites of inclusion of epiblast.
The commonest situation for a facial dermoid is just above the
outer canthus of the eye, that is at the external extremity of the
orbito-nasal fissure. Sometimes this cyst may have a deep pro-
cess passing through the bone and into the cranium, hence the

76 CLINICAL APPLIED ANATOMY.

danger of removing them unless there is absolute asepsis. The
other fissures of the face much more rarely have true dermoids
associated with them.

The branchial clefts in the neck may sometimes develop der-
moids lined wholly with skin, but more frequently the cysts formed
in connection with them are of the nature of tubulo-dermoids,
sometimes called " hydroceles " of the neck.

Dermoids may be occasionally seen about the pinna of the ear,
and occur there owing to sequestration of epithelium during the
fusion of the primitive auricular tubercles.

Dermoids in connection with the scalp and dura mater may be
explained by the original continuity of these two layers, which
later become separated by the formation of membrane bone
between them.

Implantation cysts, which bear a resemblance to sequestration
dermoids, are found in various parts of the body, and are due to
portions of epithelium being driven by violence into the deeper
tissues, or left behind accidentally during the progress of an
operation. Hence such cysts are usually seen about the palm of
the hand and the fingers, because these parts are so exposed to
cuts and pricks.

Tubulo-dermoids. — These arise in congenital tubes, which
as a rule become obliterated before birth. There are chiefly
three which may be the origin of tubulo-dermoids, the thyro-
glossal duct or tract, the post-oral fissures, and the post-
anal gut.

From the first may arise tubulo-dermoids in the middle line of
the base of the tongue, in front of the thyro-hyoid membrane,
and in the middle line of the neck below this and down to the
isthmus of the thyroid body. It is important to recollect that
the cyst may pass up behind the hyoid bone into the substance
of the tongue, and to rid the patient of the trouble necessitates
complete extirpation of the dilated duct, and not a mere opening
of the fluid sw^elling, which is so commonly mistaken for an
abscess.

Similar cysts have been described with pedicles passing between

DEEMOIDS. 77

the mandible and the hyoid bone and between the cricoid and
thyroid cartilages.

The post-oral fissures sometimes develop tubulo-dermoids, which
will appear in the anterior triangle of the neck, and are placed
beneath the deep fascia.

The post-anal gut gives rise to two forms of tubulo-dermoids.
One, which is ordinarily termed a congenital sacro-coccygeal
tumour, projects from between the rectum and the coccyx, and
presents characters of both alimentary and nervous tissue. The
other lies between the rectum and the hollow of the sacrum, and
may sometimes find its way through the rectal wall, and, ulcer-
ating, discharge its contents through the anus.

Ovarian and Testicular Dermoids. — It is particularly interest-
ing that there may be associated with the ovary and with the
testis a species of tumour w^hich has all the characteristics of a
dermoid. In connection with the ovary they probably arise
from the oophoron, or that portion of the organ which develops
the follicles, and are probably due to cells which were originally
connected with epiblast. They are therefore essentially the
resultant of a true embryonic intrusion into the ovary, and may
stand in close relation to teratomata or parasitic foetuses.

Dermoid tumours of the testis must not be confounded with
scrotal dermoids, that is, those sequestration dermoids which are
to be found in the middle line of the scrotum — in the raphe —
the evidence of the original fusion of its two halves. There
appear to be true dermoids of the testis proper, developed in
probably the same manner as dermoids of the ovary, namely
from a misplaced portion of epiblastic embryonal tissue.

Dermoid Patches, or hairy moles. — These are essentially moles,
or rather hairy moles. It is questionable whether all moles
should be classified as dermoid patches, but those which occur
in the middle line and in the lines of congenital fissures, as
for instance in the line of the fissure between the maxillary
process and the mandibular arch, are certainly of such a
character. Hairy moles are also seen on the limbs and on
the conjunctiva.

78 CLINICAL APPLIED ANATOMY.

Cysts.

Cysts may be conveniently classified under three headings,
firstly, cysts due to distension of previously existing cavities ;
secondly, cysts of new formation ; and thirdly, cysts of congenital
origin.

Retention Cysts occur wherever there is a secreting organ
which possesses a duct, the lumen of which becomes occluded,
while at the same time secretion continues. Possibly the most
frequent form of this variety is seen in the common sebaceous
cyst of the skin, or the mucocele of the mucous membrane.

Distension Cysts are those in which a potential cavity, lined
with a secreting membrane but with no exit therefrom, becomes
distended with its own secretion. A typical example of this is
distension of the tunica vaginalis testis with serous fluid,
forming a vaginal hydrocele.

Cysts of New Formation are those originating in connection
with a new growth or a parasite, an excellent example of the
latter being a hydatid cyst.

Cysts of Congenital Origin are very numerous, and for the
most part depend upon the dilatation of developmental tubes
Avhich should cease to exist or remain merely as remnants.
Congenital neural cysts are due to arrest of the fusion of the
edges of the neural groove. Spina bifida usually occurs in the
lumbar region where the neural plates are the last to close. The
plates are also late in closing at the anterior end of the groove,
and a meningocele or encephalocele may form at this site and
project at the root of the nose or into the nasal cavity. A
cerebral meningocele may also project between the two cartila-
ginous portions of the supra-occipital bone.

SPECIAL DISEASES AND INJUKIES.

CHAPTEK YII.
FKACTURES.

General Anatomical Conditions.

A fracture of a bone implies in addition some injury to soft
parts because of the close relationship of muscles through their
attachment to the osseous tissue, of the proximity of nerves and
vessels running in bony grooves and canals or through foramina,
and of the subjacent position of viscera. It is when severe
injury of soft parts is induced that a complicated fracture is in
evidence.

Bones enter into the formation of joints, therefore a fracture
occurring near or through the articular end of a bone may involve
a joint ; or a dislocation may be associated with the fracture,
constituting a further form of complicated fracture.

The attachment of muscles to bones causes in most cases the
deformity which so often follows upon a fracture, and the precise
degree or variety of deformity depends upon the position of the
fracture and the relative attachment of muscles to the fragments.
The laceration of small blood vessels and the consequent
extravasation of blood produces in part the swelling which
so quickly follows a fracture.

The abnormal mobility present after a fracture is the result of
the solution of the continuity of the bone, and the direction
of the movement is to a great extent dependent upon the
anatomical relations of the bone.

80 CLINICAL APPLIED ANATOMY.

Pain is experienced at the seat of fracture owing to nerve
endings being torn or bruised ; pain may also be referred in
consequence of the irritation of nerve trunks implicated opposite
the fracture.

A fracture which does not in any way communicate with the
outer air is said to be closed, or " simple." A fracture which
does communicate with the outer air, it matters not how, is said
to be open, or " compound." It is well to remember in this
connection that the track along which air and therefore septic
micro-organisms may reach the fractured ends of a bone may be
a very devious one. This is particularly so in bullet injuries,
where the wound of entrance may be very remote from the site
of fracture.

Emphysema, or air in the tissues, may follow the fracture
of certain bones because of their anatomical position. Most
commonly it is found after fracture of the ribs because of a
co-existent wound of the underlying lung. Fracture of the nose
leads frequently to laceration of the nasal mucous membrane,
and thus to escape of air into the frontal tissues, as also will a
fracture involving the frontal sinus, or the antrum of Highmore.
Occasionally fractures of the hyoid are associated with escape of
air derived from the larynx, and fractures of the pelvis with
gas derived from the rectum.

Special Fractures.

Fractures of the Nasal Bones. — The nasal bones forming the
roof of the nose are usually prominent and thus considerably
exposed to injury. The bones are to a certain extent protected
by the overhanging forehead, and supported by the septum and
nasal processes of the maxillae. Fracture is therefore most
commonly through the lower third where they are least supported.
A fracture caused by direct violence is usually accompanied by
laceration of the mucous membrane of the nasal fossa, even if
the skin is entirely untorn. Epistaxis follows ; frequently the
nose is blown to clear out the blood, and air may be thus forced

FEACTUEBS OF THE JAWS. 81

through the rent in the lining membrane into the tissues at the
root of the nose, and up on to the forehead.

The grave lesion of an open fracture of the ethmoidal portion
of the base of the skull may occasionally be produced by the
violence which breaks the nose, and therefore prognosis in this
common accident must not always be too sanguine, since septic
meningitis may ensue.

Fractures of the Maxilla (Upper Jaw). — The maxilla is
quite superficial, and contains a large air cavity, the antrum, the
walls of which, at least anteriorly, are of no great thickness.
In spite of these anatomical facts, however, fractures of this bone
are not common. But violence, such as a kick from a horse,
however, may break it in spite of the protection afforded by the
prominent malar bone, the nose, and the symphysis menti. If
the fracture involves the antrum, air may escape into the tissues
of the cheek, giving rise to a characteristic crackling sensation
on palpation. If the aveolar border be fractured, teeth are apt
to be displaced, and the mucous membrane of the gum torn, the
fracture being then an open (compound) one. The infra-orbital
nerve running in its groove and canal is liable to primary or
secondary involvement.

The floor of the orbit being formed chiefly by the upper surface
of the maxilla, it follows that a fracture of the bone including
this portion may cause extravasation of blood into the tissues of
the orbit, which, if sufficient in amount, may lead to proptosis.

The lachrymal (or nasal) duct is also liable to laceration or
pressure in consequence of a fracture of the maxilla, passing as
it does through the inner part of the bone on its way to open into
the inferior meatus of the nose.

Fractures of the Mandible (Lower Jaw). — The mandible
is the only bone of the face which is moveable. The chin, and
each angle, form projections which are liable to be met by blows,
and yet a fracture at any one of these spots is not at all common,
probably owing to the greater thickness of the bone at these
points. The weakest part of the bone is in the body, rather
nearer the symphysis than the angle, where the incisive fossa,

C.A.A. 6

m CLINICAL APPLIED ANATOMY.

the canine socket, and the mental foramen all tend to lessen the
solidity of the jaw.

All the fractures of the body of the mandible involve the
mucous membrane of the gum, and are therefore open (compound)
fractures. Hence haemorrhage into the mouth is a usual, if not
a universal, sign. There is generally some displacement in these
fractures, but the amount depends very greatly upon the force
applied, whether direct or indirect. As a result the regular
curved line of the teeth, or their horizontal level, may be altered,
a tooth or teeth may be missing, and one may even have dropped
between the fragments. In the most typical displacement, the
larger or anterior of the fragments where the fracture is on one
side of the symphysis, is drawn backwards and downwards by
the depressor muscles, the digastric, mylo-hyoid, genio-hyoid and
genio-hyo-glossus, and the posterior or smaller portion pulled
upwards and outwards by the elevator muscles, the masseter,
internal pterygoid, and temporal. If there is a fracture on both
sides of the symphysis, there will be a tendency for the median
fragment to be drawn backwards and downwards by the depressor
muscles, and as a consequence the tongue may fall back, covering
the upper opening of the larynx, and inducing dyspnoea or even
suffocation.

The inferior dental nerve runs in a canal in the body of the
mandible, but is not as a rule torn when the bone is fractured,
owing to the fact that displacement is not great. If it is
lacerated, the lower lip and the anterior teeth may be anaesthetic.
Later, if the nerve becomes secondarily involved in callus, its
functions may be interfered with, or there may be much neuralgic
pain over its distribution. Fracture of the ramus is rare owing
to the protection afforded by the masseter and internal pterygoid
muscles. Further, if fracture is present, these muscles, acting
practically as splints on either side, prevent much, if any, dis-
placement of the fragments. The condyle may be broken by
indirect violence, such as a fall upon the chin. The coronoid
process is well protected by the zygoma, and is rarely broken
without this arch being fractured at the same time.

FEACTUEES OF THE CLAVICLE. 83

Fractures of the Upper Extremity.

Fractures of the ClaYicle. — The collar bone is one of the
commonest bones to be broken. There should, therefore, be
certain anatomical reasons for its liability to fracture.

The bone is set between the sternum and the scapula. It thus
has to bear the brunt of all falls upon the shoulder, and to a great
extent those upon the outstretched hand. Thus fracture by
indirect violence is easily produced. The bone is long and slender,
and has a thick layer of brittle compact tissue, derived from
ossification in membrane, enclosing cancellous tissue, without
a medullary cavity. Therefore it readily gives way under direct
violence. Lastly it is ossified at quite an early intra- uterine age,
and is consequently less capable of withstanding injury in infant
life than are some other bones which are still partly composed of
cartilage. Fractures of the clavicle in young life are often
incomplete, " greenstick," owing to the thick periosteal covering.
When the clavicle is broken by a fall on the extended and
abducted arm or upon the greater tuberosity of the humerus,
force is applied to it through the glenoid fossa of the scapula and
the coraco-clavicular ligament, and causes a species of torsion of
the clavicle at the junction of the outer with the middle third. It
is at this point, therefore, that an oblique fracture usually occurs.

Immediately there is a triple displacement of the outer frag-
ment. The weight of the arm, aided perhaps by the traction of the
pectoralis minor, the lower fibres of the pectoralis major, and the
latissimus dorsi, induces a downward displacement. Moreover, the
trapezius is as it were thrown out of gear, and can no longer support
the weight of the upper limb. Inward displacement is caused by
the pull of the pectorals, the trapezius, the levator anguli
scapulae, the rhomboids and the latissimus dorsi. In addition,
the outer fragment is rotated so that its inner end looks backwards,
the point of the shoulder turning forwards. This change of
position is brought about chiefly by the action of the pectorals.

The inner fragment is but slightly if at all altered in its
position. This is due to the antagonistic action of the clavicular

6—2

84 CLINICAL APPLIED ANATOMY.

fibres of the sterno-mastoid above, and the clavicular fibres of the
pectoralis major below, in conjunction with the costo-clavicular
ligament. Owing, however, to the downward displacement of the
outer fragment the skin tends to become stretched over the outer
end of the inner fragment, which on this account appears as if it
were tilted upwards.

Thus it comes about that the two fragments override one
another, the inner surmounting the outer, and a shortening of
the long axis of the bone is occasioned.

In the recumbent posture, the vertical weight of the arm is
removed, and thus the downward displacement lost or greatly
minimised. In this position the weight of the limb tends
to draw the shoulder back, and so to reduce the amount
of the inward displacement and of the rotation of the shoulder
forwards.

It is rare for the important structures which lie posterior to
the clavicle to be involved in fracture by indirect violence. The
subclavian vein, the subclavian artery, the brachial plexus of
nerves, the suprascapular vessels, and the dome of the pleura,
usually escape injury. In some cases of fracture by direct
violence, one or both fragments may be driven against them.
It is further rare for a fracture of the clavicle to be an open one.
This is owing to the laxity of the tissues superficial to the bones
which allow them to slip aside in direct violence, and to stretch
over the bony projection in fractures due to indirect violence.

Fractures of the Scapula. — The only fairly common fracture
of the scapula is the breaking off of the acromion process,
frequently really a separation of the acromial epiphysis which
does not coalesce with the rest of the bone until about the age of
twenty-two. This fracture is usually the result of direct violence,
such as pitching upon the shoulder, or running the shoulder
against some unyielding structure. Much displacement is, there-
fore, uncommon, and the more so because of the thick fibrous
covering of this part of the bone. The deltoid may drag the
detached fragment somewhat downwards.

The coracoid process may be fractured by direct violence, or by

FEACTUEES OF THE HUMEEUS. 85

muscular action. It will then be detached from its base, but its
displacement is slight, owing to the hold upon it exerted by the
coraco-acromial and coraco-clavicular ligaments, which are
seldom torn.

The rarity of fracture of the body of the scapula is due to its
free mobility, and its close investiture by the supraspinatus,
infraspinatus, and subscapularis muscles. Separation of the
fragments is but small, and crepitus may be difficult to elicit,
because of the position of the same muscles.

In a fracture through the neck of the scapula, which is the
constricted portion internal to the glenoid fossa, the coracbid
process will be attached to the outer, smaller fragment.
Hence the fragment will be drawn downwards by the pectoralis
minor, the biceps and coraco-brachialis, and if the coraco-
clavicular and coraco-acromial ligaments are torn, there will be
a distinct lengthening of the arm.

Fractures of the Humerus. — Fracture of the surgical neck. —
The surgical neck of the humerus is the one which is most
commonly the seat of fracture, partly on account of its being a
weak part of the bone, but chiefly because in certain positions of
the upper extremity it is subjected to a very considerable strain,
as, for instance, when the arm is abducted. The bone breaks as
a rule between the base of the tuberosities and the upper part of
the insertions of the latissimus dorsi and the teres major muscles.
When the lesion has occurred, there is generally a very charac-
teristic displacement of the fragments occasioned by the action of
muscles. The upper fragment is abducted by the supraspinatus
and externally rotated by the infraspinatus and the teres minor.
The lower fragment has its upper end drawn upwards by all the
muscles running in a vertical direction, namely the biceps, the
deltoid, the coraco-brachialis, and the triceps. It is also adducted
by those which have a more or less horizontal direction, namely,
the pectoralis major, the latissimus dorsi, and the teres major.
In addition, there may be some forward displacement by the
action of the great pectoral muscle. If the two fragments remain
in apposition as sometimes happens, it is probable that the long

86 CLINICAL APPLIED ANATOMY.

tendon of the biceps acts as a strap, and, together with the long
head of the triceps, prevents the other muscles from causing any
alteration in the relationship of the two fractured ends. Separa-
tion of the upper epiphysis of the humerus, which is an accident
whicli may occur in persons under the age of eighteen, entails a
very similar displacement to that mentioned above. The
epiphyseal cartilage in general remains attached to the epiphysis
rather than to the diaphysis. It is in these two lesions that the
circumflex nerve ma}^ be involved.

Fracture of the shaft. — This commonly occurs about the
middle of its length, and may therefore be just above or just
below the insertions of the deltoid and the coraco-brachialis. If
above these insertions the displacement will be that the upper
fragment is drawn inwards by the muscles passing from the
trunk to the arm, namely the pectoralis major, and the latissimus
dorsi, while the lower fragment will be drawn upwards by the
deltoid, the biceps, the coraco-brachialis, and the triceps, and
slightly outwards by the deltoid. If, however, the line of
cleavage is below the insertions of these two muscles, the upper
fragment will now be abducted by the deltoid, and the lower
fragment is drawn upwards and inwards, to a slight extent by
the biceps and the triceps, still further tending to push the
lower end of the upper fragment outwards. The intervention of
the muscular fibres, which surround the bone in the region of
the fracture, between the fragments may effectually prevent union.
In some instances these fibres are actually driven into the
medullary cavity of the bone. Two other explanations of non-
union from an anatomical point of view are also given, one that
the nutrient artery which enters the bone near the seat of the
fracture is itself liable at the same time to be torn across, and
the other that there is apt to be movement at the site of the
fragments, when the elbow joint is fixed by the splint adjusted
for treatment.

The musculo-spiral nerve runs a course from within outwards
behind the shaft of the bone, lying in a musculo-osseous canal
close against the bone itself. Hence it follows that there is a great

FEACTUEES OF THE HUMEEUS. 87

liability for it to be either injured at the time of the fracture by
the broken ends of the bone, or to become involved in the callus
which quickly forms around the fragments. The first lesion
produces what is called primary paralysis, and the second
produces what is termed secondary paralysis, and is the more
common of the two. The effect of this paralysis is to produce
wrist -drop, and it is therefore readily recognisable.

The musculo-spiral nerve is best exposed behind the middle of
the shaft of the humerus by an incision which is made posteriorly
exactly in the middle in all directions, that is, half way between
the apex of the shoulder, and the tip of the elbow, and half way
between the outer and the inner sides of the arm. If the
incision be deepened through the substance of the triceps the
nerve is exposed without difficulty. It is important to remember,
when the nerve has been freed by operation from the callus, that
a layer of muscular tissue derived from the adjacent triceps
should be inserted between the nerve and the bed of callus from
which it has been lifted, otherwise the nerve may be again
caught. When implicated in fractures of the shaft of the
humerus below its middle, probably the best incision to expose
the nerve is one placed obliquely across the centre of a line
drawn from the insertion of the deltoid to the outer condyle of
the humerus, when the nerve will be found lying between the
brachio-radialis (supinator longus) and the brachialis anticus.
If the incision is made too internal, the external cutaneous nerve
may be exposed and mistaken for the musculo-spiral.

It is interesting to note that the humerus is more frequently
broken by muscular (indirect) violence than perhaps any other
bone, with the exception of the patella. This is commonly the
outcome of a great effort in throwing, and the shaft snaps just
below the deltoid insertion. The contraction of the muscle
suddenly arresting the movement of the bone at this spot, the
impetus already gained carries the lower end of the bone and the
attached forearm forwards, and under the strain induced, the
humerus gives way.

Fracture of the lower end, — Several fractures may occur in

88 CLINICAL APPLIED ANATOMY.

this region. Of these the two commonest are fracture of the
internal epicondyle, and a transverse fracture just above the level
of the olecranon fossa.

That part of the inner condyle which is outside the capsule of
the joint is styled the epicondyle (or sometimes the epitrochlea).
From its prominence it is greatly exposed to injury and is
frequently detached by violence. When separated, the flexor
muscles arising from it tend to drag it downwards and somewhat
forwards. The close proximity of the ulnar nerve to the
posterior aspect of the process renders it liable to injury or to be
involved in callus.

The transverse fracture is generally the outcome of indirect
violence and is only transverse so far as its lateral direction is
concerned, for it is oblique from behind downwards and forwards
when its antero-posterior axis is examined. Thus the displace-
ment of the fragments is easily explained. The lower end of the
upper fragment comes forward and apparently downwards and
will even injure the brachial vessels and the median nerve lying
in front of it. In some cases it may actually perforate the skin
above the crease of the elbow. The lower fragment, together
with the bones of the forearm, is carried backwards and upwards
by the action of the triceps aided by the pull of the biceps and
brachialis anticus. Thus the arm, measured from the acromion
process to the external condyle, will be shortened.

Fractures of the Ulna alone. — There is only one common
form of fracture of the ulna alone, and that is a fracture of the
olecranon process, which may be broken either by direct or in-
direct violence. It is a fairly common lesion owing to the
exposed position of the process and the strength of the muscles
which act upon it.

By direct violence the fracture may be either near the tip, or
some little distance lower down where there is a slight narrowing,
at the spot where the bony projection joins the shaft.

In indirect violence — that is, by the action of the triceps— as
a rule only the tip of the process, or the olecranon epiphysis is
dragged off.

FKACTUEES OF THE KADIUS. 89

A fractured olecranon always involves the elbow joint. Im-
mediately after the fractm-e the triceps, acting upon the upper
fragment, draws it away from the lower, the extent of separation
depending first upon the activity of the muscles, and secondly
upon the amount of tearing of the tendino-aponeurotic fibres
investing the process laterally. The fragments may be further
separated by the dipping in of a fringe-like apron of the stretched
and lacerated surrounding aponeurosis. The result of this
separation is that in most cases where wiring is not undertaken
union occurs only by fibrous tissue.

Fractures by direct violence are often associated with but
little separation, and some of these may possibly unite by bony
tissue. In the majority of cases of fracture of the olecranon
process with marked separation, exposure and wiring of the
fragments is indicated.

Fractures of the Radius alone. — This fracture is most com-
monly seen close above the distal extremity of the radius in the
form of the well-known CoUes's fracture. It is usually produced
by indirect violence, as by a fall upon the outstretched palm of
the hand, by which there is induced extreme dorsi-flexion of the
wrist. This will bring about a nearly transverse fracture of the
radius within three-quarters of an inch of its lower articular
surface. Immediately upon the break of the bone, the weight
of the body continuing to act forces the lower fragment towards
the radial side of the forearm. It is further, for the same reason,
carried upwards and backwards, and also rotated so that the
lower articular surface, instead of looking directly downwards,
now looks downwards and somewhat backwards. Thus it
happens that the tip of the styloid process of the radius, which
normally is at a lower level than that of the ulna, now comes to
lie at the same level or even higher. Not infrequently the
triangular fibro-cartilage drags off the ulnar styloid process.
When impaction occurs, as it frequently does, the posterior
portion of the upper fragment is impacted into the anterior
portion of the lower fragment.

The unsatisfactory results following upon Colles's fracture are

90 CLINICAL APPLIED ANATOMY.

due to several anatomical causes : first, because the deformity
will not have been corrected if impaction has not been reduced ;
secondly, because if the fragments have been unimpacted muscular
action tends to reproduce the deformity unless the fracture is
very carefully set ; and, thirdly, because there is a possibility of
the extensor tendons becoming involved in the callus. Most
cases, however, even those in which the deformity has not been
entirely removed, obtain free movement if massage and manipu-
lation are assiduously employed. It is well, generally speaking,
that passive movements of the wrist and the more distal joints
should be carried out during the whole process of treatment, so
as to make the possibility of stiffness remote.

Separation of the lower radial epiphysis, occurring before the
age of seventeen, may be considered as equivalent to a Colles's
fracture in young persons.

Fractures of both Bones of the Forearm. — This is most
commonly caused by direct violence, and the Hne of fracture will
be transverse and at the same level in both the bones. As a
rule it occurs about the middle of the forearm, or a little below
this point. When the fracture is situated distal to the insertion of
the pronator radii teres, the upper fragment of the radius tends
to be drawn into the position which is midway between pronation
and supination by the action of the muscle, and the upper end
of the lower fragment of the radius is adducted towards the ulna
by the pronator quadratus. Owing to this adduction there is
always a risk of cross union taking place, and the movements
of supination and pronation of the hand lost.

In fractures of the bone above the pronator radii teres, the
upper fragment is supinated by the biceps and supinator brevis,
and for this reason it is necessary to set the fracture with the
elbow flexed and the hand in the position of full supination,
which position is more likely to bring the fragments of the radius
together into line. On the other hand, in a fracture below the
insertion of the pronator radii teres, a position of the hand
midway between pronation and supination is more advantageous.
The position secures accurate ai)position, seeing that there is

FEACTUEES OF THE PELVIS. 91

moderate pronation of the upper fragment, and at the same time
it is one which gives the greatest comfort to the sufferer.

Fractures of the Metacarpals. — The metacarpal hones are
often hroken, either hy direct violence, or by indirect force applied
at the knuckles. When not impacted, there is a tendency for
the two fragments to assume an angular deformity, probably
owing to the action of the interossei and the flexors, as well as
by the direction of the violence and the weight of the finger.

Fractures of the Pelvis.

The bones constituting the pelvis have to be looked upon, from
a point of view of fracture, both as a whole and individually.
As a whole, the sacrum and the two ossa innominata form a
complete ring, in which fracture may occur from indirect violence,
the circle giving way at its weakest parts. Thus, when a cart-
wheel passes over the pelvis of a person lying in the dorsal
position, the bony ring is subjected to pressure from before
backwards, and consequently the symphysis will tend to approxi-
mate to the sacrum. Hence the weak parts of the bones, namely,
the rami of the ischium and of the os pubis, on one or both sides,
give way. Then, if the compression continues, the iliac bones
will be pressed away from the sacrum, but owing to the strength
of the sacro-iliac ligaments, either the ala of the sacrum or that
portion of the iliac bone immediately external to the articulation
is torn away. This, it will be seen, is an evidence of the elasticity
of ligaments in contrast with the brittleness of bone.

On the other hand, should the pressure be upon the pelvis
laterally, with the patient lying upon his side, there will be
again a tendency for the anterior segment of the ring to give
way, and for the two halves of the pelvis to approximate in front,
with severe dragging upon the posterior sacro-iliac ligaments,
frecjuently inducing fractare of the lateral mass of the sacrum.

Another fracture of the hip bone by indirect violence is seen
when the acetabulum is broken by the head of the femur being
forced against it from falls upon the great trochanter, the violence
being transmitted through the neck of the thigh-bone.

92 CLINICAL APPLIED ANATOMY.

Direct violence will occasion fracture of the prominent parts
of the pelvic bones, the crest of the ilium and the coccyx being
the most frequently damaged. Falls, kicks, and blows may all
react upon these exposed parts. In the case of the crest of the
ilium not much displacement will occur, owing to the surrounding
muscles holding the fragments together. When the coccyx,
however, is broken, it is apt to be considerably displaced from
the lower end of the sacrum.

The pelvic bones enclose important viscera, and when a fracture
is present there is a great liability for some of these organs to be
injured, either by the fragments themselves or by the force
which induces the fracture. The urethra passing beneath the
pubic arch is most frequently damaged. Extra - peritoneal
portions of the bladder are also exposed to injury, and likewise
the termination of the rectum. In some cases urine may be
extravasated through the wound of the urinary passage, or gas
may pass into the tissues through the laceration of the rectal wall.

The nerves and vessels passing through the greater and lesser
sacro-sciatic foramina, because of their close proximity to the
line of fracture in the ilium or sacrum, may also be injured,
with resulting paralysis or extravasation of blood.

Feactures of the Lower Extremity.

Fractures of the Femur. — Fractures about the neck of the femur
are much influenced by anatomical conditions. They consist of
two main varieties, the intra-capsular and the extra-capsular,
dependent upon the method of their production.

The first of these, the intra-capsular, is as a rule due to indirect
violence. The neck of the femur is the upper part of a long lever, is
usually placed at an angle of about one hundred and twenty-five
degrees with the shaft in the adult, and it is questionable whether
this obliquity diminishes to any extent towards old age unless there
is actual disease of the part. Any sudden force, even if slight,
applied to the lower end of the lever, — that is, to the foot — such,
for instance, as catching the toes in the edge of a carpet, produces

FEACTUEES OF THE FEMUE. 93

an unexpected strain upon the bone forming the neck, the muscles
not contracting sufficiently quickly to relieve the osseous tissue
of the brunt of the violence. The neck, therefore, breaks well
within the capsule of the joint.

The amount of separation in these cases is but little, and must
necessarily be so on account of the anatomy of the part. In the
first place, the amount of violence which has occasioned the frac-
ture may be so slight that the cervical reflection of the capsular
ligament remains wholly or partially untorn. This reflection is
seen in the form of fairly strong bands passing up from the
lower attachment of the capsule along the neck to the margin of
the articular surface of the head. Secondly, even if these
retinacula are torn through, the amount of separation will still
be limited by the untorn true capsule itself, and its strengthening
bands. Thus it comes about that the shortening in an intra-
capsular fracture of the neck by slight indirect violence hardly,
if ever, amounts to more than one inch in an adult.

Often although the violence has been so slight, the constitu-
tional disturbance is great, owing to the injury being generally in
an aged patient, and attention may not, therefore, be directed
specifically to the seat of fracture. Bruising about the hip is
but seldom seen, all the blood effused being within the untorn cap-
sule of the joint. The eversion of the foot, however, should draw
attention to the possibility of fracture. This eversion is brought
about chiefly by the natural weight of the limb, which is greater
externally than internally, and partly by the action of the
irritated external rotators.

This fracture seldom, if ever, unites by bony tissue, and this
probably from three reasons : first, there is great difficulty in
obtaining and maintaining approximation, should the fragments
have become separated, owing to the inability to manipulate the
upper one ; secondly, owing to the limited blood supply of the
acetabular fragment, which receives only a small vessel from the
obturator along the ligamentum teres ; thirdly, owing to the
osteoporosis, that is, the thinning of the bony tissue and the fatty
degeneration of the medullary substance, found in persons of

94 CLINICAL APPLIED ANATOMY.

advanced years in whom the fracture usually occurs. Occasionally,
where the retinacula are untorn, they maintain the fragments
in close approximation, and may also be a source of vascular
supply to the proximal fragment, and thus bony union may
occur.

The second or extra-capsular variety of fracture of the neck
of the femur is as a rule due to direct violence, usually of a
severe character. In this form the fracture is partly within but
chiefly without the capsule of the joint, the line of the fracture
being posteriorly outside although close to the intertrochanteric
crest and therefore external to the capsular fibres, whilst in front
it runs internal to the upper portion of the spiral line to which
the capsule is attached.

The fracture is most commonly induced by a fall from a height
upon the great trochanter, and immediately upon the solution of
continuity the proximal fragment is driven into the distal and
becomes impacted, sometimes splitting the great trochanter.

The shortening in these cases is much greater than in the
non-impacted intra-capsular fractures, and may amount to as
much as three inches in the adult. It is occasioned by the dis-
placement caused by the actual violence that induced the injury.
The alteration in the position of the lower fragment will bring
the great trochanter above its normal level. This relaxes that
portion of the fascia lata which lies between the iliac crest and
the trochanter, so that there is here a certain amount of loss of
resistance on the injured side.

Much bruising about the hip-bone may be present, owing to
the fall rupturing blood vessels and giving rise to extravasation.

The position of the foot, which was one of marked eversion in
the case of intra-capsular fractures, is in the impacted extra-
capsular variety in the position in which it was when impaction
took place, and is most commonly somewhat everted.

The union of this variety of fracture is always by bony tissue
owing to the impaction, which occasions the interlocking of the
fragments and maintains the vascular supply.

Fractures of the shaft. — When fracture of the shaft occurs

FRACTUEES OF THE FEMUR. 95

immediately below the lesser trochanter, a characteristic displace-
ment of the proximal fragment is induced by the action of the
ilio-psoas. The fragment is flexed, so that its lower end tends to
project forwards, sometimes against the vessels, and in thin
persons it may almost appear as if it intended to perforate the
integument. Associated with the flexion will be found some
amount of external rotation and abduction, caused by the
pull of the obdurator muscles and the quadratus femoris.
The distal fragment at the same time will be drawn somewhat
upwards, backwards and towards the middle line, chiefly by the
action of the hamstrings aided by the quadriceps and the adductors,
thus inducing an angular deformity in two directions, that is,
with the apex of the angle both outwards and forwards.

It is obvious from this description of the deformity that there
will be considerable difficulty in getting the two fragments into a
proper line of apposition, unless the knee is raised by flexion, and
traction is made upon the distal fragment to overcome its
upward displacement.

Fractures of tJie middle of the shaft by indirect violence as a
rule are oblique, and the displacement may be considerable.
Again the muscles passing from the pelvis to the femur, such as
the ilio-psoas, pectineus, adductor brevis and adductor longus,
tend to flex the upper fragment and externally rotate it, but in
contradistinction to the abduction of the proximal fragment as
seen in the previous fracture, there is a tendency in fractures of
the middle of the shaft for the lower end of the proximal frag-
ment to be drawn somewhat inwards, that is, adducted. The
lower fragment is drawn upwards, backwards, and inwards,
chiefly by the hamstrings and the great adductor, and its upper
end may tend to push outwards the lower end of the upper
fragment, thus counteracting the tendency to adduction just
mentioned. In addition to the upward, backward and inward dis-
placement, the lower fragment is markedly rotated outwards
by the weight of the limb. There may also be, from powerful
action of the adductor magniis, some adduction of the lower
fragment and the leg, with the result that an angular deformity

96 CLINICAL APPLIED ANATOMY.

with the apex outwards may occur at the seat of the fracture.
One of the nutrient vessels of the femur may be torn, and the
amount of extravasation of blood is often very great.

In the treatment of such fractures the shortening may be over-
come by the application of an extension apparatus, which, whilst
acting by a distinct drag upon the lower fragment in a distal
direction, will also tire out the muscles and so bring about their
relaxation. The outward rotation is easy to correct, but it is diffi-
cult to prevent its recurrence owing to the weight of the limb.

Transverse fracture of the middle of the shaft of the femur is
not uncommon in children, particularly in those who are the sub-
jects of rickets, but in these fractures the displacement as a rule
is but slight.

Fractures close above the condyles are not infrequently caused
by falls upon the front of the lower end of the thigh, in which case
an oblique fracture occurs, running from behind downwards and
forwards. The lower end of the upper fragment in such a case,
being sharp and at the same time forced forwards and downwards,
may penetrate the lower end of the quadriceps and skin render-
ing the fracture an open one. The upper end of the lower frag-
ment at the same time may be somewhat flexed by the gastrocne-
mius and plantaris and carried upwards by the hamstrings, so as
possibly to press upon or even seriously damage the popliteal
vessels. The same effect upon the vessels may occur in cases of
simple transverse fracture above the condyles ; hence it is always
wise to feel for the pulse in the dorsalis pedis and posterior tibial
near the ankle.

The flexion of the distal fragment is difficult to overcome, so it
is usual to put the limb up on a double inclined plane or an
anterior angular wire splint, and thus to obtain flexion of the
proximal fragment and bring it into line with the distal. The
objection to this method of treatment is chiefly to be found in the
fact that whilst pressure upon the vessels by the lower fragment
is relieved, the angle of the double plane may itself cause pressure
on them from behind and at a slightly lower level.

In separation of the lower epiphysis of the femur the line of

FEACTUEES OF THE PATELLA. 97

fracture is as a rule immediately distal to the attachment of the
heads of the gastrocnemius. The consequence of this is that the
lower end of the upper fragment may be drawn backwards and
downwards, and press upon the vessels, whilst the epiphysis itself
may be dislocated forwards.

Fractures of the Patella. — The patella is covered in front by
the skin, superficial and deep fasciae, and a tendinous expansion
from the quadriceps. Posteriorly it is coated with articular car-
tilage save at its tip, where is the attachment of the ligamentum
patellae. Hence it follows that all fractures of the patella which
traverse the whole thickness of the bone, except its lowest part,
necessarily lacerate the aponeurosis anteriorly and implicate the
joint behind.

The position of the patella, placed as it is between the insertion
of the quadriceps above and the patellar ligament below, renders
it liable to a very great longitudinal strain particularly in such
efforts as to save oneself falling after missing a step in ascending
the stairs. Hence this bone is more frequently broken by that
form of indirect violence known as muscular than any other in
the body. Its exposed position on the summit of the knee also
renders it liable to direct violence, which may also lead to its
fracture.

In the lesion by muscular action it is somewhat doubtful whether
the transverse fracture which occurs is due to leverage, the patella
resting by its posterior surface on the trochlear surface of the
femur as on a pivot. If the movement of the knee in flexion and
extension is accurately observed, it will be found that at no time
is any part of the patella really unsupported. It glides upon, but
always remains co-apted to, the articular surface of the condyles
of the femur. Hence it follows that the common transverse
fracture is the outcome of an almost pure longitudinal strain,
which in the great majority of cases breaks the bone, but may
tear the quadriceps tendon at or near its insertion, may lacerate
the ligamentum patellae, or may even drag off the tubercle of the
tibia. In most instances where bone, tendon or ligament has to
bear a strain, the breaking force is least readily borne by the bone,

C.A.A. 7

98 CLINICAL APPLIED ANATOMY.

which, being brittle rather than extensile, snaps. This peculi-
arity is seen not only in the case of the patella and the olecranon,
but also in Pott's fracture.

In the transverse fracture, the upper fragment as a rule is larger
than the lower. Frequently the line of laceration of the tendinous
expansion over the front of the bone does not correspond to the
line of fracture in the bone itself, but is at a different level.
Further, this aponeurosis is stretched before it is torn, so that its
lacerated edge may be very ragged, and the ribbon-like portions
may easily find their way between the fragments of bone, and
possibly bring about a want of bony union.

A transverse fracture may also occur by direct violence, but
stellate or comminuted, and vertical fractures are more commonly
.the outcome of this form of violence.

The amount of separation in a transverse fracture of the patella
varies greatly, and is dependent upon several factors. The first
of these is the action of the quadriceps muscle, which by its inser-
tion into the upper fragment tends to draw this away from the
lower ; but the distance that it can be dragged upwards is regulated
by the amount of tearing of the lateral aponeurosis associated with
the insertions of the vasti. Secondly, two other minor factors
come into play, firstly whether or not the joint is passively or
actively flexed after the injury has occurred, and secondly the
amount of effusion of blood and synovial fluid which occurs into
the joint.

Hence it is obvious that it will not be politic to attempt to bring
the fragments into apposition until the almost spasmodic contrac-
tion of the quadriceps has passed off and some of the effusion into
the joint has been absorbed. Thus it is incorrect to endeavour by
mechanical, or operative means, to approximate the fragments
until three or four days at least have elapsed since the lesion
occurred. There are two other reasons for delay in the operative
treatment of fractured patella, namely, to allow time for the torn
vessels to become closed,' and to give ample opportunity for
obtaining asepsis of the operation area.

Fractures of the Bones of the Leg. — Fractures of the bones of

FEACTUEES OF THE TIBIA AND FIBULA. 99

the leg occur very frequently. Both bones may be broken by
direct violence, when the fracture will occur in each at the same
level. The fracture is then usually transverse, and the amount
of displacement but little.

Fracture of the tibia alone by indirect violence is rare on
account of the fact that the fibula is a slender light bone, and if
the w^eight of the body is thrown upon it, after a fracture of the
tibia, it also snaps, breaking as a rule at its weakest point, in
its upper fourth.

On the other hand fracture of the fibula alone is extremely
common, and generally due to direct violence, the fracture taking
place at the spot to which the violence is applied. The fibula in
its natural condition, when pressed by the fingers of one hand
applied above and the fingers of the other hand applied below,
bows towards the tibia, a definite spring being experienced. In
order to obtain this practical demonstration of the continuity of
the fibula, it is necessary to remember that the fingers must
rest definitely upon the bone, and that the fibula is placed in a
position w^hich is distinctly posterior to that which it is some-
times thought to occupy. When the bone is broken the spring
is lost. There is little if any displacement of the fragments,
owing to the unbroken tibia acting as a splint. There may,
however, be an extensive extravasation of blood, due to laceration
of the peroneal artery or one of its branches, which lie in close
apposition to the bone.

That part of the external malleolus which lies below and
posterior to the facet for the astragalus is weakened by the
presence of the groove which lodges the middle and posterior
bands of the external lateral ligament of the ankle. Consequently
this part of the fibula may be detached by direct violence or
sudden twists of the foot which drag upon the ligamentous
fasiculi.

Fracture of the tibia and fibula with outward partial dislocation
of the ankle (Pott's fracture). — In order to understand the pro-
duction of this lesion, which is in reality a fracture-dislocation, it
should be remembered that it is nearly always due to a strong
^. ^ ^ :r^ 7—2

100 CLINICAL APPLIED ANATOMY.

abduction of the foot by slipping off from a higher on to a
lower level, and thus on to the inner side of the sole of
the foot.

This movement throws strain upon the internal lateral ligament
of the ankle joint, and through it upon the internal malleolus to
which the apex of the deltoid ligament is attached. As a rule,
as has already been seen in the case of the patella, the bone
snaps before the ligament tears, and thus the internal malleolus
is dragged off. Immediately, the weight of the body is thrown
through the astragalus against the external malleolus. The
fibula, however, is held to the tibia by the strong inferior tibio-
fibular (interosseous) ligament, and therefore a strain is thrown
upon the lower part of the fibular shaft close above the ligament.
It is here that the fibula then breaks, and the upper end of the
lower fragment is tilted towards the tibia, simultaneously with a
marked deflection of the foot outwards, and the foot is also
usually carried somewhat backwards and the heel slightly raised
by the action of the calf muscles.

Most commonly a dimple in the skin may be seen in the early
stages opposite the site of the fibular fracture, and a marked
stretching of the skin over the fractured internal malleolus, at
which latter spot the skin is likely to give way, and render the
fracture-dislocation an open one.

In reducing the fracture, difficulty may be met with, firstly in
overcoming the outward displacement and eversion, probably
owing to interlocking of the fibular fragments preventing the
restoration of the astragalus to within the malleolar arch ;
secondly, in correcting the backward and upward displacement,
owing to the contraction of the muscles inserted in the tendo
Achillis. This pull may to a great extent be overcome by flexing
the leg upon the thigh and the thigh upon the abdomen, or
altogether by division of the tendon, or by placing the patient
under the influence of an anaesthetic.

Diipuytren's fracture is present when, in addition to the con-
ditions found in Pott's fracture, the portion of the tibia to which
the lower tibio-fibular ligament is attached is dragged off, or

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FKACTUEES OF THE SKULL. 101

this ligament itself is lacerated, the portion of the tibia remain-
ing intact.

Outward dislocation in these cases is apt to be much aggravated,
and the foot is considerably drawn upwards on the outer side of
the leg.

Fractures of the Os Calcis. — In a vertical fracture of the os
calcis near its posterior extremity, the hinder fragment is pulled
upwards by the action of the muscles attached by the tendo
Achillis.

Fractures of the Skull.

These consist of (1) Fractures of the cranium. (2) Fractures
of the bones of the face.

Injuries about the scalp, wdth which open fractures of the
vault of the skull are practically always associated, are of con-
siderable importance, and it may be as well to allude to them at
this point.

Wounds of the Scalp. — There are several anatomical facts
concerning wounds of the scalp which are of the greatest
importance. (See Fig. 4.)

The tissues forming the scalp are the skin, thickly beset with
hairs, the subcutaneous tissue, the aponeurosis of the occipito-
frontalis muscle, the underlying loose areolar tissue and the
pericranium.

Any wound which does not involve the aponeurosis is not
serious, except on account of haemorrhage and the liability of
superficial sepsis. The arteries lie in the dense subcutaneous
tissue, and when divided this tends to prevent them from con-
tracting and retracting. Hence the severe bleeding which is
likely to result, and the difficulty of controlHng it either by forci-
pressure or by ligature. The underlying bone, however, will
enable pressure to be applied by the dressing and bandage, and
this will usually be sufficient to control the haemorrhage.

When a scalp wound involves the aponeurosis, blood, or
inflammatory fluids such as pus, are liable to spread over the
vault of the skull, being limited only by the attachments of

102 CLINICAL APPLIED ANATOMY.

the aponeurosis, which are as follows : — the supra-orbital ridges
in front, the zygomatic arches laterally, and the superior curved
lines behind.

The arteries found in the scalp are, from the mid-line in front
to the mid-line behind, the frontal, the supra-orbital, the anterior
and posterior branches of the superficial temporal, the posterior
auricular and the occipital. They all run in a direction which is
more or less upward, and they freely anastomose with one
another. Incisions to free a collection of pus beneath the
aponeurosis will have to be planned so as to be vertical, or nearly
so, and thus to lie between the scalp arteries.

In an extensive scalp wound a flap may be raised owing to the
great looseness of the tissue beneath the aponeurosis. There is,
however, little likelihood of the flap sloughing, because it carries
the blood-vessels with it. In the same way, even a large flap
turned downwards during various intracranial operations is sure
of a good blood supply.

Scalp wounds caused by even blunt instruments may be very
clean cut, because the tissues are stretched as it were over the
firm bone beneath when the violence is applied.

Abscess of the Scalp. — A collection of pus above the apo-
neurosis of the scalp is like a superficial abscess elsewhere, and
may be dealt with in the same manner, due attention being paid
to the arteries.

An abscess beneath the aponeurosis is much more difficult to
treat, and requires many incisions owing to its extent. Further,
such abscesses may be long in healing, partly due to imperfect
drainage and partly to want of rest owing to the activity of the
occipito-frontalis muscle.

The most dependent points for evacuation of the pus vary with
the posture of the patient, but the posterior occipital region and
the lateral temporal regions are most likely to be the positions
that should be selected. Incisions in the frontal region leave
very conspicuous scars, in addition to being unsuitable for efficient
drainage.

Hsematoma of the Scalp. — Every blow upon the head is liable

FEACTUKES OF THE VAULT. 103

to be followed by extravasation of blood, and this may collect
in the subcutaneous tissues and form the ordinary bruise so
frequently seen.

If the haemorrhage be in a deeper plane, there is a tendency
for the blood to be diffused in the loose areolar tissue beneath
the aponeurosis, and a considerable quantity of blood may be
poured out, and the scalp may thus be raised so as to rest upon
a veritable blood cushion. Provided that sepsis is excluded, all
the blood will be eventually absorbed.

In other cases the blood may be poured out between the
pericranium and the bone beneath. It is then generally spoken
of as a cephalhsematoma, and is often seen soon after birth as a
result of injury during the passage of the child's head along the
maternal channel. The pericranium is but loosely attached to
the bone except where it is continuous with the tissues at the
sutures. Hence it follows that in cephalhaematoma there may be
a complete concealment of a single bone, which has led to the
assumption that the bone — most usually the parietal — is absent.

The pericranium is more firmly adherent over the temporal
bone than elsewhere, and it is rare to get a hsematoma beneath
it in this region.

Fractures of the Cranium.

These may consist of fractures of the vault or fractures of the
base, or of a fracture which runs from one into the other.

Fractures of the Vault. — The bones of the vault of the skull
for the most part are flat bones composed of two tables, an outer
and an inner, of compact tissue, and an intervening layer — the
diploe — of cancellous tissue.

Four main sutures between these bones may be recognised in
the full-grown subject, any one of which may have to be dis-
tinguished from a fracture. Their exact position is therefore a
matter of some import. (See Fig. 5, p. 104.)

The coronal, or fronto-parietal, has its summit at the bregma,
a point in the median antero-posterior plane of the skull where

104 CLINICAL APPLIED ANATOMY.

a line, in the adult, drawn vertically upwards from the external
auditory meatus cuts it. From the bregma a line carried down-
wards and forwards to a spot called the pterion represents the
coronal suture. The pterion is placed on a line drawn backwards
from the external angular process of the frontal, parallel to the
zygoma, at a spot where a second line drawn upwards from the
middle of the zygoma cuts the first.

The sagittal suture runs backwards in the middle line from
the bregma to the lambda, the latter being approximately placed
one-third the distance along the line leading from the bregma
to the inion, or external occipital protuberance.

From the lambda down to the base of the mastoid process will
be found running the lamboid suture. The remaining suture is
the squamo-parietal, which forms a curved line with its convexity
upwards, starting from the level of the centre of the zygoma and
terminating at the base of the mastoid, the highest point of the
curve reaching about one-third the distance along the line passing
from the external auditory meatus to the bregma.

Fractures of the vault occur in three forms — the undepressed,
the depressed, and the elevated.

In the undepressed, there may be a linear or stellate fissure
involving the whole thickness of the bone. The presence of
either of these as a closed or simple fracture cannot be absolutely
diagnosed, but only surmised. An open or compound linear
fracture has to be diagnosed from either a mere slit in the peri-
cranium without a break in the bone, or a suture exposed by the
scalp wound. A fracture may be diagnosed from a mere slit in
the pericranium chiefly by the fact that blood will well up
through the fissure from the diploe. From a suture a fracture
may be diagnosed by the same fact, and also that most of the
sutures exhibit a much greater irregularity because of their
serration.

Particular care must be taken in scalp wounds of the temporal
region not to mistake the margin of the squamous portion of the
temporal bone, overlapping the lower border of the parietal, for
a fracture in this reerion.

Cranial Landmarks.

External
angular
process.

Superior and
inferior
temporal
Pterion. ridges. Bregma.

Asterion.

Lambda.

Supramastoid crest.
Suprameatal spine.

Fig. 5. — View of the left side of the skull, showing landmarks. (After Edward Taylor.)

[To face page 104.

Middle Meningeal Artery.

Coronal suture.

Outer aspect of dura mater.

Middle mehingeal artery (posterior branch).

Temporal fossa

Middle of the zygoma.

Fig. 6. — View of the left side of skull showing the middle meningeal artery. (After Zuckerkandl.)

[To face page 105.

UNDEPEESSED FEACTUBES. 105

Compression of the brain, due to haemorrhage occurring within
the cranium but external to the dura mater, is most commonly
associated with a Hnear fracture across the anterior inferior angle
of the parietal bone. At this spot the inner surface of the bone
is grooved by the anterior or larger branch of the middle
meningeal artery, the main trunk of which having entered the
skull through the foramen spinosum soon divides into two branches.
(Fig. 6.) It is rare to get haemorrhage from the trunk itself.
Occasionally the anterior branch lies in a complete canal rather
than in a groove. When a fracture occurs, the artery lying upon
or rather somewhat in the fibrous tissue forming the dura mater
may be torn. Blood is then effused between the bone and the
membrane, depressing the latter inwards so as to compress
the cerebral substance. It will thus be seen that the blood
poured out is sub-cranial but extra-dural, and it is better not to
speak of it as a meningeal haemorrhage. The extent to which
the blood strips up the dura mater from the inner surface of the
bone is limited below by the firm attachment of the membrane
to the base of the skull, but above only by the want of force with
which the blood is thrown out. The amount of blood, however,
which collects immediately internal to the site of the fracture is
quite sufficient to cause such compression as in most cases to
bring about hemiplegia and later coma.

When the bleeding point has been exposed by the removal of
the overlying bone at the pterion, it is as a rule impossible to
pick up the artery with a pair of pressure forceps, because of its
being somewhat embedded in the tissue forming the dura mater.
It is therefore necessary to carry a ligature by means of a curved
needle into the membrane and beneath the artery in order to
secure it.

When the vessel lies in a complete bony canal, a further
difficulty will be encountered in arresting the haemorrhage, and
it will then become necessary either to remove the bone carefully
from around the artery, or to plug the canal by means of a spicule
of bone or some material such as aseptic wax.

Depressed fractures of the skull are as a rule the outcome of

106 CLINICAL APPLIED ANATOMY.

direct violence. The bone which is depressed may be the whole
thickness of the vault — that is, the outer table, the diploe and the
inner table — and this condition is the commonest. On the other
hand the external table alone may be driven in without the
internal table being in any way depressed. This occurs most
usually and typically where the two tables are separated from one
another, not by diploe, but by an air space, as for instance in the
region of the frontal sinus.

It is doubtful whether depression of the internal table alone
ever occurs.

In quite young subjects, owing to the elasticity of the bones
entering into the formation of the vault, it is possible for depres-
sion to occur without an actual fracture, and in some cases the
depressed bone may become spontaneously restored to its normal
position.

In depression of both tables it is usual for the internal to be
depressed over a wider area than the external, which is due to the
radiation of the force from the point at which it is applied, and
the curvature of the bone entering into the formation of the skull.

In the diagnosis it is important to distinguish depressed frac-
tures from natural depressions about the skull. Perhaps the most
likely spot at which a mistake may arise is in the anterior part of
the temporal region, where the upper border of the zygoma, the
external angular process of the frontal bone and the commence-
ment of the temporal ridge together form a raised margin, which,
if associated with the history of a blow and the presence of a
haematoma of the scalp, very closely simulates a depressed frac-
ture. A conclusive diagnosis however can easily be made by
comparing the sound with the injured side, the former exhibiting
the pseudo-depression even more markedly than the latter. Other
natural depressions sometimes mistaken for depressed fractures
are found about the occipital region in connection with the spaces
between the nuchal lines.

An elevated fracture is usually seen at the aperture of exit of
a bullet, and is therefore commonly an open fracture, the scalp
as well as the bone having been traversed by the missile. In this

FEACTUKES OF THE BASE. 107

case the external table will be elevated over a raore extensive
area than the internal.

Fractures of the Base. — Fractures of the base of the skull
may be the outcome of direct or indirect violence. A linear frac-
ture of the vault may run down into the base.

Almost every fracture of the base is open, through the mucous
membrane covering a large proportion of the bones entering into
its formation. Thus a fracture of the anterior fossa may com-
municate with the external air through the mucous membrane of
the nose ; a fracture running across the petrous portion of the
temporal bone through the mucous membrane lining the tym-
panum ; and a fracture of the posterior fossa through the mucous
membrane lining the roof of the pharynx. It will thus be seen
that in many of these fractures the meninges of the brain may
be put into direct communication with air that may be septic,
and meningitis is therefore apt to follow these fractures.

Further, the same fact of laceration of the soft tissues cover-
ing the bones leads to the escape of blood from the nostrils, into
the tissues of the orbit, through the ears, down the pharnyx, and
into the muscles of the back of the neck. Likewise, cerebro-
spinal fluid may pass through the same channels. Again, the
exit of the cranial nerves through the base of the skull explains
the great frequency with which they may be involved when frac-
tures in this region occur. Thus it is, that the three cardinal
symptoms or signs of a fracture of the base of the skull, that is to
say the loss of blood, the loss of cerebro-fluid and the primary or
secondary injury to the cranial nerves, are dependent upon
strictly anatomical reasons.

Fractures involving the anterior fossa may give rise to haemor-
rhage from the nose when the cribriform plate of the ethmoid is
damaged, or the passage of blood into the tissues of the orbit,
leading to subconjunctival haemorrhage or even proptosis, w^hen
the orbital plate of the frontal bone is fissured. The nerves
which may be involved in this fossa are the olfactory, inter-
ference with which it is difficult to demonstrate, and the optic,
damage to which is apparent from the blindness which occurs.

108 CLINICAL APPLIED ANATOMY.

When the injury to the optic nerve is primary, that is to say
when it is torn coincidently with the fracture of the bone, the
loss of vision is usually permanent, but when the amblyopia is
due to pressure on the nerve filaments by inflammatory exudation
or callus, it may be only transitory.

In the middle fossa the following cranial nerves may be in-
volved— the third, the fourth, the fifth and the sixth. Inter-
ference with the third, fourth and sixth gives rise to squint,
and that of the fifth causes failure of movement of the muscles
of mastication and loss of sensation in the skin of the whole of
the face, except that area supplied by the great auricular over
the parotid gland.

When the posterior fossa is involved, particularly where the
fracture runs across the petrous portion of the temporal bone and
involves the tympanic cavity, blood and cerebro-spinal fluid escape
from the external auditory meatus. The nerves that may be
injured are the seventh, the eighth, the ninth, the tenth, the
eleventh and the twelfths

Facial paralysis as the outcome of primary injury to the
seventh nerve whilst it is passing through the aqueduct is common
in fractures involving the petrous bone. Loss of function of the
nerve may again be due to secondary inflammation.

Injury to the eighth nerve may induce loss of hearing.

In the case of the nerves passing through the posterior lacera-
ted foramen the damage so usually implicates the tenth that
sudden death may result.

The hypoglossal nerve, when torn or pressed upon by fractures
running through the anterior condyloid foramen, is deprived of
function, and impairment of action, or paralysis, of the muscles
of the tongue ensues.

Fractures of Ribs.

Ribs are exposed to violence in one of two ways, either by
a direct blow, when the bone will break at the spot to which
the violence is applied, or by pressure from before backwards —

FEACTUEES OF EIBS. 109

as in buffer accidents or squeezing in a crowd — when the rib will
break at the point of maximum strain, as a rule slightly outside
the angle.

In fracture by direct violence there is a tendency for the
broken ends to be driven inwards upon the underlying viscera,
particularly the lungs, whereas in fracture by indirect violence
the broken ends tend rather to be forced outwards, away from
the enclosed organs. Vertical displacement of the fragments is
prevented by the attachment of the intercostal muscles and
membranes.

The adhesion of the parietal pleura to the inner surface of
the rib practically necessitates its laceration in every case of
fracture, and the passage of the upper division of the intercostal
artery along the subcostal groove indicates how rupture of this
vessel may occur. The blood from the artery will pass into the
tissues of the intercostal space and through the tear in the
parietal pleura into the pleural cavity, and may be so much in
amount as to give evidence of haemothorax.

The position of the intercostal nerve explains the reason
why pain in a fractured rib may be present at the site of fracture
and also referred to the extremity of the nerve.

The close proximity of the lung, covered by the visceral
pleura, to the chest wall readily shows how easy it is for this
viscus to be injured. It may be bruised by the direct violence
which occasions the fracture, or lacerated by the broken ends
driven by that force into its superficial parts. The wound of the
lung causes haemorrhage, partly into the lung substance and
partly into the pleural cavity. The haemorrhage into the alveoli
and smaller bronchioles of the lung may be evidenced by
haemoptysis, but the expectoration of blood may be delayed for
some hours, on account of the length of the respiratory passages
through which it has to travel.

During inspiration air may be drawn from the lacerated lung
tissue into the pleural cavity, and during expiration this air may
pass from the pleural cavity, across the wound in the parietal
pleura and between the fractured ends of the bone and torn

110 CLINICAL APPLIED ANATOMY.

muscles into the subcutaneous tissues, there to produce
" surgical emphysema." The air thus forced into the tissues
may travel through the whole of the subcutaneous tissues of the
body, except where the skin is tightly bound down, as for
instance in the regions of the palms of the hands, the soles of
the feet, the auricles, and to a certain extent the scalp.

The ribs which are most commonly fractured are those of the
middle of the series, the fifth, sixth, seventh, eighth, and ninth.
Those in the upper part of the thorax are more protected, the
first being practically covered by the clavicle, and therefore
fracture of the first rib seldom occurs unless accompanied by a
fracture of the collar bone. The lower ribs, the eleventh and
twelfth, having no attachment through their costal cartilages
with the costal cartilages of the other ribs, easily slip out of the
way when violence is applied, and thus generally escape a
solution of their continuity.

Fracture of any of the ribs below the sixth may involve injury
to the diaphragm and the subjacent liver on the right and of the
spleen and possibly the stomach on the left, whilst fracture of
the tenth, eleventh, and twelfth may be accompanied by damage
to the kidneys.

In the union of a fractured rib much external callus is usually
in evidence, owing to the fact that it is well-nigh impossible to
get complete immobility of the fractured ends, on account of their
movement during respiration.

Fractures of the Sternum.

Fracture of the sternum is a rare fracture, and usually pro-
duced by direct violence. It is in most cases associated with
such grave injury to the thoracic viscera, particularly the heart,
that the sufferer but rarely survives. The sternal fragments are
driven backwards, and come into violent contact with the right
side of the heart or the great vessels which lie immediately
behind the bone. The shock is so severe that, even if no vessel
is torn, death nearly always ensues.

FRACTUEES OF THE SPINE. Ill

Fractures of the Spine.

Fractures of the vertebrae may occur without dislocation,
although it is rare for a dislocation to occur without an accom-
panying fracture, owing to the intricate manner in which
vertebrae are articulated together. In the dorsal region particu-
larly the spinous processes may be broken off, or the laminae
driven towards the spinal cord without displacement of the rest
of the bone. This lesion occurs as a rule from direct violence.
The enclosed spinal cord is liable to injury either by pressure
from the fragments of bone themselves, or from the extravasated
blood, which may be found either without or within the thecal
sheath.

Fracture-dislocation occurs most usually at the more flexible
parts of the spine. Hence it is commonly seen at the lower
cervical and dor si- lumbar regions. As a rule indirect violence
induces the lesion, the fracture often involving both the centrum
and the neural arch as the result of the sudden and forcible
wrenching of one centrum from another. The spinal cord
lying in the vertebral canal will almost certainly be acutely
bent and pressed upon by the dislocated bones. In the case of
dislocation of the body of the upper vertebra forwards and down-
wards, it is the posterior superior edge of the lower vertebra
w^hich causes the mischief to the cord. On the other hand, when
the body of the upper vertebra is dislocated backwards, often
with crushing and fracture of the neural arches involved, it is
the lower and posterior edge of this upper centrum which presses
upon the spinal cord.

Most of the symptoms are referable to the damage done to the
cord itself. As a rule injury to the cord is not recovered from in
that there is no power of regeneration, at any rate so far as the
grey matter is concerned. It therefore follows that even if death
does not take place, restoration of function is very unlikely.

Owing to the fact that the area over which the cord is involved
extends some little distance above the actual site of the fracture-
dislocation, it will be evident that the peripheral signs will not

112 CLINICAL APPLIED ANATOMY.

accurately correspond to the level at which the dislocation has
occurred.

In fracture-dislocation between the fifth and sixth cervical
vertebrae, with the usual resulting pressure upon or laceration of
the spinal cord, all the parts supplied distally will probably be
completely paralysed. There is therefore motor paralysis of
every voluntary muscle and anaesthesia of skin and mucous
membrane. The patient's respiration is entirely abdominal,
that is, it is carried on by the action of the diaphragm alone,
this muscle receiving its innervation through the phrenic
arising higher than the lesion. Owing to the irritation of the
cord close above the actual site of injury, a zone of hyperaesthesia
is generally present in the skin supplied by the fifth and sixth
cervical nerves, which is roughly over the outer side of the arm
and forearm. The centres for defaecation and micturition (and
also for parturition) will remain intact in the lumbar segment of
the cord. Hence it follows that the rectum will be emptied,
though unconsciously, and the bladder will fill and then involun-
tarily evacuate itself or overflow. Priapism may be present.

Fracture-dislocation involving the third, fourth or fifth cervical
vertebra will almost certainly involve the origin of the phrenic
nerve from the third, fourth, and fifth cervical roots, and will
lead to very rapid death by failure of the respiratory movements,
the diaphragm as well as the inter costals being paralysed.

Fracture-dislocation of the first two cervical vertebrae is usually
fatal at once owing to the proximity and compression of the vital
centres in the medulla. Earely the displacement is slight and
death is not immediate. In such cases incautious voluntary
movement may cause further dislocation with fatal consequences.

In the dorsi-lumbar region, fracture-dislocation involves the
nerve supply of the lower extremities, causing painful paraplegia,
with muscular wasting.

Since the spinal cord terminates at the lower end of the first lum-
bar vertebra in the adult, fractures below this level can only involve
the long roots of the cauda equina and these may escape compres-
sion since they occupy a smaller space in the vertebral canal.

CHAPTEE YIII.

DISLOCATIONS.

A DISLOCATION is the partial or complete separation of bony
surfaces normally in contact at an articulation.

From this definition it will be apparent that the anatomical
relationships of a joint are of importance in determining the
frequency, the extent and the treatment of a dislocation. For
instance, the imperfect co-aptation of the head of the humerus
and the glenoid cavity of the scapula explains to some extent the
frequency with which dislocation occurs at the shoulder. On the
other hand the great strength of the crucial ligaments of the
knee is a reason for the fact that a dislocation at this joint is
rarely other than a partial one. And again, the intimate relation-
ship of the bones of the elbow means less likelihood of dislocation
and more difficulty in reduction.

In most dislocations there is more or less laceration of the
capsule and ligaments of the joint, with but little tearing of
the surrounding muscles. Thus the amount of blood extravasated
is not as a rule so great as it is in a fracture occurring in the same
region. Blood-stained synovial fluid, however, is often secreted
so abundantly as to cause considerable swelling of the part.

Special Dislocations.

Upper Extremity.

Dislocations at the Sterno-claYicular Joint. — This articulation
is one of great strength, even in spite of the want of close
co-aptation of the articular surfaces, and is the only one
connecting the upper extremity with the trunk. The posterior
sterno-clavicular ligament is stronger than the anterior. The
costo-clavicular ligament holds the clavicle very firmly down to

C.A.A. 8

114 CLINICAL APPLIED ANATOMY.

the cartilage of the first rib, which costal cartilage lies immediately
below the sternal end of the clavicle. Because of this relation-
ship, it will be readily understood that dislocation can only take
place in one of three directions — forwards, backwards and upwards.
In all reduction may be easy, but retention in place difficult, owing
to the slight adaptability of the joint surfaces, the laceration of
ligaments and the weight of the upper extremity.

Forward dislocation is the most frequent, being permitted by
the weakness of the anterior ligament, which is always torn,
together with part of the costo-clavicular or rhomboid ligament.

Backward dislocation comes next. In this there is a greater
laceration of the capsule and usually a complete tearing away of
the rhomboid ligament. The sternal end of the clavicle slips
backward and lies behind the manubrium sterni and the origins
of the sterno-hyoid and sterno-thyroid muscles, and by posterior
pressure on the left side upon the oesophagus produces dysphagia,
by pushing the trachea over to the opposite side induces dyspnoea,
by direct pressure on the subclavian artery diminution or stoppage
of the radial pulse, and upon the innominate vein much congestion
of the parts from which this vessel drains the blood.

Upward dislocation is rare, owing to the stability of the
rhomboid and the inter-clavicular ligaments, and of the inter-
articular fibro-cartilage. When it occurs all these three fibrous
structures are usually ruptured.

Downward dislocation can only take place simultaneously with
a separation of the first costal cartilage.

Dislocations at the Acromio-claYicular Joint. — The joint
depends for its strength chiefly upon the coraco-clavicular
ligaments. The acromial end of the clavicle may be dislocated
upwards upon the acromion process, or downwards beneath it.
The former is the more usual owing to the plane of the joint
surface, which is from above downwards and inwards. In the
upward displacement there is a laceration of the slender capsule,
and more or less of the coraco-clavicular ligaments. Reduction
may be easy, but retention is difficult.

Dislocations at the Shoulder- Joint. — The shoulder-joint is the

DISLOCATIONS OF THE SHOULDEE. 115

most freely movable joint in the body. The head of the humerus
is much larger than the glenoid fossa with which it articulates,
the capsule is loose and, below and internally, unsupported by
muscles. The joint depends chiefly for its stability upon (1) the
long tendon of the biceps, which, arising from the supra-glenoid
tubercle, passes through the joint above the head of the humerus,
a little internal to its middle line, and leaves through an opening
in the capsule beneath the transverse humeral ligament, to pass
vertically downwards in the bicipital groove : (2) certain muscles,
notably the subscapularis, supraspinatus, infraspinatus and
teres minor ; these muscles are often termed capsular muscles :
(3) the coraco-acromial arch, consisting of the coracoid process,
the acromion process, and the coraco-acromial ligament thrown
between the two : (4) atmospheric pressure. Unless distended
with fluid, there is no true cavity in the joint, and its interior
practically constitutes a vacuum, so that if the capsule is perforated
and air permitted to enter, the laxity of the capsule will allow
the articular surfaces to become very distinctly separated.

It will thus be seen that, although there are these four powerful
factors maintaining the stability of the joint, they are to a great
extent counteracted by the want of co-aptation between the head
of the humerus and the glenoid fossa, together with the laxity
of the capsule.

The shoulder-joint is the one which is most commonly the seat
of dislocation, generally the outcome of falls upon the outstretched
hand, upon the elbow, or upon the point of the shoulder. In any
of these accidents the head of the humerus tends to be pushed
forcibly against the anterior part of the capsule, and if the
muscles surrounding the joint are taken off their guard, a rent
in the capsule will occur, through which the head of the humerus
will be protruded.

The most frequent dislocation is that in which the head is
displaced forwards and inwards, so that it comes to lie beneath
the coracoid process, and the displacement is therefore termed
sub-coracoid. In the majority of such dislocations the head
usually reaches a point which is somewhat internal to the line of

8—2

116 CLINICAL APPLIED ANATOMY.

the coracoid, the posterior surface of the anatomical neck resting
as a rule upon the anterior margin of the glenoid fossa. It will
thus be seen that, strictly speaking, the position is rather intra-
coracoid than sub-coracoid. The subscapularis muscle is usually
lacerated during the displacement of the head, although sometimes
it remains untorn, but greatly stretched over the surface of the
bone. The supraspinatus, infraspinatus and teres minor are
taut over the now-empty glenoid fossa; and in some instances
they may drag off the great tuberosity of the humerus.

If the head of the humerus is displaced still further inwards, so
as to lie between the pectoral muscles and the serratus magnus —
a position which can only be assumed in a wide laceration of
the capsule with the muscles attached to it — the dislocation is
frequently termed sub-clavicular.

As a rule there is marked evidence from examination of the
shoulder- joint that one of these two forms of dislocation has
occurred. The first obvious sign is that, owing to the displace-
ment of the head inwards, the deltoid muscle will pass vertically
from its attachment to the acromion to the outer side of the shaft
of the humerus, its fibres being no longer raised and curved by
the head articulating with the glenoid fossa. The affected
shoulder thus appears distinctly flattened. For the same reason
a straight line, such as the edge of a splint, can now touch the
tip of the acromion process and the external condyle of the
humerus at one and the same time, whereas in the normal
condition the axis of the humerus will prevent this.

Further the anterior wall of the axilla may be bulged, and the
infraclavicular fossa obliterated. Thus it comes about that
the vertical measurement round the shoulder and axilla will be
greater on the affected than on the sound side.

Again, the range of movement at the dislocated shoulder is
decidedly limited, and it will be found that the sufferer is unable
to place the palm of the hand of the affected limb upon the
opposite shoulder with the elbow applied to the side of the chest,
owing to the long axis of the humerus being now directed
downwards and a good deal outwards.

DISLOCATIONS OF THE SHOULDEE. 117

The displacement of the head of the bone inwards will neces-
sarily bring about pressure upon the structures lying internal to
it. The axillary vein is frequently the first to suffer, and oedema
of the limb distally, from obstruction to the return of venous
blood, is a common sign. If the compression is great and is
maintained too long, there is a possibility of gangrene occurring.
It is well also to remember that in dislocations which have
remained unreduced for some length of time, adhesions may have
formed between the vessels and the protruded head, and there
is some likelihood of their being torn in too energetic attempts
at reduction.

Pressure upon the nerves of the brachial plexus gives rise to
referred pain, and in some cases paralysis, particularly of the
deltoid, as a result of interference with the function of the
circumflex nerve.

In the reduction of this form of dislocation by the common
method of manipulation, it is desired first to stretch the opening
in the capsule by bringing the elbow to the side and firmly rotat-
ing the humerus outwards ; secondly, to bring the head of the bone
well under the acromial arch by raising the elbow and carrying
it somewhat inwards across the chest. The last step in the mani-
pulation, namely rotating the arm suddenly inwards and carry-
ing the elbow still further across the chest, will cause the head
to slip through the rent in the capsule and over the margin of
the glenoid fossa into its natural position.

There are two other varieties of dislocation of the shoulder.
In one the head also leaves the capsule at its unprotected area,
namely below and somewhat in front, and rests, hitched as it were,
beneath the glenoid fossa : this displacement is in consequence
styled sub-glenoid. In this way some lengthening will be observed
on the affected side, if a measurement is taken from the acromion
process to the external condyle of the humerus.

In the last variety the head is displaced backwards through a
rent in the posterior and lower part of the capsule, and, tearing
up the infraspinatus muscle, it comes to lie beneath the spine
of the scapula, the dislocation is therefore termed sub- spinous.

118 CLINICAL APPLIED ANATOMY.

Dislocations at the Elbow- Joint. — The elbow- joint is anato-
mically a fairly secure articulation. The greater sigmoid cavity of
the ulna very closely embraces the trochlear surface of the
humerus, which is limited internally by a prominent margin.
While the shallow cup-shaped facet on the upper surface of the
head of the radius cannot be said to have much co-aptation with
the capitellum of the humerus, yet the ligaments adjacent, par-
ticularly the orbicular and the external lateral, together with the
supinator brevis muscle, serve to keep the bony surfaces securely
in contact.

The smallness of the lip of the coronoid process, the liabiUty
of the upper extremity to severe violence, and the complicated
movements of pronation and supination all tend to neutralise the
anatomical peculiarities making for safety. Thus it comes about
that the elbow is more frequently the site of dislocation than any
other joint except the shoulder, and the temporo-mandibular
joints.

The bones of the forearm entering into the elbow- joint may be
dislocated together or separately. There are, however, only two
common dislocations, one where both the ulna and radius are
displaced backwards, and the other where the radius alone
has its head dislocated forwards. The backward displacement is
probably most usually brought about by a fall on the extended
and pronated hand, with the elbow slightly flexed. The anterior
ligament and the anterior portions of the lateral ligaments are
suddenly put upon the stretch, they snap, and allow the coronoid
process to slip around beneath the trochlea into the olecranon
fossa, dragging the head of the radius surrounded by the orbicular
ligament with it. At the same time the lower end of the humerus
is forced forwards, completing the laceration of the anterior
ligament and the displacement of the bones. Occasionally the tip
of the coronoid process is broken off, but it does not carry with
it the attachment of the brachialis anticus. The fracture of
the process however leads almost necessarily to a recurrence
of the displacement after reduction, owing to the want of an
anterior lip to the sigmoid cavity to hold the ulna in position.

DISLOCATIONS OF THE ELBOW. 119

The diagnosis is very simple, for the alteration in the ana-
tomical relationship of bony points is very great.

There are four prominences of bone about the elbow- joint, the
tip of the olecranon process, the internal epicondyle, the external
epicondyle and the head of the radius. Their exact relations to
each other and in all positions of the forearm are of the greatest im-
port, and a comparison of the two limbs should always be made.

In the fully extended position of the bones of the forearm, the
olecranon sinks into its proper fossa and therefore becomes less
prominent. Its upper margin will then be on a level with a line
drawn across the back of the arm from the most prominent points
of the epicondyles. As flexion occurs the olecranon becomes more
and more prominent, and sinks to a level below the intercondy-
lar line, and when the arm and forearm are at right angles the
olecranon is the lowest point of the elbow. With full flexion the
olecranon is carried forwards, and comes to rest anterior to the
lower articular extremity of the humerus. The coronoid process
cannot be felt, being thickly covered by the brachialis anticus
muscle.

The head of the radius lies immediately below the dimple caused
by the line of the radio-humeral articulation, that is, a short dis-
tance below the external epicondyle. If the finger be placed
over it and the hand pronated and supinated, the radial head is
readily felt to rotate, while if the finger Hes upon the epicondyle
this is found to remain stationary.

In a backward dislocation, the normal relationship of the
olecranon to the other bony points is altogether lost. Further,
seeing that the bones of the forearm are carried backwards, the
length of the forearm measured from the external epicondyle to
the styloid process of the radius will necessarily be diminished.

Forward displacement of the head of the radius is often
caused when a child is caught up by the hand. The sudden
strain thus thrown upon the ligaments of the wrist-joint, through
the metacarpus and the carpus, acts upon the head of the radius
rather than the ulna, and jerks the head of the radius out of the
orbicular ligament, with or without a laceration of the latter.

120 CLINICAL APPLIED ANATOMY.

The immediate consequence of this displacement is a pro-
nounced alteration in the relationship of the head of the radius
to the external condyle of the humerus when compared with the
opposite, normal, side. The prominence of the head of the bone
in front of the capitellum explains the reason why flexion is so
limited, seeing that the head soon comes in contact with the soft
tissues of the arm.

The bone can usually be comparatively easily reduced into
position, but the difficulty is to maintain it there. This difficulty
is entirely due to anatomical reasons. If the orbicular ligament
is lacerated, there is nothing to keep the head of the radius in
place, while if this ligament remains intact, it is impossible by
manipulation to reinsert the head of the radius within it.

Dislocations at the Wrist Joint. — These dislocations are of
extreme rarity, probably owing to the strength of the ligaments of
the radio-carpal articulation and the manner in which the strain
of a fall upon the palm of the hand is shared by the several articu-
lations of the carpus. When, however, one does occur it is usually
backward. In these dislocations it will be noticed that the
styloid processes retain their normal anatomical relationship,
namely, that of the radius being at a somewhat lower level than
that of the ulna, and further that the hand has little or no
tendency to a radial displacement. Both of these facts serve to
distinguish this dislocation from fracture of the lower end of the
radius or separation of its distal epiphysis.

Dislocations at the Metacarpo -phalangeal Joints. — These are
most frequently seen in the case of that of the thumb, in which
the proximal phalanx is displaced backwards.

The anterior ligament is stretched and the head of the meta-
carpal bone tears it transversely away from its attachment, and
when the base of the phalanx is displaced backwards the sheet
of glenoid ligament is carried with it so as to come to lie on the
dorsal aspect of the metacarpal bone. Sometimes, however, the
anterior or glenoid ligament is split vertically, when one half
will lie embracing either side of the neck of the metacarpal bone
when the phalanx is dislocated dorsally. In all the backward

DISLOCATIONS OF THE THUMB. 121

dislocations the two tendons of the flexor brevis polUcis, together
with their enclosed sesamoid bones, will occupy a similar position.
At the same time one or other lateral Hgament, generally the
outer, is lacerated.

It is probable that the difficulty in reduction is due chiefly to
the fact that when extension is applied to the proximal phalanx,
the torn glenoid ligament is drawn taut, and forms a sheet which
prevents the return of the base of the phalanx forwards into its
natural position. At the same time the tendons of the flexor
brevis, together with the sesamoid bones, grasp the neck of the
metacarpal bone much in the same way as a button-hole does
the shank of a button, and thus still further interfere with
reduction.

In order to overcome this difficulty in reduction, an anaesthetic
may be required, and a series of particular manipulations should
be carried out. The first manoeuvre is to adduct the metacarpal
bone towards the palm of the hand ; the second is to acutely
dorsi-flex or hyper-extend the first phalanx, so as to bring its
base up on to the head of the metacarpal bone, and thus open up
the sides of the "button-hole" and displace the torn glenoid
ligament forwards. Then a sudden flexion of the phalanx
towards the palm of the hand, whilst its base is steadied by the
surgeon's thumb, placed behind it, causes the head of the meta-
carpal bone to slip through the button-hole formed by the
tendons of the flexor brevis and the sesamoid bones and the base
of the phalanx to pass into its normal position.

Should these manipulations fail, operative interference is
necessary. This is best carried out by the open method. A
median incision over the protruding head of the metacarpal bone
on the palmar aspect will readily show the encircling tendons
with their sesamoid bones. If these are hooked on one side and
the glenoid ligament drawn forwards, it is usually easy to press
the head of the bone backwards through the "button-hole," and
so bring the base of the phalanx into position. If a few stitches
are inserted so as to hold the torn parts of the ligament together,
there is but little chance of a recurrence of the displacement.

122 CLINICAL APPLIED ANATOMY.

Dislocations at the Interphalangeal Joints. — The dislocation
most commonly seen is a backward displacement of the distal
phalanx of the little finger, and as a rule the anterior ligament is
fully torn. Eeduction, however, by extension is fairly easy, and
a dorsal splint will prevent recurrence.

Lower Extremity.

Dislocations at the Hip- Joint. — The conformation and strength
of the hip-joint, including the depth of the acetabular cavity and
the perfect way in which the head of the femur fits into it, the
thickness of the capsule and the strength of the muscles that
surround the joint, explain the comparative rarity of traumatic
dislocations at this articulation. On the other hand, it must be
remembered that the head of the femur is at the end of a long
lever even when violence is applied to the knee, and much more
so when it is applied to the foot, a factor which it might be
thought would predispose to displacement of the head from its
socket, but as a matter of fact fracture of the neck of the femur
is much more common than dislocation at the joint. The
probable explanation of these two lesions, both arising from the
same kind of violence, is to be found in the position of the limb
at the time when the force is applied. In order that fracture
of the neck may occur, the limb should be in the fully extended
position, without abduction or adduction ; in order that dis-
location should occur, the hip- joint must be flexed and the limb
abducted.

The only dislocations at the hip-joint which are seen with any
comparative frequency are those which are termed " regular,"
in which the ilio-femoral or j^-shaped ligament remains intact.
The lower portion of the acetabulum is shallowest and the margin
is notched, and it is at this position as a rule that the head of
the bone slips out of the socket.

The most usual dislocation is a dorsal one, in a direction
upwards and backwards. The capsule is torn posteriorly, and as
a rule the ligamentum teres is ruptured. As soon as the head of

DISLOCATIONS OF THE PATELLA. 123

the femur leaves the acetabulum, it passes most commonly above
the tendon of the obturator internus muscle. Many of the
muscles about the joint are torn, but to a different degree in
various cases. The gluteus maximus often has its deeper fibres
lacerated, and frequently the gluteus medius, pyriformis and
even the obturator internus and gemelli are damaged. The ilio-
femoral ligament, as has been mentioned, remains intact,
although its external or upper fibres will be found very tense.

The head of the bone being displaced backward, the great
trochanter comes to look forwards, and there will be marked
shortening of the limb, the actual amount depending upon the
distance to which the head of the bone has ascended upon the
dorsum ilii. The foot is inverted so that the ball of the great toe
rests against the instep of the sound foot, the long axis of the
dislocated femur being directed across the lower third of the
sound thigh.

In the reduction of this form of dislocation by manipulation,
flexion of the thigh upon the abdomen relaxes the ilio-femoral
ligament, and some abduction still further induces this condition.
Slight internal rotation disengages the head from behind the
acetabulum, then traction upon the limb in the line of the femur
brings the head of this bone over the socket, into which it will
generally slip.

Dislocations of the Patella. — Again, dislocation of the patella
is a rare displacement, the only comparatively common variety of
the accident being a dislocation outwards. The line of contrac-
tion of the quadriceps muscle has a tendency to drag the patella
outwards, seeing that the direction of the large bulk of the fibres
of this composite muscle is downwards and inwards. This
obliquity of action is naturally considerably increased in cases of
genu valgum, in some instances of which the patella may slip
outwards over the external condyle whenever the knee is flexed.

Dislocations at the Knee. — The great strength of the liga-
ments entering into the knee joint explains the rarity of dis-
location at this articulation, and even when it occurs, it is
usually but partial.

124 CLINICAL APPLIED ANATOMY.

In dislocation backwards of the tibia, the posterior ligament
of the knee joint is as a rule torn, and many of the other ligaments,
particularly the crucial, must partially or completely give way.
The vessels and nerves of the popliteal space are severely
pressed upon by the posterior margin of the head of the tibia, in
backward dislocation of this bone, or are tightly stretched in the
popliteal notch in forward displacement of the tibia. In both
cases, the pulse in the tibial arteries may be obliterated.

Dislocations of the Semilunar Cartilages. — Displacement of
the internal semilunar cartilage is undoubtedly more common
than that of the external. As a rule, the fibro-cartilage is torn
away from its anterior attachment to the front of the spine of the
tibia, and from the anterior third of its marginal attachment.
The anatomical explanation of the frequency of the displacement
of the internal cartilage may be the following : — First, that this
cartilage is perhaps more insecurely attached than the external,
particularly so far as its marginal attachment to the head of the
tibia is concerned ; secondly, because in the position and move-
ment of the joint in and during which a dislocation of the car-
tilage occurs, namely, flexion at the knee with rotation outwards
of the leg, the lower end of the femur is driven as it were against
the circle of the cartilage and tears it from its attachment, forcing
it away from the interior of the joint. Sometimes the prominence
formed by it after dislocation on the inner side can be distinctly
palpated and the joint is locked, so that extension cannot be
brought about until the cartilage has been forced into position.

If dislocation of the cartilage constantly recurs, its removal
operation as a rule brings about a very satisfactory result, the
loss of the cartilage in no way affecting the function of the
joint even when a small portion near the posterior attachment is
left behind.

Dislocations at the Ankle- Joint. — Owing to the conformation of
this joint, dislocation of the whole foot including the astragalus
can only occur backwards or forwards, apart from an accompanying
fracture, lateral dislocations of necessity requiring a solution of
continuity of one of the bones.

DISLOCATIONS OF THE ASTEAGALUS. 125

Dislocations of the Astragalus alone. — Dislocation of the
astragalus alone from the malleolar arch as a rule takes place in
a forward direction, and generally results from the weight of the
body coming upon the upper surface of the astragalus when there
is ventro- flexion at the ankle joint, as in alighting upon the toes
when jumping from a height. The bone when it is shot forwards
as a rule passes somewhat outwards and comes to lie beneath the
tendons of the extensor longus digitorum, which together with
the skin are tightly stretched over it, and unless the bone is
reduced or excised by the surgeon, the integument will slough
because it is deprived of its blood supply by the tension to which
it is subjected.

Skull.

Dislocations at the Tempore -mandibular Joint. — The condyle
of the mandible may be displaced out of the glenoid fossa of the
temporal bone on one or both sides. A hollow will appear in the
place where the condyle should naturally be, and the condyle will
lie in front of the eminentia articularis. The external pterygoid
muscle draws forwards the condyle and with it the meniscus.
The temporal, internal pterygoid, and the masseter muscles
pull the mandible upwards and constitute the main obstacle to
reduction, since they tend to prevent the condyle from passing
beneath the eminentia articularis and so back into the glenoid
fossa.

CHAPTEK IX.

DISEASES OF BONES AND JOINTS.

Diseases of Bones.

Inflammation of Bone. — Because of close continuity, it is
highly improbable that inflammation attacks any one constituent
part of a bone. Thus, in periostitis there is always a certain
amount of osteitis, and in osteomyelitis it is usual for the perios-
teum to be sooner or later involved.

Periostitis may be of a simple or a specific origin. Simple trau-
matic periostitis occurs most frequently in those bones which are
chiefly exposed to injury. Hence it is common in the tibia, which
is so liable to meet with blows or kicks. Moreover, acute infec-
tive periostitis also as a rule attacks those bones which may meet
with traumatism ; therefore the femur, the tibia, the radius, the
clavicle and the lower jaw are most generally affected. The
micro-organisms inducing the disease are generally conveyed to
the injured portion of the diaphysis by the blood stream, the
patient not infrequently having a small focus of suppuration
somewhere in the body, such as a boil or patch of impetigo con-
tagiosum. The inflammation as a rule starts in the diaphysis
not far from an epiphysis, and most usually near to that epiphy-
sis from which the bone chiefly grows in length, as for instance,
the proximal end of the tibia, the distal end of the radius and the
distal end of the femur, possibly owing to the greater vascularity
of the part. The inflammation is limited to the diaphysis
because of the close adhesion of the periosteum to the epiphyseal
cartilage. Therefore while the whole of the shaft of the bone
may perish from the fluid effused beneath the periosteum
depriving it of its blood supply, the epiphysis retains its vitality
because its enveloping periosteum is not stripped off, and its

CAEIES OF THE SPINE 127

arterial twigs are so numerous. For the same reason, the
adjacent joint is comparatively rarely involved. The separated
diaphysial periosteum may, if the patient lives, throw down fresh
bone at some distance from the necrosed shaft, and it will be this
newly-formed bone which will support the limb after the removal
of the sequestrum. Therefore it follows that if that portion of
the extremity is attacked which only contains a single bone, it is
absolutely necessary that a large quantity of ensheathing bone
should be thrown out before the necrosed portion is removed,
otherwise great and permanent shortening of the limb will
occur.

Chronic Abscess of Bone. — Whether due to tuberculous or
staphylococcic infection, it is the cancellous tissue at the epiphy-
sial end of a long bone which is usually the seat of a chronic
abscess. Enlargement occurs, and a tender spot is often present
evidencing the line along which the pus is endeavouring to obtain
an exit, and indicating the spot at which the abscess should be
attacked. It is interesting to note that the pus finds its way out
through the bone to the skin much more frequently than through
the articular cartilage into the joint, the non-vascular cartilage
being a highly resistant structure.

Ccnies of the Spine. — The deposit of tubercle bacilli apparently
takes place most usually in the newly formed bone deep to the
epiphyseal discs of the centrum. The regions commonly affected
are those where most movement occurs, hence the dorsi-lumbar
and cervico-dorsal junctures are frequent sites of the disease.

As destruction of the bone forming the body progresses, the
weight of the superincumbent parts causes the centra to be
pressed together, whereby the spinous processes become prominent
in an angle, and give rise to the typical kyphosis or angular
curvature.

The spinal nerve roots issuing from the intervertebral fora-
mina are liable to be irritated by the inflammation associated
with the tuberculous granulation tissue, hence pain, referred to
the peripheral distribution of these nerves, is a very common
occurrence. Consequently a child suffering from lower dorsal

128 CLINICAL APPLIED ANATOMY.

caries may complain of pain in the abdominal wall, which may be
attributed to intestinal colic, rather than spinal disease.

Tuberculous disease involving the occipito-atloid joint has
referred pain over the mastoid process, on account of the termi-
nation of the suboccipital or first cervical nerve in this region ;
and again the same lesion in the atlo-axoid joint is associated
with pain in the occipital region of the scalp, from the distribution
of the great occipital branch of the second cervical nerve. In
atlo-axoid disease the transverse ligament behind the odontoid
process may be eaten through, and in consequence the head,
together with the atlas, slips forward, and the odontoid crushes
the spinal cord and induces instant death.

Paraplegia may occur in the course of tuberculous disease of
the spine, occasioned by the pressure of tuberculous granulation
tissue derived from the diseased centres of the vertebrae. The
posterior common ligament, so long as it remains intact, offers a
barrier for the extension backwards of the inflammatory products,
but when it is eroded, or is rendered flaccid by the falling together
of two or more vertebral bodies, pressure is allowed upon the
anterior columns of the spinal cord through the thecal sheath,
and paraplegia results. It is seldom that the actual bony tissue
in curvature of the spine induces the pressure upon the cord.

It is obvious that from its position it is a difficult matter to
reach this mass of granulation tissue in order to remove it and
thus relieve the pressure upon the cord. If it is approached from
behind by laminectomy, the whole thickness of the cord lies
between the operator and the tuberculous material which is
producing the deleterious pressure.

Diseases of Joints.

Synovitis. — In synovitis there is secreted an increased amount
of synovial fluid, causing the joint cavity to be filled and the
synovial membrane to bulge. The actual space within a joint is
relatively small. Thus, in the case of the largest joint in the
body — that of the knee — it requires only two ounces of fluid to

SYNOVITIS OF THE SHOULDER. 129

fully distend it in the adult. In consequence of the increase of
fluid, all the natural depressions about a joint become obliterated,
or even converted into elevations, and thus the outline of the
limits of the synovial membrane becomes apparent.

Joints of the Upper Extremity. — Sterno- Clavicular. Owing
to the weakness of the anterior ligament, fluid in this joint shews
itself by a distinct prominence over the front of the joint.

Shoulder-joint. — When distended with fluid the bony surfaces
may be appreciably separated, owing to the laxness of the capsule,
the rotundity of the deltoid is increased, the elbow is carried a
little backward and humerus rotated internally, and thus a shght
lengthening of the arm may be demonstrated. The hollow groove
between the pectoralis major and the deltoid is obliterated, and
fluctuation may be determined by manipulation of that part of
the capsule which may be felt in the axilla.

There are three diverticula of the synovial membrane of
the shoulder, all in connection with tendons. Beneath the
subscapularis in front and to the inner side, around the long
tendon of the biceps for some distance down the bicipital groove
anteriorly, and beneath the infraspinatus near its insertion
behind. All of these become distended with fluid in synovitis.

In suppurative synovitis pus may track along any one of these
pouches. If it escapes by the subclavicular route, it may spread
between the subscapularis and the venter of the scapula. When
it leaves the joint cavity by the bicipital groove, it may ultimately
appear at the lower and anterior border of the deltoid. Escaping
behind the joint, purulent fluid nearly always progresses forw^ards
towards the anterior aspect of the limb, this being the path of
least resistance owing to the denseness of the fascia covering the
deltoid.

Elbow-joint. — The elbow- joint when filled with fluid, as the
result of inflammation, loses most of its natural contour, and all
the guiding bony points become greatly obscured. The oblitera-
tion of the fossae on either side of the olecranon process is very
marked, and readily indicates the existence of synovitis.

Pus within the joint as a rule finds its way to the surface about

C.A.A. 9

130 CLINICAL APPLIED ANATOMY.

the posterior and outer aspects of the articulation, this being
again the line of least resistance, since the front of the joint is
well protected by the brachialis anticus muscle.

Wrist-joint. — In acute inflammatory conditions of the wrist
and carpal joints, not infrequently seen in acute rheumatism and
gonococcic infection, the actual distension of the joint cavities
themselves is frequently masked by the swelling in the tissues
around, particularly in the extensor tendon sheaths. It is well
therefore to be careful not to overlook the joint lesion, which, as
a rule, may be diagnosed by the pain produced by jarring the joint
surfaces together without simultaneously throwing into action
the flexor or extensor muscles.

In suppurative synovitis abscesses will make their appearance
chiefly about the dorsal aspect which is only covered by a slight
amount of soft tissue.

Joints of the Lower Extremity. — Hip-joint. Owing to the
great depth at which this joint is placed, distension of its cavity
in synovitis is not readily detected, but on comparing the two
groins, especially in children, and in thin persons, there will
appear to be some fulness on the affected side. Occasionally a
similar condition may be made out behind and internal to the
great trochanter.

As a rule the position in which the limb is placed is that of
flexion, abduction and external rotation. This is the position of
rest, because it is that in which most of the ligaments are relaxed.

It has also been thought that the position occurs owing to a
reflex contraction of the muscles about the joint, together with
the fact that the flexors, abductors, and external rotators are
stronger than their opponents.

Pain in synovitis of the hip, and particularly in that form de-
pendent upon infection by tubercle, is felt not only in the region
of the joint itself but is often referred to the knee, and peculiarly
to the inner and posterior aspect of the distal joint. This fact is
due to the anatomical reason that at least two nerves supply
twigs to both of the articulations, namely the obturator and the
anterior crural. It is possible that the referred knee joint pain is

SYNOVITIS OF THE KNEE. 131

most marked in those instances in which the (so-called) ligamen-
tum teres is diseased, for the obturator nerve sends a special
branch into the substance of this structure.

It is possible also that pain from inflammation of the anterior
part of the hip may be even referred, through the internal
saphenous nerve, to the inner side of the ankle, and also that
pain may be felt in the heel or foot owing to the fact that the
twigs supplying the posterior part of the hip-joint and the nerve
fibres constituting the great sciatic and its divisions are all derived
from the same source, namely the sacral plexus. It is well to
bear in mind however that pain referred to these various places
is by no means always present in morbus coxae, and because of
its absence inflammation of the hip must not be overlooked.

In suppurative synovitis (arthritis), the purulent material as a
rule perforates the capsule posteriorly where it is thinnest, and
gives rise to an abscess behind. Subsequently, however, the pus,
following the line of least resistance, tracks forward beneath the
gluteus minimus and medius, and at the anterior border of these
muscles it passes internal to the tensor fasciae femoris and deep
to the upper part of the sartorius, forming a swelling in the
upper and outer part of Scarpa's triangle.

When the acetabulum is perforated, as it may readily be in
children in whom the Y-shaped cartilage is still in existence, pus
will collect within the pelvis between the bones and the obturator
internus. Hence a rectal examination should not be neglected in
any case of suppuration in connection with the hip-joint.

Knee-joint. — Probably synovitis of the knee-joint occurs almost
more frequently than inflammation of any other joint except the
ankle. The synovial cavity of the knee-joint is the largest in the
body and yet it only requires an ounce and a half to two ounces
of fluid to completely distend it in the normal adult articulation.

The limits of the synovial cavity are readily seen when fluid is
poured out as the result of inflammation. All the natural de-
pressions around the joint are obliterated, and elevations appear
in place of them. Thus, bulging will be seen on either side of
the highest part of the ligamentum patellae and laterally to the

9—2

132 CLINICAL APPLIED ANATOMY.

rectus tendon. The patella also is raised on the surface of the
fluid and can be made, by a sharp tap on its anterior surface, to
pass backwards through the fluid and to strike the anterior sur-
face of the condyles of the femur. In order to obtain this latter
sign satisfactorily, it is well to have the quadriceps thoroughly
relaxed and to press the fluid from the upper part of the synovial
cavity into that portion which lies immediately behind the
patella.

Suppurative synovitis is always an extremely serious matter,
particularly when depending upon staphylococcic infection,
because of the large absorbing surface bathed with purulent fluid.
The various recesses of the synovial cavity of this joint make it
an extremely difficult one from which to get efflcient drainage ;
there are two condylar pouches which terminate above and
behind the condyles, beneath the heads of the gastrocnemius ; a
synovial prolongation of the outer pouch which lies along the
tendon of the popliteus; and the great subcrureus bursa. (Fig. 7.)
It is well to remember, in making lateral incisions for drainage,
that the one placed on the outer side will probably be the more
eflScient, because the patient naturally tends to externally rotate
the limb — hence the external surface becomes the most dependent
part — and because fewer muscular fibres have to be cut through,
from the fact that the fibres of the external vastus do not descend
so low as those of the internal vastus. Opening the condylar
pouches of the joint on the posterior aspect needs great care on
account of the structures lying in the popliteal space.

Ankle-joint. — Inflammation of the ankle-joint is extremely com-
mon, generally as the outcome of traumatism, such as a sprain.
Again, all the natural depressions abou.t the joint will become
obliterated, and a puffiness or swelling will appear on either side
of the fendb'Achillis ari'^ about the 'anterior suHacie of the joiti^-
deep to the extensor tendons. ^--- • - -

Tuberculosis of Joints.^^—iiifeetion' of'" a 'synovial iiieinbrahe''
with the tubercle bacillus is very frequent, and probably so
because it is well supplied with blood, its capillaries are some-
what smaller than in other tissues, and from movement and

Knee-Juint.

Quadriceps

Popliteal vein.

Internal popli
teal nerve.

Posterior
ligament of
knee-joint.

, , , , Fibula.

'^''vL\ \ Anterior

\ ) \\ tibial

''/■"111 artery

r'V V passing

■^ ^''^ through

s_,,! interosseous.

y^ ' membrane.

• "H

Fig. 7.— Sagittal section of a knee-joint, showing extent of the synovial cavity, and some of the
adjacent bursae. (Modified from Bardeleben.)

[To face page 132.

TUBEECULOSIS OF JOINTS. 133

external violence slight amounts of traumatism are constantly-
occurring, leading to inflammation and a favourable soil for the
growth of the bacilli.

It is well to remember that the synovial membrane itself only
lines the inner surface of the ligaments up to the margin of the
articular cartilage. It is only in cases of disease that the
membrane tends to creep over and to veil the articular cartilage
— a condition so common in tuberculous arthritis.

Tuberculosis leads to the destruction of ligaments and to sub-
sequent pathological dislocations. The direction in which the
bones are displaced depends greatly upon the comparative
strength of the muscles acting upon them. Thus, for instance,
in the case of the knee-joint the tibia is drawn backwards and
flexed by the ham- strings which are stronger than the extensors,
and is rotated outwards by the biceps, the action of which is more
powerful than that of the internal rotators of the leg, namely the
sartorius and popliteus.

CHAPTER X.

DISEASES OF MUSCLES, TENDONS, FASCIA, AND
BUESiE. TALIPES.

Muscular Dystrophies.

The distribution of the wasting in the muscular dystrophies
does not correspond to that met with in infantile paralysis or in
progressive muscular atrophy. In both the latter diseases there
is reason to believe that the distribution is determined by the
segmental representation of muscles in the spinal cord. Neither
does the wasting in the dystrophies correspond to the groups of
muscles supplied by individual peripheral nerves. It has been
assumed, on slight evidence certainly, that the muscles which are
the first to be developed in the foetus are the first to become
degenerated when muscular dystrophy supervenes.

A knowledge of the influence of various muscles in producing
the normal contour of the body, and also of their actions, is
essential for the investigation and discrimination of the various
types of muscular dystrophy. The annexed table shows the
muscles which need investigation in the different forms, but it
must not be forgotten that intermediate varieties occur, and that
sometimes the disease is exceedingly widespread.

The deltoid abducts the humerus to a right angle, and in so
doing tends to rotate the scapula so that the acromion points
downwards. This tendency is counteracted by the contraction of
the acromial fibres of the trapezius. The anterior fibres of the
deltoid carry the arm forwards in a horizontal plane. The fibres
forming the posterior third of the muscle are said to adduct the
arm to the body. When the deltoid is paralysed the shoulder
becomes flattened and the head of the humerus tends to sink

MUSCULAE DYSTEOPHY.

135

away from the acromion, a tendency which is much accentuated
when the supraspinatus is also affected.

The i7ifraspinatus rotates the arm outwards. The muscle being
comparatively superficial, alteration in the way of wasting or of
hypertrophy is easily recognised.

Types of Muscular Dystrophy.

Face.

Pseudo-hypertrophic

(Duchenne).

Atrophic Form (Leydeu and

Moebius).

Normal.

Arm and Deltoid

Shoulder. Supraspinatus
Infraspinatus
(especially)
Triceps ?
Biceps ?

i- Enlarged.

Pectoralis Major

(lower part) \

Latissimus Dorsi
Biceps >- Wasted.

Supinator Longus ?
Intrinsic Muscles I

of Hand ?

Pelvis, Glutei

Thigh, Quadriceps (espe-

and Leg. cially Vastus

Externus)
Calf Muscles

Flexors of Hip
Flexors of Knee

Peronei
Anterior
Group

Tibial

Enlarged.

Wasted.

Juvenile
(Erb).

Facio-scapulo -humeral

(Landouzy and

Dejerine).

Normal,

Zygomatici
Lev. Labii

Superioris
Orbicularis

Oris
Orbicularis

Palpebrarum

Wasted.

Deltoid \

Supraspinatus

Infraspinatus |- Escape. \

Muscles of Fore-

Triceps \

Biceps I Wasted

Brachialis Anticus [ early.
Supinator Longus '

Whole Trapezius
Pectoralis Major
(lower part espe-
cially)
Serratus Magnus
Latissimus Dorsi
(lower part espe-
cially)
Rhomboids
Sterno-mastoid

Glutei

Flexors of Hip
Qimdriceps and

Muscles above

Knee

Flexors of Knee
Peronei

^ Also
'wasted.

Wasted.

Wasted./

As in Erb's Juvenile
Type.

The triceps extends the elbow. Its long head also adducts the
arm. Paralysis of the triceps renders supination of the extended
forearm impossible, for the biceps which supinates is also a flexor
and will flex the forearm when supination is attempted unless it
is antagonised by simultaneous contraction of the triceps.

The pectoralis major consists of two portions, clavicular and

136 CLINICAL APPLIED ANATOMY.

sternaL One of these may be wasted without the other. The
action of the two parts of the muscle is demonstrated as follows.
If the arm is advanced in the horizontal plane and then carried
towards the mid-line of the body against resistance, both parts
of the muscle stand out. If, in this position, the arm is raised
against resistance, only the clavicular fibres contract; if it is
depressed against resistance only the costo-sternal fibres are in
action. The sternal part is frequently involved in the muscular
dystrophies, and wasting of the latissimus dorsi is often associated.
The clavicular part is usually affected together with the serratus
magnus. Wasting of the clavicular fibres of the pectoralis major
gives rise to subclavicular depressions.

The latissimus dorsi retracts and adducts the humerus, the
arm being carried across the back as in the action of placing the
hand in the coat-tail pocket. The muscle can be made to stand
out by executing this movement against resistance. By palpating
the posterior axillary fold the muscle can also be felt to contract
during coughing or sneezing. Its contracture during these
expiratory efforts is probably for the purpose of fixing the lower
ribs in order that the external oblique muscle, which rises from
them, may compress the abdomen.

The hiceps is a flexor and supinator of the forearm. When
supination without flexion is required this muscle is antagonised
by the triceps.

The brachialis anticus is a flexor of the elbow.

Wasting of the triceps, biceps and brachialis anticus produces
the slender cylindrical arm seen in muscular dystrophy.

The supinator longus or brachio-radialis flexes the elbow and
is usually said to always bring the thumb uppermost from any
position. It is, however, a pure flexor without any pronator or
supinator action. Its fleshy belly at the outer side of the ante-
cubital fossa is easily recognised when the forearm is flexed
against resistance.

The ijitrinsic muscles of the hand. — The dorsal interossei
abduct and the palmar interossei adduct the extended fingers
away from or towards a line running through the middle finger.

MUSCULAE DYSTEOPHY. 137

In addition the interossei and lumbricales, by means of their
attachments to the long extensor of the fingers as that passes
over the proximal phalanges, flex those phalanges and extend the
two distal ones. The long extensor of the fingers is practically
responsible only for the extension of the proximal phalanges to
which, paradoxically enough, it is not attached.

When the interossei and lumbricales are paralysed, the action
of the long extensor on the first phalanges, and of the long flexor
on the two terminal phalanges of each finger are not antagonised
and a claw hand results. The intrinsic muscles of the hand are
but rarely involved in the muscular dystrophies.

The trapezius. — The clavicular and the lower portions of
this muscle must be considered separately.

The clavicular portion. When the arm is to be abducted
laterally from the body the scapula must lie applied to the back
of the thorax in such a way that it can become tilted in a trans-
verse vertical plane. This allows the glenoid cavity to be directed
upwards and outwards. To permit the scapula to glide backwards
into the appropriate position, the outer end of the clavicle is
carried directly backwards. This is the function of the clavicular
fibres of the trapezius. The deltoid then abducts the arm and
the serratus magnus, by tilting the scapula, acromion upwards,
completes the elevation.

The lower portion. This part keeps the scapula in apposition
with the thorax during the first part of the action of advancing
the arm. When the humerus has been moved by the deltoid
through 45 degrees the serratus magnus comes into action and
performs a similar function to that of the trapezius, at the same
time tilting the scapula. Consequently a slight starting of the
vertebral edge of the scapula away from the thoracic wall, or
"winging," at the commencement of the advance of the arm
may be caused by paralysis of the lower part of the trapezius.
If the serratus magnus be intact the deformity will disappear
when the arm reaches the horizontal plane, whereas the deformity
due to serratus paralysis is at its maximum in this position,
especially if a pushing eflbrt be made at the same time. A

138 CLINICAL APPLIED ANATOMY.

similar sequence of events is noticed when the arm is abducted
laterally instead of advanced. But now, instead of becoming
winged, the inferior angle of the scapula moves a short distance
towards the spine. As soon as the serratus commences to act
the bone moves in the opposite direction towards the axilla.

The serratus magnus is best put in action by causing the
patient to push directly forwards against resistance. The part
played by the muscle in elevating the arm has already been
alluded to. Without the aid of the serratus magnus in tilting
the glenoid cavity upwards the deltoid cannot raise the humerus
above the horizontal line.

The rhomboids. — When the teres muscles are in action,
depressing and adducting the humerus, they at the same time
tend to draw the inferior angle of the scapula into the axilla, and
this actually happens if the rhomboids are paralysed, since the
latter, with the lower part of the trapezius, normally counteract
this displacement.

The gluteus maximus is a powerful extensor of the hip. It is
not employed in standing or walking on the level, but comes into
action in such movements as going upstairs or rising from a seat
or stepping up on a chair. Paralysis of this muscle causes the
pelvis to remain tilted when standing and so produces a lordosis
of the lumbar spine. This lordosis disappears when the patient
sits, since the tilting of the pelvis is then counteracted. Weakness
of the glutei also gives rise to a peculiar method of extending the
trunk by pressure of the hands on the thighs. This is usually
known as climbing up the thighs.

The gluteus medius and gluteus minimus are important in
the act of walking. Their function is to draw the trunk over
towards their own side so that the centre of gravity of the
body is brought over the head of the femur. The muscles of
the two sides act alternately, swaying the pelvis and trunk
from one side to the other as the corresponding foot is planted
on the ground.

The ilio-psoas is a flexor of the hip. There is a divergence of
opinion as to its rotatory action, but it is perhaps correct to regard

DISEASES OE MUSCLES. 139

it as an internal rotator, its point of attachment being outside the
axis of rotation of the femur.

The calf muscles are plantar flexors of the foot, and when
weak there is inabihty to stand on tip-toe. Contracture of the
interstitial tissue of the enlarged calf muscles in the pseudo-
hypertrophic form of the disease produces talipes equinus.

The quadriceps is an extensor of the leg. Weakness of this
compound muscle causes difficulty in extending the leg to gain
the erect position. It also allows the knee to come forwards in
advance of the foot in walking. The vastus internus portion
when enlarged is easily recognised owing to the increase of
the fleshy portion of this muscle which lies just above the inner
side of the patella.

The erector spincE muscle of each side is sometimes affected.
If at the same time the glutei are intact the resulting lordosis
is distinguished from that due to paralysis of the latter muscles
by the fact that the pelvis is not tilted forwards.

Other Diseases and Injuries of Muscles.

A muscle may be said to consist of a mass of contractile tissue,
enclosed within a fibrous sheath. As a rule, a muscle has- a
free portion or belly between two or more attachments, termed
the origin and the insertion of the muscle. The anatomical
disposition of certain muscles renders them peculiarly liable to
disease or injury.

Inflammation of Muscle (Myositis). — This is usually of a
chronic nature, and especially due to tubercle or syphilis. The
disease may be primary, or, more usually, in the case of tubercle,
secondary.

Muscles surrounding joints, the seat of tuberculous mischief,
are very apt to become involved in the infection, and subsequently
the spread of the purulent material is greatly influenced by the
sheath of the particular muscle it has invaded, or by the inter-
muscular planes it reaches. This influence is particularly well
seen in the case of the psoas magnus muscle. This muscle is

140 CLINICAL APPLIED ANATOMY.

attached to the sides of the bodies of the last thoracic and all the
lumbar vertebrae. When the lower thoracic or the lumbar centra
become infected with tubercle, and caseation or suppuration
occurs, the tuberculous material is prevented from passing
forward by the anterior common spinal ligament, is hindered
from invading the spinal canal by the posterior common liga-
ment, and therefore tracks laterally, and enters the substance of
the psoas muscle. The muscular tissue gradually becomes dis-
placed or absorbed, and the sheath filled with the tuberculous
material. This is then conducted by the sheath downwards along
the brim of the pelvis, behind Pouparfc's ligament to point in
Scarpa's triangle not far from the insertion of the muscle into the
lesser trochanter.

When such a collection of caseous matter is opened in the
lumbar region, and the finger introduced, it is often found that the
cords of the lumbar nervous plexus have been dissected out, and
remain stretched across the cavity.

Injuries of Muscles. — Laceration of muscular fibres is a very
common accident. A muscular belly may be completely ruptured
within the sheath. The sheath of a muscle may be lacerated
without the contained muscular fibres being torn, in which case a
protrusion, or hernia, of the fibres may occur. A muscle and its
sheath may both be ruptured simultaneously. Certain muscles
from their attachments, position or functions are more liable to
injury than others. Thus it is that some of those muscles which
have their attachments widely separated and are subjected to
sudden and violent strain, are often the site of laceration or rup-
ture. The great stretching which the sterao-mastoid from its
position must necessarily undergo during the birth of the after-
coming head, by no means infrequently leads to some laceration,
resulting in the formation of a hsematoma, which constitutes the
so-called tumour or gumma of the sterno-mastoid. Torticollis
may result from the subsequent contraction.

The physiological action of the rectus abdominis in parturition,
or even def aecation, may occasion some laceration of its fibres, and
the consequent extravasation of blood which occurs within its

DISEASES OF TENDONS. 141

sheath may be widespread. Should the haematoma suppurate,
the pus will at first be confined by the sheath of the rectus, but
may track for a considerable distance within it, leading some-
times to most troublesome sinuses.

The biceps cuhiti arises by two heads, the long from the upper
border of the glenoid fossa, the short from the tip of the
coracoid process. The long tendon is a part of the muscle
which not infrequently gives way, and its passage through the
joint over the head of the humerus conduces to its laceration,
particularly when the tendon has been thinned by friction in
cases of osteo-arthritis. It may then acquire an attachment
lower down in the bicipital groove. The short head is rarely
torn. The belly of the muscle may be ruptured in very forcible
flexion against much resistance. The muscle is inserted by means
of a tendon into the posterior part of the bicipital tubercle of the
radius. In some cases of strong action, the tendon may be torn
away from its attachment, and may even drag a piece of bone off
with it.

The plantaris, arising from the back of the femur just above
the external condyle, has a small belly, terminating in a long,
slender tendon which is inserted into the tendo Achillis or into
the inner side of the posterior surface of the os calcis. The
tendon may be snapped in wrestling, slipping on the stairs,
tennis, etc.

The quadriceps extensor cruris. — Sometimes, and for the same
reasons that the patella is transversely fractured by muscular
action, the tendon of the quadriceps may be torn across close
above its insertion, the patella remaining intact.

Diseases of Tendons.

Many tendons, especially when long as those of the flexors
and extensors of the fingers and toes, are surrounded by a
fibrous sheath lined by a synovial membrane. Such tendons
from their anatomical position are liable to considerable action,
and often to external violence.

142 CLINICAL APPLIED ANATOMY.

Tenosynovitis. — Inflammation of the tendon sheaths of an acute
character occurs either from simple over-exertion, as in the flexor
sheaths of the wrist from rowing, or from infection by a punctured
wound, as in many cases of whitlow.

Tendon Sheaths of Wrist and Hand. — The flexor tendons as
they pass deep to the anterior annular ligament of the wrist are
covered with a synovial sheath of a large size which is common
to all except the flexor longus pollicis. This sheath extends
upwards for two fingers' breadth above the upper border of the
annular ligament. Downwards it tends to spread out upon the
tendons, terminating in three diverticula about the middle of the
metacarpal bones of the index, middle and ring fingers, but in
the case of the little finger, it is prolonged downwards as far as
the base of the terminal phalanx. In addition, the tendons
belonging to the three outer fingers have additional and separate
synovial linings to their sheaths, starting opposite the heads of
the several metacarpal bones, and ending at the bases of the last
phalanges. It will thus be seen that there is an interval between
the large common synovial sheath in the palm and the special
sheaths in these digits.

The flexor longus pollicis tendon has its own sheath lined by
synovial membrane, which extends from about one-and-a-half
finger's breadth above the annular ligament continuously to the
base of the second or terminal phalanx of the thumb. Sometimes
this special synovial sheath communicates with the larger common
sheath near the annular ligament.

Pricks of the pulp of the digits, as with a needle or pin, are
very apt to be followed by septic inflammation, leading to the
varieties of whitlow. It is easy to see how a synovial sheath may
become secondarily infected from this adjacent inflammation.
It is possible that at certain spots, particularly opposite the
interphalangeal joints where the fibrous sheaths are thin or
even fenestrated, the synovial membrane may bulge and become
primarily inoculated with bacteria.

If the theca of the flexor tendons of the little finger is involved,
the inflammation may spread directly into the common synovial

DUPUYTEEN'S CONTEACTION. 143

sac. If the theca of the tendons of the index, middle or ring
finger is the site of the mischief, it may be confined to the
digital part, but sometimes it may pass over the gap and involve
the common sac. If the theca of the flexor longus pollicis is
infected, suppuration may be limited to it, though occasionally
pus may find its way into the large palmar sac.

If a thecal abscess is present, flexion of the terminal phalanx of
the digit becomes impossible, when the intermediate phalanx is
prevented from being flexed by the pressure of the surgeon's
finger against its palmar aspect. If the pus is superficial to
the sheath, this function of flexion of the terminal phalanx is pre-
served. An incision to evacuate the pus in a theca should be so
planned as to cause the least possible damage to the surrounding
structures. It is best to approach the sheath between the head
of the metacarpal bone and the first interphalangeal joint on the
palmar aspect, and in the median line of the digit.

When incisions are needful higher in the palm of the hand,
they must not be carried nearer the wrist than the level of the
abducted thumb for fear of wounding the superficial palmar arch,
and should be in a line continued upwards from the middle line
of the finger.

Diseases of Fascia.

Contraction of the Palmar Fascia (Dupuytren's) . — The deep
fascia of the palm consists of three portions, the dense central
part or the palmar fascia proper, and the lateral portions, much
less important, covering the thenar and hypothenar muscles.

The central portion consists of a strong, triangular layer of
white fibrous, almost ligamentous, tissue. The apex is attached
to the lower edge of the anterior annular ligament, and is con-
tinuous with the termination of the palmaris longus tendon, when
this is present.

A very large number of fine bands pass from its superficial
aspect to become attached to the deep aspect of the skin. When
these are shortened, as in Dupuytren's contraction, they tend to

144 CLINICAL APPLIED ANATOMY.

drag inwards small islets of skin and so to form deep narrow pits,
into which often nothing larger than the head of a pin can be
passed. The deep surface of the fascia is quite smooth, and
overlies the tendons.

As the fascia proceeds towards the digits it broadens out, and
at the heads of the four inner metacarpal bones it divides into
four slips, one of which passes to the root of each finger. Here
it is connected with transverse fibres, constituting the superficial
transverse inter-metacarpal ligament ; it then divides into two,
passing on either side of the digits to blend with the fibrous
sheaths of the flexor tendons.

Contraction of this central part of the fascia and particularly
its inner portion gives rise to " Dupuytren's contraction of the
palmar fascia." One or more of the digital processes of the fascia
becomes for some reason contracted, and the resulting deformity
is characteristic. First, the finger connected with the shortened
process is flexed more or less markedly at the metacarpo-
phalangeal joint, with often the terminal phalanx slightly flexed
upon the second. Greater flexion of the affected digit can be
brought about, but active or passive full extension is impossible.
The little and ring fingers are the most frequently and the first
to be contracted. Secondly, when forcible efforts are made to
extend these fingers, very distinct bands of fascia stand out
under the skin of the palm, and the pits which have already
been mentioned become increased in depth.

Operative treatment is generally indicated, and may consist of
either multiple subcutaneous division of the contracted bands or
their exposure and removal by dissection. Strict asepsis is
essential for the success of such operative measures, whether
open or subcutaneous. The flexion of the fingers, sometimes
extreme, and the creases and pits in the skin of the palm render
cleansing peculiarly difficult. Thorough scrubbing of the opposed
surfaces and the depths of the depressions is almost impossible,
so that it is desirable to soak the hand in an antiseptic solution
for a lengthened period before operation is undertaken, in order
that all parts may be reached by the germicide.

DISEASES OF BUES^. 145

Diseases of Burs^.

A bursa is strictly speaking a closed sac wholly lined with
synovial membrane. Some sub-tendinous so-called bursas have
direct communications with joint cavities, and are then in reality
extensions from the joint and are lined with a prolongation of
synovial membrane continuous with that of the joint itself.

Enlargement of Bursse. — Bursitis. — A bursa may become
enlarged, usually by over-distension with bursal fluid, without
any obvious signs of inflammation, though probably inflammatory
influences are the ultimate cause of the increase in secretion.
There are certain bursse which from their anatomical position
are peculiarly liable to intermittent pressure or irritation, and
are consequently those which are most frequently enlarged.

Pre-patellar bursa. — The bursa which is found in the tissue
between the skin and the anterior aspect of the patella is more
commonly over-distended than any other in the body. This
bursa lies over the lower part of the patella and the upper part
of the ligamentum patellae, and is usually called the prepatellar
bursa. It is the largest bursal sac which normally exists.
Often its interior is divided by crossing bands of fibrous tissue
and it is not infrequently multilocular.

Inflammation of this bursa with a large excess of bursal fluid
is very apt to occur from kneeling, and particularly in that form
of kneeling and leaning forwards with a certain amount of
movement of the parts knelt upon, as is occasioned in the
process of washing a floor. It is thus that the enlargement is
often seen in housemaids, carpet layers and others whose occupa-
tion entails such a position. Sometimes the walls of the bursa
become very much thickened, and the tumour formed may be
practically a solid one, but its position indicates its probable
origin.

Excision of the bursal sac is the most satisfactory treatment.
This can be accomplished without difficulty or danger, though
perhaps warning should be given on two points. The first is
that the skin over the front of the knee is not infrequently much

C.A.A. 10

146 CLINICAL APPLIED ANATOMY.

thickened and furrowed in those who kneel, and it requires a
considerable amount of care to render it thoroughly aseptic.
The second is that when the bursa is very much enlarged it may
laterally overlap the capsule of the knee-joint, and dissection on
the deep surface of the sac must be carried out with due caution
not to open the joint cavity.

Owing also to the exposed position of this pre-patellar bursa,
it is liable to be the site of punctured wounds, such as from
needles, which may carry infection into the sac. An acute septic
bursitis results. This may also follow infection by the blood
stream. Pus within the sac of the pre-patellar bursa will be
prevented from finding its way through the overlying skin owing
to its denseness. Nor will it be able, fortunately, to pass easily
into the cavity of the knee-joint because of the resistance of the
capsule. It will, therefore, when it transgresses the wall of the
sac, become extravasated as it were into the loose subcutaneous
cellular tissue about the joint. Sometimes this condition has
been mistaken for septic arthritis, but the fact that the patella is
buried in the inflammatory material instead of being prominent,
and riding on the surface of the fluid, should easily lead to a
correct diagnosis. Free evacuation of the pus is necessary,
otherwise the overlying skin may slough, being to a great extent
cut off from its blood supply.

Post-ligamental bursa. — This bursa lies between the posterior
aspect of the patellar ligament and the front of. the upper part
of the head of the tibia. It may be sometimes enlarged from
the irritation produced by repeatedly using the knee to fix a
piece of wood against a carpenter's bench. The bursa does not
communicate with the knee-joint, but in spite of this fact dis-
tension may simulate a collection of fluid within the joint. The
swelling, however, caused by the bursa only obliterates the lower
natural depressions, namely, those on either side of the liga-
mentum patellae and not those seen laterally above the patella, all
four of which concavities are lost in synovitis of the knee-joint.

Semi-memhranosus bursa. — This sac is a so-called bursa situated
between the tendon of the semi-membranosus and the inner head

BNLAKGEMENT OF BURS^. 147

of the gastrocnemius, or in some cases more directly between
that head and the posterior ligament of the knee-joint. In by
far the greater number of cases the bursa communicates with
the knee-joint, and there is a great tendency for it to be dis-
tended with fluid when there is inflammation of the synovial
membrane of this joint. In the flexed position of the knee the
bursa becomes less tense, and it is possible to squeeze some of
its contents into the cavity of the articulation. In this way the
enlarged bursa is said to disappear in this position of the limb.
In extension fluid is forced from the interior of the joint into
the bursa, which now becomes palpable as a tense cyst lying
on the inner side of the posterior aspect of the joint, just
external to the tendon of insertion of the semi-membranosus
muscle.

The bursa is probably the starting point in many instances
of a synovial cyst which later on may be entirely disconnected
with the joint, and may enlarge peripherally for some consider-
able distance. Such synovial cysts are frequently tuberculous in
nature.

Sartorius bursa. — The bursa placed between the expanded
tendinous insertion of the sartorius muscle and the insertions
of the gracilis and semi-tendinosus is sometimes the seat of
enlargement. The bursa does not communicate with the knee
joint.

Sub-crureal bursa. — This bursa lies between the quadriceps
tendon and the anterior surface of the lower part of the shaft of
the femur, and is in reality a prolongation upwards of the
synovial membrane of the joint. Hence it follows that a dis-
tension of the synovial cavity is usually accompanied by a
filling- up of this sac with fluid, which may readily be pressed
out of the sac into the joint, so as to make the sign of riding of
the patella easily obtainable.

It follows from the position of this bursa and the two others
which communicate with the knee joint, namely the semi-
membranosus and the popliteal, that a punctured wound
involving any one of them, although appearing to be at some

10—2

148 CLINICAL APPLIED ANATOMY.

little distance from the joint proper, may yet give rise to septic
arthritis.

Ischial tuberosity bursa, — From prolonged sitting, and parti-
cularly when associated with a certain amount of movement
upon the seat, the bursa superficial to the tuber ischii becomes
chronically inflamed. Hence coachmen, omnibus drivers,
weavers with a hand loom, and others with similar occupations
are liable to this affection. It is, moreover, not an uncommon
site for gummatous disease.

Trochanter bursa. — The bursa lying over the trochanter major
of the femur may also become the seat of inflammation, parti-
cularly in persons who are thin and who have to lie upon hard
substances, or who carry a bag which intermittently rubs over
the region of the bursa.

Psoas bursa. — This lies on the front of the hip-joint beneath
the psoas and may communicate with the articular cavity.

Olecranon bursa. — The bursa normally found over the lower
part of the olecranon process is apt to become irritated and thus
inflamed in persons following certain occupations, such as
packers and miners. Effusion into this bursa produces a
swelling in the middle line posterior to the bone, and obscures
the olecranon, instead of the swelling on either side of this
process as in synovitis of the elbow. But it is perhaps more
commonly the site of acute septic inflammation from punctured
wounds, the outcome of falls upon the point of the elbow. In
these cases long-continued suppuration, and perhaps even
necrosis of the bone, may result unless free discharge of the pus
is provided for.

Sub-deltoid bursa. — This bursa is situated between the deltoid
and the capsule of the shoulder joint. It may become enlarged
as the result of chronic inflammation, and the swelling thereby
caused may be mistaken for inflammatory mischief in the
shoulder-joint. The position of the bursa, however, indicates
that it is unlikely that any fulness can be felt or seen in the
axilla, whilst the deltoid appears much more stretched and
tense. It should also be remembered that distension of the

TALIPES. 149

shoulder-joint, even when inflammation is present, is rarely
well marked.

In addition to the above natural bursse, certain exposed bony
points which are prone to receive intermittent pressure may have
adventitious bursse developed over them. The most common
example of this is the bursal sac which forms over the inner
side of the head of the first metatarsal bone and the first
metatarso-phalangeal joint, particularly in cases of hallux valgus,
constituting what is ordinarily called a bunion. Chronic or
acute inflammation of this bursa is by no means infrequent. If
suppuration occur, pus may find its way into the subjacent joint
and lead to acute septic arthritis.

Hsemorrhage into Bursse. — Bursal sacs may become distended
with blood as the result of falls or blows upon them. This is
particularly liable to occur in the case of the pre-patellar and the
olecranon bursse.

Talipes.

Flat-foot (Talipes valgus). — Flat-foot is a very common
complaint. The longitudinal arch of the foot is made up of a
posterior and an anterior pillar. The posterior is the shorter
and more vertical of the two, and consists of the whole of the
OS calcis and all of the astragalus except the anterior part of its
head, namely that portion which is received into the cup-like
depression on the posterior surface of the navicular. The
anterior pillar consists of the tarsus and metatarsus, but readily
falls into two portions, an inner, made up of the navicular, the
three cuneiforms and the three inner metatarsals, and an outer
composed of the cuboid and the two outer metatarsals. The
phalanges take no share in forming the arch.

The conformation of the bones, particularly the articulating
surfaces of the head of the astragalus and the posterior facet of
the navicular, is one of the factors in the preservation of the
longitudinal arch.

In close contact with the bones are the ligaments, the second

150 CLINICAL APPLIED ANATOMY.

factor in the maintenance of the arch. Of these the important
are, — (1) The inferior calcaneo-navicular, attached behind to the
front of the sustentaculum tali and in front to the under and inner
surface of the tubercle of the navicular. This ligament underlies
and therefore supports the head of the astragalus, the only part
of that bone which can in any way be termed the keystone of
the arch. The ligament contains much elastic tissue, and is often
termed the ''spring" ligament. (2) The long plantar ligament,
attached behind to the under surface of the os calcis and in front
to the margins of the groove on the under surface of the cuboid,
in front of the tuberosities, and the bases of the third, fourth and
fifth metatarsals. (3) The short plantar ligament, attached
behind to the front of the under surface of the os calcis and in
front to the under surface of the ridge forming the posterior
boundary of the groove on the inferior aspect of the cuboid.
(4) The anterior part of the internal lateral ligament of the ankle
joint.

The third factor in maintaining the arch is formed by the
tendons of certain of the leg muscles. Of these the most
important are those of the tibial muscles.

The tibialis posticus tendon passes in a groove behind the
internal malleolus, then across the inner surface of the susten-
taculum tali to the under and inner surface of the tubercle of the
navicular, superficial to the inferior calcaneo-navicular ligament.
The tendon also sends expansions backwards to the sustentaculum,
outwards to the cuboid and forwards to the bases of the second,
third and fourth metatarsals. It will thus be seen that this
muscle is a most powerful supporter of the longitudinal arch of
the foot, particularly from its position in reference to the spring
ligament, and through it to the head of the astragalus. The
tibialis anticus tendon lies anterior to the lower end of the
tibia, and crossing inwards on the dorsum of the foot runs to
be inserted into the inner and under surface of the internal
cuneiform and base of the first metatarsal. Both of these
tendons come out into prominent relief when a person stands
over on the outer edge of the foot. In addition to these two

Flat-foot,

- Tibialis anticus.

— Tibialis posticus.

Flexor longus digitorum.
— Flexor longus hallucis.

Plantar fascia.

Fig. 8.— Diagrammatic representation of structures maintaining the longitudinal arch

of the foot.

[To face page 150.

FLAT FOOT. 151

tendons, those of tlie flexor longus digitorum and the flexor
longus hallucis aid in supporting the arch.

The next factor is constituted by certain of the short muscles
of the sole of the foot, especially the abductor hallucis on the
inner side and the flexor brevis digitorum in the middle. After
this the strong plantar fascia bears its share in the support ; and
lastly, the skin also takes a part.

To recapitulate the factors which maintain the longitudinal
arch, they are : — the bones, certain ligaments, the tendons of
some of the long muscles of the leg, certain short muscles of the
sole of the foot, the plantar fascia and the skin. (Fig. 8.)

The pain felt in many cases of flat-foot is mostly due to the
pressure exerted on the nerve-terminations in the ligaments
which are subjected to stretching, it being a well-known fact
that although ligaments and tendons may be cleanly divided
with but little discomfort, yet longitudinal tension of the same
leads to severe pain. When the bones constituting the longi-
tudinal arch have become so displaced as to no longer cause
tension of the ligaments, rigidity results and pain subsides
almost entirely.

In flat-foot an extra bony point becomes prominent on the
inner side of the sole of the foot. Normally the internal
malleolus, the tuberosity of the navicular, and the base and head
of the first metatarsal are the bony points readily discernible.
When the arch is lost the head of the astragalus forces its way
into prominence between the internal malleolus and the tuberosity
of the navicular, the front of the foot being abducted and, as it
were, partially dislocated outwards at the astragalo-navicular
articulation.

The transverse arch is most marked at the line of the tarso-
metatarsal joints, and is chiefly caused by the wedge shape of
the three cuneiform bones and of the bases of the metatarsals.
The tendon of the peroneus longus, and possibly the adductor
obliquus hallucis and the transversus pedis (adductor transversus
hallucis) muscles help to maintain the transverse arch.

Congenital Talipes Equino- varus. — Equino- varus is the most

162 CLINICAL APPLIED ANATOMY.

common compound or secondary form of club-foot occurring
congenitally. The heel is raised, and the foot, particularly in
front of the transverse tarsal joint (that is, the combination of the
two joints between the astragalus and os calcis posteriorly and the
navicular and cuboid anteriorly) is turned inwards. The tendons
which are taut are the tendo Achillis behind, inducing the equinus,
and the tibialis anticus, tibialis posticus, together with the flexor
longus digitorum and flexor longus hallucis on the inner side,
inducing the varus. On the outer aspect of the foot the anterior
end of the os calcis becomes very evident, and not infrequently
the external surface of the neck of the astragalus can be readily
felt. The head of the astragalus looks somewhat inwards,
because the neck is markedly elongated on its outer aspect and
shortened on its inner. The external malleolus is prominent,
while the internal malleolus may be somewhat buried. A well
marked vertical furrow may be seen on the inner side of the foot,
indicating the transverse axis at which adduction and internal
rotation has occurred, while on the outer side after the child has
commenced to walk, a callosity and even an adventitious bursa
may be formed.

It will thus be seen that in the treatment of these cases, if the
tendons which are contracted can be stretched and the anterior
part of the foot abducted and externally rotated, a cure may
be effected. Forcible manipulation and massage commenced
immediately after birth will in a large number of cases lead to a
restoration of position by obtaining the above results. The
equinus as a rule is more difficult to correct than the varus by
these manipulative procedures.

Should the case, however, be one in which the correction of
the deformity has been imperfect, or, if the patient is not seen
until the parts have become considerably fixed, certain tenotomies
are needful. The tendons most commonly requiring division are
those of the tibialis anticus and posticus and the tendo Achillis.
It is desirable that the division of these tendons should be done
in the following order : — the tibial tendons first and the tendo
Achillis last, so that after division of the tibials the tendo Achillis

TALIPES EQUINO-VAEQS. 153

may still act as a point from which manipulation may be under-
taken to cure the varus.

The place at which division of the three tendons should be
carried out must be carefully noticed. The tibiahs anticus may
be conveniently divided close above its insertion into the inner
and plantar aspect of the internal cuneiform and base of the first
metatarsal and therefore below the ankle joint. The tibialis
posticus can be satisfactorily attacked immediately behind the
internal border of the tibia, at the base of the internal malleolus.
The tenotome placed between the bone and the tendon cuts,
backwards and inwards, and may easily at the same time divide
the flexor longus digitoriim. There is not the least disadvantage
in so doing, provided the knife does not go further and injure the
posterior tibial artery immediately posterior to the tendon of
the long flexor of the toes. Behind this again will be found the
posterior tibial nerve and posterior to it the flexor longus hallucis
tendon ; but none of these structures should ever really be in
danger in tenotomy of the posterior tibial tendon.

The section of the tendo Achillis is best performed where that
structure is rounded, namely, a little below the level of the tip
of the internal malleolus. A puncture is made with a sharp
tenotome from the inner side in front of the tendon, care being
taken not to insert the point of the instrument into the substance
of the tendon, which is decidedly thick at this spot. A blunt
tenotome is then introduced, and its cutting edge directed
towards the anterior surface of the tendon. Whilst the last
fibres are being divided, and particularly the moment when they
give way and the foot is released, the skin lying posterior to the
tendon is very apt to be cut through, an accident which may lead
to disastrous results.

Even after the division of these tendons it may be found that
full correction is impossible, mainly owing to the contraction
of other tissues on the inner side of the foot, including skin,
fascia, the abductor hallucis and even the ligaments. It may,
therefore, become necessary to divide all these constricting
structures down to the bones themselves, but as a rule such

154 CLINICAL APPLIED ANATOMY

a proceeding should not be carried out without an accompanying
tarsectomy.

A cuneiform tarsectomy for varus has the base of the wedge
looking outwards and somewhat upwards. The section as a rule
passes through the anterior part of the os calcis and the head of
the astragalus posteriorly; through the joint between the cuboid
and the fourth and fifth metatarsals, across the base of the
external cuneiform and through the navicular anteriorly. There-
fore the parts removed will consist of portions of the anterior
part of the os calcis and the astragalus, the whole of the cuboid
and parts of the external cuneiform and the navicular. In the
young subject it must be remembered that all this mass is to
a very great extent cartilaginous.

Acquired Talipes Equino- varus. — Infantile paralysis is the
most common cause of acquired varus or equino-varus. In this
condition the deformity is brought about by the active contraction
of the unopposed non-paralysed muscles and the subsequent
shortening of the muscular tissue between the approximated
noints of their origin and insertion. Hence it comes about that
a deformity will result with rigidity of the neighbouring joints.
In order that equino-varus should occur, paralysis of the anterior
tibial group is necessary — that is to say, paralysis of the tibialis
anticus, extensor proprius hallucis, extensor longus digitorum
and peroneus tertius, supplied by the anterior tibial nerve. In
some cases, moreover, the peroneus longus and brevis may be
likewise affected. Seeing that anterior tibial paralysis is the most
common form met with as a result of anterior poliomyelitis, it
follows that equino-varus is the usual variety of deformity that
ensues.

In cases, however, where paralysis involves both the anterior and
posterior tibial groups, it is extremely unlikely that contraction
and rigidity will occur, but laxity and flail-like joints will result.

In those cases in which one group of muscles alone is paralysed,
an interesting anatomical question arises in connection with
the method of treatment by tendon-grafting or tendon -trans-
plantation. In cases of equino-varus resulting from paralysis

TALIPES CALCANEO-VALGUS. 155

of the anterior tibial group, it may be possible to bring a part of
the tendon of the active tibialis posticus forwards around the
inner side of the tibia, and to graft it into the tendon of the
paralysed tibialis anticus. Supposing that the peroneus longus
retains its activity, part of its tendon may be carried across the
antero-external surface of the leg above the external malleolus,
and fixed to some or even all of the tendons of the paralysed
extensor group. On the other hand, should the peronei have
lost their function, the outer part of the tendo Achillis may be
fixed to them.

Talipes Calcaneo-valgus. — It is uncommon to get pure talipes
calcaneus or pure talipes valgus (if fiat-foot is excluded), and not
very common even to see the combination of the two.

The position of the foot in calcaneo- valgus is that the anterior
portion of the foot is dorsi-flexed, abducted and somewhat
externally rotated.

In acquired cases from infantile paralysis, the contracted
tendons are those of the anterior tibial and peroneal group,
particularly the peroneus longus and brevis and the extensor
longus digitorum. In the operative treatment by tendon -grafting,
a portion of the active tibialis anticus tendon may be grafted
into the paralysed tibialis posticus, and the whole of the peroneus
longus spliced into the tendo Achillis.

CHAPTER XI.
DISEASES OF THE NEKVOUS SYSTEM.

The Brain and its Membranes,
meningitis.

SuppuratiYe meningitis may be local or diffuse. The common
form is a diffuse leptomeningitis involving the base or the
convexity of the brain or even the whole area of the subarachnoid
space. The wide extent and loose meshwork of this space
especially favour the diffusion of the suppurative process. On
the convexity of the brain the pus at first lies in the sulci where
the spaces between pia and arachnoid are larger than over the
convolutions.

The meningitis is always associated with encephalitis because
the lymphatic sheaths of the pial vessels carry the infection to
the superficial layers of the brain substance. The interior of
the brain may also be invaded by extension along the pia and
arachnoid where they become invaginated into the cerebral^
ventricles at the great transverse fissure.

The infection of the meninges may be direct or through the
medium of arteries, veins, or lymphatics.

Direct infection is the result of open fractures of the vault of
the skull, of perforating wounds or of basal fractures which
involve the cavities of the nose, the naso-pharynx or the ear.
Infection through the medium of the arterial stream occurs in
certain general infective diseases of which pneumonia may be
taken as an example, and also in pyaemia. The emissary and
some of the diploic veins of the skull may carry suppurative
organisms to the sinuses and so to the membranes. In some
cases the lymphatic sheaths surrounding the arteries which enter

POSTEEIOE BASIC MENINGITIS. 157

the skull or the sheaths which surround the cranial nerves may
serve as channels of invasion.

Acute meningitis is often secondary to disease of the ear or
nose ; it may also follow disease of the air sinuses of the skull,
the orbit, globe of the eye or brain itself.

From the ear there are several paths of invasion. The canal
of the facial nerve affords a direct channel from the tympanum,
when its bony casing is incomplete. In disease of the cochlea
the sheath of the auditory nerve may convey the infection. The
veins of the tympanum may infect the superior petrosal or lateral
sinuses, and in infants and young persons the petro-squamous
suture may be permeable. Defects in the tegmen tympani may
afford a direct path for infection of the overlying membranes,
but here a subdural or temporo-sphenoidal abscess occurs rather
than leptomeningitis, since the dura, arachnoid and pia all lie in
the closest contact in this region.

The free communication of the perineural lymphatics of the
olfactory nerve filaments with those of the nasal mucous mem-
brane explains the occurrence of leptomeningitis in connection
with nasal disease. Caries of the ethmoid will afford a direct
path to the membranes or the bone may be perforated during
operations in this region. Disease of the frontal or ethmoidal
sinuses may spread directly to the meninges in the neighbourhood.

Suppurative disease of the orbit may extend to the interior of
the skull along veins or lymphatics and suppuration in the globe
of the eye may spread back to the membranes along the sheath
of the optic nerve.

Abscesses near the surface of the brain can infect the pia and
arachnoid directly, and a localised leptomeningitis also may be
found overlying superficial cerebral new growths.

Posterior basic meningitis is due to infection of the walls of the
great subarachnoid cisterns which lie at the base of the brain
and around the pons and medulla. The inflammation extends
through the transverse fissure to the interior of the ventricles
and may also involve the membranes of the cord by con-
tinuity. The infective agent is probably carried to the meninges

158 CLINICAL APPLIED ANATOMY.

in the first place by the blood stream, but it has been suggested
that the primary invasion may be from the nasopharynx along
the perineural and perivascular lymphatic sheaths or by way of
the Eustachian tube to the tympanum and thence to the meninges
by veins which traverse the petro- squamous suture if that be still
open. If this suture be closed there are still other efferent veins
from the tympanum which may carry infection.

The subarachnoid space communicates directly with the tubular
investment of the auditory nerve and so with the perilymph
spaces of the internal ear, but it does not communicate with the
endolymph spaces or with the tympanum. Consequently it is
improbable that infection travels to the meninges from the middle
ear along the auditory nerve sheath. Infection, however, may
and does travel in the reverse direction, and in this way otitis
interna sometimes develops secondarily to the meningitis, but
the otitis media of posterior basic meningitis is more commonly
due to infection along the Eustachian tube from the nasopharynx
of a stuporous patient.

In early cases of posterior basic meningitis the subarachnoid
cisterns are filled with a greenish exudation so that their
extent and connections become quite obvious. These cisterns are
formed by the wide separation of the pia and the arachnoid at
certain spots, whilst in other positions these membranes are
closely connected by a very small meshed areolar bond.

At the base of the brain a sheet of arachnoid passes between
the under surfaces of the temporal lobes near their inner margins,
and by bridging over the interpeduncular space forms the
cisterna basalis. This basal cistern is prolonged laterally along
the Sylvian fissures and anteriorly round the front of the corpus
callosum into the great longitudinal fissure. Posteriorly the
cisterna basalis is continuous with the cisterna pontis, which at
its fore part has lateral prolongations around the crura cerebri
leading to the large angular interval which lies dorsal ly between
the front of the cerebellum and the corpora quadrigemina. The
cisterna pontis is (continued behind into the tubular investment
of the medulla. This investment when viewed from below is

Meningitis.

Cisterna
pontis.

Cisterna

magna.

(Posterior

arachnoid

bridge.) 't

_ Olfactory lobes.

Optic nerve.

Internal carotid
arteiy.

- Tin id nerve.

- Fourtli nerve.

- - Fifth nerve.

Sixth nerve.

Seventh and
eighth nerves.

Ninth, tenth,

and eleventh

nerves.

Twelfth nerA-e.

Fig. 9.— Suppiirative meningitis, showing the outlines of the infected arachnoid cisterns
and the positions in which the cranial nerve trunks appear on the surface of the
arachnoid mater.

[To face page 159.

POSTEEIOE BASIC MENINGITIS. 159

seen to be limited by fusion with the pia on the under surface of
the cerebellum some distance away from the sides of the medulla
and pons, whilst it becomes abruptly narrowed at the lower part
of the medulla where it is continued as the arachnoid sheath of
the spinal cord. The dorsal part of the arachnoid sheath of the
cord is continued over the dorsal part of the medulla as far as just
within the foramen magnum and then turns back rather abruptly
to fuse with the under surface of the cerebellum. It thus forms
the posterior boundary of the cisterna magna, which occupies the
angular interval between the medulla and lower part of the cere-
bellum. The sheet of arachnoid just described as passing from
the medulla to the cerebellum is sometimes called the posterior
arachnoid bridge, and by careful removal of this the openings in
the pial covering of the fourth ventricle can be investigated.
This pial covering forms the anterior boundary of the cisterna
magna which, like the other cisterns, is a space between the pia
and arachnoid. (See Fig. 9.)

The great blood-vessels of the brain penetrate the arachnoid and
then lie in the subarachnoid cisterns, whilst sheaths of arachnoid
tissue are prolonged along the issuing nerves. Irritation of the
first cervical nerve where it traverses the subarachnoid space just
below the medulla may account for the rigidity of the neck and
retraction of the head which are such a marked feature in posterior
basic meningitis. This nerve supplies the short muscles which pass
between the atlas and axis and the occiput, and also the overlying
complexus, whilst the next one or two cervical nerves supply the
splenius and the trachelo-mastoid. It is said that the rotatory
movements between the head and spine are usually retained, c
at all events not resisted. It is also possible that inflammatory
irritation of the superior vermis of the cerebellum and the region
of the corpora quadrigemina accounts for the retraction and
opisthotonos which may occur. At the transverse fissure of the
brain, which lies immediately above the corpora quadrigemina, a
fold of j)ia mater with a basis of arachnoid tissue, forming the
velum interpositum, becomes invaginated ; this affords a track
by which inflammation spreads to the cavities of the ventricles.

160 CLINICAL APPLIED ANATOMY.

When the spinal theca is invaded, symptoms due to spinal
nerve irritation may be met with. One such symptom is an
increased irritability of the hamstring muscles, and is the basis
of Kernig's sign. Even under normal conditions the length
of the hamstrings is insufficient to allow the knee to be fully
extended when the thigh is flexed on the abdomen, but in spinal
meningitis and some other conditions the range of extension is
still further limited. Care must be taken, when eliciting the
sign, that the other thigh is kept in contact with the bed, lest
flexion of the pelvis on the spine conceal an imperfect flexion of
the thigh on the abdomen and so allow fuller extension of the
knee. If the greatest possible angle made by the back of the leg
with the back of the fully flexed thigh be less than a right angle
and a half, Kernig's sign may be considered to be present.

Hydrocephalus is usually secondary to posterior basic inflam-
mation. Sometimes it can be definitely attributed to obstruction
of the channels of communication between different parts of the
ventricular system. Such obstruction has been found at the
foramina of Monro causing distension of one or both lateral
ventricles ; in the iter, when the third ventricle is also distended ;
completely closing in the fourth ventricle, when the foramina of
communication between the ventricles and the subarachnoid
space are of necessity blocked ; or in the cervical region, just
below the foramen magnum, completely cutting off the spinal
from the cerebral subarachnoid space. The velum interpositum
may be matted to the edges of the transverse fissure, but the
veins of Galen are rarely occluded, so their influence in causing
hydrocephalus is problematical.

Hydrocephalus often exists without any obstructions such as
have been mentioned. It is then due to inflammations of the
ventricular cavities and can be drained by lumbar puncture,
the fluid passing from the fourth ventricle into the space between
the arachnoid and pia of the cord. The spinal cord terminates
in the adult at the lower border of the first lumbar vertebra, but
in the child extends to the third. The subarachnoid and sub-
dural spaces reach to a point opposite the middle of the second

TUBEECULOUS MENINGITIS. 161

sacral vertebra. Hence at all ages lumbar puncture may be
effected between the laminae of the third and fourth or fourth
and fifth lumbar vertebrae without risk of injury to the spinal
cord. The drainage is usually facilitated by flexion of the head
during the tapping since this movement opens up the angle
between the lower aspect of the cerebellum and the fourth
ventricle, and so allows free exit of the fluid. The subdural
space has no communication with the subarachnoid space and
the ventricular cavities, but in the treatment of hydrocephalus
an artificial communication is sometimes made in the hope that
the vessels of the dura may dispose of the excess of fluid which
has accumulated in the ventricles and subarachnoid space.

Tuberculous meningitis is in most instances a secondary
infection, the bacilli being carried to the leptomeninges in
the blood stream. A primary focus is commonly found in the
mediastinal glands, but sometimes the infection is derived from
the mesenteric glands, the lungs, bones, joints, or generative
organs. Occasionally direct infection of the brain substance can
be traced from the petrous bone, or the bones of the nasal cavity.
The meningeal tubercles are found in the pial sheaths of the
cerebral vessels ; they chiefly accumulate in the walls of the basal
cistern of the subarachnoid space and in its Sylvian prolongations,
and so follow the course of the middle cerebral arteries. A
moderate degree of hydrocephalus with consequent flattening of
the convolutions co-exists, the ventricles being invaded along the
velum interpositum which is invaginated into the brain at the
great transverse fissure. The inflammation is carried from
the meninges to the surface of the brain along the perivascular
sheaths of the small vessels passing into the cortex from the pia,
and a moderate amount of diffuse softening is thus produced.
Similar inflammatory softening is also present around the
ventricular cavities. In some instances the inflammation of
the pia and arachnoid is sufficiently intense to cause occlusion
of larger arterial branches which lie in the subarachnoid spaces
and then definite areas of softening may be found in the central
ganglia and sometimes in the cortex. In such cases the ganglia

C.A.A. 11

162 CLINICAL APPLIED ANATOMY.

suffer most because their circulation is absolutely terminal and
without anastomosis, whilst the amount of cortical anastomosis
varies in different individuals.

The symptoms of tuberculous meningitis correspond, in the
main, to the visible distribution of the lesions. The cranial
nerves of that part of the base affected usually suffer fairly early
in the disease ; the third, sixth and seventh are most commonly
picked out ; and squints, ptosis, and facial paralysis of the
complete nuclear type result. Partial facial paralysis of the
cortical type is due to extension of the inflammation along
the Sylvian fissures and towards the convexity of the hemispheres.
The prodromal aphasias and mental disturbance are attributed to
cortical oedema which may be transitory. Later on convulsions,
coarse tremors and rigidities point to cortical invasion, as also do
paralyses of hemiplegic or monoplegic distribution.

Head retraction is usually moderate and caused by extension
of inflammation to the posterior part of the base. The coma
may be explained by increasing ventricular distension. Throm-
bosis of the cerebral veins and sinuses is rare ; since the veins
of the cortex, unlike the arteries, communicate freely.

Tuberculous spinal meningitis is usually secondary to or
associated with meningitis of the cerebral meninges, the mem-
branes of the brain and cord being directly continuous. Like
the cerebral form, the spinal variety is a leptomeningitis
accompanied by effusion into the space between the pia and the
arachnoid. Owing to the dorsal posture assumed in the later
stages of the cerebral lesion, the morbid changes are best marked
on the dorsal aspect of the cord, and the posterior sensory nerve
roots are especially apt to suffer. The peripheral zone of the
cord itself may be invaded along the paths afforded by the pial
septa, the anterior and posterior roots, and the vessels which
enter the margin of the cord from its pial investment.

Diffuse syphilitic meningitis usually originates in the pia
and arachnoid as a rich cellular infiltration. The lesion, however,
is not limited to the leptomeninges, but spreads along the vessels
of the pia to the brain tissue on the one hand and to the adjacent

SYPHILITIC MENINGITIS. 163

dura on the other. The disease, therefore, presents itself as a
diffuse gummatous meningo-encephahtis and the resulting cranial
nerve paralyses may be associated with symptoms referable to
lesions of the crura, pons or medulla. These parts of the cerebro-
spinal axis may be compressed by the infiltrated membranes or
their nutrient vessels may become occluded and softening result.
Under these circumstances various forms of true " crossed-
paralysis" may present themselves, the cranial nerve paralysis
being on the opposite side to the hemiplegia. Crossed paralysis
may also be simulated; the paralysis of the cranial nerve and
the hemiplegia being caused by two separate and distinct foci of
disease, indeed syphilitic meningitis is characterised by its erratic
distribution as well as by its tendency to spontaneous remission
and relapse.

The vertex is sometimes the seat of the disease and the exposure
of the head to blows may appear to favour manifestations in this
locality. If the meningitis lies over the precentral convolution,
Jacksonian epilepsy may be expected. Syphilitic meningitis is,
however, most characteristically seen at the base of the brain,
especially in the region of the optic chiasma and between the crura
cerebri. The relations of the cranial nerves to each other as
they lie in the membranes and to the three fossae of the base of
the skull are of importance in the diagnosis and localisation
of the mischief. The relations which different nerve trunks bear
to each other on their course through the membranes to their
foramina of exit is in several instances very different from the
relations of the nuclei of the same nerves in the cerebro-spinal
axis, and thus disease in the meninges may be differentiated from
disease within the brain. An accurate knowledge of the relations
of the nerves to the different fossae of the skull is of further
assistance in localisation of the lesion.

In the anterior fossa lie the olfactory nerves ; to the middle fossa
belong the fifth and sixth nerves, with those above them, except the
olfactory ; to the posterior fossa belong the fifth and sixth nerves
and those below them. The fifth nerve may be said to lie at the
junction of the middle and posterior fossae, its stem of origin

11—2

164 CLINICAL APPLIED ANATOMY.

from the pons belongs to the fore part of the posterior fossa,
whilst the Gasserian ganglion and the three subdivisions of the
nerve belong to the middle fossa.

In the middle fossa the third, fourth and sixth nerves may be
involved where they are concentrated in the cavernous sinus or
at the sphenoidal fissure, and in such case the optic nerve is also
involved as a rule. Affection of the optic chiasma may cause
hemianopia.

The fifth nerve may be picked out by itself as also may one of
the ocular nerves. Since the sixth nerve where it pierces the
dura is nearer to the fifth than to any other cranial nerve the
two may suffer together.

In the posterior fossa the fifth and seventh nerves may be para-
lysed together ; or the fifth with the ninth, tenth, eleventh and
twelfth ; or the seventh and eighth. Paralysis of the vago-accessory
and hypoglossal nerves, producing unilateral paralysis of palate,
tongue and soft palate, is also characteristic of a lesion at the
base, outside the medulla and in the region of the jugular and
hypoglossal foramina. Or the hypoglossal nerve and the spinal
portion of the spinal accessory nerve may be damaged in the
membranes near the foramen magnum, producing an associated
paralysis of the trapezius, sterno-mastoid and corresponding half
of the tongue.

Special combinations of nerves pointing to basic as opposed to
pontine lesions are fifth and sixth, seventh and eighth, eleventh
and twelfth. The nuclei of origin of these pairs of nerves are
more widely separated than their trunks are where they lie at the
base of the brain. But the intimate relation of the seventh and
eighth nerves in the petrous bone renders exclusion of disease
of the ear necessary before the inference of a meningeal affection
is drawn from their associated paralysis.

CEREBRAL HEMORRHAGE.

The corpus striatum and its immediate neighbourhood are by
far the most common situations of haemorrhage into the substance

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CEREBEAL H^MOEKHAGE. 165

of the brain. Hgemorrhage may also occur in the centrum ovale,
the cortex, the pons, and the medulla. The right and left cerebral
hemispheres are equally liable, the vascular arrangements being
identical. There are several reasons why the arteries of the
central ganglia should rupture more frequently than those of
the other parts. The arteries are short and come off directly
from the large main stem, they are terminal vessels with no
collateral circulation to relieve the pressure in them, and
they receive poor support from the surrounding grey matter.
The pressure in these central vessels is probably nearly as
great as the pressure in the internal carotid at their point
of origin. (See Fig. 11, p. 166.)

The actual starting point of the hasmorrhage in the corpus
striatum depends on the vessel which gives way. A clot in the
head of the caudate nucleus is derived from the perforating
branches of the anterior cerebral artery ; haemorrhage into the
middle part of the nucleus comes from the lenticular or lenticulo-
striate branches of the middle cerebral artery ; haemorrhages in
the posterior part are derived from the lenticulo-optic branches
of the same main trunk. The lenticulo-striate artery from the
frequency with which it is the source of the bleeding has been
called the artery of cerebral haemorrhage. Tliis vessel passes
upwards from the anterior perforated spot through the putamen
or outer zone of the lenticular nucleus to terminate in the internal
capsule and the body of the caudate nucleus. Extravasations of
blood from this artery lie immediately outside the motor section
of the internal capsule on which they exercise pressure or into which
they plough their way, producing hemiplegia. They also tend to
separate the putamen from the external capsule since anatomi-
cally there is but little adhesion between these two structures.
Haemorrhage from the lenticulo-optic branch of the middle
cerebral artery is in a position to cause pressure on the posterior
or sensory portion of the capsule. (Fig. 10, p. 165, Fig. 12, p. 179.)

The origin of cerebral haemorrhage may be in the optic
thalamus instead of in the corpus striatum. The lenticulo-optic
artery may be responsible for haemorrhage here also, and its

166 CLINICAL APPLIED ANATOMY.

relation to the sensory portion of the capsule has just been
indicated. Branches derived from the posterior cerebral artery
help to supply the outer part of the thalamus, and these may
give rise to bleeding which also causes pressure on the sensory
part of the capsule, and may extend either towards the third
ventricle or downwards into the crus. The posterior cerebral
and posterior communicating arteries supply branches to the
ventricular portions of the optic thalamus, and haemorrhage from
these may easily break into the ventricles. (Fig. 10, p. 165.)

A large haemorrhage in the white matter of the hemisphere
has usually spread into it from the corpus striatum. When
primary haemorrhages occur in the white matter they are usually
small and of oval outline, being compressed into this form by the
general direction of the nerve fibres among which they lie.
Branches of the calcarine arteries from the posterior cerebral
trunk are the sources of haemorrhages in the white matter of the
occipital lobe close to the visual centre.

Large haemorrhages in the hemispheres tend to burst into the
ventricular cavities rather than on the surface. They travel in
the direction of least resistance. Having gained access to the
lateral ventricle the blood passes from one cavity to another
through the natural communications, and may ultimately reach
the fourth ventricle and exercise pressure on the important
bulbar nuclei or induce glycosuria. Blood from the ventricles
may appear outside the brain by traversing the transverse or the
choroidal fissures, or may burst through the floor of the third
ventricle, or in some cases invade the pituitary body. The blood
when it appears on the brain surface infiltrates the subarachnoid
space and may form a thin coating over the cerebellum and other
parts.

Branches of the posterior cerebral trunk and of the posterior
communicating artery supply the cms, but are seldom responsible
for primary haemorrhage into its substance. -The crus may also
be infiltrated from above by a haemorrhage which has ploughed
up the basal ganglia or from below by a haemorrhage extending
from the pons. Crossed paralysis or alternate hemiplegia

Cerebral Arteries.

Cortical arteries.

Leuticulo-stiiate
artery.

Middle cerebral
artery.

Caudate nucleus.
Optic tlialamus.

Tuber cinereum.

Optic tract.

Anterior per-
forated space.

Lenticular and lentioulo-optie arteries.

Fig. 11.— Diagram showing tlie nianrier of distribution of the cortical and central
branches of the cerebral arteries. (From Morris's Anatomy, after Arthur Robinson.)

[To face page lOG.

CEREBEAL HEMORRHAGE. 167

involving the third nerve of one side and the opposite half of the
body is characteristic of a lesion in the crus. This form of
paralysis may, however, be mimicked by multiple lesions else-
where, and also produced by pressure on the crus from without
by tumours.

The substance of the jums is dense and resistant. This part
of the cerebro-spinal axis consists of interlacing fibres, some
longitudinal and some transverse, moreover, it is provided
with a central raphe. Haemorrhages are therefore small, and
may be confined to one side. The extravasated blood may travel
out in the middle cerebellar peduncle towards the cerebellum,
or as mentioned before, up in the lower portion of the crus.
Each half of the pons is supplied by median branches of the
basilar artery and by radicular branches which pass in along the
nerves. The radicular branch which is most liable to give way
is the branch to the large trunk of the fifth nerve. The proximity
to the pons of the ocular nuclei, the presence in it of the nuclei
of the fifth and seventh nerves as well as the fact that it transmits
the motor and sensory tracts account for the important symptoms
which are associated with pontine haemorrhage. Haemorrhages
which encroach on the dorsal part of the pons may rupture into
the fourth ventricle.

Haemorrhage into the cerebellum is said to come from that
branch of the superior cerebellar artery which supplies the
dentate nucleus. The superior cerebellar artery is itself a branch
of the basilar. Cerebellar haemorrhage may rupture into the
fourth ventricle or spread over the surface of the cerebellum
beneath the pia and arachnoid.

Haemorrhage into the ventricles is usually secondary to
haemorrhage into other parts of the brain. Occasionally primary
haemorrhage occurs, and may be derived from the arteries w^hich
supply the wall of the ventricles. These arteries are mainly
branches of the posterior cerebral vessels, but the anterior
choroidal branches of the internal carotid also take part. It is
possible that ventricular haemorrhage is sometimes venous, being
derived from the striate veins.

168 CLINICAL APPLIED ANATOMY.

MENINGEAL Ha:MOKRHAGE.

Meningeal haemorrhage is called extra- dural when the blood is
effused between the skull and the dura mater ; sub-dural when it
lies between the dura and the arachnoid ; sub-arachnoid when it
lies between the arachnoid and the pia.

Extra-dural haemorrhage is usually due to traumatic rupture
of the middle meningeal artery, and from its position gradually
induces compression of the adjacent motor cortex and by gravi-
tation also comes to compress the nerves of the middle fossa on
the side of the haemorrhage.

Sub-dural haemorrhage may exist by itself or in association
with the other varieties. This form of haemorrhage may spread
widely in the subdural space and even surround the medulla or
spinal cord. A subdural collection of blood may come from the
meningeal arteries or veins, or from the great sinuses as a result
of their rupture. A particular variety is termed sub-dural
haematoma : it arises in connection with head injuries and is also
often associated with insanity.

Sub-arachnoid haemorrhage may result from rupture of
aneurysms at the base of the brain since the trunks on which
these aneurysms occur are contained in the sub-arachnoid spaces.
Haemorrhage from the interior of the brain may also make its
way into the same spaces in the manner already described.

CEREBRAL EMBOLISM.

A constricted or ulcerated mitral valve is the commonest cause
of cerebral embolism. Emboli are sometimes derived from clots
in the recesses of the left auricle or from the aortic valves, or
from an aneurysm of the arch of the aorta.

Clots from the systemic veins, large enough to produce embolic
softening of the brain, cannot traverse the pulmonary capillaries,
so when embolism accompanies thrombosis of the veins of the
uterus, lower extremities, or other parts, there is usually a left-
sided endocarditis or an abscess of lung to account for it. A

CEEEBEAL EMBOLISM. 169

patent foramen ovale or a defect in the ventricular septum might
conceivably allow a clot from one of the systemic veins to reach
the brain, but such an occurrence must be exceedingly rare.
In certain cases microbic emboli may be carried from the lungs
by the pulmonary veins and set up suppuration in the brain.

Emboli are frequently arrested at the points where vessels
bifurcate or become suddenly narrowed by giving off large
branches. As examples may be cited the internal carotid where
it breaks up into its branches near the base of the brain and the
division of the middle cerebral artery into a leash of cortical
vessels. Branches which form a more or less direct continuation
of the main trunk from which they spring are more likely to
receive plugs than those which come off at sharp angles. The
left common carotid is in a direct line with the first part of the arch
of the aorta, whilst the innominate trunk from which the right
common carotid is derived comes off from the aorta at a con-
siderable angle, consequently emboli are rather more frequent in
the left middle cerebral artery than in the right. Farther, an
embolus travelling in the internal carotid artery is much more
likely to enter the middle cerebral artery than the anterior cere-
bral, since the former is a direct continuation of the main trunk.

The left vertebral artery, arising from the left subclavian artery
where that is distinctly ascending, is a more direct continuation
of the subclavian than is the right vertebral artery which comes
off the subclavian nearly at a right angle, so the left vertebral
artery is much more likely to receive an embolus. Since the
vertebral arteries unite to form the basilar trunk, and that in turn
bifurcates symmetrically, each of its posterior cerebral branches
is equally liable to be plugged.

The cerebellar arteries come ofif their parent trunks at acute
angles and are rarely the sites of embolisms. The basilar artery
too is rarely occluded since a clot which can traverse the vertebral
artery is unlikely to be arrested in the larger basilar trunk formed
by the union of the two vertebrals, but such clots are sometimes
entangled at the point of bifurcation of the vessel.

The results of embolism differ in different regions of the brain

170 CLINICx\L APPLIED ANATOMY.

owing to variations in the degree of collateral circulation which
is possible. When perforating arteries are occluded, softening of
the parts they supply is inevitable ; on the other hand the
anastomosis of cortical branches in the pia mater may be sufficient
to maintain the integrity of the cortex.

The position of the anterior communicating artery at the
commencement of the anterior cerebral arteries explains how
softening of the head of the caudate nucleus may be the only
result of a plug in the first part of one of these vessels. When
the middle cerebral artery is occluded near its origin softening
may be expected in the central ganglia and at the anterior
perforated spot. The amount of cortical softening is rarely
co-extensive with the distribution of the vessel, and in some
cases there may be none. The cortical collateral circulation
appears to vary within considerable limits. The distribution of
the cortical branches of the middle cerebral artery to Broca's
convolution, to the precentral or ascending frontal convolution
which contains the motor centres, to the higher visual cortex and
to the auditory centre render this artery of great importance.
The central or perforating branches of the same vessel supply
the neighbourhood of the internal capsule. It may here be noted
that the leg centre is in part supplied by the anterior cerebral
artery and the posterior part of the internal capsule receives
some branches from the posterior cerebral trunk.

The collateral circulation of the cortical branches of the
posterior cerebral trunks is usually sufficient to prevent much
softening in their area of distribution. These important vessels
supply the optic radiation and the occipital visual cortex. They
also supply the visual portion of the thalamus, the anterior and,
in part, the posterior corpora quadrigemina. The relation of
their branches to tlie posterior limb of the internal capsule has
been mentioned. The crus cerebri receives part of its supply
from the same source.

The optic tract is supplied by the anterior choroidal branch of
the internal carotid. The cerebellar arteries anastomose so freely
that, even if they are occluded, any extensive softening is rare.

THEOMBOSIS OF CEEEBEAL AETEEIES. 171

The size of the communicating branches of the circle of Willis
materially influences the results of blocking of the main feeding
trunks. If the communicating trunks are healthy and of fair
size and the blood pressure remains high, the integrity of the
l)rain may be maintained by an adequate collateral circulation.
If the vessels are diseased or the blood pressure is low, as after
severe haemorrhage, serious cerebral symptoms may be expected.
Thus cerebral thrombosis, a condition in which the vessels as
a rule are extensively diseased, is more serious than embolism
of a healthy trunk ; also ligature of the carotid after severe
haemorrhage is more likely to induce hemiplegia than when
there has been no loss of blood.

The posterior communicating artery may be able to supply
sufficient blood to the middle and anterior cerebral arteries of the
same side when the carotid artery is blocked in the cavernous
sinus, and in this connexion it is important to remember that
the right posterior communicating artery is almost invariably
larger than its fellow. Abnormal arrangements of the arteries
at the base of the brain may be responsible for anomalous
distribution of cerebral softening.

THROMBOSIS OF CEREBRAL ARTERIES.

Thrombosis of the cerebral arteries is usually the result of
pre-existing vascular disease. The arterial disease is in most
cases due to syphilis, but occasionally other forms of arteritis
produce the same result. Karely the pressure of tumours or
spread of inflammation from the meninges causes vascular
occlusion. The large vessels at the base of the brain, such as the
basilar artery and the middle or posterior cerebral arteries, are
most likely to suffer. These vessels lie in the subarachnoid cisterns
and their prolongations, have but little external support, and the
pressure in them is high. The perforating arteries to the interior
of the brain are given off from the large basal vessels and do not
anastomose, hence cerebral softening is an inevitable consequence
of the occlusion of these small branches. Owing to the proximity

172 CLINICAL APPLIED ANATOMY.

of the vital centres of the bulb to the vertebral and basilar arteries,
thrombosis of these vessels is a more serious menace to life than
occlusion of the middle or posterior cerebral trunks. Thrombosis
of cortical branches may produce slight or transient symptoms,
since there is usually a fairly free anastomosis of vessels in the
pia mater. Sometimes the vascular disease at the base is so
situated as to occlude the perforating branches without materially
obstructing the main trunk, softening of the pons Varolii, and of
the central ganglia of the brain may be brought about in this
way.

The grey matter of the brain is much more richly supplied with
vessels than is the white matter, hence softening in the grey
substance has a red appearance in its earlier stages, whilst in the
white substance the red coloration is wanting. Thrombosis in
a main trunk may spread by continuity to the branches which
the trunk gives off. Thus a clot in the internal carotid artery may
spread into the anterior and middle cerebral vessels or into the
ophthalmic artery.

It is obvious that thrombosis of the middle cerebral artery can
produce hemiplegia from either capsular or cortical softening,
since it supplies the former by perforating and the latter by
cortical branches. Aphasia may result from the cortical softening,
and such softening is nearly always thrombotic, for in embolism
of the same trunk the healthy anastomosing vessels aided by the
higher blood pressure are usually sufficient to carry on the
circulation. In the ordinary type of hemiplegia the leg suffers
less than the arm and recovers more rapidly, but when the focus
of softening is in the posterior part of the capsule producing
hemianaesthesia and hemianopia, the motor weakness may be
expected to be most marked in the lower limb, since the motor
fibres of the leg lie nearer the sensory portion of the capsule than
do the motor fibres for other parts of the body. (Fig. 12, p. 179.)

The area of distribution of the posterior cerebral artery has
already been indicated in the section on cerebral embolism.

Symptoms pointing to occlusion of the basilar artery are almost
always due to thrombosis, for the anatomical conditions here do

THEOMBOSIS OF CEEEBEAL SINUSES. 173

not favour embolism as has previously been explained. Since
the occlusion is not at first complete, remissions and exacerba-
tions of symptoms may be expected, and these fluctuations
in the amount and distribution of paralysis may help in the
distinction of thrombotic from embolic softening. The lower
part of the basilar artery is held to supply the median or
chief branches to the vagus centre ; its upper part is directly
continuous with the posterior cerebral trunks into which the
clot may extend. If unilateral softening occur in the pons above
the decussation of the facial fibres the resulting hemiplegia will
not differ from the capsular type ; face, arm and leg all being
affected on the side opposite to the lesion. If the softening be in
the lower half of the pons, an alternate, or crossed, paralysis may
occur and the face suffer on the same side as the lesion, whilst
the limbs are paralysed on the opposite side. Of course both
halves of the pons may become softened and so produce bilateral
paralysis. The sixth nerve nucleus is some distance below the
third and fourth nuclei, so in lesions of the lower half of the pons
the sixth may be paralysed on the same side as the facial nerve,
i.e., opposite to the limbs. As the sixth nucleus is the centre for
conjugate deviation to its own side the patient will look away
from the lesion owing to the unantagonised action of the muscles
of the other side.

The vertebral artery is a variable vessel ; the left is usually
larger than the right, indeed the basilar artery may appear to be
chiefly formed by the left vertebral. The vertebral is responsible,
near its termination, for the blood supply of the hypoglossal and
spinal accessory nuclei, and its occlusion produces unilateral labio-
glosso-laryngeal paralysis on the side of the. lesion as well as
interference with the motor and sensory tracts of the medulla.

THROMBOSIS OF CEREBRA.L SINUSES.

Thrombosis of the cerebral blood sinuses may be primary,
traumatic, or inflammatory. Primary thrombosis is met with
in certain debilitating conditions at the two extremes of life.

174 CLINICAL APPLIED ANATOMY.

Traumatic thrombosis is usually associated with fracture, and is
frequently inflammatory when it ranks with the next group.
Inflammatory thrombosis may be due to direct extension of
contiguous inflammation to the sinus walls, or the infection may
be carried to the sinus by veins which drain an inflammatory
focus.

The lateral sinus is involved more frequently than any of the
others. Its intimate connection with the ear accounts for this,
an inflammatory process being set up by extension of caries
from the antrum or tympanum to the bony groove in which the
sinus lies. The sinus may also be infected by certain of the
tributary veins which it receives from the ear. The petro-
squamous vein, which receives radicles from the tympanum and
attic, joins the lateral sinus behind, and also communicates with
the middle meningeal vein in front. The blood from the laby-
rinth, and from the cochlea, is returned by the internal auditory
veins, which open into the inferior petrosal sinus, which is in
turn a tributary of the lateral sinus.

Thrombosis of the lateral sinus may spread to the sinuses
which communicate with it, or to the opposite lateral sinus across
the torcular by venous communication. The right lateral sinus
usually communicates chiefly with the superior longitudinal
sinus, which drains the cortical regions of the brain, whilst the
left is continuous with the straight sinus which receives blood
from the ventricles and basal ganglia. Sometimes the throm-
bosis extends along the petrosal sinuses to the cavernous sinus
or to the veins of the hemisphere.

The efferent veins of the lateral sinus are the internal jugular,
the mastoid, and the posterior condylar. Extension of the infec-
tion to the jugular vein gives rise to a tender cord-like swelling
under the sterno-mastoid ; the surrounding lymphatic glands are
also enlarged, and rarely the inflammation attacks the nerves
which pass out through the jugular foramen. The jugular blood
stream may also convey infection to the lungs, giving rise to infarc-
tions and abscesses. Theoretically it is possible for the jugular
bulb to be directly infected from the inner ear by means of the

THEOMBOSIS OF CEEEBEAL SINUSES. 175

vein which passes out through the aqueductus cochleae without
participation of the lateral sinus. The mastoid emissary vein is
responsible for the production of mastoid oedema and superficial
suppuration, but the oedema may occur as a result of mastoid
disease without sinus thrombosis. The posterior condylar veins
which pass to the suboccipital and thence to the vertebral veins
may become involved, and associated with this the posterior
cervical venous plexus which lies at the upper part of the
posterior triangle of the neck may be the site of thrombosis.
The vertebral vein, by its connection with the lateral sinus
through the posterior condylar vein, sometimes affords another
path for infection of the lungs, when the internal jugular has
been ligatured. Suppurative meningitis and extradural abscess
are often associated with thrombosis of the lateral sinus, and
infection may also spread from the sinus to the cerebrum or
cerebellum, giving rise to abscesses in these structures. The
external suture between the squamous and petrous bones lying
behind the external auditory meatus affords a track by which
inflammation in the ear may spread to the surface and so
may save the sinus, but this suture closes in the second year
of life.

Thrombosis of the cavernous sinus is uncommon, although its
free venous communications render it liable to infection from
many places. Lateral sinus thrombosis caused by ear disease,
may spread along the petrosal sinuses to the posterior end of the
cavernous sinus. The ophthalmic veins which enter the front
of the sinus may carry infection to it from the territories of the
angular, facial, or supra-orbital veins. Disease of the nose may
extend to the sinus by way of the sphenoidal air cells, or by the
medium of the ethmoidal veins which enter the ophthalmic trunk,
or of veins in the sphenomaxillary fossa which enter the pterygoid
plexus, which in turn communicates freely with the cavernous sinus.
Ulcerations of the tonsil and pharynx, retropharyngeal abscesses
and nasopharyngeal diphtheria have all occasionally caused
cavernous thrombosis ; infection being carried by the veins of
the pterygoid plexus, which enter the sinus from below through

176 CLINICAL APPLIED ANATOMY.

the foramen lacerum medium, the foramen of Vesalius, if present,
and the foramen ovale. Alveolar abscesses, and necroses of the
jaw and orbit may have the same result.

Owing to the serious obstruction to the return of blood from
the orbit and the intimate relation of the third, fourth, fifth and
sixth nerves to the walls of the sinus, the signs of cavernous
thrombosis resemble those of cellulitis of the orbit combined with
ophthalmoplegia. The lids are swollen and oedematous, and
discoloured, the eye is prominent, and there is much chemosis.
At the same time the movements of the eye are restricted
or lost, and there is considerable pain in the territory of the
supraorbital branch of fifth nerve.

Since the sinus communicates freely by means of the circular
sinus with the cavernous sinus of the opposite side the throm-
bosis sooner or later becomes bilateral. As nearly all the veins
of the sinus drain into the internal jugular veins, these are the
vessels which convey pysemic infection to the lungs and other
parts of the body. Any attempt to exclude the cavernous sinus
from the circulation calls for a ligature of the internal jugular,
very low in the neck.

The superior longitudinal sinus is usually affected in marantic
thrombosis, but is sometimes thrombosed as the result of fractures
and injuries to the vertex of the skull, and rarely as a sequel to
lateral sinus disease. There are several reasons why, with
failing circulation, thrombosis should appear in this sinus. The
blood flow in it is retarded because the stream has to pass back-
wards whilst the blood in the veins of the cerebral hemispheres
is projected into it in the opposite direction ; again, the blood
from the ascending arteries of the cortex is carried on into the
sinus by veins which also ascend, and so the flow is not
assisted by hydrostatic pressure, and lastly the lacunae laterales
form as it were small backwaters in which thrombosis may
commence.

As a rule the symptoms of thrombosis of the superior longi-
tudinal sinus are indefinite, but sometimes oedema of the scalp
occurs and the veins of the parietal, frontal, and occipital regions

ABSCESS OF THE BRAIN. 177

are turgid. Epistaxis may be present in childhood and inter-
ference with the circulation of the cerebral cortex may induce
convulsions or paralysis. In early life the foramen caecum
transmits to the sinus a small vein from the nose and this may
be the source of the epistaxis. The communication with the
sinus of the parietal emissary vein may account for venous
congestion and oedema in this part of the scalp.

ABSCESS OF THE BRAIN.

The intimate relations of the tympanic cavity and of the
mastoid cells to the temporo-sphenoidal lobe of the brain and
to the cerebellum account for the frequency with which ear
disease is the cause of temporo-sphenoidal and of cerebellar
abscesses. In like manner the proximity of the upper part of
the nasal cavity and of some of the accessory sinuses of the
nose to the frontal lobe of the brain may give rise to frontal
abscess when the nasal cavities are diseased.

Brain abscess may also be a sequel of disease or injury of
other bones of the skull, and in such cases the abscess as a
rule lies in close relation to the diseased or injured bone.
Sometimes the abscess is in a part of the brain remote from
the site of injury, but at the same time in a direct line with
it; such a position appears to be determined by the bruising
due to contrecoup. In this way a frontal injury has been
known to produce an occipital abscess.

Blood-borne infection from a distance may also be a cause
of cerebral abscess. The focus of such infection is usually in
the lung, and the infective agent is carried by the pulmonary
veins to the left side of the heart, and thence by the arterial
system to the brain. Bronchiectasis, empyema, and sometimes
phthisis, produce abscesses in this way. Ulcerative endocarditis
occasionally leads to embolic abscesses of the brain, but is
more likely to induce haemorrhage or cerebral softening.
Brain abscesses may also occur in general pyaemia. Abscesses
due to blood-borne infection are usually multiple.

C.A.A. 12

178 CLINICAL APPLIED ANATOMY.

Temporo - sphenoidal and cerebellar abscesses are nearly
always caused by suppurative ear disease. Caries of the tegmen
tympani or of the tegmen antri may give rise to extradural
abscess or subdural abscess in the middle fossa, but the brain
membranes often become adherent to the lowest temporo-
sphenoidal convolution which lies directly over the tegmina,
and a temporo- sphenoidal abscess results.

Extension of inflammation through the labyrinth to the internal
auditory meatus produces similar results in the neighbourhood
of this opening. The membranes may become adherent and
the front part of the lateral lobe of the cerebellum be found
to contain an abscess. But temporo- sphenoidal and cerebellar
abscesses may occur without caries or perforation of the bone
and without adhesion of the brain membranes. In such cases
the veins or the perivascular lymphatics are the tracks along
which infection travels. The abscesses in the brain or in the
cerebellum may be multiple, as many as three having been
found in the temporo-sphenoidal lobe and the same number
has been known to occur in the cerebellum. The superior
petrosal sinus receives veins from the tympanum and from the
temporal lobe, so this sinus may provide the link between the
two. The lateral sinus receives veins from the mastoid region
and the cerebellum, and may allow the transference of the
infective agent from one to the other. It is difficult to conceive
that such transference can occur unless the sinuses in question
are thrombosed.

At birth there is a petro- squamous suture in the roof of the
tympanum, but this is obliterated in the second year and has
no influence in the causation of temporo-sphenoidal abscesses,
since these are not met with at this period of life.

Disease of the nose and of its accessory sinuses may lead to
abscess in the frontal lobe of the brain. The cribriform plate
of the ethmoid forms a very fragile septum between the brain
and the roof of the nose. The frontal air sinuses when of
average size extend about an inch upwards in the adult, from
the upper orbital margin, and nearly an inch backwards along

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ABSCESS OF THE BEAIN. 179

the orbital roof. These sinuses are of insignificant size until
the sixth or seventh year of life. A very thin plate of bone
separates the fully developed sinus from the frontal lobe of the
brain, so that caries and perforations of its inner wall may
cause extradural, subdural or intracerebral abscess. In the
latter case the brain membranes are often closely adherent to
the perforated bone, but in some instances there is no perfora-
tion and no adhesion, the infection having been carried by the
lymphatics or veins of the diploe.

The anterior and posterior ethmoidal cells are separated
from the anterior fossa of the skull by the ethmoidal edge of
the frontal bone, but occasionally a posterior ethmoidal cell,
extending backwards, intervenes between the roof of the
sphenoidal sinus and the base of the brain. It is easy to see
that infection of the brain membranes and the brain might
originate from these cells.

The roof of the sphenoidal air sinus lies in contact with the
olfactory peduncles, the optic commissure, the pituitary body
and the front part of the pons Varolii. Infection is not often
transmitted through it.

An abscess in the temporo-sphenoidal lobe is so situated
that it may cause motor paralysis of either cortical or capsular
type. By pressure on the adjacent lower end of the ascending
frontal convolution or by the spread of inflammatory oedema to
that region, convulsions or paralysis may be produced, and in
each instance the face may be expected to suffer first, then the
arm, and lastly the leg, owing to the arrangement of motor
centres in that order from below upwards. (Fig. 14, p. 183.)
Any anaesthesia which is present will be of the patchy and
incomplete cortical type.

By pressure exerted inwards, and by the inward spread of
inflammation, the internal capsule becomes involved in its
posterior part. The motor paralysis is then of capsular type,
and the leg, the fibres of which lie most posterior of the motor
fibres, will suffer first. (Fig. 12.) Since the posterior part of the
capsule is involved, hemiansesthesia and hemianopia may occur.

12—2

180 CLINICAL APPLIED ANATOMY.

The auditory centre lies in the posterior part of the upper
temporo- sphenoidal convolution and the angular and supra-
marginal visual centres are adjacent. Hence alexia, agraphia
and word-deafness may accompany extensive or acute temporo-
sphenoidal abscesses of the left side. The deafness which
accompanies these abscesses and usually also the occasional
complete facial paralysis are accounted for by the lesion in
the ear on the side of the abscess. Rarely, cortical deafness
occurs in the opposite ear, but frequently this ear is also
diseased.

Temporo-sphenoidal abscesses have a great tendency to rup-
ture into the ventricles of the brain and naturally break into
the descending cornu of the lateral ventricle since this traverses
the lobe in which they lie.

The third cranial nerve on the same side as the abscess
often shows signs of weakness in the form of ptosis or paralysis
of the muscles of the globe or inactive pupil. The nerve
lies in the front part of the tentorium cerebelli, and is possibly
subject to pressure from the swollen temporo-sphenoidal lobe,
for the uncus of this lobe is often deeply grooved by the
edge of the tentorium.

The knowledge of the localisation of cerebellar functions is
scanty, so the application of anatomical facts is difficult.
Cerebellar abscesses are subtentorial, and may produce pressure
symptoms in the posterior fossa, such as occipital headache
radiating down the neck, and distension of the ventricles of
the brain.

From the dentate nucleus of the cerebellum fibres stream out
to the superior peduncle and so reach the opposite cerebral hemi-
sphere. Interference with these fibres is supposed to produce a
particular type of paralysis which consists in considerable
brachial monoplegia on the side of lesion, coupled with
this may be some weakness of the lower extremities. This
paralysis is explained by the assumption that the cerebellar
hemisphere normally augments the action of the cerebral
hemisphere of the opposite side. Since the cerebellar abscess

INTEACEANIAL TUMOUES. 181

is usually in the outer and fore part of the hemisphere, the
dentate nucleus and its fibres escape and paralysis of the above
type is then absent. Cerebellar lesions do not produce any
anaesthesia.

Karely the abscess lies in the flocculus and then the cranial
nerves in the proximity may be paralysed. The nerves in im-
mediate relation are the seventh, the eighth and the pars
intermedia; but the fifth, sixth, ninth and tenth are not far
off. Unfortunately for localisation, the seventh and eighth
nerves may be affected in the diseased petrous bone and
indeed are more likely to suffer here than in the neighbour-
hood of the flocculus.

INTRACRANIAL TUMOURS.

After obliteration of the fontanelles, a process which is com-
plete before the second year of life, the cranium is practically a
closed cavity. The majority of intracranial tumours occur some
time after this closure, i.e., between puberty and middle adult life,
hence the pressure effects produced by these growths are more
marked and more extensive than those produced by new growths
in any other part, save perhaps the vertebral canal. Tumours
growing in the thorax and bony pelvis afford the nearest approach
to similar conditions elsewhere in the body. Tuberculous tumours
sometimes occur before the period of closure of the anterior fon-
tanelle, but even then the mass often lies below the tentorium
cerebelli, and so the patency of this fontanelle has but little
modifying influence on the direct pressure symptoms, although
it may permit distension of the ventricles of the brain.

The strength and firm attachment of the tentorium cerebelli,
which forms a fibrous dome over the posterior fossa of the skull,
account for the marked pressure symptoms associated with
tumours which grow beneath it. The parts of the brain which
lie in the posterior fossa are the cerebellum, medulla, pons, and
cranial nerves below the fifth. The veins of Galen and the
straight sinus may be occluded by subtentorial tumours, and

182 CLINICAL APPLIED ANATOMY.

the exit of fluid from the third and lateral ventricles may be
obstructed by the pressure these tumours exert on the iter
or behind it.

The sagittally directed falx cerebri, although firmly fixed at
its two extremities and above, has only a slight influence in
restricting pressure signs to one or other hemisphere of the
brain.

Tumours are occasionally found to compress certain large
arterial trunks at the base of the brain, and then areas of
softening may occur in addition to the new growths.

Tumours which interfere with the outlets of the ventricles
produce a peculiar train of symptoms, amongst which are
apathy, drowsiness, headache, and coma. Such symptoms may
accompany tumours of the corpus callosum or of the structures
forming the boundaries of the third ventricle or tumours
beneath the tentorium.

Of the general symptoms of cerebral tumour, headache is of
some localising value if accompanied by local tenderness, and
this is most likely to occur if the tumour is on the convexity of
the brain. Speaking generally, frontal headache accompanies
tumours of the frontal lobes ; occipital headache tumours of the
occipital lobes ; and similar headache extending into the nape of
the neck, and often accompanied by, retraction of the head,
tumours of the subtentorial region. With a cerebellar tumour
headache may occur in the opposite frontal region ; the crossed
connexion of each cerebellar hemisphere with the frontal lobe of
the opposite side is held by some to account for this anomaly.

Vomiting, another general symptom, is most severe and most
common with tumours below the tentorium, presumably on
account of the proximity of the vagus centre.

The fact that the motor tract traverses the brain from medulla
to cortex explains how tumours in widely different situations can
produce motor paralysis. The fan-like radiation *of the corona
radiata from the genu and anterior part of the posterior limb of
the internal capsule to the cortex of the Eolandic region allows
cortical and subcortical tumours to cause paralysis, which may

The Motor Tracts.

Cortex of
the sensor
motor area

Caudate
nucleus.

Third nervi

Fifth nerve.

Lateral

pyramidal

tract.

Anterior

pyramidal

tract.

Anterior
nerve-root.

Anterior
commissure.

Spinal cord.

Fig. 13. — Diagram of the pyramidal fibres and the nuclei of the cranial and spinal
motor nerves. (From Morris's Anatomy, after Arthur Robinson.)

[Tn face ]>age 1S2.

H <; w M

CEEEBEAL TUMOUES. 183

be at first limited to one limb or to parts of a limb on the
opposite side of the body. Jacksonian epilepsy may be associated.
If such a tumour happen to be at the spot where the leg centre^
which stands highest in the precentral convolution, adjoins the
trunk and arm centres which lie next below it, weakness of
the hip and shoulder on one side may result. (Fig. 14.) A
tumour in the neighbourhood of the internal capsule will
tend to produce hemiplegia of gradual development, and
so also wil] a tumour in the upper part of the crus com-
pressing the motor tract in the crusta. In the pons and
medulla, where the motor tracts of the two sides of the body
approximate, a bilateral paralysis may result, but symmetrically
placed tumours in the hemispheres may have the same effect.
(Fig. 13.)

When a tumour is so situated as to paralyse a cranial nerve on
one side of the body and the limbs on the opposite side, the so-
called '* crossed paralysis " is produced. Tumours in the crus,
the pons or the medulla may do this. A tumour of the crus may
involve the third nerve on the same side, and the rest of the
body on the opposite side. (Fig. 13.)

In the upper part of the pons, the fifth nerve may be paralysed
on the side of the lesion, and the face, tongue, and limbs on the
opposite side. The facial tract crosses the mid line at the junction
of the upper and lower halves of the pons to reach the facial
nucleus, so a tumour in the lower part of the pons will completely
paralyse the face on the same side and involve the opposite half
of the tongue and opposite limbs as well, by pressing on the
motor tracts to these parts above their decussation. (Fig. 13.)

A tumour on one side of the medulla, above the decussation of
the motor tracts in the pyramids may paralyse the tongue on
the same side, and the limbs on the opposite side, but this is
uncommon.

The presence of certain varieties of cranial nerve paralysis is
important in fixing the locality of a tumour. The nucleus of the
third nerve extends from the back part of the floor of the third
ventricle to the groove between the anterior and posterior corpora

184 CLINICAL APPLIED ANATOMY.

quadrigemina, the nucleus lies in the front part of the floor of
the iter, and the nerve emerges from the inner side of the crus.
Tumours of the crus therefore tend to paralyse this nerve as
already indicated. (See Fig. 17, p. 191.)

The fourth nerve nucleus also lies in the floor of the iter,
immediately behind the nucleus of the third, and corresponds to
the fore part of the posterior corpora quadrigemina. The nerve
emerges dorsally from ihe valve of Vieussens, and winds round
the outside of the crus. It may suffer in association with the
third when tumours occupy the quadrigeminal bodies or be com-
pressed by a tumour near the anterior end of the cerebellar vermis.

The sixth nerve nucleus lies beneath the eminentia teres
in the anterior part of the floor of the fourth ventricle; the
nerve fibres emerge in the groove between the top of the pyramid
and the lower border of the pons. Owing to its long intracranial
course, paralysis of this nerve has little localising value, but the
nerve lies between the ventral surface of the pons and the basilar
process, and is likely to be compressed in subtentorial lesions.
Paralysis of all the ocular muscles of one eye, often associated
with blindness of the same eye, is likely to be caused by a tumour
of the sella turcica, which lies adjacent to the cavernous sinus,
and contains the pituitary body.

The sixth nerve nucleus may be considered to be the centre for
conjugate deviation of the eyes towards its own side, its crossed
connection with the nucleus of the opposite third nerve accounts
for this. The communication is effected through the posterior
longitudinal bundle. A tumour in the pons or corpora quad-
rigemina affecting the sixth nucleus will render impossible con-
jugate deviation of the eyes towards the same side, since it will
paralyse the associated actions of the external rectus of its own
side and the internal rectus of the opposite eye. If both sixth
nuclei be involved the eyes will remain fixed in the mid position.
When the facial nerve is paralysed by tumours within the pons,
the nucleus of the sixth nerve around which the genu of the
facial root turns, may also suffer. Outside the pons facial paralysis
is more likely to be associated with paralysis of the auditory

The Sknsory Tracts.

r^ensori-
motor area.

]^'iftli nerve.

Inferior

peduncle of

cerebellum.

Eighth

nerA-e.

Ninth nerve.
Tenth nerve.

Sensory decussation
(decussation of
fillet).

Nucleus cuneatus.

Nucleus gracilis.

Postero-median

column.

Postero-lateral

column.

Direct cerebellar

tract.

Posterior nerve-root

Gowers'
tract.

Fig. 15.— Diagram sliowmcr some of the paths by which a sensory impulse may
asceiKl from tlie spinal cord to the brain. (From Morris's Anatomy, after
Arthur Robinson ) The fibres from the nucleus gracilis and nucleus cuneatus
to the opposite side of the cerebellum are not shown.

[To face jxujn 185.

CEEEBEAL TUMOUES. 185

nerve which lies contiguous to facial trunk in the membranes
and internal auditory meatus.

The spinal accessory nerve may be paralysed by tumours in
the medulla and its vicinity. Isolated paralysis of the sterno-mas-
toid and trapezius points to tumour outside the medulla, as these
muscles are innervated by the purely spinal portion of the nerve.

The tract of the sensory fibres in the brain is not so well
known and not so well localised as is the motor tract. The
fibres traverse the posterior part of the posterior limb of the
internal capsule, and a tumour here may produce complete
hemianaesthesia. Tumours of the gyrus fornicatus (callosal
gyrus) have the same effect. Even tumours of the so-called
motor cortex produce a blunting of sensation in the part most
paralysed, and, what is more striking, loss of power to accurately
localise sensory impressions on the part. The sensory fibres
reach the internal capsule by traversing the tegmental region of
the crus, but lesions here seldom produce marked anaesthesia.
Hemianaesthesia may be produced by tumours of the pons and of
the medulla. (Fig. 15.)

Intracranial tumours may be so situated as to involve the
sense of sight or the sense of hearing.

The visual fibres may be involved anywhere between the eye-
ball and the occipital cortex. Bilateral homonymous hemianopia
will result when a tumour involves the optic tract or optic radia-
tion or the occipital visual cortex of one side, for these structures
are in relation with a half of each retina, since only the fibres
from the nasal half of the retina decussate.

When a tumour presses on the central part of the optic chiasma
bitemporal hemianopia results, since the decussating fibres from
the nasal halves of the retinae are affected, and the nasal halves
of the retinae correspond to the temporal halves of the visual
fields. Frequently a central defect of vision suggestive of tobacco
amblyopia precedes the full development of the hemianopic defect.
If the concentration of light on the blind half of the retina in
hemianopia still produces a pupil reflex, the afferent fibres in the
optic tract must be able to convey impulses as far as the point

186 CLINICAL APPLIED ANATOMY.

where a connection is established with the third nerve, i.e., the
lesion producing the hemianopia must be above the external
geniculate body, and somewhere between it and the occipital
cortex.

Hearing may be involved as the result of tumour pressure on
the auditory nerve. Tumours in the pons or at the base of the
brain can do this, and the deafness is on the same side as the
lesion. Tumours of the auditory centre in the temporo- sphenoidal
lobe may also produce subjective noises or deafness and then the
deafness is of the opposite ear owing to the decussation of the
tract.

Intracranial tumours which spring from the base of the skull
are usually either sarcomatous or carcinomatous. Their usual
seats are the petrous portion of the temporal bone, the sella
turcica or the occipital bone in the neighbourhood of the foramen
magnum. Growths in the region of the sella turcica tend to
compress all the nerves of one eyeball and may press on the
optic chiasma with results already mentioned ; they may also
cause loss of smell by pressure on the olfactory tract. Growths
of the petrous bone are adjacent to the Gasserian ganglion and
the fifth nerve, hence they may produce facial neuralgia,
anaesthesia in the territory of the fifth nerve, paralysis of
masticatory muscles, and even keratitis. These tumours may
also invade the posterior fossa, since the petrous bone is one of
its boundaries. The nerves of the posterior fossa may thus be
involved and occlusion of the lateral sinus also result. In the
substance of the petrous bone the growth may erode the carotid,
and so produce bleeding from the ear, whilst masses of glands
may appear beneath the mastoid deep in the upper part of the
neck. Tumours in the neighbourhood of the foramen magnum
may implicate any of the nerves behind the fifth, but chiefly the
lower ones. They also exercise pressure on the motor tract for
the opposite side of the body, but cannot produce conjugate
deviation of the eyes, since for this to occur the nucleus of the
sixth nerve within the pons must be involved.

Tumours of the middle and anterior fossae of the skull may

DISEASES OF THE OPTIC NEEVE. 187

invade the orbit through the sphenoidal fissure and cause pro-
ptosis. Tumours of the middle fossa sometimes involve the roof
of the nasopharynx, and tumours of the posterior fossa may give
rise to masses in the neck behind, or under cover of, the mastoid
process.

Cranial Nerves,
the optic nerve and tract.

The accessibility of the optic disc to ophthalmoscopic examina-
tion renders possible the detection of slight degrees of inflam-
mation which probably pass unrecognised in other cranial nerves.

The optic nerve is invested by tubular sheaths prolonged from
the pia, arachnoid, and dura, therefore inflammation of the
meninges can produce optic neuritis by extension along these
nerve sheaths. Effusions of blood and serum may also extend
in the same direction or local hgemorrhage may occur within the
firm dural sheath as the result of injury; injurious compression
of the nerve fibres may thus be set up.

At the optic foramen the periosteum of the orbit is continuous
with the dural sheath of the nerve, and thus periosteal inflamma-
tion of the orbit, due to bone disease or even secondary to dental
caries, may extend to the nerve and induce neuritis.

As the nerve passes through the optic foramen it is only
separated from the sphenoidal air sinus by a thin bony lamina,
which is sometimes imperfect, and inflammation of this air sinus
may secondarily involve the nerve. Fractures in the neighbour-
hood of the foramen may compress or actually sever the nerve
fibres, and bony growths in this situation may also cause pressure
upon the nerve.

The optic foramen is really a narrow canal and is traversed by
the ophthalmic artery as well as the optic nerve, consequently
inflammatory swelling of nerve or periosteum may give rise to
severe compression of the visual fibres.

Broadly speaking, the fibres from the periphery of the retina
lie at the periphery of the nerve trunk and in a lesion near the

188 CLINICAL APPLIED ANATOMY.

foramen are the first to suffer, giving rise to concentric diminution
of the visual fields.

The ophthalmic artery lies below and to the outer side of the
nerve in the intracranial portion of its course, but leaves the dural
sheath to curl over the nerve when the orbit is reached.
Aneurysms may compress the nerve in either situation. The
central artery of the retina which is sometimes the site of
embolism, passes into the nerve a short distance behind the
eyeball.

The optic chiasma practically forms part of the floor of the
third ventricle, and so may be compressed by effusions in the
ventricular system. Immediately behind the chiasma lies the
pituitary body, tumours of which may give rise to a characteristic
form of visual defect, bitemporal hemianopia. The internal
carotid arteries occupy the outer angles of the chiasma and nasal
hemianopia may be produced by aneurysms or calcification of
these vessels, but is rare. The sphenoidal air sinuses are in the
floor of the middle fossa below the chiasma, and the latter lies in
the cisterna basalis so that it is liable to invasion by gummatous
and tuberculous tumours, and inflammation of the meninges.

Disease processes which affect the chiasma act chiefly on its
central portion and accordingly the characteristic symptom of a
chiasma lesion is bitemporal hemianopia due to interference
with the decussating fibres from the nasal halves of the retina,
which in turn receive impressions from the temporal halves of
the visual fields. The temporal fibres are uncrossed, and chiasma
lesions often extend irregularly to one side or the other and so
may involve temporal fibres also in varying degree. (Fig. 16.)

A lesion limited to the non-decussating (temporal) fibres of
one side should produce nasal hemianopia, but this is exceptional.

The adjacent motor nerves of the eye are liable to be involved
in affections of the chiasma.

The optic tract extends backwards from the chiasma to
terminate in the anterior corpus quadrigeminum, the external
geniculate body, and the pulvinar of the optic thalamus. In part
of its course it is closely applied to the fore part of the crus

A

Thk Visual Paths.

'^^TSu^^

Fig. 16. — Diagram of the visual paths (from Vialet, modified by Osier). OP.K,
optic nerve; OP.C, optic cliiasma ; OP.T., optic tract; OP.R., optic
radiation; GEN., geniculate body; THO., optic tbalamus ; C.QU., corpora
quadrigemina ; C.C., corpus callosum ; V.S., visual speech centre; A.S.,
auditory speech centre ; M.S., motor speech centre. A lesion at 1 causes
blindness of that eye ; at 2, bi-temporal hemianopia ; at 3, nasal hemianopia.
Symmetrical lesions at 3 and 3' would cause bi-nasal hemianopia ; a lesion at 4
hemianopia of both eyes, with hemianopic pupillary reaction ; at 5 and 6,
hemianopia of both eyes, pupillary reflexes norm.al ; at 7, amblyopia,
especially of the opposite eye ; at 8, on left side, word blindness.

[To face, jmge 189.

DISEASES OF THE OPTIC NEEVE. 189

cerebri, and both may suffer together as the result of tumour
infiltration. The tract, bending round the crus, lies under cover
of the temporo- sphenoidal lobe and may be compressed by new
growths in this situation. It is also liable to injury by tumours
springing from the base of the skull.

The visual defect which results from a lesion of the tract is
homonymous hemianopia since the tract contains uncrossed
fibres from the temporal half of the retina of its own side and
crossed fibres from the nasal half of the retina of the opposite
side ; hence the blindness involves the nasal half of the field on
the side of lesion and the temporal half of the field of the
opposite side. (Fig. 16.)

If no light reflex can be obtained from the blind halves of the
retina, or if the reflex from these halves is very sluggish, the
hemianopic pupillary reaction is said to be present. This is of
value in that it localises the lesion in the chiasma or tract as
distinguished from the optic radiation in the hemisphere. This
indication is based upon the fact that the fibres which carry the
impulse from the eye to the pupil nucleus in all probability leave
the optic tracts at their partial termination in the anterior corpora
quadrigemina, passing thence to the third nerve nucleus. Con-
sequently a lesion which produces the hemianopic reaction must
involve the visual fibres not further back than the corpus
quadrigeminum.

The anterior choroidal branch of the internal carotid artery
closely follows the course of the optic tract and distributes
branches to it.

The apparent termination of the optic tract in the superior
quadrigeminal body, the external geniculate body, and the pulvinar,
might lead to the expectation that disease of these structures
should produce defects of vision, but clinical confirmation of this
is still needed.

The optic radiation consists of fibres which pass from the
external geniculate body and the pulvinar to the cortex. These
fibres lie in the retrolenticular part of the posterior limb of the
external capsule ; sweeping thence round the posterior cornu of

190 CLINICAL APPLIED ANATOMY.

the lateral ventricle they terminate in the occipital cortex. Some
of the fibres possibly pass to the angular region, but the optic
radiation lies immediately subjacent to this part of the parietal
lobe, and may be indirectly injured by lesions in this situation
even if it do not in part terminate here. (Fig. 16.)

The optic radiation may be damaged by softening, haemorrhage,
tumour or injury of the optic thalamus, or the posterior part of
the internal qapsule. In such cases hemianaesthesia or hemiplegia
may be associated with homonymous hemianopia. Lesions in
the occipital lobe, the occipital cortex, and possibly in the parietal
lobe, may also damage the tract.

The blood supply of the occipital visual cortex is derived from
the occipital branch of the posterior cerebral artery. This branch
also supplies the optic radiation. Sight may be impaired as the
result of embolism or thrombosis of this vessel, hemianopia
resulting. The parieto-occipital and the calcarine branches of
this occipital artery lie in the superior and inferior limiting sulci
of the cuneal lobule and the parieto-occipital branch supplies a
secondary cuneal branch which lies in a fissure in the cuneus
parallel to the calcarine artery.

Since the posterior cerebral artery supplies the temporal lobe
in part, lesions of this lobe may be associated with lesions of the
occipital visual centres.

The angular region of the cortex lies in the area of distribution
of the middle cerebral artery.

The visual portion of the thalamus is supplied by the posterior
perforating branches of the posterior cerebral artery. (Fig. 10,
p. 165.)

The superior quadrigeminal and the external geniculate bodies
are also supplied by the posterior cerebral artery.

OPHTHALMOPLEGIA.

Anatomically considered ophthalmoplegia may be divided into
supranuclear, nuclear and infranuclear varieties.

Supranuclear ophthalmoplegia. — Areas of the frontal lobes
and possibly also of the parietal and occipital lobes are connected

Cranial Nerve Nuclei.

Third ventricle,

Nucleus of third nerve

Descending root of

fifth )ierve.

Nucleus of fourth nerve.

Upi)er sensory nucleus

of fifth nerve.

Motor nucleus of

fifth nerve.

Middle sensory of

nucleus of fifth nervp

Nucleus of sixtl
nerve.

External dorsal
nucleus of eighth
nerve (Deiter's
nucleus).

Internal dorsal nucleus

of eighth nerve. .

Nucleus of seventh

nerve.

Sensory nucleus of

ninth nerve.

Fasciculus solitarius.

Lower sensory nucleus

and ascending root of

fifth nerve.

Sensory nucleus of

tenth nerve.

Nucleus ambiguus.

Nucleus of twelfth nerve.

Uiiper quadrigeniinal
body.

Lower quadrigeminal

body.

Lateral fillet.

Superior peduncle of
cerebellum.

Eniinentia teres.
Superior fovea.

Middle peduncle
of cerebellum.

Eminentia acustica.

Inferior peduncle
of cerebellum.
Auditory stria?.

Trigonum
acusticum.

Inferior fovea.
Trigonum
hypoglossi.
Trigonimi vagi.

Tubercle of Rolando.

Funiculus cuneatus.

Fig. 17. — Diagram of the floor and lateral boundaries of the fourth ventricle, showing
the positions of the nuclei of the cranial nerves on the left side. (From Morris's
Anatomy, after Arthur Robinson.)

[To face, page 191.

OPHTHALMOPLEGIA. 191

with the nuclei for the eye muscles. (Fig. 14, p. 183.) The
track from the cortex is supposed to pass through the internal
capsule near its genu, and thence to the nuclei through the
mesial third of the basal portion of the crus cerebri. Supra-
nuclear lesions do not produce isolated ocular paralyses, but
manifest themselves by temporary conjugate deviations of the
eyes. The crus cerebri, however, is traversed by the rootlets of
the third nerve on their way out from the adjacent nuclei, and
consequently the paralysis produced by lesions of this part of the
brain are of a nuclear or infranculear type.

Nuclear Ophthalmoplegia.— The nucleus of the third nerve is
compound, its total length being about a third of an inch. Its
anterior part encroaches on the floor of the third ventricle, and
its posterior or lower limit corresponds to the groove between
the anterior and posterior quadrigeminal bodies. Degenerative
nuclear disease, such as, for example, results from syphilis, may
pick out portions of the compound nucleus, producing paralysis
of isolated muscles or of specially associated ocular movements.
Such isolated paralyses as loss of accommodation, loss of the
pupil contraction which normally accompanies convergence of
the eyes, loss of convergence and accommodation although the
internal recti still act in conjugate movements, and paralysis of
a single extraocular muscle, are examples of this selective action.
The most familiar example of all is the Argyll Eobertson pupil, in
which myosis and loss of light reflex co-exist. It is true that the
usual explanation of this double phenomenon is that the myosis
is due to a lesion of the fibres of the cervical sympathetic in some
part of their course through the central nervous system before
emerging by the cervical roots, and that the failure to react to
light is due to a lesion of Meynert's fibres which pass between
the superior corpora quadrigemina and the nucleus of the third
nerve. It is possible, however, that actual degeneration of a
part of the third nucleus can produce both phenomena. The
ophthalmoplegia of nuclear disease may be very extensive and
is often bilateral. Weakness of the orbicularis palpebrarum is
sometimes associated with ophthalmoplegia, leading to the

192 CLINICAL APPLIED ANATOMY.

presumption that the motor fibres to this muscle, which reach it
through the facial nerve, are really derived from part of the third
nerve nucleus.

The nucleus of the fourth nerve innervates the superior oblique
muscle of the eye, and lies in the floor of the iter beneath the
posterior quadrigeminal bodies. This nucleus is in serial con-
tinuity with the nucleus of the third, and suffers in a similar way.

The nucleus of the sixth nerve is some way behind that of the
fourth. It lies beneath the eminentia teres of the fourth ventricle,
immediately above the acoustic striae. The sharp bend which
the issuing fibres of the facial nerve make around the sixth
nucleus explains how a comparatively small lesion may involve
both the sixth and the facial nerves. The sixth nucleus is
important in that it is the nuclear centre which produces
conjugate deviation of the eyes to its own side, the associated
action of the opposite internal rectus being brought about by
fibres of the posterior longitudinal bundle which connect the
sixth nucleus with the appropriate part of the third nucleus of
the opposite side.

In addition to being subject to degenerative lesions the ocular
nuclei may be damaged by vascular lesions of the pons or crus,
and by gross lesions of the cerebral structures in their immediate
neighbourhood. Tumours of the pons, corpora quadrigemina,
pineal gland and optic thalamus may all be in a position to do
this, and tend to involve the nuclei of both sides. Again, all the
nuclei lie near the floor of parts of the ventricular system, being
situate in the grey matter of the third and fourth ventricles and
connecting iter, consequently they may be irritated by ventricular
inflammation and compressed by large ventricular effusions.

Infranuclear ophthalmoplegia is produced by lesions of the
nerves below the level of the nuclei.

After leaving its nucleus and before appearing at the base of
the brain, the third nerve traverses the crus cerebri. The motor
tract of the opposite side of the body also traverses the crus, so
the typical paralysis produced by a lesion of this part of the brain
is a crossed or alternate paralysis, the third nerve palsy being

OPHTHALMOPLEGIA. 193

associated with paralysis of face and limbs on the opposite side.
The nerve fibres passing to their point of exit in the oculomotor
groove of the crus at first converge from the separate portions of
the compound nucleus, and so a lesion in the crus may involve
only a few of the converging rootlets, the ophthalmoplegia will
then be incomplete and practically indistinguishable from a lesion
of part of the compound nucleus itself. Again, of all the motor
fibres in the crus those of the face are nearest the third nerve,
and so a small lesion may pick out the third nerve and the facial
fibres, the rest of the motor tract escaping. The resulting facial
paralysis is in all cases of supranuclear type, the lower part of
the face being chiefly involved.

It is sometimes difficult to distinguish a lesion in the crus itself
from one at the base of the brain which compresses it ; in such
cases the presence of symptoms due to involvement of the
corpora quadrigemina which form the dorsal part of the crus
enable the lesion to be located in the crus itself.

The fourth nerves after leaving their nuclei, skirt the iter,
decussate and appear on the dorsal aspect of the brain at the
valve of Vieussens. They thus come into relation with struc-
tures far removed from the other ocular nerves, and consequently
the superior oblique muscles may be paralysed by the pressure
of a tumour of the anterior end of the cerebellar vermis, or of
the posterior quadrigeminal bodies, or of the valve of Vieussens.
Both nerves are likely to be involved in such cases.

The sixth nerve on its way from its nucleus to its point of
exit at the lower border of the pons, traverses the lower and
ventral part of the latter. Its paralysis may be associated
with opposite hemiplegia if the lesion be in the pons.

At the base of the brain the third nerves lie in the narrow
interpeduncular space, and both may be compressed by a
growth here or by an aneurysm of the posterior cerebral
artery.

The fourth nerve winds round the outer aspect of the crus.

The sixth nerve has the longest course in the meninges
coming into relation with the ventral aspect of the pons,

C.A.A. 13

194 CLINICAL APPLIED ANATOMY.

consequently paralysis of the sixth nerve, i.e., of the external
rectus, has no great localising valve.

In the cavernous sinus the third, fourth and sixth nerves
have come together, and are associated with the first division
of fifth. A lesion in this region may involve all the nerves
mentioned, necessarily on one side only. Thrombosis of the caver-
nous sinus, growths of the j)ituitary body, or aneurysms of the
intracranial part of the internal carotid, are lesions possible here.

At the sphenoidal fissure the same nerves are close together
and the optic nerve adjacent. A basic meningitis or a perios-
titis may involve them all.

In the orbit the same nerves may be involved by cellulitis,
wounds, or rarely growths. In such cases proptosis may be
associated, but this may also result from cavernous sinus
thrombosis.

If defects of vision are associated with ocular paralyses the
nature of the defect should be ascertained. A lateral homony-
mous hemianopia points to a lesion of the optic tract behind
the chiasma, i.e., in the region of the crus or the pulvinar.
Bitemporal hemianopia indicates a lesion in the chiasma
region.

THE FIFTH NERVE.

The fifth being a mixed nerve, both motor and sensory
symptoms may result when it is either irritated or paralysed.
The sensory fibres, after entering the pons, end in the sub-
stantia gelatinosa Kolandi, and in an expanded terminal portion
of this structure which is known as the sensory nucleus. The
cells of termination of the sensory part of the nerve form a
column of considerable vertical extent which reaches from the
level of the middle cerebellar peduncle to that of the second
cervical nerve. (Fig. 17, p. 191.) The whole of this long
column is very unlikely to be affected by disease within the pons,
and, as a rule, complete anaesthesia in the territory of the fifth is
due to a lesion of the collected sensory fibres as they lie in the
issuing nerve root.

FIFTH CEANIAL NEEVE. 195

The motor nucleus which lies in the grey matter at the
lateral angle of the fourth ventricle, at the level of origin of
the nerve root from the pons, may be damaged by gross
lesions at this level, or involved together with other bulbar
nuclei, in degenerative disease. The nucleus is connected with
the motor cortex of the opposite frontal region by fibres which lie
in the genu of the opposite internal capsule. (Fig. 12, p. 179.)

The descending root of the fifth, which arises in the grey
matter around the aqueduct of Sylvius, is now held to be
motor rather than sensory and probably joins the motor
division of the nerve. The rare condition known as facial
hemiatrophy is thought to be due to disease of this root.

The roots of the nerve, on their way to the surface, intersect
the fibres of the middle cerebellar peduncle and appear on the
lateral surface of the pons nearer to its upper than its lower
border. The position of the issuing root is made use of as an
arbitrary point of division between the pons and the middle
peduncle. A tumour in this locality may occasion paralysis
of the fifth nerve with deafness, from implication of the eighth
nerve, and cerebellar symptoms from interference with the
cerebellar peduncle.

In the membranes at the base of the brain lie the nerve
roots, the Gasserian ganglion and the three terminal divisions.
The ganglion bears the same relation to the sensory fibres as
a posterior root ganglion does to a sensory spinal nerve. The
small motor root does not enter the Gasserian ganglion but
passes beneath it to join the mandibular nerve. The position
of the ganglion in a hollow near the apex of the petrous
bone, renders it liable to implication by tumours or other
diseases of the middle or posterior fossa, or of the i3etrous
bone. Gummatous or tuberculous disease of the membranes
may involve the issuing root, the ganglion, or the terminal
divisions between the ganglion and their foramina of exit.

The ophthalmic division of the fifth traverses the cavernous
sinus and the sphenoidal fissure, and is most likely to suffer
in conjunction with the motor nerves of the eyeball. It may

13—2

196 CLINICAL APPLIED ANATOMY.

be damaged by growths of the adjacent pituitary body, by
aneurysm of the internal carotid artery, by periostitis at the
sphenoidal fissure, or by lesions in the orbit. The close relation
of this nerve to the cavernous sinus constitutes a serious diffi-
culty in the complete removal of the Gasserian ganglion.

The maxillary division, after its exit from the skull by the
foramen rotundum, traverses the spheno-maxillary fossa, applies
itself closely to the orbital aspect of the palate bone, and enters
the infraorbital canal. It may be damaged by bone disease or
fractures. Its relation to the maxillary antrum, in the roof of
Avhich it lies, accounts for the paralysis caused by maxillary
tumours and the neuralgia which may result from antral disease.

The mandibular nerve, unlike the other two divisions, con-
tains motor as well as sensory fibres. This division is rarely
the sole seat of paralysis, but is sometimes damaged by fractures
or callus of the mandible and by parotid tumours.

The motor filaments of the fifth supply the muscles of
mastication. Of these the temporals and masseters are super-
ficial, and their action can be gauged by feeling the hardening
they undergo when called into action. Wasting of these
muscles causes flattening above and below the zygoma, and
if they undergo secondary contracture they may interfere with
the free opening of the mouth. Loss of power in the pterygoid
muscles causes the lower jaw to deviate towards the paralysed
side when the mouth is opened, owing to the unbalanced action
of the muscles of the opposite side. The tensor palati which
appears to derive its motor nerve from the fifth, is probably
innervated from the spinal accessory nucleus, and escapes in
ordinary fifth nerve paralysis. Paralysis of the mylo-hyoid and
anterior belly of the digastric, both of which are supplied by
the mylo-hyoid branch of the inferior dental nerve, is not easily
recognised clinically, other muscles being also able to elevate
the hyoid bone. Earely irritation of a sensory filament of the
fifth causes trismus or tonic contraction of the muscles of
mastication. This is said to be especially associated with irrita-
tion of the last molar tooth from caries or abscess. It may also

FIFTH CEANIAL NEEVE. 197

occur when there is disease of the temporo-mandibular articula-
tion, which is supplied by the auriculo-temporal branch of the
fifth nerve.

The sensory symptoms referable to the nerve may, like the
motor, be either irritative or paralytic. The cause of epilepti-
form neuralgia, such as is treated successfully by excision of the
Gasserian ganglion with its attached sensory root is obscure.
Similar intense neuralgia may be produced by the irritation
of a tumour of the meninges, for the fifth nerve distributes
recurrent filaments to them. If its trunk is implicated by
the tumour, anaesthesia as well as neuralgia may be expected.
When terminal filaments of the nerve are exposed to irritation
the pain is often referred to other parts to which the nerve
is distributed. Malignant disease of the tongue is well known
as a cause of pain referred to the ear, which pain may be
accompanied by salivation, also brought about through the
agency of the fifth nerve. During eruption of the temporary
molars, children may be observed to pull and rub their ears,
and otitis may be suspected. Pain in a decayed tooth is often
referred to the corresponding tooth in the jaw of the same
side. Decayed teeth may also give rise to frontal, infraorbital,
mental, or auricular pain. Frontal headache may accompany
disease of the nose or its accessory air sinuses. As already
indicated, the grey matter of the sensory nucleus is continuous
with that from which the cervical nerves spring, and this may
account for the radiation of pain from the territory of the fifth
to that of adjacent cervical nerves.

Herpes often occurs in the area of distribution of the fifth
nerve. When the nasal branch is involved, as is shown by the
appearance of the eruption near the tip of the nose, ulceration
of the cornea, iritis or even cyclitis may supervene. This
association is explained by the fact that nerves for the front parts
of the eye are derived from the nasal nerve during its course
through the orbit, reaching the eye through the lenticular
ganglion.

The rapid destruction of the eye which sometimes occurs in

198 CLINICAL APPLIED ANATOMY.

disease of the ophthalmic division is probably an irritative and
not a paralytic phenomenon, and so is not a result of anaesthesia
of the cornea, and consequent failure to remove irritating
particles.

The areas of the face supplied by the three divisions of the
fifth nerve overlap each other ; the area supplied by the posterior
division of the second cervical nerve (the first has no posterior
division) also overlaps the posterior parts of the areas of the
first and second divisions of the fifth, while the skin overlying
the parotid gland is in part supplied by the great auricular
nerve, derived from the anterior division of the second cervical.
Consequently the areas of ansesthesia produced by lesions of the
several divisions are much smaller than the anatomical distribu-
tion would lead us to expect. The boundary between the fifth
and cervical areas may be designated as the vertex-ear- jaw line,
since it extends from the vertex in front of the ear and along the
margin of the mandible. A line drawn through the supraorbital
notch to the interval between the two bicuspid teeth of the low^er
jaw passes over the points of exit of the three divisions of the
fifth on the face. The infraorbital division appears close below
the lower margin of the orbit, and the mental nerve half way
between the alveolar edge and the lower margin of the jaw.

The distribution of the fifth nerve to the mucous membranes
of the nose, mouth, and tongue, anterior parts of the palate and
fauces, and to the conjunctiva and cornea should be borne in
mind. The fifth nerve is not immediately concerned in the sense
of smell, but changes in the mucous membrane of the nose, con-
sequent upon lesions of the fifth nerve, may indirectly affect this
special sense.

There is no doubt that taste fibres are present in the root,
and in the first, second, and third divisions of the fifth. It
is held that the taste fibres from the anterior part of the
tongue travel in the lingual trunk to the point where the
chorda tympani leaves it ; thence by the chorda tympani to the
facial trunk and geniculate ganglion, and from the latter by the
great superficial petrosal nerve to the sphenopalatine ganglion.

Diagram op Course op Taste Fibres.

OphCh&lmic Div"(f Fifth

Superior MAxillary
DivC of Fifch

Meckel's GangHon--
Vidian Nerve ■'''

--Auditory Nerve

Geniculate Ganglion
'of Facial Nerve

Lesser Superficial

Petrosal Nerve

--■ Nerve to Stapedius

Jacohson's Nerve

Fig. 18. — The thick black lines indicate the course believed to be taken by the
taste fibres. 1. From the front and sides of the tongue tlirough the chorda
tyrnpani to the facial trunk, thence through the great su])erticial petrosal
and Vidian nerves to Meckel's ganglion and so to the superior maxillary division
of the fifth nerve. 2. From the back of the tongue and neighbouring parts
through the glossopharyngeal nerve, its tympanic branch (Jacohson's nerve)
and the lesser superficial petrosal nerve, to the otic ganglion and the inferior
maxillary division of the fifth nerve.

[To face page 199.

FACIAL NERVE. 199

and second division of the fifth. Thus is explained the fact that
a lesion of the petrosal nerve has abolished taste on the anterior
part of the tongue.

The taste fibres from the posterior part of the tongue and the
circum vallate papillae travel up in the glossopharyngeal nerve,
but leave this by the tympanic branch, and, running in the small
superficial petrosal nerve, travel by way of the otic ganglion into
the third division of the fifth. (Fig. 18.)

Within the pons the taste fibres are separate from the com-
mon sensory fibres of the fifth, and by some unknown path reach
the internal capsule of the opposite side, finally terminating in a
taste centre at the tip of the temporo- sphenoidal lobe.

Another description of the peripheral course of the taste fibres
is given by Edinger. According to this writer the terminal nucleus
of taste is a mass of grey matter, which has the same vertical
extent as the sensory nucleus of the fifth, and which receives
afferent fibres in succession from the glossopharyngeal nerve,
through its petrous ganglion ; the chorda tympani, through the
geniculate ganglion of the facial, and the portio intermedia ; and
the lingual nerve, through the Gasserian ganglion.

FACIAL PARALYSIS AND FACIAL SPASM.

The facial, like other cranial nerves, may be paralysed by
supranuclear, nuclear, or infranuclear lesions.

A supranuclear lesion may involve the cortex or the con-
ducting fibres from the cortical centre to the facial nucleus.
The lower end of each ascending frontal convolution is connected
with the opposite facial nucleus by fibres which traverse the
genu of the internal capsule and pass along the base of the crus.
In the crus the facial fibres are immediately internal to the
innermost fibres of the pyramidal system, following the general
rule that the fibres which decussate first lie nearest to the mid
line of the body.

The cortical centres for articulatory movements of the tongue
and movements of the larynx lie in the lowermost part of the

200 CLINICAL APPLIED ANATOMY.

ascending frontal convolution, and in the adjacent part of the
third frontal convolution, just below the face centre. The cortical
centres for the arm lie in the ascending frontal convolution above
the face centre. (Fig. 14, p. 183.) Consequently lesions of the
face centre usually involve also the centres for speech and for arm
movements. In a similar manner disease of the conducting tracts
below the face centre tends to implicate the adjacent fibres for the
tongue and limbs. Thus it comes about that the supranuclear
facial paralysis usually presents itself as part of a hemiplegia.

The paralysis caused by a supranuclear lesion is incomplete.
In this type of paralysis, which is sometimes called " cerebral,"
the weakness of the lower facial muscles is more obtrusive than
that of the orbicularis palpebrarum and frontal portion of the
occipito-frontalis muscles. The escape of the upper part of the
face is probably explained by the fact that the facial nucleus
receives fibres from both hemispheres of the brain, and some of
these fibres preside over the movements which are retained.
There is no reaction of degeneration in the paralysed muscles.
Emotional expression in the face and the winking reflex are
retained in cortical and subcortical lesions. The optic thalamus
appears to be concerned in emotional expression, and the winking
reflex depends on the integrity of the afferent fibres of the optic
or ophthalmic nerves, the facial nucleus and the efferent infra-
nuclear facial tract. The supranuclear facial tract crosses the
mid line about half way down the pons to reach the facial
nucleus. (Fig. 13, p. 182.) Lesions involving the tract above
the decussation cause incomplete facial paralysis on the side
opposite to the lesion.

Nuclear and infranuclear lesions. — Lesions below the decussa-
tion in the pons affect the face on the same side as that on which
they occur, and since they are near the nucleus of the nerve
usually cause complete paralysis.

The facial nucleus lies in the ventral part of the tegmentum,
near the junction of the pons with the medulla. (Fig. 17, p. 191.)
Isolated lesions are rare. There is reason to suspect that the
fibres which the facial nerve distributes to the orbicularis oris

FACIAL PAEALYSIS. 201

are really derived from the hypoglossal, and not from the facial
nucleus. It is also possible that the fibres for the orbicularis
palpebrarum and the frontalis muscle arise in the posterior part
of the third nerve nucleus, and join the facial fibres by way of
the posterior longitudinal bundle. If these statements are correct,
in an isolated nuclear lesion of the facial nerve, the muscles
thus innervated from other nuclei should escape.

The radicular fibres of the facial nerve may be injured in the
pons after they have emerged from the nucleus. They form a
bundle which does not pass direct to its point of exit, but first
sweeps around the nucleus of the sixth nerve. If these fibres
are damaged the facial paralysis which results is complete,
involving all the muscles of the face. Associated with the
paralysis of the face may be conjugate deviation of the eyes
away from the lesion, and weakness of the tongue and limbs
on the opposite side of the body. The conjugate deviation is
due to damage to the sixth nucleus as it lies in the loop formed
by the radicular fibres of the facial nerve, and the weakness of
tongue and limbs is caused by implication of the adjacent
pyramidal tract.

Complete facial paralysis is characteristic of infranuclear
lesions. It is sometimes termed radicular or peripheral. It
differs from the cerebral type in that the orbicularis palpebrarum
and the frontalis muscles are as much paralysed as the rest of
the face. Consequently the eye on the affected side cannot be
properly closed, although the associated upward movement of
the eyeball appears on the attempt to do so. The tears of the
affected eye run down the cheek, either because the weakened
lids fall away from the globe so that the puncta lachrymalia are
not kept in proper position, or because the paralysis of Horner's
muscle renders difficult the passage of the tears into the nasal
duct. In both types of facial paralysis the failure of the
buccinator allows food to collect between the cheek and gums,
and, owing to the drawing of the mouth towards the sound side,
the tongue may appear to deviate from the mid line when pro-
truded. It still, however, maintains it proper relation to the

202 CLINICAL APPLIED ANATOMY.

front teeth. There is a reaction of degeneration in the paralysed
muscles in the complete type of paralysis, since they are severed
from the facial nucleus.

At the base of the brain the facial emerges close to the
auditory nerve, the latter lying external and the portio
intermedia between the two. The nerves appear at the lower
border of the pons, immediately above the restiform body, and
they pass together into the internal auditory meatus. As they
pass towards the meatus the facial lies in a groove on the upper
and fore part of the auditory trunk, whilst the pars intermedia
and the auditory artery lie between them. The close relation
of the nerves explains why gummatous and other new forma-
tions involving the dura at the base of the skull are so
likely to cause both facial and auditory paralysis. Lesions of
the facial trunk in this situation should not involve the fibres
which subserve taste, being above the level at which these
are generally supposed to pass into the great superficial
petrosal nerve on their way to the fifth trunk.

A few cases of facial nerve paralysis are due to inflammation
or caries of the tympanum. The aqueduct of Fallopius
which transmits the facial trunk lies in the inner w^all of
the tympanum, behind the foramen ovale, forming the inner
boundary of the isthmus of communication between the attic
and the antrum. The wall of the aqueduct is occasionally
incomplete, which accounts for the readiness with which the
nerve suffers in some cases of otitis, moreover the apertures which
transmit the chorda tympani, the nerve to the stapedius and the
stylomastoid artery may allow invasion of the aqueduct from the
middle ear. The nerve is liable to damage in this position from
operations on the mastoid, and the external semicircular canal,
which lies immediately behind and above the Fallopian aqueduct,
may be injured at the same time. Fractures of the base of the
skull may cause facial paralysis when they traverse the petrous
bone ; in fact the facial nerve is more often paralysed in fracture
of the base than any other cranial nerve. Impairment of taste
on the front part of the tongue indicates a lesion of the facial

FACIAL PAEALYSIS. 203

nerve in such a position as to involve the trunk between the point
where the chorda tympani joins it and the point where the great
superficial petrosal nerve leaves the geniculate ganglion, since
the taste fibres leaving the facial nerve pass by the petrosal nerve
to enter the brain by way of the fifth nerve. (Fig. 18, p. 199.)

In the adult the trunk of the facial nerve emerges from the
stylomastoid foramen in a protected position, but in the infant
the opening of the canal is practically exposed on the lateral
aspect of the skull and is liable to injury by the forceps during
delivery. The posterior auricular branch, which supplies the
retrahens aurem and the occipitalis muscles is given off imme-
diately after the exit of the nerve, so these muscles occasionally
escape when the nerve is injured near the mandible by wounds
or direct violence. The nerve trunk enters the parotid gland just
above the level of the tip of the lobule of the ear, hence it may
be involved by parotid tumours or inflammations, or by vertical
incisions into the gland carried above the level indicated. The
nerve had also been compressed by gummatous and lymphatic
glandular swellings in this region and injured by operations
undertaken for removal of the latter. The exposed position of
the filaments of distribution on the face is no doubt a contributing
factor in the production of the ordinary or so-called rheumatic
type of facial paralysis. It is doubtful whether the usual explana-
tion that the nerve is compressed in the aqueduct of Fallopius
on account of its own swelling is a valid explanation of the
production of this form of palsy.

Although the facial nerve is usually considered and described
as purely motor in function certain sensory symptoms may
accompany facial paralysis. The defect of taste on the fore part
of the tongue has already been mentioned. There may also be
some defect of smell on the paralysed side, which may be
attributed to weakness of the sniffing movements of the nostril
on that side. Defect of hearing when present may be due to
inflammation of the tympanum or to simultaneous implication
of the facial and auditory nerves at the base of the brain. When
the stapedius muscle is paralysed the unbalanced action of the

204 CLINICAL APPLIED ANATOMY.

tensor tympani increases the sensitiveness of the ear to musical
tones. Neuralgic pain at the back of the ear and in the teeth
and gums of the paralysed side may accompany facial paralysis.
The anatomical explanation is obscure but it has been supposed
to be due to irritation of sensory fibres of the fifth nerve which
have joined the facial nerve in the Fallopian canal.

The pathology of facial spasm is obscure, but it is sometimes
due to reflex irritation from the territory of the fifth nerve and
particularly from its orbital branches. Exceptionally irritation
of the facial nerve near its origin from the pons or of the cortical
facial centres originates the spasm.

THE AUDITORY NERVE.

The auditory nerve consists of two distinct portions ; of these
one is called vestibular and is concerned in equilibration or
orientation of the body, and the other is called cochlear and con-
cerned in hearing. The ampullary and cochlear portions of the
labyrinth in which these nerves respectively commence are
continuous, and the combined nerves form a common trunk as
far as the surface of the pons ; the nuclei of termination in the
fourth ventricle are also closely adjacent, but the ultimate central
terminations of the two nerves are widely separated. Hence in
labyrinthine lesions and lesions of the common auditory trunk
both portions of the nerve are equally exposed to injury, and it
is usual to find that impairment of hearing is associated with
vertiginous sensations. The latter, especially if of sudden onset,
may be so obtrusive that for some time the accompanying deaf-
ness may be overlooked, the more so since in labyrinthine lesions
the defect may only be marked in the case of the higher pitched
sounds.

The organ of hearing being enclosed in the petrous bone can
receive and appreciate vibrations directly from the bone. This
fact is taken advantage of when a tuning fork or watch is applied
directly to the mastoid or vertex in testing nerve conduction, the
failure to appreciate vibrations applied in this way being an

AUDITOEY NEEVE. 205

indication of nerve deafness. The presence of the internal
carotid artery in a canal in the petrous bone probably accounts
for the pulsatile tinnitus which occurs in some cases.

Inflammatory disease of the labyrinth may originate in it
or extend to it from the middle ear through the foramina in
the inner wall of the tympanum, or pass from within the skull
along the sheath of the auditory nerve, for the subarachnoid
space around the auditory nerve communicates with the perilymph
spaces of the internal ear. Such an extension is not uncommon
in leptomeningitis.

A combination of nerve deafness with facial paralysis and
suppuration of the middle ear indicates that the inflammation
involves the bony labyrinth. Paralysis of the same two
nerves with a healthy tympanum would lead to the inference
that the lesion was in the internal meatus or at the base of the
brain. New growths in the petrous bone or posterior fossa of
the skull, gummatous and other varieties of meningitis in this
locality, and occasionally an aneurysm may involve the facial and
auditory nerves at the base. Sometimes the sixth and other
adjacent nerves are also paralysed. It has been observed that
the facial nerve (portio dura) is more resistant to the effects of
surrounding inflammation than the eighth nerve (portio mollis).

The fibres of the vestibular nerve are derived from the semi-
circular canals, the utricle and the saccule. After traversing the
local ganglia in the petrous bone they are continued through the
internal meatus towards the restiform body. Up to this point,
as already mentioned, both parts of the auditory nerve are likely
to suffer together. On reaching the surface of the brain the
vestibular fibres diverge from the cochlear fibres to enter the pons
on the ventral aspect of the restiform body, which thus becomes
interposed between the two portions of the auditory nerve. The
vestibular fibres terminate in certain nuclei in the outer angle of
the fourth ventricle, including Deiter's nucleus. (Fig. 17, p. 191.)
The fibres are thus brought into connection with other parts of the
mechanism of equilibration, including the cerebellum, the ocular
nuclei and the antero-lateral columns of the spinal cord. These

206 CLINICAL APPLIED ANATOMY.

complex connections explain the extreme vertigo and inco-ordina-
tion induced by sudden lesions of the vestibular nerve.

The fibres of the cochlear or auditory portion of the nerve
commence in Corti's organ in the cochlea and join the spiral
ganglion of the latter. Thence fibres traverse the meatus in
company with the vestibular portion of the nerve. Diverging
finally from the vestibular nerve and passing dorsal to the resti-
form body, the fibres terminate in a couple of ganglia closely
applied to the latter and known as the acoustic tubercle and the
ventral cochlear nucleus.

In localising the position of a lesion in the pons or higher
parts of the brain which causes deafness, a knowledge of the
course taken by the auditory impulses from the nuclei in the pons
to the auditory perceptive centres in the temporal lobes is
essential, since it is only by the associated symptoms that the
localisation can be effected.

Most of the fibres from the nuclei, bat not all, cross to the
opposite side of the pons, some passing dorsally through the
striae acusticae which are visible on the floor of the fourth ventricle
and other passing more ventrally in the trapezoid body. Uniting
in the lateral fillet this double set of crossed fibres passes through
the internal geniculate body, traverses the sensory limb of the
internal capsule and passes thence by the corona radiata to the
superior temporo- sphenoidal convolution. The afferent tracts
are also connected with the superior olivary bodies and the
posterior corpora quadrigemina. The whole tract consists of an
elaborate system of nerve cell relays. It will be gathered that
each ear is connected not only with the auditory centre of the
opposite side but also with that of the same side.

The association of word deafness with a certain amount of
defect of hearing in the right ear points to the left temporal lobe
as the seat of disease. Deafness from a lesion of the internal
capsule is associated with hemianopia and hemianaesthesia since
the auditory fibres are in immediate relation here with the
visual tract and the fibres of common sensation.

Deafness from a lesion in the corpora quadrigemina or from

NINTH, TENTH AND ELEVENTH NEEVES. 207

pressure on the adjacent fillet, such as might occur from quadri-
geminal tumours or enlargement of the pineal body, will be
associated with defects in the movements of the eyes and other
symptoms referable to the corpora quadrigemina.

Deafness from involvement of the auditory tract in the pons is
rare, probably because lesions of the pons usually occur in the
tegmental or dorsal region, whilst the auditory tract lies lateral
in the lateral fillet and ventral in the corpus trapezoides. The
occurrence of paralysis of other cranial nerves which arise from
the pons and of opposite hemiplegia will localise the lesion
sufficiently.

THE GLOSSOPHARYNGEAL, VAGUS, BULBAR AND SPINAL
ACCESSORY NERVES.

From both the anatomical and the clinical points of view the
glossopharyngeal, vagus and bulbar portion of the spinal accessory
nerves are best considered together as forming parts of one large
nerve. The fibres are mixed, some being afferent or sensory,
and others efferent or motor in function.

Unilateral lesions of the motor cortex or motor tracts above
the motor nucleus of the nerve do not produce any appreciable
paralysis of the larynx, pharynx or palate to which the nerve is
distributed, but if botJt cortical centres or supranuclear tracts be
damaged a condition known as pseudo-bulbar paralysis is induced.
Hence the inference that the bulbar nucleus is connected with
each hemisphere of the brain.

The motor fibres arise from the nucleus ambiguus which
extends from the level of the highest issuing roots of the glosso-
pharyngeal down to the point of decussation of the fillets which is
a short distance above the decussation of the pyramids. (Fig. 17,
p. 191.) From this nucleus the motor fibres for the larynx, pharynx
and soft palate arise, consequently it has been termed the nucleus
of phonation and deglutition. The unity of the nucleus explains
the combination of paralyses met with in bulbar palsy, i.e., of
larynx, soft palate and pharynx, to which may be added paralysis
of the tongue and lips if the hypoglossal nucleus is also affected.

208 CLINICAL APPLIED ANATOMY.

Chronic nuclear degeneration producing this type of paralysis
may exist alone or be a part of tabes, general paralysis, syrin-
gomyelia or amyotrophic lateral sclerosis. Acute affections of
the nucleus may occur in haemorrhage or softening of the medulla.
Since the reflex arc is interrupted, loss of the palatine, pharyngeal
and laryngeal reflexes may be expected in nuclear lesions, whereas
they are retained in lesions above the level of the nucleus.

In the membranes at the base of the brain and also at the base
of the skull, the glossopharyngeal, vagus and bulbar accessory
nerves are close together and are in addition joined by the spinal
portion of the accessory nerve. The last nerve is distributed
to the sternomastoid and trapezius, consequently the involvement
of these two muscles as well as the larynx, palate and pharynx
points to a lesion of the membranes or bones of the base. Basal
meningitis, basal tumours and aneurysms of the vertebral artery
are lesions which may cause this combination of paralyses.

The action of the laryngeal motor mechanism is easily investi-
gated with the laryngoscope and may afford valuable indications
not only in disease of the bulbar nuclei but also in certain
intrathoracic diseases such as tumour and aneurysm which also
cause laryngeal paralysis.

The superior laryngeal nerve, which conveys motor impulses
to the crico-thyroid muscle, is also the sensory nerve of the upper
part of the larynx. The nerve trunk is comparatively short and
running deeply is well protected, consequently isolated paralysis
of the crico-thyroid muscle is exceptional. Suicidal wounds of
the neck and tumours or enlarged glands in this position may
involve the nerve. The crico-thyroid may also be paralysed by
lesions of the vagus at or above the level of the ganglion of the
trunk from which the superior laryngeal nerve is given off, but
then the other laryngeal muscles will also be affected. The
function of the crico-thyroid is to tilt backwards the cricoid
cartilage, and so render tense the vocal cords.

The motor fibres for the other laryngeal muscles run in the
recurrent laryngeal nerves. The long course of these nerves
exposes them to damage in widely separated localities. Bilateral

LAKYNGEAL PAKALYSIS. 209

paralysis may be produced by cancer of the upper parts of the
oesophagus or by tumours of the thyroid gland or operations at
the root of the neck on either of these structures, for both
recurrent nerves are in close contact with the sides of the gullet
and the thyroid. The left recurrent nerve, winding as it does
round the aortic arch, is frequently compressed by aortic
aneurysms, whilst aneurysms of the innominate or right sub-
clavian arteries may paralyse the right nerve, but this is more
commonly implicated in glandular enlargements within the
thorax and may be damaged by phthisis near the pleural dome.

In progressive lesions of the recurrent laryngeal nerve the
muscles usually fail in a definite order according to Semon's law,
the abductors first and then the adductors. The nerve bundles
in the recurrent laryngeal trunks for the abductor and the
adductor groups are distinct, but this anatomical arrangement
does not altogether explain the greater vulnerability of the
abductors. They have been compared in this respect to the
extensor muscles of the limbs.

In abductor paralysis the paralysed cord during inspiration
appears both shorter and higher than its fellow. This appearance
is due to the sloping surface of the cricoid facet on which the
arytenoid cartilage rests, so that when the abductors come into
play the latter cartilage is dragged downwards as well as back-
wards and outwards. The free edges of the true cords are
directed upwards as well as inwards, and when the abductors
of both sides are paralysed the inspiratory rush of air tends
to drive the cords together like a valve, producing urgent
dyspnoea.

The arytenoideus muscle escapes in unilateral laryngeal
paralysis, possibly because it is supplied by both recurrent nerves.

Paralysis of the soft palate also points to an affection of the
motor fibres of the vago-glossopharyngeal group. The lowermost
fibres are those concerned, and these are usually spoken of as the
bulbar accessory fibres. They arise from the nucleus ambiguus
and supply the levator palati, probably reaching the palate
through the pharyngeal plexus. Hence the palate is paralysed

C.A.A. 14

210 CLINICAL APPLIED ANATOMY.

in disease of the bulbar nuclei or of the nerve roots in the
subdural space. Like the pharynx it may also be paralysed by
peripheral neuritis such as occurs in diphtheria. Unlike the other
palatine muscles, the tensor palati is held to be supplied by the
motor division of the fifth nerve through the otic ganglion. Care
must be taken not to mistake asymmetry of the soft palate for
paralysis ; defect of movement is the only safe diagnostic guide.
The afferent fibres of the glossopharyngeal nerve end in the
posterior or dorsal vago-glossopharyngeal nucleus subjacent to
the trigonum vagi, and in the fasiculus solitarius or ascending
root of the glossopharyngeal which, in many respects, resembles
the large ascending root of the fifth nerve.

Irritative symptoms referable to the vago-glossopharyngeal
group are more common than paralyses. They include cough,
vomiting, laryngeal spasm, vertigo and derangements of cardiac
action.

It appears that cough may be reflexly induced from any
territory supplied by branches of the vagus and glossopharyngeal
nerves, and sometimes from other regions as well. The glosso-
pharyngeal filaments from the tonsil, pharynx and middle ear,
and the vagal filaments from the auditory meatus, pharynx,
oesophagus, stomach, larynx, trachea, bronchi, lungs, and possibly
also the filaments from the pericardium and heart may convey
impulses which originate cough.

As with cough, so with vomiting ; it is well known that irrita-
tion of the fauces, pharynx or auditory canal may induce this as
also may lesions of the lungs, mediastina, pleurae, heart, peri-
cardium, stomach, liver, kidneys, pancreas and adrenals, to all of
which the vagus distributes filaments.

Laryngeal spasm as the result of sensory irritation is seen in
connexion with foreign bodies and inflammations of the larynx,
pressure on the trachea and bronchi, and as a symptom of tabes.
Cardiac irregularities have been found in some instances to be
due to tumours implicating the cardiac plexuses. Fatal cardiac
arrest sometimes follows exploratory puncture of the chest owing
to reflex inhibition of the heart.

PAEALYSIS OF THE HYPOGLOSSAL NEEVE. 211

THE HYPOGLOSSAL NERVE.

As with other motor nerves, paralysis of the hypoglossal may
be of supranuclear, nuclear, or infranuclear origin.

Supranuclear Paralysis. — The cortical centre for the tongue
lies at the posterior extremity of the third left frontal convolution,
and is connected by the pyramidal fibres with the hypoglossal
nucleus of the opposite side. Lesions of the centre or of the
conducting tracts above the nucleus rarely affect the tongue
alone but usually give rise to a hemiplegia which is more or less
complete. The reasons for this have already been given when
dealing with the other motor cranial nerves.

Nuclear Paralysis. — The hypoglossal nucleus lies ventral to
the central canal of the cord, and when the canal opens up into
the fourth ventricle the nucleus lies subjacent to the trigonum
hypoglossi. (Fig. 17, p. 191.) The nucleus is implicated by the
same types of lesion as those already indicated when dealing with
the vago-glossopharyngeal nucleus, indeed the two nuclei being
closely adjacent usually suffer together. The results of intra-
cranial disease have led to the suggestion that the hypoglossal
nucleus gives rise to the motor fibres of the lips as well as to
those of the tongue.

Infranuclear paralysis of the hypoglossal may be the result
of a lesion of the medulla where this is traversed by the issuing
nerve roots. In such a case there is every likelihood that the
adjacent pyramidal tract will be damaged so that a crossed
paralysis of tongue on side of lesion and limbs on the opposite
side of body will be produced.

Lesions in the subdural space will implicate the nerve some-
where between its points of exit in the groove between the pyramid
and the olive and its passage through the anterior condyloid
foramen. This foramen is only separated from the jugular fora-
men by the bony eminence known as the eminentia innominata.
Given a lesion in this neighbourhood the adjacent vago-glosso-
pharyngeal fibres are almost certain to suffer at the same time
as the hypoglossal, so that a combined unilateral paralysis of the

14—2

212 CLINICAL APPLIED ANATOMY.

tongue, soft palate and vocal cord results. A lesion outside
the base of the skull may involve the same nerves after their
exit and produce paralysis of similar distribution. Tumours
and inflammatory affections at the base of the skull, disease of
the occipito-atloid joint and caries of the highest cervical vertebrae
may all implicate the hypoglossal and adjacent nerves in this
way.

Unilateral paralysis of the tongue results in its deviation
towards the paralysed side when protruded owing to the un-
balanced action of the sound genio-glossus muscle. When at
rest in the mouth the root of the tongue appears higher on the
paralysed side from loss of tone in the hyoglossus of that side.
Unless the paralysis is bilateral there is but little interference
with the power of chewing, deglutition or articulation. If the
lesion be nuclear or infranuclear the tongue wastes, and as a
result the mucous membrane of the affected half appears too
large for it and is thrown into folds. There is also a reaction
of degeneration in the affected muscles.

The Spinal Cord,
myelitis.

In most cases myelitis appears to be due to an infective agent
carried to the spinal cord by the blood stream. The rarity with
which inflammation of the spinal cord follows injury is no doubt
due to the efficient way in which it is protected by the vertebral
canal, and the intervention of the membranes with their fluid
contents between the cord and its bony sheath. Notwithstanding
this, inflammation of the cord has been known to follow falls
from a height on to the feet, blows, twists or wrenches of the
spine, quite apart from fractures and dislocations.

Inflammation may spread directly to the cord from the verte-
bral canal, or from the encasing membranes, and, in the latter
case, may show an annular peripheral distribution which is no
doubt brought about by the way in which the pial septa penetrate
the periphery of the cord carrying with them small vessels.

MYELITIS. 213

Inflammation may also travel to the cord along the connective
tissue sheaths of the nerves, and the so-called " reflex urinary
paraplegia" is prohably an example of this method of invasion.

The distinction of a mere softening of the cord, the result of
vascular occlusion, from the softening which is the result of
inflammation is not at all easy. The myelitis which is met with
within a couple of years of syphilitic infection is, with considerable
reason, regarded by many as a primary vascular softening. In
such cases the vascular obstruction must be the result of endar-
teritis of minute terminal vessels in the cord, for there is a free
vertical anastomosis not only of the spinal arteries on the surface
of the cord but also, to a less degree, of the larger arteries in the
cord itself.

As the result of myelitis the nervous structures at the site of
the disease are more or less destroyed, but, in addition to this,
certain secondary degenerations of the cord are found. These
secondary degenerations occupy definite tracts in the white
matter, and some ascend from the site of lesion whilst others
descend. The degeneration of these tracts is dependent on their
severance from their trophic cells. The descending degenerations
involve the crossed and direct pyramidal tracts, whilst tracts
which undergo ascending degeneration are the direct cerebellar
tract, the antero-lateral ascending tract of Gowers, and the tracts
which form the postero-internal and postero-external columns of
the cord, or the column of Goll and the column of Burdach.
(Fig. 19, p. 222.) The lumbo-sacral fibres of the postero-external
column do not pass up to the bulb in this column, but after a
short upward course enter the postero-internal column and com-
plete their ascent in this. Consequently the postero-external
column is only degenerated for a short distance above the lesion,
whilst the degeneration in the postero-internal column passes as
high as the grey matter of the nucleus gracilis. The higher the
lesion the more complete the degeneration of the postero-internal
column, since the nerve fibres which enter it from the upper
lumbo-sacral sensory roots are affected as well as the lower.

But inflammation may also extend from the local lesion for a

214 CLINICAL APPLIED ANATOMY.

Table of Kkpkesentation of Muscles in Spinal Segments.

-

C.l

X
X
X
X
X

D.l

2

X
X
X
X
X
X

2

3

X
X
X
X
X
X
X
X

3

4

X
X
X
X

?
4

0

X
X

1

X
X
X
X
X
X
X
X
X
X
X
X

X

9

5

6

X

•?

V

?

1

V
X
X

■/

X
X
X
X
X
X

•)
6

X
X

S.1

7

X
X
X
X
X
X

7

X

X
X
X
X

2

s

••
V

9
9

?

X
X
X
X
X
X

8

X

X
X
X
X

8

D.l

X
X

9

X

X
X
X
X

4

10

X

X
X
X
X

5

11

X

X
X
X
X

12

X

X
X
X
X

Small flexors of head

Depressors of hyoid bone

Small rotators of head

Complexus

Splenius

Sterno-mastoid

Levator anguli scapulas

Scaleni

Trapezius

Diaphragm

Rhomboids

Supraspinatus

Infraspinatus

Teres minor

Coraco-brachialis

Biceps

Brachialis anticus

Deltoid

Supinator longus

Supinator brevis

Pectoralis major

Pectoralis minor

Serratus magnus

Subscapularis

Teres major

Pronator radii teres

Pronator quadratus

Latissimus dorsi

Triceps

Extensors of wrist

Extensors of fingers . . ....

Flexors of wrist

Flexors of fingers

Interossei

Thenar muscles

-

Intercostals . .
Pupil dilator . .
Rectus abdominus .
Obliquus externus
Obliquus internus
Transversalis . .

X

X
X

2

X
X

3

X

4

X
X

5

-

L.1

Quadratus lumborun

Cremaster

Ilio-psoas

Pectineus

Sartorius

Adductors of thigh

Quadriceps extensor

Gracilis

Small external rotate

Gluteus medius and

rs of thigh

X

f

X
X
X
X
X

V

X
X
X
X
X

X
X

X

X

X
X
X
X

•)

X

1

X
X

X
V

X
X

X
X

X
X
X
X

Y

X
X

X

V

X
X

X
X

Gluteus maximus
Hamstrings . .
Gastrocnemius
Soleus ..

Extensors of foot an
Flexors of foot and t
Peroneus longus
Peronei . .

Intrinsic muscles of
Muscles of perineum
Sphincter ani . .

d toes
oes

foot

••

DISTEIBUTION OF KEFLEXES.

215

W
><!

Ph

O

o

M

H

s

H
02

O

>A
W

■*

: : : i : i : : : : : X

=^ 1 : : : ::::::!: X

^' : : : :::::: X X :

2 \ '■ '■■ '■■ iiiiiXXX;

o

: : • : : : : : X : : :

^ : : : ! ! : i X i i ! i

« : i : : : ! : X ; i : ;

'>' ':':'■. : : : X : : i : :

2 1 ; : ; ; : ; x : : : : :

s : i : : ! X ; : : : : i

^ : : : : : X i • ! i • •

Si;: : i X : ; i : : i

^- ; : : : : X i ; ; : : :

^ : : : : : X i : ! • i i

! : : : X ;::::; ;

» 1 i : ; •: X : : 1 ; : 1 1

"--^ : : : : X :::::• i

n i i : i X i ; ; 1 : 1 i

^ : i : X ; i : : i : i :

•^^ : : : X i :::::• i

s

: i i -::::!!;!

00

: X X :::::::::

t- : X : :::::::::

o

X X : :::::::::

irt

: X ; !!:;!:!::

"* : : : :::!!:!:!

CO

: : : :::::::::

ff^

(5

: ; ; ::!:!::::

1

; X : c : : : : : --•— . : : :

: CI • o ...

t : .^ ^1 -g 1 -g ^ %.t.

216 CLINICAL APPLIED ANATOMY.

short distance upwards along tracts which should degenerate
downwards and vice versa. For instance the pyramidal tracts
may be found degenerated upwards for a short distance. This is
probably due to a direct spread of inflammation in the neuroglial
planes, and is quite comparable to the way in which inflammation
spreads by continuity in other parts of the body, and of the same
nature as the inflammation which is found in the nerve roots,
which arise from the cord at the site of the myelitis.

Two distinct groups of symptoms occur in myelitis. The first
group comprises motor and sensory phenomena which are due to
the interference with the transmission of impulses up and down
the cord, the second group consists of symptoms due to the
destruction of local centres at the site of the myelitis. Anaesthesia
and loss of power below the site of the lesion belong to the first
group, whilst local atrophy of muscles with loss of electrical
reactions in them and abolition of reflexes are indications of
local destruction. A zone of hypersesthesia just above the level
of the lesion is due to irritation of the sensory roots at the upper
level of the myelitis. As a rule the reflexes of the parts below
those actually supplied by the diseased segments of the cord are
exaggerated and the nutrition of the muscles fairly preserved,
but there is reason to believe that when the lesion is completely
transverse, which is equivalent to a transection of the cord, the
reflexes below the lesion are abolished.

The upper limit of a myelitis is best determined by the situation
of the upper limit of anaesthesia, whilst the vertical extent of the
lesion can be gauged by the loss of reflexes and distribution of
muscular wasting.

The dorsal region of the cord supplies nerves to the inter-
costals, the long muscles of the back and the flat muscles of the
abdomen. Wasting of individual intercostal muscles is not easily
observed, and the long muscles of the back and flat muscles of
the abdominal wall do not appreciably waste since they receive
nerves from a great number of dorsal segments.

The cervical and lumbar enlargements supply muscles of the
limbs, and detection of wasting and of the reaction of degeneration

INFANTILE PAEALYSIS. 217

in these muscles is a simpler matter. Cervical myelitis in the
region of the fourth segment causes paralysis of the diaphragm,
and since the impulses to the intercostal muscles are also blocked
by the same lesion, death results from respiratory failure. A
cervical myelitis is also liable to spread to the adjacent medulla
involving the vital centres in this region.

A myelitis so situated as to involve the region of the cervical
cord which supplies the arm may give rise to alterations in the
size of the pupil, as will be explained in the section on
compression of the cord.

It is not easy to give a simple description of the way in which
cord inflammations affect the mechanism of the urinary bladder.
If that part of the cord corresponding to the origin of the third
and fourth sacral nerves be involved there is no power to retain
the urine, which dribbles away almost as soon as it enters the
bladder, because the sphincter is paralysed. When the lesion is
at the junction of the dorsal and lumbar regions there is reten-
tion with overflow. "When the lesion is above the ninth dorsal
segment the act of micturition may occur automatically as soon
as a fair quantity of urine has accumulated in the bladder, the
patient being quite unconscious of the act. In this case all the
local bladder centres are intact, but their higher connections are
severed.

ACUTE ANTERIOR POLIOMYELITIS.

This disease, commonly known as infantile paralysis, is due
to an acute lesion of the motor cell groups of the anterior
cornua of the spinal cord. The grey matter of the anterior
cornua, and also that forming the base of the posterior cornu, is
supplied with blood by branches derived from the anterior
spinal artery, so the lesion occurs in the territory supplied by
that vessel. (Fig. 19, p. 222.) The febrile onset of the disease
suggests an infective inflammation, but in a few of the cases
there is no fever, and this has led to a suggestion that these may
be of thrombotic origin.

The motor cells of the anterior cornua are arranged in definite

218 CLINICAL APPLIED ANATOMY.

groups. These groups are most numerous in the cervical and
lumbar enlargements and extend in a vertical direction through
a varying number of cord segments, some extending through as
many as three or four whilst others are limited to one. It is
assumed that each cell group represents a particular muscle.
If the cell group is entirely destroyed the muscle is completely
paralysed, whilst partial destruction, which is more likely to occur
when the cell group extends through several segments, leads to
paralysis of part of the muscle only.

Several types of infantile paralysis may be recognised, depend-
ing upon the position occupied by the spinal lesion.

In the leg type the peroneal and the anterior tibial groups
of muscles are involved, occasionally the posterior tibial group,
including the calf muscles, as well. Eeference to the table
of muscular representation in the cord, indicates that the
lesion in such cases is in the lower lumbar and sacral regions.
The functions of the bladder and rectum may be interfered with
owing to the proximity of the centres for these organs. The
resulting deformities affect the ankle and foot. Owing to the
continued unopposed activity of the calf muscles talipes equinus
may be produced. When paralysis preponderates in the peronei,
the foot becomes inturned, and talipes varus occurs, because of
the unopposed action of the anterior tibial group.

In the thigh type of paralysis the iliacus, psoas, quadriceps
extensor and glutei suffer, the adductors often escaping. The
lumbar region of the cord is the site of the lesion in such cases.
Owing to the unopposed action and ultimate contracture of
the hamstrings, the knee may become fixed in a position of
flexion. The head of the femur may fall from its proper
position in the acetabulum, and even become further displaced.
Paralysis limited to the muscles of the thigh produces serious
disability owing to the position of the paralysed segment at the
junction of the trunk and lower limb. Under these circum-
stances the part of limb below the knee is practically useless
although its muscles are intact.

The arm may be paralysed in either its upper or lower

PEOGEESSIVE MUSCULAR ATEOPHY. 219

segments or both. In paralysis of the lower arm type the
flexors and extensors of the wrists and fingers and the small
muscles of the hand are involved. Sometimes the intrinsic
muscles of the hand suffer alone. The supinator longus usually
escapes. The lesion in the cord occupies the seventh and eighth
cervical and the first dorsal segments. The deformity known as
claw hand may result.

In paralysis of the U2}per arm type the scapular muscles,
deltoid, triceps and supinator longus are involved. The lesion
corresponds to the fifth and sixth cervical segments. The dis-
tribution of the paralysis is very similar to that met with as the
result of lesions of the fifth and sixth cervical roots in the
posterior triangle of the neck. The paralysis of the deltoid
allows the humerus to fall away from the glenoid cavity simu-
lating dislocation. This deformity is more marked if the supra-
spinatus as well as the deltoid is paralysed.

When the spinal muscles are paralysed, certain curvatures of
the spine occur, owing to loss of muscular support and the
unopposed action of unparalysed muscles. Spinal curvature may
also result from tilting of the pelvis when muscles attached to
this are weak.

The paralysed limbs often show vaso-motor disturbance,
stunted growth and thinning of the bones. These changes are
due to the involvement of the centres in the cord which supply
vaso-motor and trophic fibres and also in part to disuse of the
limbs. Pain is sometimes complained of at the onset of the
disease, actual anaesthesia is found in rare cases, and persistent
hyperalgesia is not uncommon. Diffusion of the lesion in the
grey matter of the cord, to the adjacent tracts for painful impulses
and for common sensation, probably explains these occurrences.

PROGRESSIVE MUSCULAR ATROPHY.

This affection is sometimes called chronic anterior polio-
myelitis.

An anatomical difference lies at the root of the two types of

220 CLINICAL APPLIED ANATOMY.

this disease. The type which is known as the progressive spinal
muscular atrophy, in which spastic symptoms are absent, cor-
responds to a degeneration of the lower motor segment or
neuron. This segment comprises an anterior cornual cell, and
its axis cylinder process, which is prolonged through the corre-
sponding anterior root to a muscle. In the other type of disease,
spastic symptoms coexist with muscular wasting. This type
is known as amyotrophic lateral sclerosis, and is characterised by
degeneration of the upper motor segment or neuron, as well as
the lower. The upper neuron comprises a pyramidal cell of the
motor cortex with its axis cylinder process, which is prolonged
through the internal capsule and pyramidal tracts to become
functionally connected, through the medium of the grey matter
of the anterior cornu, with the lower neuron.

In both types the muscles which waste appear to be successively
attacked according to the order in which their cell groups are
arranged in the cord. The cervical enlargement which corre-
sponds to the brachial plexus is the most common site of
the disease, and it commences with equal frequency at
either extremity of this enlargement. Occasionally the upper
part of the lumbar enlargement suffers, and rarely other parts.
In its later stages the disease may spread upwards to the bulbar
nuclei and the signs of glosso-labio-laryngeal palsy be super-
added.

The upper part of the cervical enlargement contains the nerve
cell groups of the shoulder muscles, and its lower part those
corresponding to the small muscles of the hand. Accordingly
the deltoid muscle or the muscles of the thenar eminence are
usually the first muscles in which the disease is recognised.

When the muscles of the thenar eminence are involved the
power of abducting the thumb from the plane of the palm and
also that of opposing the thumb to the fingers, are first to
become defective, since these movements are almost entirely
performed by the short thumb muscles. At the same time
the thenar eminence becomes wasted. Ultimately the thumb
becomes rotated outwards so that its palmar surface looks

PEOGEESSIVE MUSCULAE ATEOPHY. 221

in the same direction as the corresponding surfaces of the
fingers.

Atrophy of the first dorsal interosseus muscle or abductor
indicis usually follows that of the thenar muscles. This muscle
forms the prominence which is seen on the dorsum of the hand
between the metacarpals of the thumb and index finger, and so
wasting is easily recognised, at the same time power of abducting
the index finger from the mid line of the hand is lost. The
appearance of hollows between the other metacarpal bones
indicates wasting of the rest of the interossei, whilst wasting of
the lumbricales which lie between the tendons of the long flexors
in the palm, causes those tendons to become very prominent.

Besides abducting and adducting the extended fingers the
interossei have the task of flexing the first phalanges and
extending the other two. Consequently, should they be paralysed
some time before the long flexors and extensors of the wrist
have followed suit, the claw hand is produced ; this position is
the outcome of the loss of action of the interossei, the first
phalanges being over-extended, and the other two flexed.

Still following the order of arrangement of motor cells, the
disease involves the flexors of the fingers and wrists before the
extensors of the same parts.

Of the upper arm muscles the deltoid usually suffers first,
often with the supra- and infra-spinati, and the clavicular portion
of the pectoralis major.

Muscles which usually escape are the upper part of the
trapezius, the sterno-mastoid, and the triceps. The latissimus
dor si and lower half of the pectoralis major are late in showing
wasting. The last two muscles are innervated from the sixth
and seventh cervical segments ; the trapezius by the spinal
accessory, which is derived from the second to the sixth cervical
segments. The levator anguli scapulae is innervated from the
third and fourth cervical segments.

When the legs waste, the glutei, extensors of the knee, and
muscle groups of the front and outer sides of the leg usually
suffer. These groups are represented in the lumbar enlargement.

222 CLINICAL APPLIED ANATOMY.

When atroph}^ involves the extensor muscles at the back of
the neck the head falls forwards until the chin rests on the
chest.

TABES DORSALIS.

The afferent or sensory system of the spinal cord and those
portions of the posterior roots which intervene between the
posterior root ganglia and the point of entry of the roots into
the cord, are the parts which are principally involved in tabes
dorsalis. The lumbar region and the cauda equina are usually
the sites of the most advanced disease. The peripheral nerves
of the body may also suffer in varying degrees, and certain of
the cranial nerves, both motor and sensory, may also be invaded.
Consideration of the course taken by the fibres of a posterior
spinal root on entering the cord shows that the tabetic lesions
in the posterior columns correspond to the distribution of the
posterior root fibres. (Fig. 19.)

From a posterior root three sets of intraspinal fibres may be
derived. The first set consists of fine fibres, which pass directly
to form Lissauer's tract at the tip of the posterior cornu of the
grey matter, and end in the substantia gelatinosa of that cornu.
The second set of fibres form the cornu-radicular zone. Some of
these pass directly forwards to become connected with the motor
cells of the anterior cornu, the rest do not terminate in the seg-
ment at which they entered the cord, but pass upwards for a
short distance, being gradually displaced forwards by the corre-
sponding fibres of the roots which enter above them. They are
thus pushed into the anterior and middle parts of the postero-
external column, or column of Burdach, and ultimately come
into connexion with the cells of Clarke's column, which in turn
give origin to the fibres of the direct cerebellar tract. The third
set consists of long fibres, w^hich soon pass from the postero-
external column into the postero-internal column of Goll, in
which they are continued up to the nucleus of the funiculus
gracilis in the medulla. The long fibres which ascend in Goll's
column are principally derived from the posterior roots of the

The Spinal Cord.

Median triangle.
Oval area of Fleclisi

Septo-marginal tract.
Goll's
column. Burdach's column.

Posterior spinal
artery.

^ o .

•"^ "^ (>^ (Mesial. -

Posterior
nerve-root.
Posterior root
zone of Bur-
dach's column.
Lissauer's
tract.

Direct cere-
bellar tract.
Middle root zone of
Burdach's column.
Comma tract.

Anterior root
zone of Bur-
dach's column.
Lateral pyra-
midal tract.
Lateral limit-
ing layer.

Lowentlial's
intermedio-lat.
tract.
Gowers' tract.

Antero-lateral
ground bundle.

Helweg's tract
(spino-olivary).

Anterior nerve root.

Mesial cell/ Ventral
column \ dorsal.

Anterior spinal artery

Cornu-commissural tract
Fasciculus sulco-marginalis.

Efierent ventro-lateral tract.

Fig. 19. — Diagram showing the tracts, cell columns, and vascular supply of the spinal cord.
(From Morris's Anatomy after Arthur Robinson.)

[To face page 222.

LOCOMOTOK ATAXY. 223

lumbo-sacral region. It is doubtful if any fibres are contributed
to this column by the posterior roots in the thoracic region from
the third to the twelfth inclusive. The corresponding ascending
fibres from the posterior roots of the cervical enlargement are
said to continue their ascent in Burdach's column, reaching the
nucleus of that column in the medulla.

All these sets of fibres may degenerate in tabes, and in addition
the process in some cases extends to the cells of Clarke's column,
and to the direct cerebellar tracts derived from these.

Attempts have been made to correlate the different sensory
symptoms of the disease with the different fibre groups. Thus
the loss of muscle tone and of the tendon reflexes is referred to
the interruption of those fibres which pass directly to the anterior
cornual motor cells, and so complete the local reflex arc. It is
also conjectured that the long ascending fibres of the postero-
internal columns subserve the muscle sense, that the fine fibres
which enter the grey matter through Lissauer's tract are fibres
of common sensation, and that the fibres which establish a con-
nexion with the cells of Clarke's column convey impulses to the
cerebellum, and so form part of the mechanism of equilibration.

There are certain tracts of fibres in the posterior columns of
the cord, which originate from the cells of the grey matter of the
posterior cornua, and are hence termed endogenous. These tracts
are commisural in function, and do not consist of fibres derived
from the posterior roots. They either escape entirely in tabes or
are affected very late in the disease. The tracts in question
are: — (1), the comma tract which lies in the middle third of the
postero-external column in the dorsal region ; (2), the cornu-
commisural zone, which is immediately adjacent to the pos-
terior commisure in the lumbar and sacral regions ; (3), the oval
area of Flechsig, which abuts on the posterior fissure in the
lumbar region, and is continuous in the sacral region with (4)
the sacral triangle of Gombault and Phillipe ; (5), the septo-
marginal tract, which is continuous with the oval area of
Flechsig, and can be traced upwards as high as the eleventh
dorsal seorment.

224 CLINICAL APPLIED ANATOMY.

In forming an estimate of the amount of wasting of the pos-
terior roots outside the cord, it is well to bear in mind that they
are normally twice or three times the size of the anterior. The
degeneration can be traced distally as far as the posterior root
ganglion, and there ceases. The changes in the ganglion are
often insignificant, whilst the changes in the sensory nerves
beyond the ganglion are variable, and tend to be most marked at
the periphery. In the process of development the cells of the
posterior ganglia send out processes which bifurcate, one branch
growing into the cord as a posterior root fibre, whilst the other
becomes connected with skin, muscle, joint, or tendon as part of
the peripheral sensory nerve. A lesion of the sensory nerve
trunks, or the posterior roots of the spinal cord, may cut off all
impulses from the structures mentioned. Impulses from the
joints, tendons, and muscles are mainly concerned in produc-
ing the sense of position, and deprivation of these impulses
may induce ataxy with muscular atony and loss of sense of
position, without the necessary existence of any skin anaesthesia
at all.

The ataxy which in some instances accompanies the peripheral
neuritis of alcoholism, influenza, and diphtheria, is probably due
to lesions of the peripheral sensory nerves.

When cutaneous anaesthesia is present m tabes it is of the
segmental type. Often there is an anaesthetic zone corresponding
to the fourth and fifth dorsal segments. Extending higher it
may involve the dorsal segmental areas corresponding to the
inner side of the arm, but is rarely found to extend on the
thorax above the third rib, for the skin above this is supplied
by descending cervical nerves which are rarely implicated.
Segmental anaesthesia, usually restricted to analgesia, is often
found in the areas of the lumbo-sacral roots, particularly the
first sacral which supplies the sole of the foot, and the fifth
lumbar which supplies the peroneal region of the leg. The dis-
sociation of sensation which occurs in various forms and various
degrees, is attributed to unequal affection of the various fibres
which go to make up the compound nerves, and intra-medullary

SYEINGOMYELIA. 225

projections of the nerve roots. Skin reflexes vary in their activity
inversely with the degree of local cutaneous anaesthesia.

A convenient means of testing the loss of tone in the muscles is
found by taking advantage of the fact that the hamstrings, when
possessing their normal tone are not of sufficient length to allow
the leg to be fully extended on the thigh at the same time that
the thigh is fully flexed on the abdomen. This position can
often, however, be assumed in tabes, and certain cases of
peripheral neuritis in which muscle tone is lost.

The perforating ulcer of the foot usually originates at the site
of a corn, and is obviously due to pressure and suppuration in
anaesthetic tissues.

The trophic joint and bone lesions of tabes are usually
attributed to the lesion of special trophic fibres, which are
supposed to follow the paths taken by the fibres for pain and
temperature rather than those of the other afferent tracts.

The Argyll Eobertson pupil has been discussed in the section
on ophthalmoplegia.

The intraocular portion of the optic nerve is accessible to
direct examination, and the occurrence of primary optic atrophy
may afl'ord valuable evidence in doubtful cases of tabes. Of
the other cranial nerves we can only judge by function. The
ascending root of the fifth nerve, which corresponds to the pos-
terior roots of the cord, is sometimes involved, and so bilateral
facial neuralgia exceptionally forms a symptom of tabes, corre-
sponding to the lightning pains and to the sciatica of the
lumbo-sacral form of the disease.

SYRINGOMYELIA.

Syringomyelia is characterised by the presence of a dilated
central canal or of other cavities within the spinal cord, together
with more or less proliferation of the embryonic tissue in their
neighbourhood. The lesions are practically confined to the
posterior half of the cord, and usually limited to the posterior
columns, which are formed last during the process of develop-
ment. The disease is a congenital defect, the primitive canal

C.A.A. 15

226 CLINICAL APPLIED ANATOMY.

for some reason remaining unusually large, and embryonic
tissue persisting around it. In some cases a central canal may
be recognised, distinct from the cavities in the nerve tissue.
To explain the separation of the two it is assumed that the
posterior portion of the primitive canal becomes shut off from
the anterior part, and persists in the form of a cavity in the
region of the posterior septum of the cord. In other instances
cavities lie in the posterior horns of the grey matter, and may
be due to the disintegration of the embryonic tissue which forms
the basis of these.

Syringomyelia usually occurs in the cervico-dorsal region, and
the disease accordingly manifests itself chiefly in the arms. The
symptoms are referable to disease of the grey matter, and consist
of local muscular atrophy with dissociation of sensation. The
sense of touch is usually retained whilst painful and thermal
sensations may be absent. Trophic lesions are also met with.

Table of Levels op Oeigin and Exit of Spinal Nerves.

Roots. Level of Origin from Cord. Point of Exit from Canal,

C. 1 ... Just above arch of atlas Between atlas and occiput.

2 ... Kanges from just above to just below

posterior tubercle of atlas Above axis.

3 ... At or just above spine of axis Above 3rd cervical vert.

4 ... Ranges from spine of axis to spine of 3rd

cervical vertebra ... Above 4th cervical vert.

5 ... Ranges from lower border of spine of axis

to lower border of spine of 4th cervical v. Above 5th cervical vert.

6 ... Ranges between lower borders of spines of

3rd and 5th cervical vertebra Above 6th cervical vert.

7 ... Ranges between top of 4th and bottom of

6th cervical spines Above 7th cervical vert.

8 ... Ranges between upper borders of 5th to 7th

cervical spines ... ... ... ... Above 1st dorsal vert.

D. 1 ... Ranges between space above 6th and space

below 7th spines ... ... ... ... Above 2nd dorsal vert.

2 ... Ranges between lower borders of 6th cervical

and 1st dorsal spines Above 3rd dorsal vert.

3 ... Ranges between upper edge of 7th cervical

to lower border of 2nd dorsal spine . . . Above 4th dorsal vert.

4 ... Ranges from top of 1st to top of 3rd dorsal

spine Above 5 th dorsal vert.

5 ... Ranges from top of 2nd to top of 4th dorsal

spine Above 6th dorsal vert.

6 ... Ranges from lower edge of 2nd dorsal

spine to upper of 5th Above 7th dorsal vert.

7 ... Ranges from top of 4th to bottom of 5th

dorsal spine Above 8th dorsal vert.

Segmental Cutaneous Areas.

SAC.I;

Fig. 20. — Tiiis figure shows segmental cutaneous areas. The several dorsal, lumbar.

and sacral areas are indicated each iVy the initial letter followed by a

number. (After Head.)

[To follow page 226.

Segmental Cutaneous Areas.

D.I2

Fig. 21. — This figure shows the " maxiinum spots" (seats of most marked tenderness
and pain) of the dift'erent areas. (After Head.)

[To face figure 20.

Segmental Cutaneous Areas.

C.7.

Fig. 22.-- This figure .shows segmental cutaneous areas. The several dorsal, lumbar,
and sacral areas are indicated each by the initial letter followed by a

number. (After Head.) ^^^^ ^^^^^^^ ^^^^^^ .^^_

Segmental Cutaneous Areas.

D.I2

SAC.3

Fig. 23. — This figure shows the "maximum spots" (seats of most marked tenderness
and pain) of the different areas. (After Head.)

[To face fignre^-I.

COMPEESSION OF THE SPINAL COED. 227

Table of Levels of Origin and Exit of Spinal Nerves — continued.

Roots. Level of Origin from Cord. Point of Exit from Canal.

D. 8 ... Ranges from top of 5th to top of 6th dorsal

spine ... ... ... Above 9th dorsal vert.

9 ... Ranges from midway between 5th and 6th

to top of 7th dorsal spine Above lOth dorsal vert.

10 ... Ranges from midway between 6th and 7th

to middle of 8th dorsal spine Above 11th dorsal vert.

11 ... Ranges from top of 7th to top of 9th dorsal

spine ... ... ... Above 12th dorsal vert,

12 ... Ranges between top of 8th and bottom of

9th dorsal spine ... ... Above 1st lumbar vert.

L. 1 ... Ranges from top of 9th to bottom of 10th

dorsal spine ... ... Above 2nd lumbar vert.

2 ... Ranges between 9th and 11th dorsal spines Above 3rd lumbar vert.

3 ... Ranges between top of 10th and bottom of

11th dorsal spine ... ... ... ... Above 4th lumbar vert.

4 ... Ranges between bottom of 10th and top of

12th spine ... ... ... Above 5th lumbar vert.

5 ... Ranges between top of 11th and middle of

12th dorsal spine ... ... ... ... Above 1st sacral vert.

S. 1 ... Ranges between lower border of 11th dorsal

spine and top of 1st lumbar spine ... Above 2nd sacral vert.

2 ... Usually between 12th dorsal and 1st lumbar

spines Above 3rd sacral vert.

3 ... Usually between 12th dorsal and Ist lumbar

spines Above 4th sacral vert.

4 ... Usually between 12th dorsal and 1st lumbar

spines ... ... ... Above 5th sacral vert.

5 ... At lower border of 1st lumbar spine ... Above coccyx.
Coccygeal... Between lower border of 1st and upper

border of 2nd lumbar spines

Summary.

The eight cervical nerves arise from the cord between the occiput and the sixth
cervical spine.

The upper six dorsal nerves between the sixth cervical and the fourth dorsal
spines.

The lower six dorsal nerves between the fourth and ninth dorsal spines.

The five lumbar nerves arise between the ninth and twelfth dorsal spines.

The five sacral nerves opposite the twelfth dorsal and first lumbar spines.

, COMPRESSION OF THE SPINAL CORD.

'The spinal cord, being suspended in the spinal canal, is liable
to compression, bruising, or laceration in fracture-dislocations of
the vertebral column. Moreover, the bony unyielding character
of the neural canal renders compression almost inevitable when
inflammatory or malignant disease extends into the cavity from
the adjacent vertebrae, or arises in the spinal membranes. The
dural sheath of the cord is separated from the surrounding bones

15 — 2

228 CLINICAL APPLIED ANATOMY.

by a layer of fatty tissue and a considerable venous plexus. The
former tissue may give rise to lipomatous growths or be the seat
of hydatid disease, or diffuse suppuration, and the veins may be
torn in injuries to the spinal column leading to considerable
extravasation of blood. The thickening of the dura mater which
is known as pachymeningitis may produce pressure on the cord ;
hydatids and new growths may be found inside the dura mater
and a sudden effusion of fluid into the membranes, the result of
haemorrhage or of rupture of an abscess will also produce pressure
symptoms.

The intervertebral foramina afford channels by which new
growths, abscesses or even hydatids may invade the spinal canal
from without. The close relation of the aorta to the bodies of
the vertebrae explains the ease with which aneurysms of the
descending thoracic and abdominal portions of the vessel erode
the walls of the canal and ultimately exert pressure on the
structures contained in it.

The retroperitoneal glands are favourably placed for invasion
of the spinal column and spinal canal when the site of malignant
disease, whilst the thoracic part of the spine is often the seat of
new growth secondary to carcinoma of the breast.

Tumours within the dura, being confined by that membrane,
more easily produce compression than do tumours outside it.

Since the spinal nerve roots cross the subdural space and
traverse the dura to escape through the intervertebral foramina
it is not surprising that pain should be referred to the sensory
roots at the level of compression (Figs. 20 — 23, p. 226). This
is most marked in connexion with new growths, especially those
which arise in the spinal membranes, and the pain may persist
after the skin supplied by the particular nerve roots has become
anaesthetic. Eoot pain is not such a marked feature in compres-
sion by aneurysm or caries. Since the anterior spinal roots are
motor in function, pressure on these may produce muscular
spasm of the muscles which they supply, but more commonly
the muscles simply waste.

The wasting is easily recognised when it occurs in the muscles

COMPKESSION OF THE SPINAL COED. 229

of the extremities, but recognition is not so easy when the inter-
costals or muscles of the abdomen are involved. It is possible,
however, to tell if there is any weakness of the upper or lower
parts of the recti by observing the movement of the umbilicus.
This normally does not vary its position on the patient sitting
up, but if the part of the muscle below the umbilicus is paralysed
the unopposed action of the upper part will draw up the umbilicus.
If the part of the rectus above the umbilicus is affected, the
umbilicus will be drawn downwards instead of upwards. The
rectus is supplied by the fifth to the twelfth dorsal nerves. As
the umbilicus is in the field of the ninth dorsal root, a lesion
paralysing that part of the rectus which lies below it belongs to
the tenth, eleventh or twelfth dorsal segments.

In addition to the radiating pains produced by compression of
the spinal roots, the local pressure on the dura mater is respon-
sible for a deep-seated local pain. This is probably explained by
the fact that the dura is supplied with nerve filaments, and is
known to be extremely sensitive.

Besides root symptoms, compression produces symptoms refer-
able to the cord itself. The points at which there is the least
spare space in the theca are said to lie in the mid-cervical region
and at the two extremities of the dorsal region, and these are the
situations in which most instances of compression by tumour
occur. The pressure exerted on the cord is at first more or less
localised, and so unilateral symptoms may be produced, becoming
bilateral as the pressure increases. The compression may
produce local softening, either from occlusion of vessels or the
onset of an inflammatory condition.

The compression symptoms usually, but not invariably, occur
in the following order : — Pain, motor paralysis, sensory paralysis.
The pain, which is distinct from the root pains and localised
pain already mentioned, is often referred to points at some
distance below the lesion in the spinal cord, not infrequently
to joints. Also when anaesthesia develops the sensation is first
affected in the lower parts of the body. There are two anatomical
facts which may have some bearing on this. First, the fibres

230 CLINICAL APPLIED ANATOMY.

which ascend from the lowest parts of the cord are longest and
travel further from their trophic centres in the posterior root
ganglion, hence they may be more susceptible to pressure.
Secondly, as the fibres of the successive sensory roots enter the
cord, those of them which ascend in the posterior columns tend
to displace inwards the fibres which enter immediately below
them, so that the fibres which enter lowest finally come to lie
near the surface of the postero-median column close to the
median septum, whilst the higher fibres approach nearer and
nearer the central part of the cord. Consequently fibres from
the lowest roots in the posterior columns at all events, are most
exposed to concentric compression. But it is stated that the
march of anaesthesia may be the same in eccentric pressure, such
as occurs for instance with haemorrhage into the grey matter.

The motor paralysis below the level of the lesion is of the
spastic type, and accompanied by interference with the action of
the bladder and rectum. Pressure on the pyramidal tracts
accounts for the motor symptoms. Curiously enough the direction
of invasion of paralysis is the reverse of the anaesthesia, the
highest muscles suffering first. No arrangement of fibres in the
pyramidal tracts is at present known which would account for
this method of invasion. The conversion of the spastic into a
flaccid condition in the terminal stages of the disease is held to
indicate the establishment of a total transverse lesion of the cord,
possibly induced by softening or myelitis.

There are certain motor symptoms in compression paraplegia
which are special to definite regions of the cord. These comprise
alterations in respiration, alterations in the pupils, alterations in
the heart's action, vaso-motor and secretory phenomena.

Since the main motor supply of the diaphragm is derived from
the fourth cervical nerve, fibres of which together with some
from the third and fifth nerves make up the phrenic trunk, a
lesion in this region is peculiarly dangerous. It not only cuts off
the impulses descending to the intercostals from the respiratory
centre, but also gives rise to paralysis of the diaphragm so that
respiration ceases.

COMPEESSION OF THE SPINAL COED. 231

Pupil dilator fibres, arising in the neighbourhood of the third
cranial nerve nucleus, are known to pass downwards in the
lateral columns of the cord to emerge by the first and second
dorsal roots. Thence they pass to the inferior cervical ganglion,
and so by the cervical sympathetic chain to the eye. Unilateral
pressure on the cervical cord may affect the fibres descending in
it and give rise to unilateral myosis.

The cardio-accelerator fibres in the cord pursue a similar course
to the pupil dilator fibres but emerge lower in the fourth to the
ninth dorsal roots. Compression of the cord may irritate or
paralyse these fibres, and acceleration or slowing of the heart
rate will result.

Vaso-dilatation may occur in acute compression. The vaso-
dilator fibres for the whole body leave the spinal cord in the
middle of its extent, probably reaching from about the second
dorsal to the second lumbar nerves.

The vaso-constrictor nerves have a much more extensive
outflow.

Since secretory fibres for the sweat glands also leave the cord
these are liable to be paralysed where nerve roots are compressed,
and so the injection of pilocarpine has been used to determine
the level of compression, the sweat ceasing at this line.

The upper level at which sensation is in any way altered
is usually taken to indicate the level of the compressing
lesion. The level thus determined often proves too low.
Owing to the oblique course of the nerve roots in the spinal
canal before they emerge, the seat of compression is in
most cases higher than the upper limit of anaesthesia, the
difference corresponding to the vertical length of the nerves in
the canal. Even when this is allowed for by the use of suitable
tables, the level of the angesthesia may prove to be considerably
below the level of the lesion, and this is due to the fact that
sensory root symptoms may be absent at the level of the lesion
and that all the sensory fibres ascending in the cord from the
parts below have not suffered equall}^ but that the longest
tracts have first ceased to conduct.

232 CLINICAL APPLIED ANATOMY.

The Spinal Nerves,
injuries and diseases of nerve plexuses.

The brachial plexus is responsible for the whole nerve supply
of the arm. If a lesion involves all parts of the plexus the arm
will be completely paralysed. The damage is usually incomplete
and three types of paralysis may be recognised, corresponding
to the upper, middle and lower parts of the plexus respectively.

The upper arm type is variously known as Duchenne's
obstetrical paralysis of the infant, Erb's paralysis, ansesthetic
paralysis and climber's paralysis. The muscles paralysed are
the deltoid, supraspinatus, infraspinatus, teres minor, biceps,
brachialis anticus and supinator longus. The position assumed
by the arm is characteristic. It hangs powerless by the side ; the
humerus is rotated inwards by its unopposed internal rotators ;
the flexors of the elbow being powerless the forearm is extended ;
the supinating action of the biceps is absent, so the hand is fully
pronated, and the palm directed backwards and outwards. The
muscles which are paralysed derive their supply from the fifth
and sixth cervical roots. The same muscular group may be put
in action in health by faradising Erb's motor point which lies
just behind the posterior border of the sterno-mastoid in front
of the transverse process of the sixth cervical vertebra. The
lesion is due to the shearing action of the clavicle, which under
certain circumstances compresses the plexus against the first
rib. For this to occur the arm must be abducted and raised
vertically above the shoulder, a movement which causes the
clavicle to travel directly backwards. The muscular mechanism
of the shoulder is not enough to produce this, but force must be
applied to the abducted and raised arm. Hence the lesion may
occur at birth when the arm is above the head, as the result
of forcible artificial respiration, when the weight of the body
hangs on the arm in hand over hand climbing, or when a child is
lifted by one arm. By some authors it is held that a similar
lesion may be produced, owing to traction on the upper cords of

BEACHIAL PLEXUS PAEALYSIS. 233

the plexus, when the shoulder is forcibly depressed, and the
neck laterally flexed towards the opposite shoulder.

The intermediate type of paralysis corresponds to a lesion of
the middle part of the plexus. It is usually associated with the
upper arm type, but may be observed as a residual palsy
after the upper part of the plexus has recovered. The muscles
paralysed are the triceps, and the extensors of the wrist and
fingers. The attitude is characteristic, the elbow being flexed,
tbe wrist dropped, the fingers somewhat bent, and the hand
lying midway between pronation and supination. The seventh
cervical root is the one chiefly involved.

The distal type of paralysis is known as Klumpke's. The
lesion involves the lower fibres of the plexus, corresponding
to the eighth cervical and first dorsal nerves. The small muscles
of the hand and the flexors of the fingers are paralysed. This
type of paralysis is accompanied by myosis, narrowing of the
palpebral fissure and retraction of the eyeball, phenomena
referred to implication of the oculo-pupillary fibres which pass
into the cervical sympathetic from the upper dorsal nerves.

The intermediate and distal types of paralysis are uncommon,
the corresponding nerves being protected by the fact that the
inner part of the clavicle has a forward convexity, and so does
not so readily compress the lower part of the plexus. Or, if the
lesion be due to stretching and laceration, the fact that the lower
fibres of the plexus are not rendered taut so easily as the upper
will account for their comparative immunity.

The brachial plexus may be involved by other lesions such as
tumours, disease of the cervical spine, cervical meningitis, local
pressure or wounds in the lower part of the posterior triangle of
the neck, and dislocations of the shoulder. It is sometimes the
seat of neuritis.

Anaesthesia is not so readily produced as motor paralysis, and
when present, if due to a lesion of the nerve roots, will have the
corresponding segmental distribution. (Figs. 20 and 22, p. 226.)

The lumbar and sacral plexuses may be involved by local
lesions such as malignant growths, psoas abscesses or spinal

234 CLINICAL APPLIED ANATOMY.

disease. A true neuritis may also occur. Sometimes neuritis
is a manifestation of a general toxaemia of pregnancy, sometimes
it is due to the local extension of pelvic inflammation, for the
plexus lies in the planes of pelvic connective tissue.

The most interesting lesion from an anatomical point of view
is a sudden paralysis which may come on during childbirth.
The paralysis is attributed to pressure by the foetal head on its
passage through the pelvis. The muscles supplied by the
peroneal nerve are usually affected. The peroneal nerve is
derived from the dorsal divisions of the lumbo-sacral cord, and
the first and second sacral nerves. The dorsal constituents of
the lumbo-sacral cord lie next to the bone as the cord passes
over the true pelvic brim and so are exposed to pressure, whereas
the lower roots of the sacral plexus lie on the pyriformis muscle,
which affords some protection. The gluteal nerves are some-
times involved at the same time as the peroneal ; these nerves
are also derived from the dorsal divisions of the lumbo-sacral
cord and first and second sacral nerves.

INJUEIES TO THE PERIPHERAL NERVES OF THE LIMBS.

Division of the peripheral nerves of the extremities is a common
lesion, especially in the upper limb. Hence a thorough know-
ledge of the distribution of these nervous trunks is of great
practical importance. Injury may be the result of accident or
operation.

The Upper Extremity. — The chief nerves that may be damaged
are the ulnar, the median and the musculo-spiral.

The ulnar nerve arising from the inner cord of the brachial
plexus runs along the inner side of the arm, and enters the fore-
arm in the space between the internal epicondyle of the humerus
and the olecranon process of the ulna, in which position it is
liable to injury in fracture of the condyle, in excision of the elbow
joint and in punctured wounds. Passing between the two heads
of the flexor carpi ulnaris, it pursues a course down the ulnar
side of the forearm under cover of this muscle, and at the wrist,
lying on the radial side of the pisiform bone, it enters the palm

ULNAE NEEVE PAEALYSIS. 235

of the hand superficial to the anterior annular ligament, quickly
to divide into its superficial and deep divisions.
In its course it is distributed as follows : —
Muscular. In forearm : —
To flexor carpi ulnaris.
To flexor profundus digitorum, ulnar half.
As a consequence of the paralysis of these muscles, adduction
of the hand towards the ulnar side and full flexion of the last
phalanx of the ring and little fingers is lost.
In hand : —

By main trunk to palmaris brevis.

By deep branch to abductor minimi digiti, flexor brevis

minimi digiti, flexor ossis metacarpi minimi digiti, all

seven interossei, two ulnar lumbricales, adductor trans-

versus pollicis, adductor obliquus pollicis, flexor brevis

pollicis, deep part.

The deep branch runs between the flexor brevis and abductor

minimi digiti muscles, and often grooves the ulnar side of the

base of the process of the unciform bone, and at this spot it may

be divided by a punctured wound. It is easily found between

the pisiform bone and the unciform process.

By paralysis of these muscles the following movements cannot
any longer be carried out : — abduction of all the digits except
the thumb, adduction of the thumb, index, ring and little fingers,
flexion of the first phalanx of all the fingers, and perfect extension
of the second and third phalanges. It will thus be seen that a very
characteristic form of paralysis is induced, which can readily be
demonstrated by asking the sufferer to attempt to move the index
and little fingers away from the next to which they are placed.

In its earlier stages the typical claw-hand {main en griffe) of
ulnar nerve paralysis is seen in the over-extension (dorsi-flexion)
of the first phalanx of the ring and little fingers, with partial
flexion of the second and third. This position of these two
digits is probably due to the unopposed action of the extensors
and of the flexor sublimis tendons owing to the paralysis
of the two ulnar lumbricales. If it were dependent upon

236 CLINICAL APPLIED ANATOMY.

the loss of action of the interossei alone, then the index
and middle fingers should also be affected, but in the early
stages at least this is not the case. Later all four fingers may
assume the typical position, but the ring and little fingers always
exhibit it in a more pronounced manner.

When degeneration of the muscles, cut off from their trophic
supply, occurs, great diminution of the hypothenar eminence
and some diminution in that of the thenar eminence follows.
Intermetacarpal hollows also appear on the dorsum of the hand,
particularly noticeable in the first space by the disappearance
of the abductor indicis or first dorsal interosseus.
Cutaneous . In for ear 711 : —

The palmar cutaneous branch, given off in the lower third
of forearm, pierces the deep fascia, passes into the palm
superficial to the anterior annular ligament, and is
distributed to the skin of the hypothenar eminence and
ulnar half of palm.
The dorsal cutaneous branch often given off as high as in the
middle third of the forearm, is directed obliquely back-
wards and downwards deep to the tendon of the flexor
carpi ulnaris, and becomes cutaneous at the back of the
ulnar side of the forearm in its lower fourth. On the
dorsum of the hand this branch supplies filaments to
the skin of the ulnar side, and terminates by sending
branches to the dorsal aspect of the ulnar side of the little
finger and the contiguous sides of the ring and little
fingers, which supply the skin as low down as the middle
of the second phalanx.
In hand : —

The superficial branch is purely cutaneous, and like the
dorsal branch supplies the skin of the palmar aspect of
the ulnar side of the little finger and the contiguous sides
of the ring and little fingers to their distal extremity,
afterwards turning round on to the dorsal aspect for the
supply of the cutaneous structures over the lower half of
the second and the whole of the terminal phalanges.

MEDIAN NEEVE PAEALYSIS. 237

It will thus be seen that when the ulnar nerve is entirely
paralysed there is loss of sensation over the ulnar half of palm,
the hypothenar eminence, the ulnar half of the back of the hand,
and the whole of the palmar and dorsal aspects of the little finger
and the ulnar half of the ring finger.

Later in the course of ulnar nerve paralysis trophic changes
occur in the same area.

It is important to recollect that if the ulnar nerve is cut
just above the wrist — perhaps the most usual spot — the dorsal
cutaneous branch may escape any injury, and the patient will
therefore retain sensation on the back of the ring and little
fingers as low as the middle of the second phalanx, but below
this the skin will be anaesthetic.
Articular.

In arm — To elbow joint.

In foreman — To wrist and carpal joints.

In hand — To ulnar two carpo-metacarpal joints.

To metacarpo-phalangeal and interphalangeal
joints of ring and little fingers.
In paralysis of the nerve, trophic changes may occur in the
small distal joints leading to a condition akin to ordinary osteo-
arthritis.

The median nerve, arising by two heads, one from the outer
and the other from the inner cord of the brachial plexus, runs a
median course down the arm, crossing the brachial artery at its
middle, as a rule superficially but sometimes deeply, from without
inwards.

It gives off no branches in the arm.

At the bend of the elbow it lies under cover of the bicipital
fascia and internal to the brachial artery. It is not often
wounded in the arm or at the bend of the elbow. The nerve
enters the forearm between the two heads of the pronator radii
teres, and it is possible for it to be compressed by this muscle
during violent exercise such as tennis playing, but being deeply
placed it is little exposed to actual division until it reaches the
lower fourth of the forearm. It is here much more superficial,

238 CLINICAL APPLIED ANATOMY.

and placed still in a median position exactly posterior to the
tendon of the palmaris longus muscle, if this is present.

Just above the anterior annular ligament is perhaps the most
usual spot for the nerve to be accidentally divided. An incised
wound caused by passing the hand through a pane of glass is
the common form of injury to cause the division. At the
same time the surrounding flexor tendons may be severed. It is
very necessary to be able to distinguish between the divided
ends of nerve and tendon, for accurate suturing in these cases is
highly essential. The following differences may be considered : —

Nerve. TeTidon.

Colour... ... Greyish pink. Dull. ... ... Yellowish white. Shining.

Cut surf ace ... Round. Tends to be frayed. ... Transversely oval. Clean cut.

Betraction ... Proximal end not greatly re- Proximal end markedly re-
tracted, tracted.

Action... ... Manipulation of distal end may Pull on distal end will cause

excite action of short muscles flexion of a digit,
of thumb.

The median nerve gives off the anterior interosseous branch
soon after it enters the forearm.

The main trunk supplies the pronator radii teres (the branch
to this muscle may arise just above the flexure of the elbow) the
flexor carpi radialis, the palmaris longus and the flexor sublimis
digitorum in the forearm.

The anterior interosseous branch supplies the flexor longus
pollicis, the radial half of the flexor profundus digitorum, and
the pronator quadratus : all of these muscles will be paralysed
if the nerve is cut just above the bend of the elbow, and the loss
of power will be easily recognised by the inability to flex the
terminal phalanx of the thumb, and the second and third
phalanges of the index and middle fingers, and to pronate the
hand.

In the lower third of the forearm the palmar cutaneous branch
is given off.

The median nerve enters the palm of the hand by passing deep
to the anterior annular ligament, and immediately gives off a
motor branch to the chief muscles of the thenar eminence, viz.,

MUSCULO-SPIEAL NEEVE PAEALYSIS. 239

the abductor pollicis, the flexor ossis metacarpi pollicis and the
flexor brevis pollicis (superficial head).

The rest of the nerve is supplied to the two radial lumbricales,
and to the skin on the palmar aspect of the thumb, index, middle
and the radial half of the ring finger. The terminal filaments
of these cutaneous branches also pass round on to the dorsal
aspect of the thumb and supply the bed of the nail, and to the
dorsal aspect of the index, middle and the radial half of the ring
finger, to supply sensation as high as the middle of the second
phalanx, about the level beyond which cutaneous hairs cease to
be found.

It will thus be seen that in division of the median nerve close
above the wrist there will be loss of power of abducting the thumb
and of directly flexing its metacarpal bone and proximal phalanx ;
also loss of sensation on the whole of the palmar aspect of the
thumb, index, middle, and radial half of the ring finger, and
over the dorsal aspect of the same, in the case of the thumb
extending upwards as far as the middle of the terminal phalanx,
and in the case of the other digits as high as the middle of the
second phalanges.

The musculo-spiral nerve is derived from the posterior
cord of the brachial plexus and lies at first behind the third
portion of the axillary and the commencement of the brachial
artery. It then winds round the inner side of the humerus to
reach the musculo-spiral groove on the posterior aspect of the
bone, between the external and internal heads of the triceps
muscle, to appear on the outer side of the arm above the elbow
between the brachio-radialis and the brachialis anticus.

During this course it supplies the following muscles: — The
three heads of the triceps, the anconeus, brachio-radialis, extensor
carpi radialis longior, and a small portion of the brachialis
anticus, in addition to giving one internal and two external
cutaneous branches. Finally, it divides into its two terminal
branches, the radial and the posterior interosseous.

The radial nerve is purely cutaneous and is distributed to the
dorsal aspect of the thumb, as low down as the bed of the nail,

240 CLINICAL APPLIED ANATOMY.

the dorsal aspect of the index, middle and radial side of ring
fingers as low down as the middle of the second phalanx. One
of these digital branches can be easily palpated as it crosses the
tendon of the extensor longus pollicis where that structure forms
the ulnar boundary of the tabatiere.

The jposterior interosseous branch of the musculo-spiral reaches
the back of the forearm between the two planes of the supinator
brevis muscle, supplying this muscle in its course, and winding
round the radial side of the neck of the radius. It is then dis-
tributed to all the extensor muscles, namely, superficially to the
extensor carpi radialis brevier, extensor communis digitorum,
extensor minimi digiti, extensor carpi ulnaris ; and deeply to the
extensor ossis metacarpi pollicis, extensor brevis pollicis, extensor
longus pollicis, and the extensor indicis.

From its deep position the musculo-spiral nerve is not greatly
exposed to external injury, but is liable whilst lying in the
musculo-spiral groove to be pressed upon by callus formed
around a fracture of the middle of the shaft of the humerus.
Also before it reaches the posterior aspect of the limb it may
be paralysed by the pressure of the handle of a crutch, or by the
pressure induced by the arm hanging over some sharp edge, such
as the back of a chair, or even the edge of an operating table.
The nerve is sometimes paralysed by a sudden and violent con-
traction of the triceps, being compressed as it lies in the musculo-
spiral groove.

The result of division will be a permanent paralysis unless the
continuity of the nerve is restored, whilst the result of pressure
may be only a temporary paralysis. The paralysis is evidenced
by wrist-drop — that is, loss of power to extend the carpus, hand,
and digits — associated in the majority of cases by anaesthesia,
partial, or complete, over the distribution of the radial nerve.

In the case of musculo-spiral paralysis from lead poisoning,
the brachio-radialis (supinator longus) muscle usually escapes.

The musculo-cutaneous nerve is derived from the outer
cord of the brachial plexus, and is perhaps the least frequently
damaged of any of the nerves of the upper extremity. It

PAEALYSIS OF THE GREAT SCIATIC NERVE. 241

passes through the coraco-brachiaUs, supplying that muscle,
and then comes to lie beneath the biceps and upon the
brachialis anticus, both of which it innervates. Above the
elbow-joint it is not so very far internal to the musculo-spiral,
and when exposed may be mistaken for the latter nerve.

The circumflex nerve is derived from the posterior cord of
the brachial plexus, and winds round the back of the surgical
neck of the humerus, supplying the deltoid and teres minor
muscles, together with the shoulder-joint and some of the skin
covering it.

The nerve is liable to injury in fracture of the surgical neck,
separation of the upper epiphysis, and dislocation of the head of
the humerus.

The Lower Extremity. — Injury to the nerves of the lower
extremity is comparatively rare, but disease affecting the
function of these nerves is not infrequently seen.

The great sciatic nerve emerges from the pelvis through
the great sacro-sciatic foramen below the pyriformis muscle,
at a point which may be roughly indicated upon a line
from the posterior superior spine of the ilium to the most pro-
minent part of the tuberosity of the ischium, at the junction of
the lower third with its upper two-thirds. Here it is deeply
placed under the gluteus maximus muscle, and can be con-
siderably stretched in complete flexion at the hip-joint especially
when the knee is kept extended. A little lower down it lies half-
way between the great trochanter and the tuber ischii, and deep
pressure here will give rise to severe pain when the nerve is
inflamed. Proceeding down the back of the thigh, it next lies
between the hamstrings and the vastus externus, dividing about
the middle into the peroneal or external popliteal, and the
internal popliteal nerves.

The sciatic nerve is accompanied by an artery which may be
of great value in the formation of a collateral circulation after
ligature for femoral or external iliac aneurysms.

The main trunk supplies the biceps, semimembranosus,
semitendinosus, and a portion of the adductor magnus.

C.A.A. 16

242 CLINICAL APPLIED ANATOMY.

In sciatica, tender spots may be found at the sciatic notch and
in the middle of the posterior aspect of the thigh.

The peroneal or external popliteal nerve passes down the outer
side of the popliteal space, and reaches the front of the leg by
winding round the outer side of neck of the fibula in the sub-
stance of the peroneus longus muscle, where it may be readily
rolled under the finger. It passes down deeply placed upon the
interosseous membrane to the front of the ankle, on the outer
side of the anterior tibial artery. On the dorsum of the foot it
runs forward in the first interosseous space to give sensation to
the contiguous sides of the great and second toes.

In its course it supplies the following structures : — two branches
to the knee-joint, the superior and inferior external articular, a
branch — the communicans fibularis — to join a corresponding one
from the internal popliteal, the communicans tibialis, to form
the external or short saphenous nerve, which is distributed to
the dorsal aspect of the outer side of the foot, and part of the
little toe ; by its musculo-cutaneous branch, both the peronei
muscles, the longus and the brevis, and the skin of the dorsum
of the foot on the inner side of the great toe, and the contiguous
sides of the second and third, third and fourth, fourth and fifth,
with a twig to reinforce the external saphenous on the outer side
of the dorsum of the little toe ; and, by the main trunk of the
anterior tibial nerve, the following muscles, the tibialis anticus,
extensor longus digitorum, extensor proprius hallucis, peroneus
tertius, and the extensor brevis digitorum.

The external popliteal nerve may be severed in punctured
wounds of the upper part of the popliteal space or at the neck
of the fibula. It is also liable to injury when the biceps tendon
is divided subcutaneously, seeing that it lies adjacent to the inner
border of this structure. Paralysis of the muscles supplied by
this nerve is also frequently seen in cases of infantile paralysis.

The internal popliteal nerve runs down the middle of the
popliteal space, and gives off branches to the following struc-
tures : — three to the knee-joint, the superior internal articular,
azygos articular and inferior internal articular ; a cutaneous

METATAESALGIA. 243

branch, the communicans tibialis, to join the communicans
fibularis from the peroneal, and to form the external or short
saphenous; and muscular branches to the two heads of the
gastrocnemius, the plantaris, the popliteus, and part of the
soleus. The branch to the popliteus is of interest, because it
arises just as the nerve passes behind the upper border of the
muscle, and passing posterior to the muscle winds round its
lower border to supply the same on its deep or anterior aspect.

The posterior tibial, the continuation of the internal popliteal,
runs down the back of the leg deeply placed, supplying in its
course the rest of the soleus, the tibialis posticus, the flexor
longus digitorum and the flexor longus hallucis, and divides a
little above the ankle joint, about half-way between the internal
malleolus and the heel, into the internal and external plantar
branches, of which the internal is the larger.

The external plantar nerve supplies the following muscles, the
abductor minimi digiti, flexor brevis minimi digiti, accessorius,
the outer two lumbricals, all the interossei, the adductor obliquus
and the adductor transversus hallucis, with a cutaneous branch
to the plantar aspect of the contiguous sides of the fourth and
fifth digits and the outer side of the little toe.

The interal plantar nerve gives branches to the abductor hal-
lucis, the flexor brevis digitorum, flexor brevis hallucis and the
two inner lumbricals, and a cutaneous supply to the plantar
aspect of the inner side of the great toe and the contiguous sides
of the first and second, second and third, third and fourth toes.
As these digital branches proceed forwards to supply the skin
covering the toes they pass between the heads of the metatarsal
bones, and as the outcome of the crowding together of the bones
by pressure of narrow boots, the nerves going to supply the
contiguous sides of the fourth and little toes may be caught
between the base of the first phalanx and the head of the
metatarsal bone of the little toe on the one hand, and the head
and neck of the metatarsal bone of the fourth toe on the other.
Pain may not only be experienced at the actual site of pressure,
but may radiate up nearly as high as the knee.

16—2

CHAPTER XII.

DISEASES OF THE VASCULAR SYSTEM.

Heart and Pericardium.

pericarditis.

Infection carried by the blood stream or by lymphatics, is
probably the commonest cause of pericarditis. This is the ex-
planation of rheumatic, tuberculous, septic and some pneumonic
varieties. The vessels and lymphatics of the serous pericardium
are intimately connected with those of the myocardium so both
the heart and its investing sac may be involved simultaneously.

Extension from neighbouring structures occasionally gives
rise to pericardial inflammation. The close way in which the
pericardium is enveloped by the lungs and pleural sacs explains
the occasional spread of inflammation to it from pneumonic,
tuberculous or gangrenous lung. Empyemata may in similar
manner give rise to purulent pericarditis. The connective tissue
basis of the pericardium is continuous with that of the lung,
pleura and mediastinum, and inflammation may simultaneously
involve all these structures or extend from one to the other.
Adjacent lymphatic glands may invade or infect the pericardium.
Four groups of these lie in immediate contact ^ith the sac. The
glands which lie along the internal mammary arteries are in
front, the cardiac group of glands above, the glands around the
tracheal bifurcation, and those about the lower end of the
oesophagus, behind. Most of these glands are in direct lymphatic
connexion with the sac, and may themselves become enlarged
as the result of pericarditis.

Occasionally aortic aneurysms burst into the pericardial cavity.
The first part of tlie aorta is actually within the sac, and the
descending thoracic aorta passes down close behind it. Aneurysms

PERICAEDITIS.

245

in either of these positions may, by rupture, give rise to intraperi-
cardial haemorrhage. Since the oesophagus is in intimate relation
with the posterior part of the sinus obhquus, the pericardium
may be perforated by foreign bodies in, or opened by mahgnant
disease of, this tube. Disease of the ribs, sternum or vertebrae may
invade the sac by continuity, and abscesses in the heart wall
may rupture through the visceral layer. Very rarely gastric

Fig. 24- The Relationships of the Pericaedium and Pleura to the

Thoracic Wall in the Apical Region. (^After Frohse, Hugliea

and Keith. ^

ulcers have been known to open into the pericardium, this
being rendered possible by the projection of the lower part of
the sac beyond the anterior margin of the left lobe of the liver,
so that only the diaphragm intervenes between it and the
stomach. In some instances the pericardium bears a similar
relation to the transverse colon near the splenic flexure.
Subphrenic abscesses may open into the lower part of the sac.

246 CLINICAL APPLIED ANATOMY.

The triangular area of superficial cardiac dulness corresponds
to that part of the pericardium which is uncovered by lung.
Its limits are the fourth costal cartilage above ; the impulse of
the heart externally; and internally, for all practical purposes,
the left edge of the sternum. The extension of this dull area in
pericarditis is due to distension of the sac, and gradual retraction
outwards of the lung margins. It is stated that the costo-
mediastinal pleural reflections do not always move outwards with
retreating lung margins, in such cases the parietal pleura still
covers the pericardium in front. The normal upper limit of the
pericardial sac corresponds to the mid-point of the manubrium
sterni, this being the summit of a tubular prolongation of the
pericardium common to the ascending portion of the aorta and
the pulmonary artery up to its point of bifurcation. (Fig. 26,
p. 249.) In moderate pericardial effusions the area of percussion
dulness is pyriform in outline, the upper narrower extension
corresponds to this tubular prolongation, the lateral limits corre-
spond with, or may pass beyond, the lateral limits of the heart
as projected on the chest wall, and the lower limit is lower than
the inferior border of the heart, for just as occurs in the case of
the pleural sac, there is a reserve space in the pericardial sac
and this space lies in front and below, so that the line along
which the pericardium leaves the upper surface of the diaphragm
in front crosses a little below the base of the ensiform cartilage.

The pericardial sac when distended, exercises pressure on the
heart, and also on the structures in relation with it externally.
The low pressure in the auricles and pulmonary veins and the
comparative thinness of their walls, renders them more suscep-
tible to pressure than are the other parts within the sac. Of the
parts outside the sac the lungs suffer most easily. Pressure on the
lower part of the left lung often gives rise to signs near the inferior
angle of the left scapula, simulating pneumonia. Occasionally
similar signs appear in the fourth and fifth interspaces of the
right side near the sternum, and correspond in situation with
the anterior part of the middle lobe of the right lung. Disten-
sion of the sinus obliquus which lies between the points of entry

THE CAEDIAC IMPULSE. 247

of the pulmonary veins gives rise to some difficulty in swallowing,
for the oesophagus lies immediately behind this part of the sac.
The vagi are in close contact with the oesophagus and some
authors refer the vomiting which occasionally occurs in peri-
carditis to pressure on these nerves. The weight of fluid in the
sac tends to depress the diaphragm, but the heart does not
travel downw^ards since it is fixed to the upper and posterior part
of the sac by the veins and arteries.

The tendency of pericardial friction to persist along the line of
the sternum is due to the fact that there is no spare room for
antero-posterior distension, the heart being interposed between
the projecting spinal column and the sternum. Distension tends
rather to occur laterally and downwards below the cardiac level.
In tapping the pericardium the pleura may be avoided by
making the puncture through the fifth or sixth intercostal space
of the left side close to the sternal edge, i.e. internal to the
internal mammary vessels ; but since it is often a matter of great
difficulty to distinguish a dilated heart from a distended pericar-
dium, it is safer to proceed surgically by resection of cartilage
and exposure of the sac before puncturing it, or the under aspect
of the sac may be reached through the abdominal wall in the
subcostal angle without opening the peritoneum.

VALVULAR DISEASE OF THE HEART.

An accurate conception of the effects of the various valvular
lesions on the heart can only be formed by a knowledge of its
surface anatomy. The normal position of the cardiac impulse,
or apex beat, the outlines of the cardiac chambers as projected
on the anterior chest wall, and the positions of the various valves,
must be thoroughly understood. (Fig. 26, p. 249.)

The cardiac impulse varies in position with age and with the
posture of the body. In the infant the heart lies higher and is
more horizontal than in the adult, possibly on account of the
higher position of the diaphragm. The impulse is consequently
found in the fourth intercostal space, but descends into the fifth

248 CLINICAL APPLIED ANATOMY.

space by the seventh year. Until the fourth year it lies outside
the line of the nipple, but should not pass more than three-
quarters of an inch beyond this. From the fourth to the ninth year
it beats in the nipple line. After the thirteenth year the impulse
may be expected to occupy the same position as in the adult.

In the erect posture in the adult, the impulse should appear
in the fifth left intercostal space, close above the sixth rib. It is
three and a half inches from the mid-line in the male and three
inches from the same line in the female. The area of impulse
should not be quite so large as that of a circle an inch in
diameter ; in other words, it is completely covered by the bell
of an ordinary stethoscope. The impulse may be made more
apparent by leaning forwards. It may appear in the fifth inter-
space in recumbency, and yet in the erect position be found
displaced behind the sixth rib, a fact which should lead to
examination of patients in both postures if possible. Even
though the heart is enlarged the actual apex may be so concealed
by the left lung as not to be felt until the patient is turned well
over on to the left side ; this often causes the impulse to appear
far back in the axilla in such cases, and gives some idea of the
increase in size of the heart.

In old age the impulse is often displaced downwards into the
sixth intercostal space, the heart being depressed by elongation of
the ascending aorta in consequence of senile changes. (Fig. 25.)

The position of the normal impulse is often loosely defined as
being in the fifth intercostal space a little below and internal to
the nipple. The variable position of the nipple is a defect in
this method of localising the position. The nipple should lie on
or just below the fourth rib, four inches from the mid line of the
body. When the breasts are enlarged or pendulous, the relations
of the nipple are subject to considerable alteration.

The cardiac impulse is normally caused by the left ventricle,
and, being superficial, affords important indications as to the
condition of the wall of that cavity, becoming heaving in hyper-
trophy and feeble and diffuse in dilatation. In diseased con-
ditions other parts of the heart may give rise to* appreciable

Dilatation of Aorta.

Liver

Contracted
stomach.
Fundus of gall
bladder.

Pulmonary
artery, dis-
placed back-
wards and to
the left.

Conns arterio-
sus (infundibu-
lum) of right
ventricle.

Hypertrophied
left ventricle.

Apex of heart,
displaced
downwards
and outwards
behind the
seventh rib.

Part of
stomach lying
subjacent to
pericardium.

Splenic flexure
of colon lying
in stomach
chamber.

reat
iientum.

Fig. 25. — Dissection of an old subject in whom the aorta was diseased and dilated,
and in consequence the heart displaced downwards and hypertropliied. The
drawinf^ also shows backward displacement of the pulmonary trunk. Below the
diaphragm the relation of the splenic Hexure of the colon to the stomach
chamber, when the latter viscus is contracted, is well seen ; also the relation
of the stomach to the pericardial sac.

ITofctce page 248.

TOPOGEAPHY OF THE HEAET.

249

impulses, and the normal impulse may be concealed. For this
reason it is more correct in all cases to speak of the visible or
palpable thrust as the cardiac impulse than as the apex beat.
The outline of the heart projected on the chest wall is as

pericar»d. arch of aorta

sup. ven. cav

sup. sp. 1
ven. cav

aortic )
valve

aur.-vent.,
groove

tricusp. f
valve

pul aorta

s\i,2^\Qft aur. app.

pul. valve
left vent.

mit. valve
right vent.
/--?<_^^^ nipple

'^^ -'sp. 4

left vent.

right vent.

apex of heart

Relation of the Heart to the Wall of the Thorax.
{Hughfin and Keith.)

follows : — The upper border is a line drawn across the sternum
at the upper edges of the third costal cartilages ; it extends half
an inch beyond the sternum to the right and an inch to the left.
The left border, which represents the margo obtusus of the
left ventricle, corresponds to a curved line drawn from the left

250 CLINICAL APPLIED ANATOMY.

extremity of the upper border to the impulse. This line is
convex outwards, and at the level of the fourth left costal
cartilage lies three inches to the left of the mid-line of the
sternum. The right border, corresponding to the right auricle,
is represented by a line, convex to the right, drawn from the
right extremity of the upper border to the sixth right costal
cartilage near the sternum. This line extends an inch and a half
to the right of the mid-sternal line at the level of the fourth
costal cartilage. The lower border, or margoacutus of the right
ventricle, extends from the sixth costal cartilage of the right side
to the impulse. This line passes to the left with slight down-
ward obliquity, crossing the sternum at the base of the ensiform
cartilage.

A line drawm obliquely across the cardiac area from the lower
border of the left third to the right sixth costal cartilage, com-
mencing at the mid-line of the sternum and terminating at the
right edge, indicates the furrow between the right auricle, which
lies above and to the right, and the ventricles which lie below
and to the left. The leftmost strip of the cardiac area, nearly
an inch broad, commencing at the lower border of the third left
costal cartilage and terminating at the impulse, represents the
anterior part of the left ventricle. Immediately above the left
ventricular strip lies the left auricular appendix.

The heart is in contact laterally with resonant lung, and
wedge-shaped portions of pulmonary tissue also pass forwards
between its anterior surface and the chest wall. These wedge-
shaped prolongations gradually thin off and leave uncovered the
lower part of the anterior surface of the right ventricle. The
part uncovered corresponds to the area of superficial cardiac
dulness. The area is limited above by the fourth left costal
cartilage, internally by the left edge of the sternum, and
externally by an obhque line starting from the fourth left costal
cartilage in the parasternal line and passing thence to the
position of the cardiac impulse. This area is dull to light per-
cussion, and can be easily determined. The deep cardiac dulness
which should correspond to the actual outline of the heart

THE VALVULAE OEIFICES. 251

requires heavy percussion, and cannot be determined with
anything hke the same accuracy owing to the intervention of
resonant puhnonary tissue and the vibrant quahties of the
sternum.

The YalYular orifices of the cavities of the heart He so closely
together that it is unsafe to assign a murmur to a definite orifice
because it happens to be loudly heard at a surface area corre-
sponding to the orifice in question. The valves which guard the
orifices of the right side of the heart lie more or less in front of
those belonging to the left cavities. This is especially the case
with the valves of the pulmonary artery and the aorta. In
diseased conditions the relations may become altered. The
aorta may displace the pulmonary artery considerably to the
left, and the tricuspid orifice may come more and more in front
of the mitral. Nevertheless, as a general rule, pulmonary, aortic
and tricuspid murmurs are best heard at spots corresponding to
the positions of the respective valves as projected on the surface
of the chest. The mitral valve is an exception, the murmurs
belonging to this valve are best heard where the left ventricle
impinges on the surface of the chest — i.e., at or near the cardiac
impulse.

The fibrous cusps of the valves are devoid of vessels. The
vegetations of early endocarditis are not actually on the free
edges of the valves, but lie in positions corresponding to the
points of maximum contact of the cusps involved. As the result
of inflammation the thinnest portions of the valves become con-
tracted, and then the vegetations may appear to lie on the free
edges. They appear on the side of the valve which is remote
from the blood pressure — i.e., on the ventricular aspects of the
aortic and pulmonary valves, and on the auricular aspects of the
mitral and tricuspid segments.

Aortic Disease. — The aortic valve lies under cover of the left
edge of the sternum close to the lower border of the third left
costal cartilage. It is in this position the aortic diastolic
murmurs are earliest detected and best heard. The ''aortic
cartilage " is the second right costal cartilage, and corresponds

252 CLINICAL APPLIED ANATOMY.

to the level at which the ascending aorta, in consequence of its
forward inclination, comes nearest to the back of the sternum.
An aortic systolic murmur is often loudest in this situation, but
a faint diastolic murmur may be easily overlooked if only sought
for at this spot. Diastolic aortic murmurs are conducted down-
wards over the left ventricle towards the impulse of the heart ;
systolic murmurs are conducted along the ascending aorta to the
great arteries at the root of the neck. The forcible distension
of the sinuses of Valsalva with blood during the elastic recoil of
the aorta and other arteries in diastole occasionally drives air
out of the overlying lung with a slight puff and simulates a
diastolic murmur. Systolic murmurs may be produced in a
similar manner. These exocardial murmurs may generally be
recognised on account of the marked way in which they vary
with the respiration.

The aortic valve segments are supported by a complete and
strong fibrous ring, which offers great resistance to dilatation of
the orifice. It is far more common for the mitral valve, which
lies next behind the aortic in the circulatory circuit to give way
under the stress of high back pressure. When dilatation does
occur at the aortic orifice it is usually the result of degenerative
lesions in later life. Paradoxically a dilated aortic orifice may
give rise to a systolic murmur, indicating obstruction, as well as
to the diastolic murmur of regurgitation. The obstructive
murmur may be due to the tight stretching of the valve cusps
across the lumen of the enlarged vessel.

The base of the anterior segment of the mitral valve is struc-
turally continuous with the bases of the aortic cusps, so inflamma-
tion can and does often extend by continuity from the one valve
to the other. The orifices of the coronary arteries lie behind the
aortic valve segments, and although this position may shelter
them from emboli, it renders them liable to implication in aortic
disease, and adds to the gravity of the situation.

When the aortic orifice is obstructed or the valve incompetent,
changes take place in the surface relations of the left ventricle.
In stenosis, these may be the result of pure hypertrophy, but in

MITRAL INCOMPETENCE. 253

incompetence, the ventricle is usually as much dilated as hyper-
trophied. In both cases the outer boundary of the ventricle is
carried to the left, and the cardiac impulse displaced downwards
and outwards. The outward displacement of the left margin of
the ventricle will increase the area of superficial cardiac dulness
towards the left owing to the retraction of the lung from the
surface of the enlarging heart. When the left ventricle is much
hypertrophied and the right chambers of the heart are as yet
but slightly involved, the impulse of the left ventricle can some-
times be felt in the epigastrium, but this is exceptional ; an
epigastric impulse as a rule is caused by the right ventricle.

Mitral Incompetence. — The mitral valve lies behind the
sternum, opposite the attachments of the fourth costal cartilages.
The right ventricle intervenes between it and the back of the
bone. The systolic murmur of mitral incompetence is best
heard at the cardiac impulse, this being the spot where the left
ventricle comes nearest to the surface of the chest. The murmur
may be traced towards the axilla, gradually fading away as the
ventricle recedes, and a thicker wedge of lung becomes interposed
between the heart and the parieties of the thorax. The murmur
may in some instances be heard at the back between the scapula
and the spine ; it is probably conducted to this spot by an
independent route, for that part of the base of the left ventricle
which lies immediately below the left auricle rests directly on the
structures in front of the spinal column. The murmur is
therefore said to be conducted by the vertebrae from the base or
*' shoulder " of the left ventricle. Another explanation attributes
the conduction of the murmur to the back to the presence here
of the left auricle which receives the regurgitant stream of blood.

A systolic murmur may exist at the mitral orifice even though
the valve cusps are not diseased. The ring of fibrous tissue
which supports the valve segments takes its origin from the
central fibro-cartilage of the heart. On the side of the orifice
which lies remote from the fibro-cartilage, the fibrous ring is
exceedingly thin and cannot offer much resistance to stretching.
Consequently the mitral valve depends for its competency on the

254 CLINICAL APPLIED ANATOMY.

transverse contractile power of the cardiac muscle rather than on
the strength of its own fibrous foundation. Temporary weakness
of the cardiac muscle therefore may occasion temporary mitral
incompetence which will disappear when the myocardium recovers
its normal tone. In conditions of high arterial tension such as
obtain in chronic renal disease and in arteriosclerosis a murmur
develops at the mitral orifice as the result of increased back
pressure, although the stronger aortic valve, which is more directly
exposed to the pressure, remains competent.

Mitral incompetence early gives rise to dilatation and hyper-
trophy of the left ventricle and the left auricle. Since the left
auricle is interposed between the base of the left ventricle and the
structures immediately in front of the spinal column, it is not
accessible to clinical examination, but the rise of pressure in the
cavity, transmitted backwards through the pulmonar}?^ veins,
gives rise to an accentuation of the second sound at the pulmonary
orifice. The pulmonary valves are superficial and lie at the
upper border of the third left costal cartilage, at its junction with
the sternum. The "pulmonary cartilage" is the second left
costal cartilage, and marks the spot where the pulmonary artery
approaches nearest to the surface of the body before dividing
into its two large branches. The accentuated sound may be
heard either over the valves or over the pulmonary cartilage ; in
the former position the valve closure may also be felt. Hyper-
trophy and dilatation of the right ventricle and auricle follow in
turn. The results of increase in size of the left ventricle have
already been discussed in the section on aortic disease, but it
must be pointed out that the alteration of the position of the
cardiac impulse in mitral incompetence is the resultant of two
forces. The hypertrophy of the left ventricle displaces the
impulse downwards and somewhat outwards, whilst the hyper-
trophy of the right ventricle tends to displace it outwards, and
using the diaphragm as a fulcrum, even to lift it up.

Mitral Stenosis. — In mitral stenosis all the cavities of the heart,
with possibly the exception of the left ventricle, ultimately
become enlarged, and, if the occurrence of a pulmonary diastolic

MITEAL STENOSIS. 255

murmur is accepted, every valve orifice, except the aortic, may
be the site of a murmur.

The presystoHc murmur of mitral stenosis is audible over a
curiously limited area internal to the cardiac impulse. Both
thrill and murmur are communicated from the solid structures
of the heart to the chest wall, and by firm pressure with the
stethoscope the murmur can be modified or even suppressed.

A systolic tricuspid murmur is common in the later stages of
the disease. This murmur is heard over an area corresponding
to the tricuspid valve. The tricuspid orifice is comparatively
superficial, and lies obliquely across the vertical mid-line of the
sternum opposite the fourth and fifth costal cartilages and
the fourth intercostal spaces. The murmur is diffused over a
considerable area of the lower part of the sternum, and often
extends as far outwards as the cardiac impulse, which it is well
to bear in mind is often caused by the right instead of by the left
ventricle in these cases. The structure of the tricuspid fibrous
ring is similar to that of the mitral, and the valve yields even
more readily to pressure. Indeed the tricuspid valve may be
said to be normally incompetent under increased pressure, this
being a device to obviate over distension and even rupture of
the right ventricle under circumstances of sudden muscular
effort.

The increased pressure in the pulmonary circuit may result in
atheromatous changes in the pulmonary artery and temporary
incompetence of the pulmonary valves. In such cases a diastolic
murmur appears a short distance to the left of the sternum
just outside the position of the aortic valves. The murmur is
transitory, disappearing when the circulation improves, and there
appears good reason for the belief that it is really produced at
the pulmonary orifice which is displaced in the same direction as
the conus arteriosus, to the position of which reference will later
be made.

The disappearance of the second sound at the impulse of the
heart, which is a common occurrence in mitral stenosis, is
probably due to interposition of the right ventricle in front of

256 CLINICAL APPLIED ANATOMY.

the left, which thus prevents the normal conduction of the aortic
second sound to the apex by the left ventricle. It is said that
the pulmonary second sound is always inaudible at the impulse.
Moreover, in mitral stenosis the aorta is insufficiently filled,
its elastic recoil is consequently less and its second sound is
fainter.

The left auricle, lying as it does immediately behind the site
of obstruction, may attain a great size and is usually enlarged
in all its diameters. Being interposed between the ventricle and
the spinal column, it may actually, when distended, indirectly
play a part in production of the cardiac impulse, by thrusting
the ventricles forwards. In such exceptional cases the com-
mencement of the impulse is really presystolic in time.

Upward enlargement of the left auricle may raise the roots of
the lungs and actually exercise some pressure on the bronchi,
since the latter are in contact with the upper part of the posterior
surface of the auricular chamber. Lateral enlargement of the
left auricle has been supposed to give rise to an outward extension
of cardiac dulness in the third and fourth left interspaces, but
this dull area is more correctly assigned to an upward enlarge-
ment of the conus arteriosus of the right ventricle. In some
instances of great enlargement transversely, the left auricle has
been found pulsating to the right of the sternal edge, having
passed across the back of the right auricle, to which it is normally
posterior, and then gained the surface on the right side. This
great transverse or horizontal enlargement is usually rather
associated with carditis and pericarditis than with mitral stenosis.

The pulmonary veins, which return the oxygenated blood from
the lungs to the left auricle, dilate on account of the increased
pressure in the latter cavity and may show patches of athero-
matous change.

The obstruction to the pulmonary circulation causes the right
ventricle to hypertrophy and dilate in its turn, and the muscular
mass of this cavity is a very important factor in maintaining the
circulation through the constricted mitral orifice. The right
ventricle forms the greatest part of the anterior surface of the

Mitral Stenosis.

Superior
vena
cava.

Conus
arterio-
sus of
right
vent-
ricle, dis-
placed
vip wards.

Friction
patch.

Anterior
margin
of left
lung.

4 Left
vent-
ricle.

Hyper-
trophied
right
ventricle
with
c friction
•^ patch.

Fis. 27.

-To show alterations in size and position of the right cavities of the heart, caused by a
moderate degree of mitral stenosis.

[To face page 257.

MITEAL STENOSIS. 257

heart. Its outline, as projected on the surface, has already been
defined. Its inferior wall rests on the diaphragm. The results
of hypertrophy of this chamber are the appearance of pulsation
in the epigastrium and an increase of cardiac dulness in two
directions, namely transversely to the left and upwards on the
left side of the sternum. The upward extension of dulness is
due to an increase in size of the conus arteriosus, which is that
part of the right ventricle from which the pulmonary artery
springs. The appendix of the left auricle normally lies in the
position occupied by the upward extension of dulness, but as a
rule the enlarging conus completely displaces the auricle. The
enlarging right ventricle, pushing its way to the left, ultimately
may completely separate the left ventricle from the anterior wall
of the chest, and also takes the place of the latter cavity in
producing the cardiac impulse. As a result the impulse is
displaced mainly to the left and not so much downwards as in
hypertrophy of the left ventricle.

The increasing pressure in the pulmonary circuit ultimately
affects the right auricle. The outer limit of this auricle normally
extends an inch and a half to the right of the sternum. It is
covered by the anterior part of the right lung, and consequently
takes no part in the superficial cardiac dulness. The presence of
a wedge of lung tissue in front of the auricle, and the close
approximation of the costal cartilages in this situation are
obstacles to the satisfactory examination of this cavity of the
heart. Increase in the size of the cavity causes the superficial
cardiac dulness to extend up to or beyond the right margin of
the sternum. Only when the auricle is much distended and the
lung retracted is actual dulness obtained to the right beyond the
sternal edge. Earely the auricle may be seen to pulsate in this
situation.

From what has been stated it will be gathered that the area of
cardiac dulness is increased in three directions by mitral stenosis.
The main increase is transverse to right and left, but there is also
an extension upwards, consequently the percussion outline of
pericardial effusion is in some instances very closely simulated.

C.A.A. 17

258 CLINICAL APPLIED ANATOMY.

CONGENITAL DISEASE OF THE HEART.

Lesions near the origin of the pulmonary artery from the
right ventricle are found in more than three-quarters of the
cases of congenital disease. The pulmonary trunk, the pulmonary
valves, or the infundibular part of the right ventricle may be
involved. It is necessary to point out that the infundibulum, or
that part of the right ventricle from which the pulmonary trunk
arises, is also known as the conus pulmonalis or the conus
arteriosus. The term bulbus arteriosus is applied to a segment
of the embryonic heart, which, becoming subdivided, not only
gives rise to the infundibulum of the right ventricle, but also to
the corresponding part of the left and to the stems of the aorta
and pulmonary artery. The bulbus, before this subdivision, is
looked upon by embryologists as consisting of two parts, one
part near the heart is the bulbus proper, and a more distal
portion is called by 4ihem the conus arteriosus. Since the latter
term is also applied to the infundibulum some confusion is
apt to arise.

The right ventricle of the human heart is formed by the
fusion of two chambers, the infundibulum, which is a part
derived from the bulbus arteriosus, and the sinus, or body
of the ventricle, which is the right half of the foetal common
ventricle. The union of these constituent parts is indicated on the
wall of the ventricle by a muscular lip, which projects downwards
into the cavity and intervenes between the tricuspid and the
pulmonary orifices. This projecting lip is known as the supra-
ventricular crest. At the level of the crest a fibrous ring of
thickened endocardium is sometimes found, and this, when
much exaggerated, forms a diaphragm with a central perforation
of varying size. When this is the case, a heart with three
ventricles results, the infundibulum being sharply separated
from the sinus of the ventricle. (Fig. 29.) In other instances
the development of the infundibulum is arrested at an early
stage, and the chamber is represented by a small cavity or even

CONGKNITAL HeART DiSEASE.

Superior vena cava
Undefended space,

Fossa ovali

Eustachian valve
Inferior vena cava

Cavity of right
ventricle.

Tricuspid valve.

Fig. 28.— Diagram of right cavities of the heart to show possible
sites of obstruction at each end of the infundibulum of the right
ventricle. Obstruction at A gives rise to a heart with three
ventricles. Obstruction at B is in the position of the pulmonary
valve. Obstruction at C involves the stem of the pulmonary
artery.

Superior vena cava i-. 1

Aorta

Dilated right auricle.

Pulmonary valve with
only two cusps.

Separated

infundibulum form-
ing a third ventricle. _

"A

Tricuspid valve.

Hypertrophied right
ventricle.

Obliterated ductus-
arteriosus.

, .Pulmonary artery.

Left auricle.

, Aortic valves.

Aortic septum.

Defect in
ventricular septum.

" "• Left ventricle.

Septum inferius.

Fig. 29. — Heart with three ventricles, from a man aged 19 years.
Semi-diagrammatic. (St. Thomas's Hospital Museum.)

[To face page 258..

CONGENITAL DISEASE OF THE HEART. 259

a narrow strait of communication between the pulmonary trunk
and the sinus or body of the ventricle.

The pulmonary cusps are developed at the distal end of the
bulbus arteriosus from endocardial projections known as cushions,
which give rise to the segments of both the aortic and the
pulmonary valves. The pulmonary orifice may become narrowed
or even completely occluded by developmental defects in this
position.

The common arterial trunk beyond the valves is the conus
arteriosus of embryologists. This becomes subdivided into the
pulmonary artery and the aorta by the growth and fusion of
dorsal and ventral ridges which, commencing above at the origin
of the fifth branchial arch, grow downwards with a spiral twist
to unite with the endocardial cushions from which the semilunar
valves are derived. Narrowing or obliteration of the pulmonary
trunk may result from a faulty position of the spiral septum.
Defect in coalescence of the ridges which form the septum may
be the cause of certain rare communications between the aorta
and pulmonary artery, whilst complete failure of the septum will
result in the presence of a common trunk which conveys blood
to the lungs and the systemic vessels as well.

Thus it comes about that congenital defects may occur on the
right side at the junction of the infundibulum with the sinus of
the right ventricle, a position normally indicated by the supra-
ventricular crest and lying just above the undefended space; or
in the infundibulum itself, or at the site of the pulmonary valve,
or in the pulmonary trunk between the valve and the ductus
arteriosus. Of these defects the commonest is one at the position
of the pulmonary cusps. (Fig. 28.)

Congenital defects of the infundibulum or of the pulmonary
artery are often associated with defects in the ventricular or
auricular septa. Malpositions of the aorta and pulmonary artery
often coexist as well. The spiral septum of the conus arteriosus
not only separates the pulmonary artery from the aorta, but
also, after fusion with the endocardial cushions of the bulbus
from which the semilunar valves are derived, projects downwards

17—2

260 CLINICAL APPLIED ANATOMY.

into the ventricle as the " aortic septum " to complete the septum
between the ventricles. Consequently it is quite possible that
the septal defects and malpositions of the great vessels may be
due to the same unknown influences which cause the pulmonary
obstruction. However this may be, the septal defects and
arterial malpositions are usually looked upon as secondary
results of the pulmonary lesion and explained as follows : —

When stenosis of the pulmonary artery occurs before the
eighth week of foetal life, the ventricular septum is as yet
incomplete, and the excess of pressure in the right ventricle is
relieved by the passage of some blood across the top of the
septum into the left ventricle. As a result the septum fails to
complete its union with the elements which enter into the
formation of its upper part and remains unclosed. The con-
gestion in the right auricle is similarly relieved by the passage
of blood across the incomplete auricular partition. The high
pressure in the right ventricle dislocates the growing ventricular
septum to the left, so that both the aorta and the pulmonary
artery retain their connection with the right ventricle, this being
the portion of the common ventricular cavity with which they
communicate at their first formation. When there is a con-
siderable aperture in the ventricular septum, this may by itself
suffice to relieve the overpressure in the right cavities, and the
auricular septum may become complete. Should the ventricular
septum be entire, having completed its growth before the pul-
monary obstruction occurs, the auricular septum, which is
completed later than the ventricular, must of necessity remain
pervious, otherwise there is no sufficient exit for the blood from
the right cavities of the heart.

Complete obliteration of the infundibular channel or of the
pulmonary artery is usually spoken of as atresia. The secondary
cardiac changes which result are similar to those which occur
with stenosis. The right ventricle carries on the systemic
circulation, the left becoming atrophied, since it fails to establish
its proper connection with the aorta. If, however, the ventricular
septum is complete and the aorta has established its normal

Congenital Hkart Disease.

Continuation of aortic
arch.

Enlarged aorta arising
from right veiitricle only.

Dilated right auricle.

Right auricular apijendix.

Enlarged and hyper-
trophied right ventricle.

Ductus arteriosus.
Left pulmonary artery.

Left pulmonary veins.
Atrophied left auricle.

Remnant of pulmonary
artery.

\"^^^^k Small hypertrophied left

'^^^^ ventricle communicating-

with the right by a septal
defect.

Fig. 30. — Atresia of trunk of pulmonary artery. Aorta arising
from the right ventricle. Death at four years of age.

Innominate artery.

Right pulmonary artery

yuperior vena cava.

Renmant of ascending
aorta.

Right auricle.

Left common carotid
artery.

Left subclavian artery.

Ductus arteriosus.
Left pulmonary veins.

Left pulmonary artery.
Left auricular appendix.
Pulmonary artery,

Right ventricle.

Fig. 31. — Atresia of aorta. The foramen ovale was patent, but
the ventricular septum complete. The left chambers of the heart
were atrophied.

[To face page 260.

Congenital Heart Disease,

Superior vena cava.

Fossa ovalis.

Inferior vena cava.

Orifice of coronary
sinus.

Right auricular
appendix.

Right ventricular
cavity.

Fig. 32. — Heart of adult with large defect in the auricular septum.

Fossa ovalis intact. (St. Thomas's Hospital Museum.)

Senii-diagvammatic.

~^\y

Infundibuluni of
right ventricle.

Cut surface of the
supra-ventricular
crest which inter-
venes between the
tricuspid orifice and
the pulmonary
orifice.

Pulmonary artery.

Pulmonary valve.

Left posterior aortic

cusp.

Right posterior aortic

cusp.

Defect in upper part
of ventricular septum.

Wall of left ventricle.

Section of wall of
right ventricle.

Tricuspid orifice.

Fig. 33. — The heart of an adult in vi^hich the highest part of the
interventricular septum is wanting. The aortic valves are seen
through the septal opening, and the aorta communicates freely
with both ventricles. (St. Thomas's Hospital Museum.)
Semi-diagrammatic.

[To face page 261 .

CONGENITAL DISEASE OF THE HEAET. 261

connexion with the left ventricle, it is the right ventricle which
atrophies since it has no function to perform. As a general rule
in congenital disease of the heart, those parts which in conse-
quence of the defect are thrown out of the circulatory circuit will
atrophy, whilst those which have increased work thrown upon
them will become hypertrophied. (Fig. 30.)

When the pulmonary channel is obliterated the blood usually
reaches the lungs through the ductus arteriosus, and this may
also carry part of the blood when the pulmonary artery is
stenosed. Sometimes, however, the pulmonary blood supply is
carried by enlarged bronchial arteries, which, as is well known,
show considerable variations in their points of origin.

Defects in the cardiac septa are very common in congenital
heart disease, and are often, as already explained, associated
with obstruction to the exit of blood from the right ventricle.
They may, however, occur without such obstruction. A know-
ledge of the development of the cardiac septa throws light upon
the positions in which septal defects are likely to be found.

Defects in the auricular septum are occasionally very large,
the septum being represented merely by a crescentic fold at the
upper and back part of the auricular cavity. The fold in such cases
occupies the position at which the septum primum or primitive
septum of the auricle is known to make its first appearance. If
the septum primam has developed to a greater degree, but still
failed to fuse with that part of the ventricular septum which lies
between the auriculo-ventricular orifices, a defect will exist just
above the top of the latter. (Fig. 32.) This opening, between
the base of the tricuspid cusp and the position of the foramen
ovale appears to correspond in position with the ostium primum
of embryologists, for this ostium is between the lower part of the
downgrowing septum of the auricles and the two endocardial
projections which divide the common auricular canal into the
right and left auriculo-ventricular orifices. Normally the ostium
is closed by fusion of these structures. The substance of the
septum primum becomes fenestrated and finally widely perforated
in its upper part, giving rise to the ostium secundum, a part of

262 CLINICAL APPLIED ANATOMY.

which persists as the foramen ovale. The ostium secundum is
closed by the downgrowth of a secondary septum from the roof
and posterior part of the auricle. This new septum, which lies
to the right of the septum primum, is known as the septum
secundum. Its curved lower edge, applied to the right side of
the septum primum, forms the annulus ovalis, and thus comes
to bound the foramen ovale above, whilst the septum primum
bounds it below. Since the septum secundum restores the
integrity of the upper part of the auricular partition, defects in
this position are attributed to failures in the development of
the septum in question.

Patency of the foramen ovale is due to a failure of development
of that part of its membranous floor which is derived from the
septum primum. An oblique valvular slit is frequently found
at the margin of the fossa ovalis, and is caused by failure of the
membranous floor to fuse with the annulus. Such an opening
is kept closed during life by the excess of the blood pressure in
the left auricle over that in the right.

Defects in the ventricular septum were at one time supposed
to be always situated at the site of the pars membrancea septi or
undefended space, but this is not strictly true. The ventricular
septum is of compound origin, being formed above by the fusion
of the endocardial cushions of the auricular canal with those of
the bulbus arteriosus and below by the septum inferius which
separates the primitive ventricle into two, and, growing upwards,
fuses with the endocardial cushions. The septum inferius
becomes attached to the anterior cushion of the bulbus in front
and with the posterior cushion of the auricular canal behind.
Between these two attachments lies the interventricular foramen.
Quite early in foetal life this foramen becomes closed by fusion
of its margins, and its site is indicated by the undefended space
of the fully formed heart.

The upper part of the completed ventricular septum, in front
of the undefended space, forms the septal wall of the infundi-
bulum of the right ventricle, and is often known as the aortic
septum. Indications of the compound nature of this portion of

Congenital IIkart Disk ash

Ascending aorta.- -

Posterior fleshy-
element of septal
wall of infun-
dibulum.

Dotted outline

indicating the

l)Osition of

aortic cusps on '

other side of

septum.
Undefended
space or pars
niembranacea
septi.

Tricuspid valve. '~

Pulmonary
artery.

Pulmonary
cusps.

Anterior fleshy-
element of
septal wall of
infundibulum.

Wall of right
ventricle.

Fig. 34.— To show the elements which constitute the aortic septum or septal wall of the
infundibular portion of the right ventricle, and the position of the pars niembranacea
septi or undefended space.

[To face page 203.

CONGENITAL DISEASE OF THE HEAET. 263

the completed ventricular septum may often be recognised. The
angle formed by the meeting of two of the cusps of the pulmo-
nary valve corresponds exactly in position with the angle between
two of the aortic cusps on the other side of the septum. The
cusps which are thus adjacent were continuous with each other
until the spiral septum divided the common passage above them
into the aorta and pulmonary artery. These cusps may be con-
veniently termed septal, and the anterior corresponding pair were
developed from the ventral endocardial cushion of the bulbus,
whilst the posterior corresponding pair arose from the dorsal
cushion. On the septal wall of the infundibulum a line or
furrow may sometimes be traced from the angle between the
septal cusps of the pulmonary valve downwards and backwards
to the undefended space. The portion of the septum in front of
this line appears as a thick muscular band passing downwards
and forwards ; this represents the false septum of the reptilian
heart. The portion behind the line passes downwards and
backwards, and becomes in part continuous with the supraven-
tricular crest already described. The line or furrow represents
in its upper part the fusion of the endocardial cushions which
divided the bulbus into the aortic and pulmonary orifices, and in
its lower part, which inclines towards the undefended space,
represents the line of fusion of the aortic septum with * the
septum inferius. (Fig. 34.)

The commonest site for a perforation of the interventricular
septum to occupy is immediately in front of the undefended
space. This corresponds to the lower part of the furrow of the
aortic septum. A perforation posterior to the undefended spot
is less common, and is usually associated with a defect in the
adjacent part of the auricular septum, since it lies at the point
of fusion of the septum inferius with the posterior endocardial
cushion of the auricular canal. The undefended space itself
may be defective in conjunction with septal defects in front of it
or behind it. (Fig. 33.) The rarest defects of all are in the
extreme fore part of the anterior region of the septum.

Apertures in the region of the undefended space and

264 CLINICAL APPLIED ANATOMY.

immediately in front of or behind it will establish a communi-
cation between the left ventricle and the sinus portion of the right.
A defect in the fore part of the septum will establish a communi-
cation between the left ventricle and the infundibulum of the
right.

Lesions at the origin of the aorta or in the aorta itself are
much less common than the corresponding lesions of the pul-
monary artery. Like the latter lesions they may involve the
conus arteriosus of the left ventricle, the orifice of the aorta or
the aortic trunk. Although rare, complete impermeability of
the aorta appears to occur more frequently than the correspond-
ing condition of the pulmonary stem. (Fig. 31.)

Stenosis or atresia of the aorta may also occur at or below
the point where the ductus arteriosus joins it. Normally
the aorta shows a slight narrowing at the situation of the
ductus, to which the term aortic isthmus has been applied.
Stenosis or atresia at this spot probably arises in connexion
with the formation of the ductus. As a result of this
the descending aorta may be entirely supplied by the ductus
arteriosus. If the ductus becomes impervious or retains its
connexion with the proximal portion of the artery, a collateral
circulation is carried on by means of anastomoses between
branches of the subclavian arteries which arise above, and the
intercostal and phrenic arteries which arise below the constriction.
The presence of the enlarged anastomising arteries may enable
the diagnosis to be made during life.

The aortic isthmus is succeeded by a fusiform dilatation known
as the aortic spindle. The lower limit of the spindle is supposed
to mark the site at which the atrophied right aortic arch joined
the descending aorta. A second constriction which sometimes
occurs lower than the constriction at the isthmus probably
arises in connexion with the obliteration of this right aortic
arch.

Congenital atresia or stenosis of the auriculo-ventricular
orifices may be attributed to defects in the endocardial cushions
which subdivide the auricular canal. (Figs. 35 and 36.)

Congenital Heart Disease.

Right auricle.

Infundibulum of right
ventricle.

Tricuspid orifice.

Lower end of aortic
septum.

Defect in ventricular

septum.
Cavity of hypertrophied
right ventricle.

Septum inferius.

Cavity of rudimentary
left ventricle.

Aorta.

Aortic isthmus.

Ductus arteriosus.
Pulmonary artery.

Left auricle.

Depression indicating
position mitral orifice
should occupy.

Fig. 35.— Mitral atresia, rudimentary left ventricle. Defect in
upper part of the ventricular septum, and patent foramen ovale.
Patent ductus aiteriosus. Descending thoracic aorta supplied
partly by aortic isthmus and partly by ductus arteriosus. Semi-
diagrammatic.

Superior vena cava.

Aorta.

Patent foramen ovale.
Right auricle.

Position of obliterated
tricuspid orifice.

Common ventricle.

Left auricle.

Pulmonary artery.

- Mitral orifice.

■\ Pulmonary cusps, fused,

\. leaving two small orifices.

Aortic septum.

IT ^

Fig. 36.— The heart of a " young person " with complete atresia of
the tricuspid orifice. The aorta and pulmonary artery are trans-
posed both laterally and antero-posteriorly. The pulmonary
artery is stenosed at the site of its valves and the septum
inferius of the ventricles is wanting. The course of the circula-
tion is indicated by the dotted arrows. Semi-diagrammatic.
(St. Thomas's Hospital Museum.)

[To face page 264.

AETEEIAL H^MOEEHAGE. 265

Excess or deficiency in the number of semilunar cusps at the
aortic and pulmonary orifices may similarly be due to malforma-
tions of the endocardial cushions of the aortic bulb.

Blood Vessels.
hemorrhage.

Loss of blood may occur from any part of the vascular system.
Hence haemorrhage is often divided into the arterial, the capillary
and the venous varieties.

Arterial haemorrhage from a normal vessel is almost always
due to a wound of the artery from without rather than a rupture
of its walls by the blood pressure from within. The wound which
implicates the vessel may be one which passes down to it through
the skin or one which is made into it by the sharp edge of a frac-
tured bone. Hence it follows that the more superficial the artery,
the more likely it is to be injured from the surface, and the closer
its proximity to a bone, the greater is its danger of laceration after
fracture.

Except in the case of gun-shot injuries, arteries of the extremi-
ties are more commonly wounded than those of the trunk, and
the vessels of the upper extremity more frequently than those of
the lower. Probably because of their position the radial and
ulnar arteries are the most common vessels to be accidentally
divided.

Arteries of Head and Neck. — Wounds of the face are apt to
be followed by severe haemorrhage from the facial artery or from
one or other of its many branches. Crossing the lower border of
the mandible immediately in front of the masseter — that is, at a
point about one-third the distance between the angle and the
symphysis menti — the vessel passes tortuously towards the angle
of the mouth, and then ascends more vertically, to terminate
near the inner canthus of the eye. In the opening of a dental
abscess in connexion with the lower molars, the artery may
be exposed to injury unless the knife is kept close to the

266 CLINICAL APPLIED ANATOMY.

bone when the incision is made from the inside, or the opening
made well in front of the masseter if it passes through the
skin. The coronary branches of the facial artery supply
the upper and lower lips, and troublesome haemorrhage may
occur from the superior during an operation upon a hare-lip,
or from either after a laceration of the frsenum of the upper
or the lower lip. The removal of an epithelioma from the lower
lip will necessitate division and ligature of the inferior coronary
vessels.

The lingual artery or its branches may be damaged in wounds
of the tongue. As a rule the bleeding vessel can be secured
by ligature, or the haemorrhage, if only slight, controlled by the
insertion of a suture. There is little, if any anastomosis
between the arteries of the two sides except about the tip of
the tongue, so that incisions made in the middle line bleed but
little.

The occipital artery is deeply placed as it passes backw^ards
before turning upwards on to the scalp, and in this situation a
punctured wound may give rise to troublesome haemorrhage.
To expose the bleeding point it may be necessary to divide the
fibres of the sterno-mastoid, the splenius capitis, the trachelo-
mastoid and even the posterior belly of the diagastric. Its
descending branch, the arteria princeps cervicis, may also be
injured in the posterior triangle of the neck.

Injuries about the tonsil and the lateral wall of the pharynx,
particularly if of the nature of punctured wounds, may be as-
sociated w^ith severe haemorrhage. It is, however, seldom that
such a large vessel as the internal carotid is opened up, seeing
that its position in the adult is at least one inch from the mucous
surface of this region. More usually the facial or one of its
tonsillar branches, or the ascending pharyngeal, is the arterial
vessel which is wounded.

In haemorrhage from any of the branches of the external
carotid artery distal to the superior thyroid, if the bleeding point
cannot be secured directly, it will become necessary to ligature
the main trunk of the external carotid. Because of the very free

EADIAL AND ULNAE AETEEIES. 267

communication between the superior and inferior thyroid arteries,
the ligature upon the external carotid should be placed distally
to the origin of the superior thyroid, so that no blood may be
brought from the subclavian through the thyroid axis and its
inferior thyroid branch to the superior thyroid, and so to the site
of haemorrhage. This anastomosis, and the danger of interfering
with the blood supply of the brain, are the reasons why under
these circumstances it is better to ligature the external rather
than the common carotid artery.

In cut- throat injuries the vessels frequently escape any damage.
This is chiefly because their position is at a posterior plane in
consequence of the projection forwards of the thyroid cartilage,
by which structure they are protected when the cut is made as
high up as it generally is.

Arteries of the Upper Extremity. — It is uncommon to get
injuries of any of the arterial trunks except those in the lower
part of the forearm. The radial and the ulnar close above the
wrist are frequently divided in association with the other
structures, especially in such injuries as occur from the hand
having been thrust through a pane of glass.

The radial artery lies on the radial side of the flexor carpi
radialis tendon, and, being quite superficial, can be easily picked
up and ligatured, if necessary, after some enlargement of the
wound.

The ulnar artery is somewhat more deeply placed, lying to the
radial side of the flexor carpi ulnaris tendon, and it is well to
recollect the close proximity of the ulnar nerve, which is placed
between the artery and the tendon, for the nerve may be damaged
at the same time that the artery is severed.

Punctured wounds of the palm of the hand may involve one or
other of the palmar arches. The superficial palmar arch, formed
as a rule by the superficial branch of the ulnar being joined by
the superficial volar of the radial, has its lowest point of con-
vexity at the level of the fully outstretched thumb. A wound of
this arch can be readily dealt with by ligature after an incision
through the palmar fascia.

268 CLINICAL APPLIED ANATOMY.

The deep palmar arch, on the other hand, is formed by the
deep branch of the uhiar anastomosing with the termination of
the radial in the palm of the hand, and the lowest point of its
convexity is placed at a level which is one finger's breadth nearer
the wrist than that of the superficial arch. It lies here deep, to
all the structures in the palm of the hand, being placed upon the
metacarpal bones. Hence it follows that a wound of this arterial
arch is very difficult to deal with. Properly applied local pressure
is probably the best treatment to adopt in the first instance to
arrest the haemorrhage, unless an aseptic exposure of the bleeding
point can be carried out. If, however, pressure should fail, or
it is not thought advisable to cut down locally, it will become
necessary to ligature the brachial artery. This vessel must be tied,
because if the radial and ulnar were secured, blood might still
be brought to the bleeding point through the crucial anastomosis
in front of the wrist, consisting of the anterior interosseous on
the proximal side, the anterior carpals laterally, and the recurrent
branches of the deep palmar arch distally.

Arteries of the Lower Extremity. — Again, injuries of these
vessels, like those of the upper extremity, are by no means
common ; they may result, however, from punctured wounds.

Undoubtedly the best treatment is to expose the injured vessel
and to ligature it on the proximal and on the distal side of the
opening into it. This, however, may be a matter of very great
difficulty, on account of the effusion of blood into the muscular
and cellular planes, the natural anatomical relations of parts
being thereby greatly altered and the liability to sepsis very
considerably increased.

Gangrene occurs more commonly after obliteration of the
femoral artery than after closure of the brachial, because the
distance from the heart — that is, from the pump — is greater,
and the periphery of the limb will consequently be insufficiently
supplied with blood. If the vein happens to be damaged at the
same time that the artery is wounded, the probability of gangrene
is still greater, the moist variety occurring on account of the
obstruction to the return of the flow.

THOEACIC ANEURYSMS. 269

Aneurysm.

Certain arteries are more prone to be the seat of aneurysm
than others, and many of the reasons for this fact are dependent
upon anatomical considerations. Aneurysm of the thoracic
aorta is more frequent than that of any other vessel. Following
upon this artery the popliteal, the superficial femoral, the
common carotid, the subclavian, the axillary, the innominate,
and the abdominal aorta are not infrequent sites.

From an anatomical point of view it is convenient to subdivide
thoracic aneurysms into three groups, namely, those arising
from the ascending aorta, those which spring from the oblique
segment of the arch, and those which occur in connexion with
the descending portion. These limits are purely artificial, and
are often overstepped by the progress of the disease. The only
aneurysms which can attain a large size without producing
serious internal pressure effects are those which project forwards
or upwards from the anterior and upper aspects of the aortic arch.

The ascending thoracic aorta, or first part of the aortic arch,
commences at the lower border of the third left costal cartilage,
just beneath the sternal edge, this being the situation of the
aortic valves. The vessel inclines upwards, forwards and to the
right, and terminates under cover of the right half of the sternum
at the level of the " aortic cartilage," which is the second costal
cartilage of the right side. This part of the aorta lies in a
pericardial sheath which is common to it and the pulmonary
artery, so that both vessels are closely invested in the serous
layer save where they come into contact with each other. The
presence of this pericardial investing sheath accounts for the
tendency of aneurysms near the root of the aorta to rupture into
the pericardial cavity. The front of the vessel is at first con-
cealed by the root of the pulmonary artery and the right auricular
appendix, but higher up it is only separated from the sternum
by the right pleura and the mediastinal tissues. Saccular
aneurysms arising here tend to present in the second and third
right intercostal spaces near the sternal edge, but they may

270 CLINICAL APPLIED ANATOMY.

present in the second interspace of the left side, especially if
they arise very near the origin of the aorta. They have also
been known to separate the manubrium from the gladiolus, a
process which is facilitated by the normal presence of a cartil-
aginous connection between these two parts of the sternum and
the occasional presence of a synovial cavity.

The superior vena cava and the right auricular appendix are
closely applied to the right side of the ascending aorta. The
cava is sometimes perforated by an aneurysm, giving rise to
highly characteristic symptoms and signs. These consist of
sudden pain, followed by cyanosis and oedema of the head, neck
and arms, the development of a continuous murmur running
through systole into diastole, and the presence of a local thrill.
When the superior cava is compressed, the resulting lividity and
oedema are restricted to the head, neck and arms, but should
the pressure be proximal to the point of entrance of the great
azygos vein, the chest will also share in the congestion.

An incomplete spiral around the ascending aorta is formed by
the pulmonary artery and its right main subdivision. The com-
mencement of the pulmonary artery lies in front of the aorta,
the main pulmonary trunk is closely applied to the left side of
the vessel, and the right branch passes behind it. The relations
of the vessels being so intimate, the pulmonary artery is liable
to compression by aneurysms of the ascending aorta. These
aneurysms sometimes rupture into the pulmonary artery. Sudden
pain, with the development of a continuous murmur, signalise
this accident, but oedema, such as occurs when the superior vena
cava is similarly perforated, rarely occurs. The right bronchus
is more or less separated from the aorta by the right pulmonary
artery, but may, like the latter, be subjected to pressure with
resulting secondary changes in the right lung. The right lung
itself is only separated from the aorta by the superior vena cava
and so may be subjected to direct pressure by the aneurysm.
The right phrenic nerve lies on the right side of the superior
vena cava, and may also be implicated.

Aneurysms at the junction of the ascending and transverse

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THOEACIC ANEURYSMS. 271

portions of the aorta sometimes rupture into the right pleural
sac, which Ues close by.

The outline of a healthy ascending aorta normally presents
several bulgings. The great sinus of the aorta, which is a
longitudinal projection of its right border, must not be mistaken
for an aneurysmal dilatation ; it is occasionally present in the
foetus, but is best marked in old age. The three sinuses of
Valsalva project near the root of the vessel. They correspond
to the positions of the aortic valves. Aneurysm of the right
sinus has opened directly into the right ventricle, with which the
sinus is in relation ; aneurysm of the anterior sinus has been
known to open into the left ventricle. But such aneurysms are
more likely to open into the pericardium with fatal results.
These sinus aneurysms may compress and actually obliterate
the adjacent branches of the coronary arteries. The orifices of
the coronary arteries lie in the anterior and left posterior sinuses,
and may be narrowed by the endarteritis which is associated
with aneurysm, causing anginal symptoms. Aneurysmal dilata-
tion of the ascending aorta has a tendency to displace the heart
downwards, and disease of this part of the vessel is often
associated with incompetence of the aortic valves which lie at
its orifice.

The arch of the aorta is the oblique segment, often loosely
termed transverse, which lies in the superior mediastinum. It
passes from behind the right side of the sternum at the level of
the second costal cartilage, at first upwards, backwards, and to
the left, and then directly backwards to the left side of the fourth
dorsal vertebra, at the lower border of which it becomes the
descending aorta.

An aneurysm in this situation may impair the percussion
note of the sternum or give rise to pulsation at the root of the
neck. The upper border of the arch as it crosses the mid-line
is usually an inch below the interclavicular notch of the sternum,
so its pulsation cannot be readily felt, moreover, even when
pulsation is recognised in this situation it may be due to the
innominate or left common carotid arteries near their origins, or

272 CLINICAL APPLIED ANATOMY.

even to a thyroidea ima artery, or a right subclavian with an
abnormal origin to the left of the mid-line. In childhood the
aorta may reach to the upper border of the manubrium, but at
this period of life aneurysm is usually out of question. The
ductus arteriosus, which connects the origin of left branch of
the pulmonary artery with the aorta joins the latter just beyond
the point of origin of the left subclavian artery. The cicatrix
can easily be recognised when the aorta is laid open, and is often
the site of atheroma. At this part of the aorta is a normal con-
striction known as the aortic isthmus, whilst beyond it the vessel
often shows a fusiform dilatation which is not aneurysmal, and
is called the aortic spindle. The arch of the aorta is moulded
on the left aspect of the lower end of the trachea. It leaves its
impress on this tube, and forces it decidedly to the right of the
mid-line. An aneurysm of the arch may increase the tracheal
displacement, so that even in the neck the air tube may be
found to be shifted towards the right side. On the left aspect of
the arch also lie the oesophagus, the left recurrent laryngeal nerve,
and the thoracic duct. All of these structures may be subjected
to pressure. An aneurysm in this region may open into the
oesophagus. When the trachea is compressed stridor may be
heard over both lungs, and is associated with a brassy cough
and paroxysmal dyspnoea. The cough and dyspnoea are probably
caused by irritation of the filaments which the vagi supply to
the trachea.

The right lung and pleural sac are fairly well protected by the
intervention of the structures already mentioned as being in
immediate relation with the right side of the aortic arch, but
aneurysms near the commencement of the arch may invade the
right pleural sac.

The left side of the arch is in relation from before backwards
with the left phrenic nerve, the superficial cardiac branches of
the left vagus and left sympathetic, the left vagus nerve and the
left superior intercostal vein. These are the only structures
which intervene between the aortic arch and the left lung and its
pleural envelope. A deep impression is made by the artery on

THOEACIC ANEUEYSMS. 273

the mediastinal aspect of the upper lobe of the left lung.
The lung ma}'' be directly compressed by aneurysms, and both
the left vagus and the left phrenic nerves may be found adherent
to the sac. Compression of the phrenic nerve causes paralysis
of the corresponding half of the diaphragm. Apart from recur-
rent laryngeal paralysis it is difficult to correlate pressure on the
vagus with definite symptoms. Eupture of the aneurysm into
the left pleural cavity is not uncommon.

The lower concave surface of the aortic arch overhangs the
root of the left lung, being placed astride the left bronchus and
bifurcation of the pulmonary artery. The tracheal tug is best
developed when an aneurysm springs from this aspect of the
arch, the impulse being communicated directly downwards to the
left bronchus, which drags on the trachea and the larynx. The
left bronchus may be obstructed or opened, and the left pulmonary
artery more or less occluded. Compression of the left recurrent
laryngeal nerve, which turns round the aortic arch beyond the
remnant of the ductus arteriosus, will produce at first abductor
and finally complete laryngeal paralysis on one side. The upper
surface of the aortic arch is in relation with the left innominate
vein and three great arteries spring from it, the innominate and
left common carotid arising close together and the left sub-
clavian further back. Pressure on the innominate veins will
give rise to enlargement of the veins of the head, arms, neck,
and upper part of the chest, whilst implication of the origin of
the arteries mentioned, or pressure on them by the aneurysmal
sac, or involvement of their lumina by the accompanying
endarteritis will modify their pulses in various ways.

Eupture into the pericardium is an unlikely accident to occur
in connection with aneurysms of the aortic arch, but aneurysms
at the junction of the arch and the descending aorta have been
known to rupture in this way after working forwards above the
left bronchus. Eupture into the mediastinal tissues gives rise
to extravasation of blood around the oesophagus and pharynx,
extending into the neck beneath the deep cervical fascia.

The descending thoracic aorta is closely applied to the back

C.A.A. 18

274 CLINICAL APPLIED ANATOMY.

of the root of the left lung and the back of the sinus obliquus
of the pericardium. Paroxysmal cough, spasmodic dyspnoea,
bronchitis, and deficient air entry in the left lung are very
characteristic of aneurysm in the region of the lung root which
presses on the back of the left bronchus, into which it may and
often does open. More rarely the aneurysm opens into the
trachea near its bifurcation. When the aneurysm lies lower
down it is behind the heart and pericardium. It is rather excep-
tional for the pericardium to be perforated in this position, but
both heart and pericardium may be forcibly pressed forwards
against the anterior chest wall, giving rise to an extensive area
of visible cardiac pulsation.

The oesophagus is at first to the right of the descending
thoracic aorta, but later comes to lie in front of the vessel, and
may even pass a little to its left side, just above the oesophageal
opening in the diaphragm. In consequence of its intimate
relation to the artery, dysphagia may be produced, and the
aneurysm may burst into the food passage. Before passing a
bougie in the investigation of dysphagia the possibility of the
presence of an aneurysm of this part of the aorta should be
carefully considered.

By backward expansion the aneurysm may erode the vertebral
bodies. The yielding intervertebral discs persist in a charac-
teristic way, while the resistant vertebral bodies are extensively
destroyed. Deep-seated gnawing pain may be the result of the
bone erosion, and the corresponding intercostal nerves may be
involved, with resulting intercostal neuralgia and segmental
hyperaesthesia or anaesthesia. Pressure may be exerted on the
spinal cord, either gradually by the advancing aneurysm or
suddenly as the result of fracture of the weakened spinal column.
In the upper part of the posterior mediastinum the descending
aorta is placed on the left sides of the bodies of the vertebrae,
and when aneurysm is present an area of dulness, and even
of pulsation with projection, may be recognised between the
spinal column and the scapula on the left side. The gangliated
chain of the sympathetic lies over the costo-central articulations

THOEAOIC ANEUEYSMS. 275

in this region and may be compressed, but this is rather too low
for the pupil fibres to be caught. Lower down in the thorax
the aorta lies in a more median position in front of the spine,
and behind the vertical part of the diaphragm.

The left pleural sac is closely applied to the left aspect of the
vessel, and an aneurysm of this part of the aorta is more likely
to rupture into the left pleura than elsewhere. But the right
pleural sac is also in relation, being only separated by the
thoracic duct and the oesophagus, and even projects behind the
oesophagus in the lower part of the thorax in the form of a
cul-de-sac, which comes very close to the aorta. So it is not
surprising that the percentage of cases of rupture into the right
pleura is quite half of that of rupture into the left.

An aortic aneurysm rarely produces symptoms of pressure on
the thoracic duct, although the latter is in close proximity ; the
pressure increases gradually, and probably a collateral lymphatic
circulation has time to establish itself.

Aneurysms of the upper part of the descending thoracic aorta
have been known to rupture into the mediastinal or sub-pleural
tissue, surrounding the oesophagus in tubular fashion, invading
the connective tissue basis of the pericardium, burying the vagus
nerves and extending even under the serous coat of the stomach.
Anomalous symptoms may thus be produced, of which anaemia
and vomiting are the chief.

An innominate aneurysm is generally associated with some
dilatation of the aortic arch itself, and often of the subclavian and
common carotid. From the position of the innominate artery
the tumour usually appears above the sternum and slightly to
its right, and tends to raise the right sterno-mastoid muscle near
its origin. The pressure it exerts upon the superior vena cava
may lead to considerable dilatation of the venous tributaries of
that vessel ; hence congestion of both upper extremities and of
the head and neck is liable to be in evidence. The right radial
pulse may be considerably altered in character, both in the way
of size and time.

An aneurysmal sac upon the common carotid artery is

18—2

276 CUNICAL APPLIED ANATOMY.

usually found near its bifurcation. Pressure symptoms will be
in evidence, such as dyspnoea, dysphagia, alteration in voice,
and cough, owing to the sac pressing upon the trachea, oesophagus
and larynx. Interference with the proper circulation of blood
through the brain on the affected side will cause giddiness and
some tendency to syncope. Embolism of one or other of the
cerebral vessels not infrequently occurs, and hemiplegia may
result.

A subclavian aneurysm is most usually met with in the third
part of the vessel, and more frequently on the right than on the
left side. The tumour develops above the clavicle external to
the sterno-mastoid, forming one of the swellings met with in the
lower part of the posterior triangle of the neck. In connection
with its diagnosis it is well to remember the possible occurrence
of a cervical rib, which may raise the artery in such a way as
to give a very close resemblance to an aneurysmal sac. The
most marked evidences of pressure are found in the oedema of
the upper limb, from interference with the return of blood
through the subclavian vein, which lies anterior to the artery ;
and in the radiating pain over the area of distribution of the
cords of the brachial plexus, which lie posterior and external to
the sac.

The axillary artery may be the site of an aneurysm, which is
most usually of traumatic origin. It frequently assumes large
proportions, on account of the looseness of the surrounding
tissues, which give the vessel but little support. Again, pressure
upon the accompanying vein leads to considerable oedema of the
limb on the distal side, and likewise pressure upon the surround-
ing nerves occasions pain, or marked interference with their
function.

An aneurysm upon the brachial artery is usually seen at the
bend of the elbow, and is dependent as a rule upon traumatism.
Not infrequently it is of the nature of an arterio-venous aneurysm,
the outcome of a wound of the median basilic vein and of the
brachial artery, over which it lies.

An aneurysm of the abdominal aorta does not as a rule give

ANEUEYSM OF THE POPLITEAL AETEEY. 277

marked evidence of pressure symptoms except upon the sub-
jacent lumbar vertebrae and the nerves associated with them.
It tends to increase forwards, this being the hne of least
resistance.

The popliteal artery has the following anatomical peculiarities
which may explain the frequency with which it becomes the site
of a sacculated aneurysm. It is constantly being bent in flexion
of the knee, whereby a certain amount of strain may be thrown
upon it ; it derives little if any support from the surrounding
muscles and tendons, and it is close above a bifurcation.

The position of the vessel upon which an aneurysm forms
determines many of the characteristic signs caused by dilatation
of the artery and the pressure of the sac upon the surrounding
structures.

The first structure to be pressed upon is its accompanying
vein. The popliteal vein is the thickest vein of its size in
the body, but is the most adherent to its artery ; hence it
follows that pressure upon it soon leads to considerable oedema
of the limb on the distal side. The internal and external
popliteal nerves may be involved in the pressure, causing inter-
ference with their function, the pain frequently induced being
attributed to rheumatism. The popliteal surface of the femur,
the posterior ligament on the knee-joint and the upper part of
the tibia all come in for their share of pressure, and considerable
erosion may occur.

It must be remembered in connection with a popliteal
aneurysm that various swellings which occur in the popliteal
space may lie superficial to the artery and obtain thereby
communicated pulsation, which without careful differentiation
may lead to an error in diagnosis.

In the treatment of an aneurysm anatomical considerations
are of the greatest importance.

For an aneurysm situated in a limb there can be little doubt
that the ideal treatment is to ligature the artery upon which the
aneurysm is placed both on the proximal and on the distal sides
of the sac, and to dissect out the sac itself. This, however, may

278 CLINICAL APPLIED ANATOMY.

be a matter of considerable difficulty, seeing that the dilatation
ui)on the vessel so markedly alters the normal anatomical
relations. It may be under these circumstances by no means
easy to find the main vessel on the proximal or distal side of
the sac, and to apply the two needful ligatures to it. Again, the
accompanying vein (or veins) may be so closely applied to or
stretched out upon the aneurysmal sac that it is well-nigh
impossible to prevent injury to or even removal of the venous
channel. Hence it follows that gangrene may be almost invited
by the procedure required for the removal of the sac. The
remarks here given apply in a peculiar sense to a popliteal
aneurysm.

A very much more simple, and at the same time not infre-
quently efficacious, operation is to ligature the main artery
leading to the sac on the proximal side of the aneurysm. The
vessel may be ligated fairly close to the sac or at some distance
on the proximal side, the point chosen depending to a very great
extent upon the length of proximal artery available. The
operation of ligature of the artery on the proximal side at some
considerable distance from the sac is probably the better of the
two operations, and that for certain anatomical reasons. The
artery will here be in its normal anatomical relations, will be
less likely to be unsound, particularly in the matter of dilatation
of its coats, and will be readily separated from the veins in its
proximity. Further, ligature at this point will secure a freer
collateral circulation. Since the artery remains pervious from a
short distance below the ligature to the aneurysm, blood can
enter it by collateral anastomosis, and so eventually reach the
aneurysmal sac, but in a small stream and under diminished
pressure. Hence it follows that there will be a greater likelihood
of the clotting of the blood thus introduced into the sac, and so
a greater probability of cure. It will also follow that the opening
up of this collateral circulation will tend to diminish the
possibility of subsequent gangrene.

Where there is not room for a proximal ligature to be applied
to the artery feeding the sac, it may be advantageous to ligate

TEEATMENT OF ANEUEYSM. 279

either the main trunk on the distal side of the aneurysm, or
one or more of the branches into which it may divide. In order,
however, that success may follow such a procedure it is necessary
that there should be no large branch given off by the vessel
between the sac and the point at which the ligature is applied.
Perhaps nowhere in the body is this anatomical requisite so
evident as in the case of the common carotid. Supposing an
aneurysmal sac to be formed on the proximal part of the vessel,
a distal ligature will effectually prevent the passage of blood
beyond the aneurysm, seeing that there is no branch into which
it can pass. Another disadvantage of a distal ligature, particularly
as seen in the limbs, is the liability of gangrene following upon the
occlusion of the artery. In instances of subclavian aneurysm
in which there is little chance of applying a ligature upon the
proximal side of the sac with any degree of safety, a distal ligature
is apt to cause death of the limb beyond, or failure in bringing
about a cure of the aneurysm. Therefore it has been considered
advisable to as it were perform distal ligation, but at the same
time to remove the part which has to be supplied with blood, by
an amputation at the shoulder- joint.

Pressure has been known to cure many aneurysms, in fact it
may be one of nature's methods of bringing about the cessation
of the continued dilatation of the sac. From its anatomical
relation the aneurysmal sac may itself cause pressure upon the
artery feeding it on the proximal side, and thus diminish the
amount of blood passing into the sac, and so allow the deposition
of clot.

This proximal pressure has been carried out by the surgeon,
but as a rule at a greater distance away from the sac than the
spot at which nature applies it. Hence in a popliteal aneurysm
digital pressure is best applied to the last part of the external
iliac or the first part of the common femoral backwards against
the horizontal ramus of the os pubis. If such pressure by the
finger is carefully applied, the return of blood through the
femoral vein will not be interfered with — an advantage not
secured by the mechanical pressure of a tourniquet.

280 CLINICAL APPLIED ANATOMY.

Digital pressure upon the artery at this spot, should it fail to
bring about a cure of the aneurysm, has not in any way been a
disadvantage in view of a subsequent ligature. First of all the
vessel will not be tied at the point over which the digital pressure
has been applied, but at a more distal spot, either at the apex of
Scarpa's triangle or in Hunter's canal. Secondly, it will have
opened up the collateral circulation, and thus have diminished
the likelihood of gangrene subsequent to ligature. It is always
easy to diminish the amount of blood passing into a limb, but
difficult to increase it.

Varicose Veins.

It is not every vein in the body which is subject to varicosity,
but certain veins, chiefly from their anatomical position, are
prone to become varicose. The superficial veins of the lower
extremity, the spermatic veins, and the veins of the inferior
hsemorrhoidal plexus are those which most frequently undergo
the change which is termed varicosity.

Varicose Veins of the Lower Limb. — The anatomical reasons
why the superficial veins of the lower extremity are so commonly
varicose may be stated as follows : they have a long column of
blood to support, in the adult often as much as four feet, though
of course the weight is partly borne by the series of bicuspid valves
present within the vein ; their distance from the heart renders the
vis a tergo of the systole less powerful than elsewhere, and
distension likely ; and their want of support, owing to their
being surrounded merely by subcutaneous tissue and not by
muscle.

There are two chief varieties of varicose veins in the lower
limb. The first is that in which one vein, generally the long or
internal saphenous, is varicose. This vein commences from the
inner side of the venous arch on the dorsum of the foot, passes
then in front of the internal malleolus, up the inner side of the
leg, behind the internal condyle of the femur, along the inner
side of the thigh, to pass through the saphenous opening and
join the femoral vein close below Poupart's ligament.

VAEICOSE VEINS. 281

The whole length of the vein is supplied with valves, the last
of the series being usually just below the passage of the vein
through the saphenous opening. Hence it is that in some cases
of varicosity a fluid swelling is found in this region simulating
somewhat a femoral hernia. In varicosity the position of the
valves is frequently evidenced by the greater dilatation of the
vein opposite them. The pain felt is in some cases due to
pressure upon neighbouring filaments of the internal saphenous
nerve.

The short or external saphenous vein may also be alone
varicose. This vessel begins on the outer side of the dorsal
venous arch, passes behind the external malleolus, up the outer
and posterior part of the calf, to pierce the deep fascia in the
popliteal space and empty into the popliteal vein.

In the second variety, varicosity is not confined to the internal
or external saphenous, but affects almost the whole of the super-
ficial venous tributaries of the limb, including the radicles beneath
the skin. Ulceration of the skin is peculiarly liable to be
associated with this form of varicosity. It occurs typically in
the lower half of the leg, and usually close above the ankle and
on the inner side. This selection of position for the varicose
ulcer is probably due to the fact that the veins of the foot itself
are supported by the wearing of boots or shoes, but just above
the upper limit of the footgear much strain is thrown upon the
veins, considerable stagnation occurs, failure in the nutrition
of the skin results, and often precursory eczema puts in an
appearance. Then it has to be borne in mind that the lower
third of the leg is open to frequent injury, and once there is
abrasion of the congested skin staphylococci gain entrance and
play havoc with the part.

The exquisite tenderness of some varicose ulcers is due to the
exposure of the fine nerve terminations by the ulceration of the
surrounding tissues.

Copious haemorrhage sometimes occurs by the erosion of a
large vein, such as the internal saphenous, during the course of a
varicose ulcer. Whilst the limb is vertical the blood lost comes

282 CLINICAL APPLIED ANATOMY.

from the proximal portion of the vein, that is the long tube on
the cardiac side, and this is owing to the fact that the valves
have become incompetent because of the dilatation of the vein
without any corresponding increase in the size of the valve
itself. Hence it is that elevation of the limb tends to imme-
diately bring about the temporary cessation of the flow of blood.

The operative treatment of varicose veins in the lower limb
usually consists in the obliteration of lengths of the vein, so as to
force the blood to be returned by the deep veins, which have free
communication with the superficial. The operation of tying the
internal saphenous just below the saphenous opening has as it
were the effect of placing a competent valve high up, and of thus
cutting off the weight of the column of blood.

Varicocele. — Several anatomical considerations show the
reason why varicocele, and particularly left varicocele, is such a
common affection.

The blood supply of the testicle, entering through the spermatic
artery, is returned by the spermatic veins. These commence by
a number of venous radicles in the hilum of the testis and soon
form the pampiniform plexus in the anterior part of the cord.
Passing upwards through the superficial abdominal ring they
unite into a smaller number of veins in the inguinal canal,
and entering the extra-peritoneal tissue at the site of the deep
ring, they join to form the two venm comites of the spermatic
artery. On the right side, these unite to form a single vein
which opens into the inferior vena cava at an acute angle, at a
varying distance below the entrance of the right renal vein. On the
left side, the two spermatic vetue comites join to form a single
trunk which opens into the left renal vein at a right angle.

The length of the veins implies a considerable column of blood
to support. Valves are either wanting or very imperfectly formed,
probably owing to the fact that the vessels are in reality stretched
veins, the testis pulling them out in its so-called descent. There
is little or no external support in any portion of the length of the
vessels. The vis a tergo is slight, owing to the great length and
small calibre of the spermatic artery, in comparison with the large

VAKICOCELE. 283

sectional area of the veins. Moreover, the veins are tortuous,
and have many inter-communications, and there is possibly some
pressure exercised upon them by the action of the muscular
fibres forming the roof of the inguinal canal.

The greater liability of the veins of the left side to be affected
is often attributed to the following anatomical reasons. The
entrance of the left spermatic vein into the left renal vein at a
right angle, and the rush of blood from the kidney across the
mouth of the spermatic vein are supposed to produce an
obstruction to the upflow of the spermatic blood. This is dis-
tinctly questionable, for this cross current may act in the opposite
way, namely, to create a species of suction. The left testis
usually hangs lower than the right, and the left spermatic vein
terminates higher than its fellow, but the difference in length
between two venous channels is not sufficiently great to make
it a marked predisposing cause of left varicosity. The left vein
has the last portion of the sigmoid flexure in front of it, and in
cases of severe constipation it may be that pressure is brought to
bear on the vein by hard scybalous masses.

The true reasons probably for the frequency of varicocele on
the left side are that the veins in the left cord are usually larger
than those in the right, and there appears to be a persistence of
numerous foetal veins on the left, veins which disappear early in
life on the right side.

In exposing the spermatic veins for their ligature, for the
relief of varicocele, the vas closely accompanied by its artery and
veins will be readily demonstrated lying deep to the spermatic
vessels in the posterior part of the cord. The spermatic artery
cannot as a rule be distinguished, and is probably usually ligated
with the veins.

After ligature of the spermatic veins the blood from the testicle
is chiefly returned through the deferential veins, passing eventually
into one of the vesical plexuses.

CHAPTEE XIII.
DISEASES OF THE LYMPHATIC SYSTEM.

Lymphatic Vessels.

Lymphangitis. — It is only in the superficial lymphatic vessels
of the subcutaneous tissue that evidence of inflammation can be
discerned by the eye. These when inflamed appear as red
streaks owing to the peri-lymphangitis which accompanies the
affection. In some instances the distribution of the lymphatic
vessels is thus clearly marked out, and the skin then becomes
mapped with a fine network of reddened lymphatics. Owing to
their proximity to the surface, an induration caused by the
inflammatory products can occasionally be readily palpated,
and is very characteristic. Because of the same anatomical
relation, lymphorrhoea is seen from the ulcerations and fissures
of portions of skin affected with filarial and other obstruction
of the lymphatics.

The deep lymphatic vessels of the limbs commence in the
bones, periosteum, ligaments, muscles and inter-muscular con-
nective tissue, altogether beneath the deep fascia. It is on
this account that inflammation of these vessels seldom gives
evidence of its existence by signs superficial to the deep
fascia, as is well observed in the early stages of acute infective
periostitis.

The deep lymphatics within the abdomen, especially those
running between the layers of the mesentery and omenta, are
but little supported, and when there is any obstruction to the
onward flow of lymph in them easily part with their contents to
form an effusion in the peritoneal cavity, in the form of chylous
ascites.

Where lymphatics lie in loose connective tissue, as for example

LYMPHADENITIS. 285

in that of the eyelids, inflammation leads to very rapid infiltration
and very great swelling of the part.

Injuries to lymphatic trunks. — The thoracic duct rises well
into the neck on the left side, arching over the apex of the pleural
sac and the first part of the left subclavian artery. It is here
exposed to injury most frequently from operative procedures at
the lower part of the left posterior triangle of the neck. In a
fair proportion of cases the duct enters by more than one terminal
vessel into the junction of the left internal jugular and left
subclavian veins, and it is possible, therefore, for a wound to
involve only one division and thus cause but little trouble. In
the thorax the duct lies along the front of the bodies of the lower
seven thoracic vertebrae and then passes to the left side of the
upper five bodies. Here it has numerous communications with
the azygos veins, which is another reason why injury to the
main trunk in the neck is sometimes followed by a minimum of
inconvenience. Fracture of one or more thoracic vertebrae may
lead to damage to the duct. Injury to the receptaculum chyli,
as it lies upon the front of first and second lumbar vertebrae,
may occur during operations at this level of the abdomen, or
from gunshot-wounds.

Lymphatic Glands.

All lymphatic vessels either pass to or proceed from lymphatic
glands. These structures, therefore, filter lymph received by the
afferent vessels and transmit it afterwards through the efferent
vessels to the vascular system. Hence the great liability for
lymphatic nodes to suffer from the entrance and arrest of
improper substances circulating in the lymph stream.

Lymphadenitis — The Upper Extremity. — The fingers and
hand are provided with a very intricate and delicate reticulum
of lymphatic capillaries, so that even a pin prick must neces-
sarily open up many lymphatic spaces. Infection, therefore, of
the superficial lymphatics is very common, and resulting lympha-
denitis is extremely frequent. The lymph is conveyed from
the palm and dorsum of the hand by vessels which correspond

286 CLINICAL APPLIED ANATOMY.

fairly with the superficial veins. Those accompanying the
ulnar vein terminate in the supratrochlear gland, those with
the median in the antecubital glands, if they are present, while
most of those following the radial vein ascend to the axillary
nodes, except a few which, running with the cephalic vein, terminate
in the deep infraclavicular glands. It will thus be evident that
infection of the inner side of hand is apt to lead to lymphadenitis
of the supratrochlear gland, and suppuration here frequently
calls for treatment. Lymphangitis of the median set of lymphatics
should involve the antecubital glands, but suppuration in front
of the elbow joint is uncommon. Infection of any portion of the
rest of the skin of the upper extremity may lead to adenitis of
the outer set of the axillary lymphatic nodes. The supratrochlear
gland cannot be felt normally, but when it is enlarged it may be
readily palpated, but should not be mistaken for the ulnar nerve,
in front of which it lies. It can be easily distinguished by its
oval shape, and by its mobility in all directions, the nerve on the
other hand being elongated as a cord, and only moving from side
to side. Symmetrical enlargement of the supratrochlear glands
is often confirmatory evidence of constitutional syphilis.

The Loicer Extremity. — The same intricacy of the peripheral
lymphatic capillaries is seen in the lower extremity as in the
upper.

The lymph is conveyed from the foot by vessels which corre-
spond fairly to the superficial veins. Thus the short saphenous
vein is accompanied by lymphatic vessels passing from the heel
and back of the leg, and entering a gland close beneath the deep
fascia at the termination of the vein in the popliteal space.
This node may be the seat of inflammation in cases of blistered
heel. There are also some four or five glands deeply placed
along the popliteal vessels which may become secondarily involved
in septic conditions. Infections occurring on the toes, the
dorsum of the foot, the front and inner side of the leg, and
the whole of the thigh are apt to lead to lymphadenitis in the
groin, where there are situated two sets of lymph nodes. One,
the vertical set, near the saphenous opening, lying above the deep

CEEVICAL LYMPHADENITIS. 287

fascia, is that which is primarily concerned with the lower
extremity, and is affected in inflammations of the regions just
mentioned. They also receive lymph from the perineum, and the
inner portion of the buttock. The other, the horizontal set, lying
superficial to the aponeurosis of the external oblique muscle
above Poupart's ligament, is that which receives lymph from the
following parts — the inner glands from the external genitals of
both sexes, including all those structures lying superficial to the
symphysis pubis and the deep perineal fascia (thus it is here
that the common bubo resulting from venereal disease is seen),
the middle glands from the lower half of the abdominal wall, and
the outer glands from the buttock.

Cervical Region. — Perhaps no part of the body is more prone
to be the seat of lymphadenitis than the neck. There are numerous
sets of cervical glands, but it must be confessed that their arrange-
ment and the number of nodes in each is by no means regular
or constant. Still, certain groups can be made out, and a
knowledge of them is of great practical utility. Keviewing these
from above downwards, they may be given as anterior auricular,
posterior auricular, occipital, submandibular, sub-mental, super-
ficial cervical, deep cervical, retro-pharyngeal and supra-clavicular.
When a patient is seen with enlarged glands in the neck, the
region where these glands are placed should be an indication as
to the source from which the irritation causing their increase in
size has been derived. On the other hand when a patient presents
himself in whom there is some disease of the lips, the tongue,
the scalp, &c., which may lead to implication of the lymphatic
glands, it is needful to know which set to examine to determine
whether or not such involvement exists. Thus it is convenient
to review here the groups of glands and see where they derive
their lymph, and then under the various diseases to state to
which set the lymph passes.

The anterior auricular glands, situated in front of the ear, and
upon and within the substance of the parotid gland, derive lymph
from the frontal and the parietal portions of the scalp, and the
upper part of the face. The posterior auricular, placed behind

288 CLINICAL APPLIED ANATOMY.

the pinna of the ear, receive lymph from the auricle, and the
posterior part of the parietal region.

Some of the submandibular placed near the middle line are
called sub-mental and receive lymph from the lower lip, the chin,
and the floor of the mouth. The lymphatic glands placed in the
region of submandibular salivary gland are concerned with the
tongue, cheek, floor of the mouth and the mandible.

The deep cervical glands placed along the carotid sheath
derive lymph from the tongue, pharynx, tonsils, larynx, trachea
and oesophagus.

The retro-pharyngeal, present in children, are atrophic in
the adult. They drain lymph from the cervical portion of the
vertebral column, and the posterior aspect of the pharynx
proper.

The supra-clavicular glands in the lower part of the posterior
triangle of the neck derive secondarily, but sometimes primarily,
lymph from the anterior thoracic wall and the mammary gland.
Those on the left side may be involved in secondary deposit incases
of malignant disease of the abdomen and thorax through their
connexion with the thoracic duct.

CHAPTER XIV.

DISEASES OF THE DUCTLESS GLANDS.

The Thyroid Gland.

Enlargements of the thyroid gland are usually spoken of as
goitres. These may be of various kinds, such as parenchymatous,
cystic, adenomatous or malignant. The goitre of Graves's
disease is sometimes termed vascular, but this does not
accurately describe the condition. From whatever cause the
gland is enlarged, its anatomical relations have important bear-
ings on the position and movements of the tumour and the
symptoms it may produce. The almond-shaped lateral lobes with
their isthmus give a characteristic horse-shoe shape to the gland
which is retained in all instances of uniform enlargement. The
right lobe is larger than the left, and this normal disproportion,
being maintained in general enlargement, may lead to an
erroneous impression that the right lobe is more increased in
size than the left. A middle lobe may sometimes be detected,
passing upwards on the front of the larynx — this is the pyramidal
lobe which is usually attached to the hyoid bone by the fibrous
remnants of the thyro-glossal duct. The well-recognised clinical
facts that thyroid tumours follow the ap and down movement of
the larynx during deglutition, and also accompany it when moved
laterally, are accounted for by the investment of the gland
in a capsule which is derived from the deep cervical fascia and
closely attached to the larynx. This fascial capsule is fixed in
front to the anterior arch of the cricoid cartilage and also to the
lower borders of the alae of the thyroid cartilage. That part of
the capsule which invests the inner and back parts of the lateral
lobes also sends fibrous prolongations to the sides of the cricoid
cartilage. These prolongations are known as the suspensory

C.A.A. 19

290 CLINICAL APPLIED ANATOMY.

ligaments of the gland, and when it is enlarged may appear as
strong supporting cords. The recurrent laryngeal nerves lie in
close contact with the outer or posterior surfaces of these ligaments.
The arrangement of the capsule on the posterior aspect of the
gland is important. As the fibrous coating is traced from the
convex surface of each lateral lobe backwards it will be found to
split into two layers, one of which remains in close contact with
the gland, completing its posterior investment, whilst the other
passes to the posterior surface of the pharynx and oesophagus,
imprisoning those tubes together with the trachea in the hollow
at the back of the gland. This part of the capsule, being dense
and firm, forms a conspicuous object during operation, and if un-
wittingly followed backwards under the beUef that it is the imme-
diate posterior investment of the gland, may lead to the infliction
of wounds on the oesophagus or trachea which are enclosed by it.
Operations on the thyroid gland necessitate the opening up of
the planes of cervical fascia, so that is there is a liability to the
occurrence of cervical and mediastinal cellulitis as complications.

Of the muscles which cover the thyroid gland, the sterno-mas-
toids are most superficial. When the gland is enlarged, these
muscles are usually displaced outwards, so that the thyroid
tumour appears in the interval between them. Occasionally
the tumour presents at the posterior border of the sterno-
mastoid displacing the muscle inwards. The sterno-hyoid and
the sterno-thyroid muscles become flattened over the enlarged
gland and may occupy grooves on its surface. The tension
exerted on the omo-hyoid which also crosses the gland on its way
to the hyoid bone, may cause the posterior belly of the muscle to
form a prominent cord-like projection across the base of the
posterior triangle of the neck.

The vascular relations of the gland are important. There is a
rich plexus of veins immediately inside the capsule, and these it
is inadvisable to wound. On each side the gland is in immediate
relation with the carotid artery and internal jugular vein.
Enlargement of the gland usually tends to displace these struc-
tures outwards, but there is a great difference in the degree of

Thyroid Gland.

Stylo-hyoid liga
ment.

Crico-tliyroid
Sterno-thyroid

Isthmus,

Trachea

Epiglottis.

Body of hyoid
bone.

Thyro-hyoid
ligament.

Levator glan-
dulfe thyroidete.
Thyroid carti-
lage.

\^ Pyramidal pro-
m; — 7\ — cess of thyroid
•^ 1 body.

Left lateral lobe.

Fig. 38. — Thyroid body, with middle lobe and levator muscle.
(From Morris's Anatomy.)

Crico-arytenoideus
posticus.

Lateral bone of
thyroid gland.

Suspensory ligament
of the left side.

Recurrent laryngeal
nerve.

Fig. 39.— The suspensory ligaments of the thyroid body. (From Morris's
Anatomy, after Berry.)

[To face page 290.

GOITEE. 291

displacement of the artery and the vem. The vein is closely con-
nected to the gland by its thyroid tributaries, and the traction on
these to a great degree anchors the vein, causing it to be closely
applied to the surface of the lateral lobe or even flattened over it.
The artery is displaced without much restraint, for the superior
thyroid arteries are tortuous and long. The same description
applies to the inferior thyroid arteries which arise from the
subclavian artery.

The superior thyroid arteries approach the apices of the lateral
lobes whilst the inferior vessels enter the hilum which lies at the
inner and back part of the lateral lobe close to the recurrent
laryngeal nerves. It is advisable to ligature both the veins and
the arteries outside the capsule, since by so doing wounds of the
venous plexus are avoided, and the arteries are ligatured where
their coats are thick, for they become attenuated after piercing
the capsule. In addition, in the case of the inferior arteries
there is less risk of damage to the inferior laryngeal nerves.

In addition to the internal jugular, the anterior and external
jugular veins may be subjected to pressure and considerable
engorgement result. Occasionally also the right and left
innominate and the subclavian veins are compressed at the
root of the neck.

It is often difficult to distinguish pulsation of the thyroid gland
itself from pulsation communicated to it by the carotid trunks.
The pulsation of the enlarged superior thyroid trunks can some-
times be recognised also. Venous and arterial murmurs may
arise in the compressed veins and arteries.

The posterior border of each lateral lobe of the thyroid gland
is in contact with the spine and prevertebral muscles, and may
become fixed to these structures as the result of malignant
infiltration. Under similar circumstances the gland may envelop
the carotid artery without displacing it.

The posterior aspect of the gland is deeply concave, the whole
being moulded on the trachea and cesophagus. The recurrent
laryngeal nerves which lie in the sulcus between the trachea and
cesophagus, are included in the bay or hollow thus formed on

19—2

292 CLINICAL APPLIED ANATOMY.

the posterior surface of the gland. The left lateral lobe is
norraally in contact with a small portion of the front of the
oesophagus where that tube deviates somewhat to the left at the
root of the neck, whilst the upper extremities of the lateral lobes
may actually embrace portions of the larynx and pharynx.
Pressure on the oesophagus and dysphagia may thus result from
thyroid swellings.

The pressure exerted by the enlarged gland on the trachea is of
serious importance and may cause death. The trachea is usually
compressed laterally and not often antero-posteriorly. The
lateral compression is no doubt aided by the pressure exerted by
the sterno-mastoid and infra-hyoidean muscles which cross the
lateral lobes. The lateral compression is often associated with
a certain amount of lateral twisting of the trachea on its long
axis, and in unilateral enlargements of the gland the air tube
may be displaced towards the opposite side of the neck. Sub-
sternal goitres, being unable to enlarge forwards, compress the
trachea antero- posteriorly.

Signs of pressure on neighbouring nerve trunks may be present.
Alteration of the voice and various forms of laryngeal paralysis
may result from pressure on the recurrent nerves. Contracted
pupil, enophthalmos and narrowing of the palpebral fissure,
indicate pressure on the cervical sympathetic which lies at the
back of the carotid sheath. Numbness and tingling in the neck
or arm may be produced by pressure on the branches of the
cervical or brachial plexus. Irregularity of the heart is attributed
to vagus compression.

The close relation of the cervical lymph glands to the lateral
lobes of the thyroid gland gives rise to some difficulty in dis-
l tinguishing malignant or tuberculous enlargements of the lymph
glands in this position from actual disease of the thyroid.

The parathyroid bodies are difficult to recognise. Two of them
may sometimes be found amongst the terminal branches of the
inferior thyroid arteries, and the other two are usually situated
at the lower extremities of the lateral lobes.

MyxoBdema and cretinism are usually associated with atrophy

MYXCEDEMA. 293

of the thyroid gland. In those cases where the gland is enlarged,
its function is assumed to be in abeyance. It is not easy to form
a definite opinion as to the presence of thyroid atrophy by an
examination of the neck. The isthmus of the gland usually
crosses the second, third, and perhaps the fourth, rings of the
trachea. If these rings can be distinctly felt atrophy may be
assumed, but in some persons the isthmus is congenitally absent,
and in others, owing to its thick coverings, the trachea cannot be
satisfactorily palpated. The lateral lobes, as a rule cannot be
felt at all.

The general increase of bulk of the body in myxoedema is due
to changes in the skin and subcutaneous tissues. Where the
subcutaneous connective tissue is lax and abundant, the swellings
are most apparent. Hence swelling may be found in the eyelids,
face, submandibular region, the lower parts of the posterior
triangles of the neck, and the backs of the hands and feet.
Where the skin is firmly bound to the subjacent fascial
structures, as in the palms, soles and scalp, the swelling is
insignificant.

The swelling of the tissues of the limbs, by destroying the
elasticity of the skin around the joints, interferes with the flexion
movements of the elbows, wrists, fingers, and thighs. The finer
movements of the hand suffer in particular. The mucous mem-
branes as well as the skin are affected. The lips become stiff,
swollen and everted, the buccal mucous membrane projects
between the upper and lower teeth and is indented. The gums
are swollen, and the lax tissues of the soft palate become infil-
trated and interfere with the movements of deglutition and articu-
lation. The tissues of the vulva and vagina may be similarly
affected.

The epidermal appendages naturally suffer with the skin. The
hair follicles, the sweat and sebaceous glands become infiltrated
and destroyed. The nails may be cracked and furrowed, and
the teeth fall out. It is possible that the peripheral sense organs
are also involved.

The supraclavicular swellings of cretinism are by no means

294 CLINICAL APPLIED ANATOMY.

constant, nor are they restricted to this variety of the disease.
They may be met with in myxoedema and in association with
some goitres, and are due to prominence of the supraclavicular
fatty tissue. Their occurrence is favoured by the absence of
superficial muscles and other resistant coverings in the situations
where they are found.

The Thymus Gland.

Enlargement of the thymus is met with in very diverse
conditions. The chief of these are Graves's disease, rickets,
myxoedema, acromegaly, leukaemia, and lymphadenoma. In the
condition known as lymphatism, enlargement of the gland is
associated with increase in the lymphoid tissue of the pharynx,
bowel, and other parts of the body. The thymus may also be
the seat of inflammation, tuberculosis, and new growths. It is
important to bear in mind that wide variations in the size of the
gland occur. The older estimates of its weight appear to be
excessive. The average weight from birth up to the age of two
years is from seven to ten grammes (quarter to half an ounce).
After two, the gland remains stationary for some time, but a
rapid diminution, accompanied by degenerative changes, occurs
at puberty. Kemnants of the gland are present to an advanced
age.

Enlargement of the thymus is difficult to detect during life
owing to the position of the gland behind the manubrium and
upper part of the gladiolus. It may, however, give rise to the
following signs : Fulness at the root of the neck, venous engorge-
ment of the neck, dulness behind the sternum, cardiac irregularity
or dilatation, and dyspnoea. The fulness at the root of the neck
is due to the fact that both lobes of the gland are prolonged for
a short distance upwards along the sides of the trachea ; indeed,
the pointed extremity of each lateral lobe can be traced upwards
in the fully-developed foetus, under the lateral lobes of the
thyroid gland to the thyro-hyoid membrane. The venous
engorgement is explained by the relations of the left innominate

HYMUS IJLAND.

Seventh ring of trachea.
Right carotid artery.

Right subclavian artery.
Right innominate vein.

Thymus gland.
Vena cava superior.

Arch of aorta. -

Thyroid cartilage.

Central portion of crico-
thyroid membrane.
Crico-thyroid muscle.
First ring of trachea.

- 'J'hyroid body.

Ligament connecting
thyroid and thymus
bodies.

Left caiotid artery

Left subclavian artery.

Lobe of thymus passing
behind vein.

Left innonnnate vein.

Arch of aorta.

Fig, 40.— Thymus gland in a child at the age of two years showing some
important relations. (From Morris's Anatomy.)

[To face page 295.

ENLAEGBMENT OF THYMUS. 295

vein and superior vena cava to the back of the gland, where
they lie in grooves. Dulness over the manubrium is due
to the presence of the glandular mass immediately behind
the sternum, in the fore parts of the superior and anterior
mediastina. The gland reaches as low as the level of the fourth
costal cartilage, a rib below the position where the upper limit
of cardiac dulness may be expected in childhood. The cardiac
hypertrophy which has been found in some instances has been
attributed to compression of the ascending aorta or pulmonary
artery. Compression of the vagi has been held responsible for
certain irregularities of the heart's action. Dyspnoea is the most
important symptom of all. There is great diversity of opinion
as to the possibility of suffocation as the result of pressure by an
enlarged thymus. It is urged that many of the sadden deaths
which are attributed to suffocation are really due to syncope.
The anatomical arrangement certainly seems to favour the
possibility of tracheal compression when the gland is large.
The space between the back of the manubrium and the front
of the vertebral column measures little more than two centi-
meters (about seven-tenths of an inch), and is occupied by the
oesophagus, trachea, great vessels and important nerves. Even
if the size of, the gland be insufficient to cause much compres-
sion of the trachea with the head in the normal position, if the
neck be suddenly bent backwards the thymus and surrounding
structures are further dragged up into the narrow thoracic aper-
ture, and the trachea may be completely occluded. It is possible
that this sequence of events might occur during life, owing to
weakness of the flexor muscles of the neck, and the softness of
the infant trachea.

Tuberculosis of the thymus must be carefully distinguished
from caseation of the superior mediastinal glands, which are in
very close relation with the thymus. Careful dissection is
requisite to define the limits of the two structures. The tendency
of the lobes of the gland to break down into a fluid consisting of
lymphocytes has often given rise to an erroneous diagnosis of
suppuration. The investment of the gland by the anterior

296 CLINICAL APPLIED ANATOMY.

mediastinal fascia explains those instances in which inflammation
has spread to the gland as a sequel of pleurisy, pericarditis,
retropharyngeal and other abscesses in the neck, &c.

The thymus gland may be the site of epithelial, sarcomatous,
lymphatic, fatty or other tumours. In this connection it is
interesting to remember that it is developed as an epithelial
structure, derived from the dorsal part of the third visceral cleft,
represented in the adult by the space in front and on each side
of the epiglottis. Later the gland is transformed into lymphoid
tissue, whether by local growth or invasion from without is
doubtful. Epithelial remnants remain in the form of the
concentric corpuscles. The surrounding mesoblast supplies the
capsule and the connective tissue stroma of the gland. Hence
there are elements from which epithelial, connective tissue, or
lymphoid neoplasms may arise.

The Spleen.

Injuries of the spleen are not very common. The depth at
which the organ lies in the left hypochondriac and adjacent part
of the epigastric regions affords it protection. When enlarged
the spleen becomes much more superficial anteriorly, and is
liable to rupture by direct violence or vigorous muscular contrac-
tion. Normally the spleen lies under cover of the ninth, tenth,
and eleventh ribs of the left side. Its long axis corresponds with
the posterior part of the tenth rib, its posterior extremity lies an
inch and a half away from the spinal column, and its anterior
border reaches the mid-axillary line. It may be wounded when
the ribs under which it lies are fractured and their broken ends
driven inwards. Under such circumstances the diaphragm is
penetrated, and the left lung and pleural sac, which overlie the
spleen, may be damaged. The elasticity of the ribs and the
yielding nature of the abdominal wall may allow the spleen to
be severely crushed against the spinal column and lacerated
without the occurrence of fracture or external bruises. The
liver is often lacerated at the same time as the spleen. The

ENLAEGEMENT OF THE SPLEEN.

297

o;reat vascularity of the spleen, due to the presence of numerous
thin-walled blood sinuses, explains the profuse and often fatal
haemorrhage which results from ruptures and penetrating
wounds. The anatomical relations of the organ sufficiently
explain why penetrating wounds are often complicated by
injuries to the pleura, lung, diaphragm, stomach, colon or

superfic. area

deep area of spleen

mid. ax fine

lower border, lun

splen. flex, colon

spleen
nth rib

12th rib

left kidney

Fig. 41.— The Position and Relationships of the Spleen. The Deep

AND Superficial Areas of its Diaphragmatic Surface are exposed.

(^Hughes and Keith.')

kidney. The greater sac of the peritoneum is of necessity
opened by such injuries.

Enlargement of the spleen varies much in degree, and is met
with in very diverse conditions. If the increase in size is very
great, inspection may reveal the outline of part of the organ
below the left costal margin, extending in the direction of the
umbilicus. An enlarged spleen takes this direction by virtue of
its surroundings, for its convex surface lies against the resistant

298 CLINICAL APPLIED ANATOMY.

ribs, its renal surface is well supported by the left kidney, and its
anterior extremity rests on the phrenico-colic fold. Consequently
the organ is enlarged in the direction of least resistance, which is
downwards, forwards, and inwards. If the phrenico-colic fold
is unusually well developed its resistance may cause the main
enlargement to take place in an upward direction, whilst if the
fold is insignificant or yields to pressure, the spleen may drop
directly downwards instead of being directed obliquely forwards
towards the umbilicus. By palpation the margin of an enlarged
spleen may be felt below the left costal margin. In infants the
spleen is felt much farther back than in adults, probably on
account of the greater mass of the liver in childhood. The
presence of the notches serves to distinguish the spleen from an
enlarged kidney. The latter, with which splenic enlargements
are often mistaken, possess a more rounded outline, and is not
notched. Another point of distinction is the fact that a large
kidney must first fill the loin, this being the position in which it
lies, whilst a large spleen presents itself anteriorly, for the
reasons mentioned above. But a very large spleen may ultimately
encroach upon the loin, and an enlarged kidney may ultimately
present anteriorly, just above the umbilicus. The spleen lies in
close contact with the diaphragm, and so shares in the respiratory
movements, unless fixed by adhesions. The kidney is also in con-
tact with the diaphragm, and so descends slightly on inspiration ;
this descent is exaggerated when the organ is enlarged.

The intervention of the lung above, the presence of the
stomach and colon in the immediate vicinity, and the thickness
of the muscular wall of the loin, much diminish the value of
percussion as a means of determining splenic enlargement.

A large spleen may exercise pressure on the diaphragm, and
so hamper the respiratory movements and induce partial collapse
of the base of the left lung. It may also exercise pressure on
the adjacent stomach or colon. Conversely collections of air or
fluid in the left pleural sac, emphysema of the lung, or intra-
thoracic tumours may cause depression of the spleen, and a
sul)-diaphragmatic abscess may have the same effect.

WANDEEING SPLEEN. 299

Infarctions of the spleen may be due to embolism or
thrombosis of the splenic artery. The terminal branches of
this artery have only a capillary connection with each other.
When they are occluded a conical area of splenic tissue under-
goes necrosis. The base of the cone is applied to the splenic
capsule, and the apex is directed towards the hilus. A thin
stratum next the capsule sometimes escapes necrosis, being
nourished by capsular branches. Splenic infarcts are usually
white, but occasionally they are red with blood which
regurgitates into them from vessels in their neighbourhood.

Passive congestion of the spleen is due to increased pressure
in the portal area. The splenic vein is a tributary of the portal
trunk, and when this trunk is obstructed in any way enlarge-
ment of the spleen may result. The intimate connexion of the
spleen with the portal system explains the rapid diminution in
the size of splenic tumours, which may be brought about as the
result of diarrhoea.

A wandering spleen is uncommon. The organ is occasionally
found in regions very remote from its normal situation. It may
become fixed in its new positions and cause considerable diffi-
culty in diagnosis. The condition is sometimes a part of general
visceral prolapse. The wandering spleen has a pedicle formed
by the gastro-splenic omentum and lieno-renal ligaments, with
the included vessels. Occasionally the tail of the pancreas
retains its connexion with the organ, the whole gland becoming
elongated and twisted. The pedicle of a wandering spleen may
become twisted and produce acute symptoms. The splenic
vessels in their normal condition are well supported at the back
of the abdomen, but when the spleen is loose or enlarged they
are subject to traction and may show signs of endarteritis, or
small aneurysms of the splenic artery may occur. Communi-
cation between the artery and vein has been described, pro-
ducing the characteristic murmur of arterio-venous aneurysm.
Thrombosis also results occasionally.

Accessory spleens are very common in the gastro-splenic
omentum and other peritoneal folds connected with the organ.

300 CLINICAL APPLIED ANATOMY.

They may undergo compensatory enlargement when the operation
of splenectomy has been performed. They sometimes form the
starting point of tumours, and have been found embedded in the
tail of the pancreas.

Abscess of the spleen is usually of embolic origin, but may
invade the viscus from without. Primary abscesses may rupture
into the left subphrenic space in which the spleen lies, or may
discharge into the stomach, colon, or left pleural sac. An ulcer
of the stomach may become adherent to the gastric surface of
the spleen and give rise to a local abscess.

The Suprarenal Bodies.

Addison's disease is nearly always due to tuberculosis of the
suprarenal bodies. The infection is usually secondary to a lesion
elsewhere and conveyed to the glands by the blood. The vascular
supply to the suprarenals is very free, there being no fewer than
three capsular arteries supplied to each. Since both bodies lie
in contact with the spinal column, from which they are only
separated by the crura of the diaphragm, it is not surprising
that tuberculous caries of the lower dorsal and upper lumbar
spine sometimes invades them by contiguity.

The semilunar ganglia and the solar plexus of the sympathetic
are intimately connected with the suprarenals and may be involved
by the spread of inflammation from them. At one time the
symptoms of Addison's disease were exclusively attributed to
implication of these nervous structures.

The receptaculum chyli is separated from the right suprarenal
by the crus of the diaphragm, but there is no distinct evidence
of obstruction to the lymph flow in Addison's disease.

A solitary thin-walled vein emerges from each capsule. That
from the right passes directly into the inferior vena cava ; that
from the left pours its contents into the left renal vein. The
efferent lymphatics accompany the veins and terminate in glands
adjacent to the aorta. A few lymphatics perforate the crura
of the diaphragm ending in small glands between the crura and

ADDISON'S DISEASE. 301

the spinal column. It is possible that obstruction of the venous
and lymphatic trunks may produce the characteristic symptoms
in those cases where disease of the suprarenals is said to be absent.
Tuberculous peritonitis sometimes complicates Addison's disease,
and may in some instances spread direct from the capsules. A
part of the right suprarenal is in contact with the greater sac
and a part of tlie left with the lesser sac. Tuberculosis some-
times spreads directly, from the right capsule to that part of the
liver which is in direct contact with it.

The small yellow fatty collections which normally occur in the
cortex of the suprarenal bodies must not be mistaken for tubercles.

The cutaneous pigmentation of Addison's disease is due to
infiltration of the cells in the Malpighian layer. In the mucous
membranes the pigment is said to be more superficial. Those
mucous membranes which from their position are subject to
friction or irritation may be the site of the pigmentary deposits.
A bluish stain may be seen where the margins of the lips come
into contact. Brown smears occur on the inner sides of the
cheek and lips where these touch the teeth. The sides and tips
of the tongue may be pigmented for the same reason. Pigmen-
tation may sometimes occur in the mucous membrane of the vulva
and vagina. Pigmentation of the skin occurs chiefly in exposed
parts, such as the face and backs of the hands. It is also evident in
parts which are naturally pigmented and those which are exposed
to friction, pressure or irritation. The natural pigmentation of
the anterior axillary folds, areolae of the nipples, lower part of
the abdomen, groins, penis, scrotum and perineum may be
exaggerated. The friction of yokes, waistbands, garters and
corsets may determine deposits of pigment, and the same may
be seen in parts which have been irritated by blisters. Scars
as a rule escape.

Accessory suprarenal bodies of small size are not uncommon.
Occasionally they are found embedded in the cortex of the kidney.
They have also been recognised in the broad ligaments and
spermatic cord, having been carried down from the neighbourhood
of the Wolffian body by the descent of the ovary or testis.

302 CLINICAL APPLIED ANATOMY.

Primary tumours of the suprarenal bodies may be carcino-
matous, sarcomatous and possibly gliomatous. The central part
of the suprarenal is derived from an ingrowth of the abdominal
sympathetic, and this may account for the presence of gliomatous
elements. The cortical part is developed within the Wolffian
ridge. The epithelial and connective tissue elements of this may
give origin to the other varieties of new growth mentioned.

Malignant tumours of the suprarenals lie high in the abdomen
and may from their position simulate tumours of the liver,
kidney or pancreas. The tumours are adjacent to the inferior
vena cava, the suprarenal and the renal veins, which they may
invade. Extension may occur from the right suprarenal into the
liver. Growths on either side may invade the adjacent kidney,
and if they open into its pelvis may be a cause of hsematuria.

The Pituitary Body.

Acromegaly, a condition characterised by overgrowth of the
tissues of the extremities, and allied to gigantism, is generally
associated with enlargement of the pituitary body The enlarge-
ment may be simple or malignant. As a result, the sella turcica
is enlarged and in part absorbed. The olivary and clinoid
processes may disappear. The sphenoidal air cells may be
opened up, or the base of the fossa entirely destroyed. The
cavernous sinus and Gasserian ganglion have been invaded.
Characteristic alterations in the visual fields arise from pressure
on the optic commissure, which lies in front of the stalk of the
pituitary body. As a result bitemporal hemianopia may be met
with, or a more general contraction of the fields may occur.

COMPLIMENTS
OF

F. Elaklston's Son Co.,

% PA.

•* W •* v •' V i ;

Opknings into the Nasal Cavity.

Frontal air sinus.

Rod in infundi
bulum.

Sphenoidal air

•••SiiCi-^---^ sinus.

Ai)erture of nasal duct
into inferior meatus.

Cut margin
of lower
turbinate.

Fig. 42. — Dissection to show openings into the nasal cavity. (After Edward Taylor.)

[To face page 303.

CHAPTEK XV.
DISEASES OF THE EESPIEATOEY SYSTEM.

Nose and Naso-Pharynx.

Rhinitis. — The air which is inspired through the anterior
nares, across the nasal cavities, and by the posterior nares into
the naso-pharynx, is passed over a large surface covered with
mucous membrane. This membrane secretes mucus upon which
should be deposited all solid particles, including bacteria, floating
in the air ; hence the liability of the upper part of the respira-
tory tract to infection and inflammation. This power of the
nasal mucous membrane to catch undesirable material is very
well demonstrated in towns during a fog.

The many accessory air cavities communicating with the nose
may one or all become the site of infection by extension. The
infundibulum, ending in the middle meatus, passes upwards into
the frontal sinus, and the frontal headache so frequently present
with a " cold in the head " indicates inflammation of the mucous
membrane lining this air cavity. From the middle meatus, also,
micro-organisms may pass through the small aperture into the
antrum of Highmore, and may occasionally give rise to an
empyema therein. The posterior ethmoidal and sphenoidal
sinuses are sometimes infected through their openings into the
superior meatus.

It is worthy of notice, also, that infection may pass directly
along the branches of the olfactory nerves, through the cribriform
plate of the ethmoid bone, into the interior of the cranium, there
to set up a septic meningitis. In like manner the thin bony
walls of the ethmoidal and sphenoidal sinuses may be eroded,
and the overlying dura mater attacked.

The close proximity of the cranial cavity to the nasal fossae

304 CLINICAL APPLIED ANATOMY.

explains the ready manner in which a sharp pointed instrument
introduced into the nostril may pass through the thin bone
forming the base of the skull in this region, and carry with it
septic material.

Foreign Bodies in the Nostril. — The difficulty of extracting
foreign bodies introduced into the nose arises from the follow-
ing anatomical facts : — First, the irregularity of the walls of
the cavity ; secondly, its many recesses ; and thirdly, the swelling
of its mucous membrane as a result of the irritation and inflam-
mation produced by the body. For these reasons it is sometimes
more easy to push the imprisoned substance backwards into the
pharynx than to draw it forwards through the anterior nares.

Polypi. — The ordinary mucous polypi, or oedematous fibromata,
are usually the result of chronic inflammatory changes in the
mucous membrane of the ethmoidal region, and spring from
that portion of the membrane over the superior and middle
turbinate bones. Their presence tends to block the nasal cavity,
and they enlarge in the line of least resistance — that is, down-
wards and forwards — until they may even protrude through the
anterior nares.

Septal Deviations. — The bony and cartilaginous septum of the
nose is hardly if ever absolutely in the middle line, but it is only
when the degree of divergence from the perpendicular plane is so
great as to cause a considerably increased space in one nasal
cavity at the expense of the other that any real significance in
the condition arises. The obstruction to the passage of air on the
side to which the septum is deviated may be so great that it is
well nigh impossible to pass a probe along it, and hence an
operation becomes necessary.

Adenoid Growths of the Naso-pharynx. — The uppermost part
of the ring of adenoid tissue about the naso-pharynx and the
fauces is very frequently the site of hypertrophy, in the form of
pedunculated masses. These constitute the so-called " adenoid
growths." The pharyngeal tonsil, situated in the mucous
membrane forming the roof of the naso-pharynx between the
two Eustachian orifices, is not infrequently chronically enlarged

LAKYNGITIS. 305

and aids in the obstruction of the airway. The position of the
funnel-shaped aperture of the Eustachian tubes on the lateral
walls of the naso-pharynx explains the frequency of the extension
of inflammation to the mucous membrane lining the tubes.
Normally the cilia of the epithelium covering the membrane
work towards the naso-pharynx, carrying secretions away from
the tympanum and preventing the entrance of bacteria into that
cavity.

The interference with nasal respiration caused by adenoid
vegetations produces typical, and not infrequently serious,
deformities. The nostrils and the nasal cavities may continue
small and ill-developed from want of full use, and the arch of
the palate remains higher than normal, with a tendency to
crowding, and frequently misplacement, of the incisor teeth.
The thoracic walls, from insufficient expansion, become con-
siderably altered in shape, and exhibit a characteristic circular
depression at the junction of the lower and middle thirds from
the traction of the diaphragm and atmospheric pressure, whilst
the upper part of the cavity seems to be abnormally enlarged.

Larynx.

Congenital malformations of the larynx are rare, but the
exaggeration of the normal peculiarities of the infantile larynx
is the basis of the condition known as congenital laryngeal
stridor. In these cases the epiglottis is much folded on itself
vertically and the aryteno-epiglottidean folds are closely approxi-
mated. During inspiration the sides of the laryngeal aperture
tend to be sucked inwards, and obstruction with a stridulous crow
results.

Catarrhal Laryngitis. — The larynx, owing to its proximity to
the nose, mouth and pharynx, is exposed to air-borne infection,
to the action of irritant vapours, and to injury during the swallow-
ing of corrosive fluids or rough solid bodies. The continuity of
its mucous membrane with that of the fauces explains the spread
of inflammation from the nose or throat. The laryngeal mucous

C.A.A. 20

306 CLINICAL APPLIED ANATOMY.

membrane being freely supplied with sensory nerves, laryngeal
spasm may be the result of catarrhal inflammation.

(Edema of the larynx may be inflammatory, when it is either
infectious or traumatic, or a passive oedema of local or general
origin. It is most marked in situations where there is the most
submucous tissue, i.e., the aryteno-epiglottidean folds, the false
cords, the ventricles, and the laryngeal aspect of the epiglottis.
(Edema of the true cords is unknown, there being no loose con-
nective tissues in this region. (Edema may cause considerable
obstruction of the upper laryngeal aperture, and this is especially
apt to be the case in childhood, since the larynx is then small.
The laryngeal opening lies on the anterior wall of the pharynx,
consequently when cedema interferes with its proper closure
during deglutition, choking may occur, and at the same time pain
may be experienced if the swelling is of inflammatory nature.

Foreign Bodies in the Larynx. — Many large foreign bodies,
such as a bolus of food, obstruct the superior aperture of the
larynx without entering its cavity. A small foreign body, having
passed the upper strait, falls upon the edge of the true vocal
cords, thereby causing sudden closure of the glottis. It may
thus be immediately ejected. On the other hand, it may be
forced into one of the ventricles of the larynx, or when the rima
glottidis is opened, it may slip through during inspiration and drop
into a bronchus. Sharp bodies, if they reach the interior, are apt
to stick in the mucous membrane of the upper half of the larynx.

Malignant disease of the larynx usually occurs as squamous-
celled carcinoma. The greater part of the laryngeal mucous
membrane is covered with columnar ciliated epithelium, but on
the true vocal cords the epithelial covering is squamous.
Squamous epithelium also lines the vestibule or upper sub-
division of the laryngeal cavity, the transition to columnar cells
occurring at the widest part of the epiglottis in front, and a line or
two above the false cords at the sides. Patches of squamous
epithelium are also found on the inner surfaces of the arytenoid
cartilages, and at the free borders of the false cords.

New growths of the larynx are usually primary, but may extend

CAECINOMA OF THE LARYNX. 307

to it from neighbouring parts. Owing to the virtual isolation of
the laryngeal lymphatic system, laryngeal neoplasms never arise
as metastatic deposits.

From a clinical standpoint carcinomata of the larynx are
divided into two classes, extrinsic and intrinsic. The extrinsic
varieties may arise on the posterior surface of the cricoid carti-
lage, in the arytenoid region, the aryteno-epiglottidean folds or
on the posterior surface of the epiglottis. Intrinsic carcinomata
usually arise from the posterior parts of the true cords, but may
spring from the false cords, the ventricles of the larynx, or the
subglottic region.

The commonest site of extrinsic carcinoma is the back of the
cricoid cartilage, whilst intrinsic cancer, as just mentioned,
usually arises from the vocal cords. Both these localities may
be considered subject to friction and irritation, the back of the
cricoid during deglutition, and the vocal cords during phonation.

The anatomical justification for the classification given above
is found in the arrangement of the laryngeal lymphatics. The
supraglottic region, the site of extrinsic carcinoma, is provided
with a rich lymphatic network which is densest where the
mucous membrane is thickest, and is in some degree continuous
with the lymphatics of the pharynx and back of the tongue.
The lymphatics of the glottic and subglottic regions, positions in
which intrinsic carcinomata originate, are more scanty, and in
the true cords are, for all practical purposes, non-existent. The
subglottic network communicates in some measure with that of
the trachea. The lymphatics of one-half of the larynx com-
municate freely across the posterior median line, but not at all
freely anteriorly. Extrinsic cancer, guided by the course of the
lymphatics, tends to spread towards the upper parts of the
larynx and the pharyngo-laryngeal region. It may perforate the
posterior part of the thyro-hyoid membrane near the exit of the
lymphatic trunks. Early glandular enlargement is the rule, and
the first to suffer is often a small gland on the thyro-hyoid
membrane. Extension downwards in the region of the vocal
cords is very slow.

20—2

308 CLINICAL APPLIED ANATOMY.

Intrinsic cancer, on the other hand, is of slow growth, and
glandular infection is rare. The growth tends to spread round
to the opposite side or to the subglottic region rather than
upwards.

The connexion between the lymphatics of the epiglottis and
the base of the tongue affords an explanation of the tendency of
cancer of the epiglottis to infect the tongue base.

The lymph glands beneath the sterno-mastoid muscle are those
which finally receive the lymphatic of the larynx. These glands
communicate below with the supra-clavicular, but not with the
mediastinal groups. The efferent lymphatics of the supraglottic
area reach the glands by perforation of the lateral part of the
thyro-hyoid membrane. Of the subglottic lymphatic trunks,
some pierce the thyro-hyoid membrane and others emerge
between the cricoid cartilage and the trachea. On their way to
the lower glands beneath the sterno-mastoid, the subglottic
lymphatics may traverse small glands on the front of the
larynx and trachea and along the course of the recurrent
laryngeal nerves.

Of the clinical symptoms, hoarseness is easily explained by
involvement of the vocal cords. Dysphagia is naturally most
marked when the epiglottis or posterior part of the cricoid
cartilage is invaded. The radiation of pain to the neck and ear
is due to reflection along the superior laryngeal nerve to the
auricular branch of the vagus. Laryngeal paralysis is of
complex origin, but in some instances may be due to involvement
of the motor filaments of the recurrent laryngeal nerve.
Laryngeal anaesthesia is due to the implication of the sensory
branches of the laryngeal nerves.

The Bkonchi and Lungs,
bronchiectasis.

The bronchi which have a descending course are more likely
to become dilated than those which pass upwards, since

BEONCHIECTASIS. 309

secretions are more likely to stagnate in them. The direction of
the larger bronchial branches of both upper lobes and of the
right middle lobe is outwards, upwards, and forwards, whilst
those of the lower lobes of both lungs pass downwards, inwards,
and backwards. Consequently it is usual to find bronchiectasis
limited to the lower and middle portions of the lungs, whilst the
upper lobes, and particularly the territory of the vertical apical
bronchi, escape. The greater length and narrowness of the
bronchi of the left lower lobe may account for the greater
frequency of bronchiectasis of the left side.

Since the connective tissue sheaths of the bronchi are
continuous with the lobular septa of the lungs, and these septa
in turn fuse with the visceral pleural envelope, it is evident that
obliteration of the pleural cavity by adhesions will permit the
inspiratory movements of the chest to make centrifugal traction
on the bronchi. If these tubes are weakened by inflammation
the traction may induce dilatation. It appears, however, that
pleural adhesions are not at all common in the early stages of
bronchiectasis, many cases of which originate in childhood as
sequels to the lung inflammations of measles and of whooping
cough.

Dilatation of bronchi is, in some instances, due to pressure on
the roots of the lungs. The left bronchus being in intimate
relation with the oesophagus, the aorta, and the bronchial glands,
pressure on this tube is usually due to aneurysm, malignant
disease of the oesophagus, or glandular swellings. The right
bronchus is in relation with the back of the ascending aorta and
the bronchial glands, so it is liable to pressure from an aneurysm
or from glandular enlargements. Extreme dilatation of the left
auricle in mitral stenosis has been known to cause compression
of the left bronchus.

A foreign body lodged in a bronchus is sometimes the cause of
bronchiectasis. There is some difference of opinion as to whether
foreign bodies are more frequent in the right or the left bronchus.
The right bronchus is the larger, and it would be expected that a
small body would either fall directly into it, or, on account of the

310 CLINICAL APPLIED ANATOMY.

deviation of the trachea to the right in the thorax, would
strike the left wall of the tube and rebound into the right
bronchus. The lung signs produced depend upon the point
of lodgment of the foreign body. The body, if small, may
slip past the bronchus of the upper lobe, and this is more
likely to occur on the right side owing to the greater size of
the main bronchus. Under such circumstances the upper lobe
will remain unaffected.

The relation of the main or stem bronchi to the chest wall is
of some interest in connection with bronchiectasis. They
commence at the bifurcation of the trachea, and passing down-
wards and backwards, terminate for all practical purposes at the
level of the eighth ribs. The bifurcation of the trachea lies to
the right of the mid-line at the level of the disc between the
fourth and fifth dorsal vertebrae. This point corresponds in
level to the fourth dorsal spine posteriorly, and to the junction
of the second right costal cartilage with the sternum in front
(level of the sterno-manubrial joint). The stem bronchi become
so small as to be negligible at the level of the eighth ribs
posteriorly, the right two inches and the left three inches from
the spines of the vertebrae. Viewed from the front of the thorax,
these terminal points correspond to the right fifth rib in the
parasternal line, and the corresponding rib on the left side just
internal to the nipple line.

In children, the trachea bifurcates opposite the third costal
cartilage in front and the terminations of the stem bronchi reach
the same ribs as in the adult, but at half the distance from the
vertebral spines.

The points at which the branches to the upper lobes arise can
be found by measuring downwards along the lines of the stem
bronchi. The eparterial bronchus, which supplies the right
upper lobe, arises one inch below the bifurcation of the trachea,
whilst the bronchus to the left upper lobe is two inches below the
bifurcation.

The middle lobe of the right lung is solely supplied by the first
right ventral hyparterial bronchus.

BEONCHITIS. 311

BEONCHITIS AND BRONCHO-PNEUMONIA.

The mucous membrane of the bronchi being continuous with
that of the nasopharynx and fauces, bronchitis may arise by
extension of infectious processes from above. Air-borne
irritants have direct access to the air tubes, and in certain
conditions particles of food from the pharynx may be aspirated
into the respiratory passages. The air tubes are supplied with
blood by the bronchial arteries, whilst the pulmonary arteries
distribute blood to the terminal bronchioles and the alveoli. The
bronchial arteries differ from the pulmonary in that they are
subject to vaso-motor control, consequently vascular changes
may be induced in the bronchi by a variety of reflex causes.
Lastly, the bronchial arteries, as part of the general vascular
system, may themselves carry infection to the bronchi, and this
explains the occurrence of generalised bronchitis in certain of the
infectious diseases.

An impervious basement membrane lies beneath the epithelial
layers of the bronchi, and this membrane probably plays an
important part in the course of bronchitis. Leucocytes and
foreign particles cannot penetrate it, as it is not traversed by
lymphatics ; consequently such particles and the secretions of
bronchitis are not absorbed but are passed upwards by the
ciliated stream and expectorated.

The walls of the lobular bronchioles are thin and their lumina
are small. Inflammatory affections of these parts tend to assume
a suffocative character and to spread to the air cells, giving rise
to broncho -pneumonia. Although there is no lymphatic absorp-
tion from the bronchi, absorption can take place from the alveoli
and air cells.

The bronchial veins play practically no part in returning blood
from the lung, as at the most they only drain the tissues of the
root. All the blood from the lung is returned by the pulmonary
veins, and consequently is poured into the left auricle of the heart.
Hence there is an anatomical reason for the early occurrence of
passive pulmonary congestion in association with diseases of the

312 CLINICAL APPLIED ANATOMY.

mitral valve. When bronchitis is accompanied by emphysema
a considerable area of pulmonary capillaries disappears. The
capillaries are derived from the pulmonary arteries which supply
the alveoli, hence the pressure is raised in these vessels, so
hypertrophy and dilatation of the right ventricle result.

The lungs of infants and young children differ markedly from
those of adults. In early life the interstitial tissue forms a con-
siderable part of the lung and is highly vascular ; the alveoli are
comparatively small and thick walled, and the extent of the
bronchial tubes is proportionately greater than that of the air
spaces. Consequently the breath sounds are not damped by the
pulmonary parenchyma to such an extent as in the adult, but
are harsh or even bronchial, and may give rise to a suspicion of
broncho-pneumonia when none is present. In children, as a
consequence of the anatomical conditions, vascular distension
and interstitial infiltration form a marked feature in broncho-
pneumonia, the small alveoli are much more easily plugged, and
pulmonary collapse is readily induced by trivial inflammations.
The yielding character of the chest wall in infancy, and the
feeble respiratory movements, also contribute to the production
of collapse of the lung.

LOBAR PNEUMONIA.

A knowledge of the relations of the fissures of the lungs to the
back, sides and front of the chest is essential for the determina-
tion of the site and the extent of the lesion in lobar pneumonia.

The great fissure, which separates the upper lobes of the lungs
from the lower parts, extends from the second dorsal spinous
process across the infraspinous fossa of the scapula, traverses the
axilla near the fourth rib, and terminates in front close to the
sixth costal cartilage near the parasternal line. The other parts
of this great fissure lie on the inner surface and base of the lung,
and, consequently, cannot be indicated on the surface of the
chest. If the elbow on the side examined be well raised above
the level of the shoulder, and the palm of the hand carried over

PNEUMONIA. 313

the opposite shoulder and applied to the spine of the scapula of
that side, the other scapula becomes so tilted that its vertebral
border practically corresponds in position with the great fissure of
the lung.

The transverse fissure of the right lung, which separates the
middle from the upper lobe, extends from the middle point of the
great fissure to the vicinity of the fourth costal cartilage near the
sternum.

At the back of the chest, the upper and lower lobes of the
lungs can be examined. In the axilla, the upper, middle and
lower lobes of the right side are accessible, and the upper and
low^er lobes of the left. In front, on the right side, the upper,
middle and very small part of the lower lobes are superficial ; on
the left the upper and middle lobes.

Just internal to the lower part of the vertebral border of the
scapula is a thinly covered portion of the chest wall. This area
is sometimes known as the triangle of auscultation, and lies over
the middle part of the lower lobe of the lung. Its boundaries
are the outer border of the trapezius, the lower border of the
rhomboideus major, and the upper border of the latissimus dorsi,
just before that muscle crosses the angle of the scapula. Over
this triangle the breath sounds are very distinct, and lung
resonance is easily obtained.

High in the axilla, over an area corresponding to the first and
second intercostal spaces, the upper lobe of the lung is very
thinly covered, and the physical signs of apical pneumonia are
often first discovered in this situation.

Pneumonia does not always involve a complete lobe, and so
the outlines of the diseased area may not sharply correspond
with the fissures of the lung ; it is not uncommon to find a lower
lobe completely consolidated and the lobes adjacent only partly
invaded. Pneumonia, too, renders the affected lobe more bulky,
and often induces partial collapse of the lobe immediately
adjacent, this must be borne in mind in attempting to
accurately localise the mischief. The visceral layer of the
pleura nearly always shares in the inflammation, and, since the

314 CLINICAL APPLIED ANATOMY.

pleural layers of the fissures are in close contact, they are easily
agglutinated by pneumonic inflammation. Localised empyemata
may form in a fissure thus sealed up.

Sometimes the pericardium is involved as well as the pleura,
but it by no means follows that this is always an invasion from
the adjacent lung. In some epidemics mitral and aortic endo-
carditis are associated with the lung disease, these are the first
valves which come into contact with blood returned from the
lungs, and this, together with the occurrence of complications in
other parts of the body far distant from the lungs, must be
attributed to blood infection. Delirium, meningitis, arthritis,
albuminuria, nephritis, enteritis, and peritonitis may be cited as
examples of this.

Obstruction to the circulation in the consolidated lung natur-
ally throws a strain upon the right ventricle, which, being at
the same time poisoned by the toxaemia, may undergo rapid
dilatation.

Pneumonia being a disease of the alveoli and the contiguous
structures the whole of the exudation in the lung may be absorbed
and carried away by the lymphatics with which the alveoli are
supplied, and none expectorated. This contrasts strongly with
what occurs in bronchitis where lymphatics play little or no part
in getting rid of the secretion.

PULMONARY PHTHISIS.

The channels by which infection may reach the lung, and the
methods of dissemination in that organ, have been pointed out in
the section on tuberculosis. Attempts to account for the primary
localisation of phthisis at the apices on anatomical grounds have
not yet produced any convincing explanation.

In making a diagnosis of apical tuberculosis from physical
signs, the normal differences between the signs at the two apices
must be borne in mind. The lungs either extend to an equal
height above the clavicles or the right is a little higher than the
left. The normal outline of the apex passes from the seventh
cervical spine outwards and upwards to a point on the anterior

PHTHISIS. 315

edge of the trapezius, an inch and a half above the clavicle;
thence the curve passes downwards and inwards towards the
clavicular attachment of the sternomastoid. The pulmonary
resonance above the clavicle is obtained by direct percussion
downwards upon the sloping anterior surface of the apical part
of the lung ; this surface lies under cover of Sibson's fascia and
the scalene muscles. Even in health a flatness or deficiency in
percussion resonance may be expected on the right side in most
individuals, possibly because of the greater muscular develop-
ment on this side of the body. At the right apex, too, the
breath sounds are louder, the expiratory murmur more audible
and, hence, apparently prolonged, the vocal resonance more
marked, and the vocal fremitus more easily appreciated. In
women and children the breath sounds at this apex may even
possess a bronchial quality. There is an anatomical basis for
these differences. The apex of the right lung is closely applied
to the side of the trachea, owing to the deviation of that tube
to the right ; consequently tracheal sounds are easily communi-
cated to the upper part of the right upper lobe, whereas on the
left side the oesophagus in part, the left subclavian and common
carotid arteries and the aortic arch all intervene between the
trachea and the lung. In addition, the right main bronchus is
rather larger than the left and sooner gives off the branch to the
upper lobe.

It is important to bear in mind the positions in which tuber-
culous deposits may be expected in the lungs and the relations
these spots bear to the chest walls. The primary and oldest
lesion is usually found in the upper lobe, about one or one and
a half inches below the extreme apex, and rather nearer to the
postero-external aspect than any other part of the surface of the
lung. From this focus the disease spreads directly backwards,
giving rise to signs in the supraspinous fossa, and also down-
wards and forwards along the anterior aspect of the upper lobe,
causing indications of its presence by abnormal physical signs
above the clavicle or in the first, second and third intercostal
spaces about an inch and a half away from the sternal edge.

316 CLINICAL APPLIED ANATOMY.

More rarely the primary lesion lies further outwards, corre-
sponding to the first and second interspaces below the outer
third of the clavicle. It is exceptional for a lower lobe to be
directly invaded across the interlobar fissure — the pleura appears
to have sufficient power of resistance to prevent this. Secondary
deposits in the other lobes are the result of aspiration from the
primary focus.

The lower lobe is usually invaded before the mischief has
extended very far in the upper lobe, the middle lobe being
passed over. The first focus in the lower lobe is an inch or
an inch and a half below the apex and the same distance from
the posterior border. Here, again, extension takes place back-
wards towards the posterior border of the lung, corresponding to
an area on the chest wall midway between the fifth dorsal spine
and the vertebral border of the scapula, and also laterally along
the line of the great fissure. This line is sufficiently well indi-
cated by placing the hand upon the spine of the opposite scapula
and raising the elbow above the level of the shoulder. The
vertebral border of the scapula then corresponds fairly with the
oblique fissure.

Infections of the opposite lung usually occupy positions
similar to those of the lesions in the lung first involved, but
occasionally the opposite upper lobe shows a deposit correspond-
ing to the upper part of the axilla, just above the interlobar
septum, hence the axilla as well as the apices should always be
carefully examined. In children and women with thinly covered
chests, bronchial breathing may often be heard over the manu-
brium sterni and upper part of the sternum, and also in the
interscapular region. These points correspond to the termina-
tion of the trachea and the commencement of the main bronchi.
At its point of bifurcation the trachea lies under the right edge
of the sternum. The bifurcation corresponds to the level of the
sterno-manubrial joint in front, and the tip of the fourth dorsal
spine behind, these being the surface levels of the disc between
the fourth and fifth dorsal vertebrae. It is sometimes stated that
the bifurcation is on the same level as the root of the scapular

PHTHISIS. 317

spine, but since this is opposite the disc between the third and
fourth dorsal vertebrae, the tracheal bifurcation is really lower
down. The bifurcation is one vertebra higher in the infant than
in the adult, but, nevertheless, it corresponds to the third costal
cartilage in front instead of to the second, owing to the less
obliquity of the ribs. The marked deviation of the lower end of
the trachea to the right is due to the pressure exerted upon it by
the aortic arch, and this leaves a distinct impress on the side of
the air tube. In children a " cracked-pot " sound may often be
obtained below the clavicle, especially on the right side; the
thinness and flexibility of the chest wall and the proximity of
the trachea and bronchi account for this phenomenon, the air
being easily driven out by forcible percussion.

A systolic murmur can often be heard in the subclavian arteries
of those who suffer from phthisis. In some cases, no doubt, this
is haemic, but the artery is in close relation to the pleural dome,
which it actually indents, and so may be compressed by pleural
adhesions or by a solid portion of the lung. The inflammatory
thickening of the apical pleura may also entangle and paralyse
certain nerves which lie adjacent to it. The recurrent laryngeal
nerves, particularly that of the right side, the phrenics and the
dorsal sympathetic fibres to the eye, are all liable to implication
in this way. Unilateral abductor laryngeal paralysis, unilateral
paralysis of the diaphragm or unilateral ptosis, myosis and
enophthalmos may thus be produced.

When there is much fibrous contraction of the lungs, the heart
comes more fully into contact with the chest-wall, and the area
of visible pulsation is increased. Under these circumstances the
conus arteriosus may beat in the second left interspace, being
drawn upwards as well as uncovered. The shock of pulmonary
valve closure can often be actually felt in this situation. On
auscultation the loudness of the second sound will be evident.
Contraction of the left lung allows the area of gastric resonance
to encroach upon the chest, and contraction of the right allows
the liver to pass upwards. The heart and mediastinum will be
drawn towards the lung which is contracted, unless previously

318 CLINICAL APPLIED ANATOMY.

fixed by adhesions. When lung contracts, compensatory em-
physema or local retraction of the chest wall may be expected.
The close adhesion of the visceral pleura to the lung, and its
permeation by some of the pulmonary lymphatics, are sufficient
to account for the frequency of pleurisy and of pleural adhesions
in phthisis. Small groups of recent tubercles may often be found
in the visceral pleura of those suffering from the disease.

PNEUMONOKONIOSIS.

In this group of diseases the inhaled dust forms a natural
injection of the lymphatics of the lungs. The bulk of experi-
mental evidence shows that no absorption of particles takes place
through the mucous membranes of the trachea and bronchi,
where the presence of an impermeable basement membrane cuts
off the lymphatics of mucosa from those of the deeper structures.
After the prolonged experimental inhalation of air loaded with
fine particles, the latter are found in the peribronchial and peri-
vascular lymphatics, in the lymphoid tissue in connection with
these and in the bronchial glands, positions to which they are
carried after they have been absorbed by the alveolar lymphatics.
In pneumonokoniosis the foreign particles lie in the desquamated
epithelium and epithelial spaces of the alveoli, in the interlobular
septa and the lymphatics which surround the pulmonary arteries
and bronchi, in the deeper layers of the visceral pleura, in the
lymphoid aggregations of the lungs and in the bronchial glands.
There is practically no deposit in the superficial layers of the
visceral pleura, for the pulmonary lymphatics do not run in
these layers, and there is no deposit in the mucous membrane
of the bronchi, since the ciliated epithelium passes the particles
upwards and no direct absorption takes place into the deeper
layers owing to the presence of the basement membrane.

EMPHYSEMA.

Interstitial emphysema is due to the rupture of an air cell
into the supporting fibrous tissue of the lung. It is practically

EMPHYSEMA. 319

limited to childhood, for only at that period of life does the
interstitial tissue form any considerable bulk of the organ.

Hypertrophic emphysema is the form of emphysema most
commonly met with. In this form the lungs are actually increased
in bulk. The emphysematous dilatation of air cells is chiefly
found in the thin and unsupported parts of the organs, i.e., along
the anterior edges, around the sharp basal margins and near
the roots. The accompanying increase in bulk is accommodated
in part by invasion of the spare pleural space and in part by
the inspiratory position assumed by the thorax, together with
exaggeration of the dorsal curve of the spine. The spare pleural
spaces which can accommodate the enlarged lungs are the
phrenico-costal and the pleuro-pericardial portions of the pleural
sinuses. The phrenico-costal sinuses, which lie below the lower
edges of the lungs between the diaphragm and the chest walls,
are of considerable potential capacity, and attain a vertical
measurement of nearly four inches in the axillary regions. In
this position the lower border of the lung normally reaches to
the- eighth rib whilst the pleural reflexion corresponds to the
tenth rib or intercostal space. The pleuro-pericardial sinus is a
part of the left pleural sac which passes further forwards over
the heart than the corresponding lung does. It is easy to see how
the emphysematous lungs by encroaching on these sinuses cause
the upper limits of the hepatic and splenic dulness to be depressed
and may diminish or obliterate the area of cardiac dulness.
When the chest wall assumes an inspiratory position, in addition
to the increase in its diameters which gives rise to the so-called
barrel outline, there is a certain amount of gliding upwards of
the ribs beneath the skin so that the surface relations become
altered. The nipple may lie on the fifth instead of the fourth
rib and the cardiac impulse may appear in the sixth space. In
emphysema, this altered relation tends to be permanent, and
must be taken into account in estimating cardiac enlargement
and displacement.

The destruction of alveolar septa which takes place in
emphysema considerably reduces the capillary area of the

320 CLINICAL APPLIED ANATOMY.

pulmonary artery, and leads to hypertrophy and dilatation of
the right cavities of the heart, with signs of back pressure in the
venous system.

Compensatory emphysema, as its name denotes, is a form of
emphysema which occurs when for some other reason part of
the pulmonary tissue becomes functionless. The whole of the
opposite lung may become emphysematous when one lung is
crippled, and under such circumstances the mobility of the
mediastinum allows the active and over-distended lung to encroach
considerably on its fellow. Similarly when one lobe of a lung
becomes collapsed the remaining lobe or lobes of the same side
may become emphysematous, and when part of a lobe is airless
or cicatrised the pulmonary tissue immediately adjacent becomes
over-inflated.

Pleura and Mediastina.
pleural inflammations and effusions.

Effusions into the pleura may be passive and non-inflammatory,
or inflammatory.

Passive effusions occur in connexion with heart failure, the
fluid poured into the sac accumulating there instead of being
constantly absorbed by the lymphatics. Earely a chylous effusion
is found, the thoracic duct rupturing into the sac in consequence
of injury or obstruction. In the posterior mediastinum the
thoracic duct lies close to the right pleural cavity, whilst in
the superior mediastinum and the root of the neck it is close
to the left one.

Inflammatory effusions are frequent, and may be either serous
or purulent. When pleurisy complicates a specific fever, such as
rheumatism or scarlet fever, it is assumed that the infection is
carried to the pleura by the blood stream. There are many
systemic capillaries adjacent to the pleura. A uniform layer of
capillary blood-vessels lies on the surface of the lung, beneath
the visceral pleura, and is derived from the bronchial arteries.
Another wide-meshed plexus lies in the subpleural connective

PLEUEISY. 321

tissue of the mediastinum, and is supplied by the mediastinal
and pericardiac branches of the aorta and by branches of the
bronchial and internal mammary arteries. A similar plexus lies
in the connective tissue beneath the costal pleura, being formed
by branches of all the arteries of the thoracic wall. These
plexuses establish a communication between the pulmonary and
pleural vessels on the one hand and the vessels of the surface of
the chest on the other ; and this may explain the beneficial
effects of counter-irritation applied to the chest in pleural and
lung diseases.

In pyaemic pleurisy the infection is carried by branches of the
pulmonary artery, having been brought to the right auricle by
the systemic veins. Infarctions of the lung and superjacent
pleurisy result.

The visceral, mediastinal, diaphragmatic, costal and apical
regions of the pleura may all be invaded by the extension of
inflammation from the structures which lie in immediate relation
to them.

The intimate relations of the visceral pleura to the connective
tissue of the lung ; and of the parietal pleura to the connective
tissue of the mediastina, chest walls, diaphragm and root of the
neck explain the occurrence of pleurisy by extension of inflam-
matory mischief from these regions, and also account for the
association of pleural and pericardial adhesions with mediastinitis.
Extension of infection to the visceral pleura is common in abscess,
infarction and gangrene of the lung. Pleurisy also frequently
accompanies pneumonia. The lymphatics of the lung and of
the visceral pleura pass into the same efferent trunks ; and the
latter also receive the lymphatics of the mediastinal tissues and
of the mediastinal pleura. Lymphatic convection, as well as mere
continuity of tissue, may therefore play a part in the production
of secondary pleurisy. In phthisis, small aggregations of miliary
tubercles may often be recognised on the visceral pleura close to
the older lung lesions. These miliary deposits are probably
situated in the lymphatics.

The structures which lie beneath the mediastinal pleura and

C.A.A. 21

322 CLINICAL APPLIED ANATOMY.

which, when diseased, may give rise to secondary pleurisy, are
the aorta, the oesophagus and the mediastinal lymphatic glands.
The transverse and descending portions of the thoracic aorta are
in relation with the left pleural sac, and adhesive inflammation
may accompany aneurysms of these parts of fhe vessel. The
ascending aorta lies in relation with both sacs. The oesophagus
in the posterior mediastinum abuts upon the right pleural cavity,
which actually forms a small cul-de-sac between it and the spine.
Above and below the oesophagus is in relation with the left
pleural sac.

The diaphragmatic pleura has intimate relations with the
peritoneum by lymphatic vessels which traverse the diaphragm.
These channels are tortuous and narrow, so the diaphragm to a
certain extent forms a barrier between the two serous sacs.
Tuberculous, septic or malignant disease may invade the pleura
by this route. Invasion may be facilitated by the occurrence of
a defect in the posterior part of the diaphragm below the external
arcuate ligament, in the region of the kidney. A small gap is
not uncommon in this situation, especially on the right side.
The fused subperitoneal and subpleural planes of connective
tissue then form the only barrier between the peritoneum and
the pleura. The base of the right pleura may be invaded directly
by abscesses, hydatids or malignant growths of the liver, the
diaphragm being perforated. The base of the left sac is separated
by the diaphragm from the left lobe of the liver, the fundus of
the stomach, the spleen and, when the stomach is contracted,
the transverse colon near its splenic flexure. Consequently the
left pleura can be invaded from any of these structures. The
upper poles of the kidneys lie upon the lower sinuses of the
pleura, the diaphragm intervening, so that perinephritic abscesses
may infect the pleural sacs.

The costal pleura may be perforated by wounds of the chest or
the ends of fractured ribs. It may also be invaded by tuber-
culous and other inflammations of the ribs or chest walls, and
over-lying growths. Axillary abscesses occasionally give rise to
pleurisy, and this may be explained by the fact that the axillary

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PLEUEISY. 323

connective tissue is continuous over the first rib with the con-
nective tissue which invests the pleural sac. The perforating
branches of the intercostal vessels and nerves also carry with
them sheaths of the same connective tissue which have been
prolonged along the main vessels and nerve trunks from the
posterior mediastinum.

Owing to the laxity of the subjacent connective tissue, the
costal pleura is much more easily stripped from the parietes
than the visceral pleura is from the lung.

The gangliated cord of the sympathetic lies over the heads of
the ribs in the connective tissue beneath the costal pleura, and
so the fibres which pass through the first and second dorsal
rami to ascend in the cervical chain to the eye may become
damaged when the pleura is inflamed.

The pleural dome is occasionally infected by suppurative
processes in the lymphatic glands and connective tissue planes
of the neck. It is also liable to injury and infection from
wounds and operative procedures immediately above the clavicle.
Its relation to the subclavian artery is important in connexion
with aneurysms and ligature of that vessel. The continuity of
the axillary vascular and nervous sheaths with the connective
tissue over the pleural dome has already been mentioned.

A close plexus of lymphatic vessels lies in the subpleural
tissue. The lymphatic efferents of the visceral pleura pass into
the superficial collecting trunks of the lung. Those of the costal
pleura open into the intercostal trunks; the diaphragmatic
pleura is drained by the diaphragmatic trunks and the medias-
tinal pleural lymphatics pass into the glands of the posterior
mediastinum. The pleural stomata, which are found in the
pleura covering the diaphragm and intercostal spaces, but not
in that of the mediastinum and ribs, facilitate the absorption of
fluid. The lymphatic trunks are provided with valves which
direct the flow away from the pleura. Thus the fluid which
normally transudes into the sacs from the blood-vessels is
constantly removed by the lymphatics through the agency of the
respiratory pump. In pleurisy the presence of inflammatory

21~2

324 CLINICAL APPLIED ANATOMY.

products prevents absorption, and in exceptional cases the effu-
sion may exercise pressure on the lymphatic trunks. Aspiration
of the fluid facilitates absorption by relieving pressure on the
lymphatics and rendering more free the respiratory movements.

Pleural effusions are naturally limited by the boundaries of
the pleural sacs. The costo-diaphragmatic reflections of the
pleural sacs are decidedly lower than the lower edges of the
lungs. The pleural reflection is about two inches below the
border of the lung in the nipple line, nearly four inches below it
in the mid-axilla, and about an inch and a half below it in the
line of the lower angle of the scapula. The left pleural sinus
overlies the stomach, and a change from resonance to dulness in
this area is very characteristic of the presence of fluid in the
pleural sac. The resonant gastric area is known as Traube's
semilunar space. The boundaries of this space are, the lower
border of the left lung above, the sloping lower edge of the left
lobe of the liver to the right, the left costal margin below, and
the anterior border of the spleen to the left. The space is
crossed midway between its upper and lower borders by the costo-
diaphragmatic reflection of the left pleural sac, consequently
fluid in the sac will encroach on the area of gastric resonance
much more than a solid lung does.

The lowest part of the pleural sac lies in the mid-lateral line
of the body. It corresponds to the tenth rib or intercostal space,
and can be readily found by drawing a horizontal line round the
trunk at the level of the lower part of the first lumbar spine.
This is the part of the pleura in which fluid can be early found,
and from which it is late to disappear. (See also page 409.)

When effusion occurs into the pleural sac, the negative pres-
sure in the sac is diminished and the mediastinum, being flexible,
very soon undergoes a suction displacement to the opposite side.
The heart lies in the mediastinum, and is displaced with it,
affording an index of its displacement. At the same time the
lung will become retracted towards its fixed point, which is its
root. In most cases of pleural effusion the manometer still
shows a negative pressure to exist within the thorax on the

PLEUEAL EFFUSION. 325

affected side, the lung is probably retracted only in the neigh-
bourhood of the fluid, and the position of the dulness does not
shift appreciably with alterations in the posture of the patient.
The root of the lung lies opposite the fifth, sixth and seventh
dorsal vertebrae, and it is at this level, near the vertebral
column, that the signs of retracted lung may sometimes be
obtained in large pleural effusions. Only when the amount of
fluid is very considerable will actual displacement of the liver or
spleen occur.

A knowledge of the surface markings of the lung fissures (see
pneumonia) is essential for the diagnosis of fluid collections,
usually purulent, between the lobes. Such collections give rise to
abnormal signs in the lobes which adjoin the fissures, and varia-
tions in these signs, such as shifting from one lobe to the other
and back again, should arouse suspicions of an interlobar
empyema.

The dome-like projection of the abdominal space into the base
of the thorax allows the peritoneal cavity to invaginate the floor
of the chest, the lungs and pleurae fitting like a cap on the
convexity of the projection. Hence peritoneal friction, produced
between the liver or other abdominal viscus and the diaphragm,
may be heard over areas which are in direct surface relation with
the pleural sacs, for the latter extend downwards between the
parietes and the peritoneum. An aspirator needle, too, may
inadvertently be passed right through the pleural sac and with-
draw fluid from the peritoneal cavity. Moreover, the action of
the diaphragm will impart a respiratory rhythm to the peritoneal
friction. Any of these occurrences may give rise to difficulty in
diagnosis. The intimate relation of the pericardial to the
pleural sacs, the former being clothed laterally by the mediastinal
pleura and overlapped by the costo-mediastinal reflections in
front, explains how inflammation of one sac may easily extend
to the other, and also accounts for pleural friction with a cardiac
rhythm. A large pericardial effusion, with retraction of the lung,
may easily simulate pleurisy, and even be tapped without
discovery of the error.

326 CLINICAL APPLIED ANATOMY.

The pleural sacs in health are potential only, the parietal and
visceral layers being in apposition. When roughened by inflam-
mation the gliding of one layer over the other, which accompanies
the respiratory movements, causes a friction sound. The
accumulation of fluid between the layers will obliterate the
sound by separating the rough surfaces. The normal proximity
of the layers accounts for the ease with which pleural adhesions
form, for the respiratory movements are lessened or absent over
the inflamed areas. The inflammation of apical pleurisy may
extend to the surrounding subpleural connective tissue and cause
compression of the vagus, phrenic or sympathetic nerves which
are in intimate relation with the pleural domes. The
association of mediastinitis with pleurisy has already been
referred to.

The narrowness of that part of the pleural cavity which
extends between the diaphragm and the chest wall renders it
inadvisable to make the incision for drainage of an empyema,
in the lower part of the sac. After the pus has been evacuated,
the diaphragm rises and approaches the chest wall, and so tends
to block up the opening. Incisions in the scapular line, with
resection of a part of the ninth rib, are free from this objection
and afford efficient drainage of the sac in recumbency. The
seventh or eighth ribs are sometimes resected, but although they
are uncovered in this position when the arm is elevated, they
are overlapped by the angle of the scapula when the arm is
lowered. For this reason, and on account of the presence of
the latissimus dorsi, some prefer to make the incision a little
more forward.

Empyemata, if left alone, may open into a bronchus, and the
danger of this undesirable occurrence has been much exaggerated.
They may also point externally. The weakest part of the chest
wall is in the interchondral spaces, where the intercostal muscles
are deficient and the anterior perforating branches of the
internal mammary afford a track. But the actual places at
which a neglected empyema may present are various. Some-
times it presents near the nipple, sometimes in the lumbar

PNEUMOTHOEAX. 327

region, and sometimes it travels downwards between the vertebral
and costal attachments of the diaphragm.

Sudden death sometimes follows aspiration or irrigation
of the pleural sac. This is attributed to reflex inhibition of
the heart tli rough the vagus filaments which are distributed
to the lung.

PNEUMOTHORAX.

The parietal and visceral layers of the pleural sacs are
normally in intimate apposition and coherent. When air by
any means gains access to the pleural sac, or exceptionally when
gasGS are generated in it by certain gas-producing bacteria,
the pleural layers become separated from each other, and
pneumothorax results.

Tlie visceral pleura is in the more direct relation with the air,
and it is by perforation of this layer that pneumothorax is com-
monly produced. In perhaps ninety per cent, of the cases the
perforation is due to pulmonary tuberculosis, but it is sometimes
caused by an empyema which has eroded the lung and dis-
charged into the air passages, and is occasionally the result of
abscess, gangrene or septic infarction of the lung. It is con-
jectured that the thin wall of an emphysematous air cell may
sometimes rupture when the alveolar air pressure is suddenly
raised by violent muscular effort. Pneumothorax has also
been caused by wound of the visceral pleura and lung during
paracentesis, but this is . rare. The visceral pleura is often
wounded by the ends of fractured ribs. Laceration of the lung
or the tearing of a bronchus near the lung root may allow air to
enter the sac. The application of a crushing force to the chest
is usually responsible for such accidents, and fractures of the
ribs usually coexist, but in children the thorax is so elastic that
the lung may be lacerated, or even a bronchus torn across
without any fracture taking place.

The parietal pleura is sometimes opened in its costal portion by
perforating wounds, and pneumothorax may be brought about in

328 CLINICAL APPLIED ANATOMY.

this way, but the firm cohesion of the pleural layers renders it
possible for a small penetrating wound to damage both pleura
and lung without the necessary access of air to the pleural sac.
The same applies to compound fractures of the ribs.

Air is sometimes aspirated into the pleural sac by respiratory
efforts during the careless performance of paracentesis.

The apical portion of the parietal pleura projects into the neck,
and consequently air may enter the sac as the result of wounds
inflicted on it during a difficult tracheotomy, or operations at the
root of the neck, such as ligature of the subclavian artery. This
part of the sac may also be wounded by the splinters of a
fractured clavicle.

The mediastinal portion of the parietal pleura may be per-
forated by abscesses of the mediastinum, and if these communicate
with the air or food passages, the pleura may become inflated.
Malignant disease of the oesophagus may produce a similar
result.

The diaphragmatic portion of the left parietal pleura is im-
mediately above that portion of the diaphragm, which forms the
roof of the stomach chamber, and is sometimes perforated by
malignant disease of the stomach or transverse colon. When
this occurs, the gas from these organs may invade the pleura.
Abscesses of the liver or other sub-diaphragmatic collections
which already communicate with the exterior of the body may
effect a further communication with the pleural sac, and thus
afford a channel for the access of air to the latter.

The lower part of the pleural sinus may be wounded during
operations on the kidney, and air may also enter the pleura of
the right side as the result of operations in the right sub-
diaphragmatic region.

Any opening in the pleura must also involve the sub-pleural
planes of connective tissue, and so pneumothorax may be ac-
companied by emphysema of the connective tissue spaces
beneath the parietal pleura, or of the connective tissue of the
mediastinum.

When air has free access to the pleural sac the pleural tension,

MEDIASTINAL EMPHYSEMA. 329

or negative pressure in the sac, is diminished, and the lung, by
virtue of its elasticity, immediately retracts, unless adhesions
prevent it. The mediastinum is drawn over to the opposite side,
and the lung of this side also retracts somewhat in consequence.
The dislocation of the cardiac impulse is an index of the displace-
ment of the mediastinum. The inflation of the pleura causes the
chest to assume an inspiratory position, and its resonance
encroaches on the cardiac, hepatic or splenic areas of dulness.
When the pressure in the sac rises above that of the atmosphere
the diaphragm becomes depressed, carrying downwards the
viscera in contact with its under surface.

Pneumothorax may be simulated on the left side by a stomach
much distended with gas. The stomach and colon may also
form the contents of a diaphragmatic hernia, and under these
circumstances, if filled with gas, may give rise to signs of air in
the left pleural sac. Kepeated examination may throw light on
the case by showing that the resonant area is at times replaced
by dulness, presumably because some fluid has been able to pass
into the incarcerated stomach or bowel.

It is exceptional to find air in the pleural sac, without some
serous fluid or pus, for the lesion which admits the air also opens
up a track for infection.

MEDIASTINAL EMPHYSEMA.

The mediastinal connective tissue surrounds the main air
passages, and is prolonged into the root of the lung, where it
becomes continuous with the connective tissue basis of that
organ. Air may gain access to its spaces by perforation or
rupture of the trachea, or a bronchus, or by the formation of a
communication between the air cells of the lung and the sur-
rounding connective tissue planes. Such communications may
occur in connection with destructive pulmonary inflammations,
extreme emphysema, or rupture of a cell during a paroxysm of
whooping cough.

The deeper connective tissue planes of the neck are continuous

330 CLINICAL APPLIED ANATOMY.

with those of the mediastina. The connective tissue of the
retropharyngeal space, which hes between condensed hiyers
known to anatomists as the prevertebral and retropharyngeal
fasciae respectively, is directly continuous with the connective
tissue of the posterior mediastinum surrounding the oesophagus.
Perforation of the latter may give rise to emphysema in these
layers. The connective tissue which surrounds the trachea is
encased by a condensed lamina known as the pretracheal fascia,
and this fascia blends with the fibrous pericardium after encasing
the innominate vein. As the result of difficult tracheotomies or
wounds of the cervical fascia, air may be sucked or driven into
the layer of connective tissue which surrounds the trachea
under the pretracheal fascia. It then passes into the superior
mediastinum, inflating the connective tissue spaces in this
region, travels onwards in the connective tissue on the front of
the pericardium, and laterally invades the connective tissue
sheaths of the pulmonary roots, ultimately reaching the inter-
stitial connective tissue of the lungs. Doubtless a valvular
arrangement of the wound leads to this inflation of the connective
tissue by violent respiratory eflbrts. Similar results may follow
the passage of a tracheotomy tube into the connective tissue
between the pretracheal layer and the trachea.

The extension of the emphysema may occur in the reverse
direction. When an air cell ruptures into the connective tissue
of the lung the air first gains access to the connective tissue of the
lung and its root, and then spreads to the mediastinum, pericardial
connective tissue, and ultimately to the neck, whence it may
overflow into the subcutaneous connective tissue also.

Invasion of the mediastinum by gas-producing bacteria
occasionally produces a spreading emphysema.

The presence of air in the extra-pericardial tissue may closely
simulate pericardial friction ; the air in the adjacent connective
tissue of the lung gives rise to crackling sounds similar to the
consonating crepitations of pneumonia ; air in the connective
tissue on the front of the thorax gives rise to a crackling which
can be heard with the stethoscope and appreciated by the hand.

MEDIASTINAL INFLAMMATION. 331

MEDIASTINAL INFLAMMATION AND SUPPURATION.

Mediastinal inflammation is frequently associated with pleural
and pericardial inflammations or adhesions. The direct con-
tinuity of the mediastinal tissue with the connective tissue of
the lung and pericardium explains this association. After
reaching and ensheathing the root of the lung the connective
tissue spreads into the parenchyma of the organ on the one hand
and extends over its surface as an extremely thin subpleural
layer on the other. In like manner the mediastinal tissue
ensheaths the fibrous pericardium and extends forwards in the
narrow interpleural space behind the lower part of the sternum.
It is also directly continuous, both in front and behind, with the
layer of loose connective tissue between the parietal pleura and
the chest wall.

There are many lymphatic glands in the mediastinum, and it
is possible that both acute and chronic inflammations may at
times spread from these. The bronchial group of these glands
is very apt to be tuberculous.

When the mediastinal tissue becomes indurated the structures
most likely to be compressed are the systemic and the pulmonary
veins. This is accounted for by the thinness of their walls.
The pulmonary artery, the aorta, and the trachea and bronchi,
having thicker walls, suffer less. Although there is only a
fraction of the circumference of the inferior vena cava in the
thorax, yet it has been obstructed by mediastinal induration.
The phrenic nerves, the vagi, and their recurrent laryngeal
branches, all lie in the mediastinal connective tissue planes, and
may suffer compression. The same holds for the sympathetic
chain which lies over the heads of the ribs in the subpleural
layer. It is exceptional for dysphagia to occur in chronic
mediastinitis, although the oesophagus lies in the mediastinum.

Mediastinal suppuration may originate from structures which
lie in the spaces or reach the mediastinum by extension from
other parts. The mediastinal glands, the thymus, and the
oesophagus may all originate the mischief. Extension may

332 CLINICAL APPLIED ANATOMY.

occur from the adjacent vertebrae, ribs, or sternum. Occasionally
dermoids and hydatids of the mediastinum suppurate. Pus may
reach the spaces from above by burrowing down in the retro-
pharyngeal space or around the trachea. When the mediastinitis
is secondary to perforations of the oesophagus or of oesophageal
pouches, it is especially likely to become gangrenous.

The course of the pus is determined by anatomical relations.
It may invade the subpleural tissue or the interstitial tissue of
the lung by continuity. It may burst into the oesophagus or air
passages, or into the pleural or pericardial sacs. Lying around
the large blood-vessels it may soften and erode their walls. The
connective tissue planes may direct it to the root of the neck, or
it may come forwards in the interchondral spaces by tracking
along the investing sheaths of the anterior intercostal vessels.
The continuity of the mediastinal tissue mth the subperitoneal
tissue around the aorta may direct the abscess through the
aortic opening of the diaphragm, or anteriorly it may pass
through the interval between the sternal and costal portions of
the same muscle.

Should an attempt be made to open the mediastinum from the
back it is necessary to bear in mind the relations the pleural
sacs bear to it. Below the eighth dorsal vertebra on the right
side a small cul-de-sac of pleura intervenes between the
oesophagus and the spinal column. On the left side the posterior
mediastinal pleura passes direct from the left side of the aorta
to the bodies of the vertebrae. Hence there is less risk of
opening the pleural sac if the space be approached from the left
side of the vertebral column in this region.

MEDIASTINAL GROWTHS.

There are many structures in or near the mediastina from
which new growths may originate. The most important are
the groups of lymphatic glands, the oesophagus, the trachea, and
bronchi. Tumours may arise in the residue of the thymus or
spring from the periosteum of the vertebrae, ribs, or sternum.

MEDIASTINAL GEOWTHS. 333

Accessory thyroids are rarely found in the superior mediastinum,
and dermoid cysts sometimes lie behind the mesosternum. Gum-
mata may also grow in mediastinal tissues.

The mediastinum is easily invaded along the connective tissue
sheaths of the bronchi by new growths which originate in the
lung. The bronchial connective tissue sheaths contain lymphatic
vessels and blood-vessels, and are directly continuous with the
mediastinal connective tissue. Pulmonary new growths may
also give rise to detached secondary mediastinal growths, which
consist of infected lymphatic glands.

A primary carcinomatous growth is theoretically most likely to
originate in the posterior part of the superior mediastinum or in
the posterior mediastinum. The presence of the epithelial
structures of the oesophagus, trachea, bronchi, and thoracic duct
in these situations accounts for this. Sarcomata arise chiefly
from the mediastinal lymphatic glands, but may grow also from
the periosteal boundaries of the space, that is from the vertebrae,
ribs, or sternum.

The positions and relations of the glandular groups are of
great importance in the consideration of the pressure symptoms
induced by mediastinal tumours.

The cardiac group of glands lies on the front of the arch of
the aorta, and is therefore in the superior mediastinum. Isolated
glands prolong this group upwards on each side to the termina-
tions of the right and left lymphatic ducts — that is, to the
junction of the internal jugular and subclavian veins. The
main mass of glands lies in close relation with the innominate
veins and the three great branches of the aortic arch. The
trachea lies posterior to them. The upward prolongation of the
right side follows the superior vena cava. Enlargement of the
glands may cause venous obstruction, inequality of pulses, and
dyspnoea.

The posterior mediastinal glands are grouped round the
oesophagus. Some are between the oesophagus and the peri-
cardium, and some lie close to the thoracic duct. These glands
are particularly likely to suffer in malignant disease of the gullet.

334 CLINICAL APPLIED ANATOMY.

The middle group of thoracic glaods is called peritracheo-
bronchial, and is by far the most important. It lies at the
junction of the superior and posterior mediastina, and on
account of the practical importance of its relations, is divided
into four sub-groups, although these are continuous with each
other. The groups comprise (1) the glands around the right
bronchus, (2) the glands around the left bronchus, (3) the glands
which lie in the bifurcation of the trachea, and (4) the glands
which follow the bronchi into the lungs and are embedded in
the pulmonary tissue.

The glands around the right bronchus are wedged in between
the termination of the trachea and the lung. When enlarged
they may press upon the superior cava which lies in front of
them, or the azygos vein which arches over them, or the vagus
which passes down behind them. They are not far removed from
the right pulmonary artery, and, extending as high as the con-
cavity of the subclavian artery, they are favourably situated to
compress the right recurrent laryngeal nerve, which turns round
that vessel.

The glands around the left bronchus occupy a corresponding
position to those around the right. They extend upwards into
the concavity of the aortic arch to reach the left recurrent
laryngeal nerve, whilst the vagus is behind them. Both these
nerves and also the pulmonary artery may be compressed by
enlargement of this sub-group.

The glands in the bifurcation of the trachea abut upon the
pericardium, which separates them from the back of the left
auricle. The posterior pulmonary plexus and the oesophagus lie
behind them. These glands, when infiltrated with malignant
growth, have invaded the pericardium and have compressed the
oesophagus.

The bronchial glands which follow the air tubes into the lung
may be traced as far as the fourth sub-divisions of the bronchi.
Disease of these glands may be mistaken for primary disease in
the lung tissue.

The enlargement of certain external groups of lymphatic

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MEDIASTINAL GEOWTHS. 335

glands may aid the diagnosis of both primary and secondary
mediastinal growths. The supraclavicular, the axillary, and
the inguinal glands are accessible, and the abdominal glands
can be palpated if enlarged to any great extent. The connection
of the supraclavicular and axillary glands with the lymphatics
of the mediastinum is not direct. The supraclavicular glands
receive no efferents from the mediastinal groups, but the ducts
of both groups open at the junction of the internal jugular and
subclavian veins. When the supraclavicular glands are invaded
in connection with malignant disease of the thorax it is probably
by retrograde infection. A small gland which lies deeply behind
the clavicular origin of the left sterno-mastoid muscle, and is
sometimes known as Virchow's gland, is usually the first gland
involved by malignant infection from below, whether from lung,
pleura, oesophagus, or stomach. It has also been pointed out
that growth may reach the posterior triangle by travelling along
the sheath of the subclavian artery.

The axillary glands are in indirect communication with the
lymphatics of the parietal pleura. The efferents from the
parietal pleura pass into the intercostal lymphatic trunks, and
the latter, by means of trunks which accompany the perforating
branches of the intercostal arteries, communicate with the axillary
glands. The axillary glands are in turn continuous with the
infraclavicular or subclavian group.

Lymphosarcomata, arising in the thoracic lymph glands, have
a tendency to creep along the mediastinal connective tissue
surrounding the air tubes and great vessels. They envelop the
trachea and bronchi, and so invade the lung from its root.
Descending in the sheaths of the pulmonary artery and aorta,
they invade the pericardium. Extending towards the heart
around the superior vena cava and the pulmonary veins, they
may actually invade the auricles. They may also invade the
myocardium by travelling along the sheaths of the coronary
arteries. They have a tendency to fungate into veins but not
into arteries, and masses of loose growth have been found in the
cavities of both sides of the heart. Passing upwards in the

336 CLINICAL APPLIED ANATOMY.

sheaths of the great branches of the aorta, the neoplasm may find
its way to the root of the neck and into the posterior triangles.

Carcinomata are said to be more destructive in their growth,
infiltrating, and so destroying, rather than surrounding, the
vessels and nerves with which they come in contact.

Any of the nerves in the thorax maybe involved in mediastinal
growths. The recurrent laryngeal nerves have already been
mentioned. The fact that the phrenic nerves and the vagi
completely traverse the chest affords many chances for their
compression. Implication of one phrenic nerve will produce
unilateral paralysis of the diaphragm. Disturbance of the
branches of the vagus probably accounts for the asthmatic
paroxysms of dyspnoea which sometimes accompany mediastinal
tumours, the vagus being the motor nerve to the bronchial
muscles. A growth in the superior mediastinum may involve
the brachial plexus, or pressing on the orbital fibres of the
sympathetic produce ptosis and myosis, but these occurrences
are rare. In both superior and posterior mediastina the inter-
costal nerves and even the spinal column may be attacked.
The intervertebral foramina allow the growth, by tracking along
the vessels and nerves, to reach the interior of the spinal canal.

Venous obstruction is a common and striking phenomenon
of mediastinal growth, but may also occur in connection with
aneurysm and mediastinitis. The veins most likely to suffer are
the superior vena cava and the two innominates. The azygos
veins are sometimes occluded. The inferior vena cava rarely
suffers ; its extremely short course in the thorax and its remote-
ness from the principal groups of glands no doubt account for its
comparative immunity. Obstruction of the superior vena cava
produces congestion in the areas of its tributaries. The parts
involved are the head, face, tongue, fauces, ears, neck, arms, and
chest. The circulation within the cranium is obstructed, the
nasal mucous membrane is turgid and inclined to bleed ; even
exophthalmos and conjunctival haemorrhage may result. If only
one innominate or one subclavian vein be obstructed the area of
congestion is more restricted. In some instances of compression

MEDIASTINAL GEOWTHS. 337

of one innominate vein, it is said that the external jugular
vein of the obstructed side remains distended during inspira-
tion, whilst the vein on the opposite side is emptied by the
thoracic suction.

When the superior vena cava or its large tributaries are
obstructed, the feeding veins become distended, and relief can
only be obtained by diversion of blood into the inferior cava.
This necessitates the opening up of collateral channels. These
channels lie, some within the body cavity, some in the depth of
the body walls and some on the surface. In rare instances the
deeper collateral channels are sufficient to relieve the congestion,
and no enlargement of the surface veins can be detected ; in
others a congested network of superficial veins appears carrying
blood from above downwards. The following are the chief
possible channels of collateral circulation (Fig. 47, p. 338) : —

1. Within the body cavity the azygos veins, which receive the
blood from most of the intercostal spaces, are connected below
with the ascending lumbar veins and so communicate with the
lumbar, renal, or iliac tributaries of the inferior vena cava.

2. Within the rectus sheath the deep superior epigastric
veins which accompany the epigastric branches of the internal
mammary artery, communicate with the deep inferior epigastric
veins which accompany the deep epigastric artery. Thus the
innominate vein is linked with the external iliac vein. The
lumbar tributaries of the inferior vena cava also communicate
with both the superior and inferior epigastric veins.

3. On the surface of the chest and abdomen, mesial, lateral,
and posterior groups of anastomosing veins exist. These
when enlarged form a striking clinical picture. The mesial
superficial veins consist above — that is, on the chest and
epigastrium — of a plexus of vessels derived from the anterior
intercostal tributaries of the internal mammary veins, and near
the free margin of the thorax, from tributaries of the deep
superior epigastric veins. A large vein may often be seen
running vertically from the ensiform cartilage to the umbilicus.
This may be called the superficial superior epigastric vein. It

C.A.A. 22

338 CLINICAL APPLIED ANATOMY.

communicates below with the venous circle of the umbilicus,
above with the internal mammary vein, and receives tributaries
from the superficial network of the epigastrium. The blood
from all these superior veins is received below by the superficial
inferior epigastric veins, which accompany the superficial
epigastric artery, by perforating tributaries of the deep inferior
epigastric veins which accompany the deep epigastric artery,
and by branches of the lumbar veins. Thus the blood can find
its way from above into the internal saphenous veins, the
external iliac veins, and the inferior vena cava.

The lateral group of superficial anastomosing veins is formed
as follows. On the side of the lower part of the thorax is a long
trunk known as the thoracico-epigastric vein. This communicates
above with the long thoracic (external mammary) vein, a tribu-
tary of the axillary vein. The long trunk communicates below,
usually in a plexiform manner, with the superficial inferior
epigastric vein, or with the superficial circumflex iliac vein, or
with both. On the side of the chest wall above, the costo-axillary
veins, which are lateral perforating vessels from the seven upper
intercostal spaces, unite and pass into the lateral main trunk,
whilst below the same trunk communicates with the superficial
lumbar veins. This long anastomosis links the axillary and
intercostal veins with the internal saphenous vein and the inferior
cava. The posterior group of anastomosing superficial veins
consists of large inter-communicating tributaries of the lumbar
and intercostal veins on the back. Engorgement of these veins
has been supposed to indicate obstruction of the azygos major
trunk.

Pressure on the air tubes causes the most serious dyspnoea,
and also gives rise to various secondary changes in the lungs.
The dyspnoea may be paroxysmal, and then is probably due to
implication of nerves. The right vagus and the left recurrent
laryngeal nerves lie at the sides of the trachea, the vagi pass
behind the roots of the lungs, and the left recurrent laryngeal is
for a short distance in immediate relation with the thoracic part
of the trachea. The forward projection of the bodies of the

Collateral Venous CiRCULATroN.

Hight
iinioininate vein.

Internal
inanunary vein.

Thoracico-
epigastric vein.

Superficial
superior
epigastric vein.

Paninibilical
veins.

Venous circle of
umbilicus.

Radicles of
azygos vein.

Deep inferior
epigastric veins
Right common
iliac vein.

Superficial
inferior
epigastric vein.

External iliac
vein.

Left innominate
vena.

Superior vena
cava.

Vena azygos
major.

(Esophageal
veins and
plexus.

\ J/ Coronary vein

\__^-:i^"" of stomach.

Portal vein.

Splenic vein.
Superior
mesenteric vein.
Retroperitoneal
venous plexus.

Inferior

mesenteric vein.
Inferior vena
cava.

Left common
iliac vein.

Superior
hsemorrhoidal
vein.
Internal iliac

Haemorrhoidal
plexus.

Fig. 47. — A diagram to show the communications which exist between the superior
and inferior caval veins, and also those which occur between the portal and
systemic veins. (After 0. Schultze, much modified.)

\To face page 338.

TUBEECULOSIS OF MEDIASTINAL GLANDS. 339

vertebrae into the thorax considerably narrows the antero-
posterior diameter, especially above, where the trachea and
bronchi lie. Hence a growth in the superior mediastinum
is in a very favourable position to produce pressure on the air
passages, and, moreover, it is in this locality that the most
important groups of lymphatic glands, the residue of the thymus
and aberrant thyroids are most likely to be found.

Dyspnoea may also be the result of pericardial and pleural
effusions. The relations of the serous sacs to the mediastinum
and its contained glands, the fact that the efferent lymphatics
and veins of the sacs pass to the mediastinum, and the continuity
of the connective tissue basis of the sacs with the mediastinal
tissue, sufficiently account for the passive effusions and inflam-
matory affections which are found associated with growth in the
thorax.

TUBEBCULOSIS OF MEDIASTINAL GLANDS.

In childhood the peritracheo-bronchial group of lymphatic
glands often becomes tuberculous. The cardiac group of glands
may also become involved. The glands first mentioned receive
the lymphatics of the lung and visceral pleura, of the heart and
pericardium, and in part of the thymus and oesophagus. The
serial prolongation of the glands into the lungs explains the
frequent occurrence of islets of caseation near the roots in
children. The anatomical relations of the glands have been
described already. They are in a favourable position to produce
vagus irritation and so give rise to a dry cough. Occasionally
the recurrent laryngeal nerves are implicated, and laryngeal
paralysis observed. The glands may interfere with the air entry
into a whole lung or one of its lobes, and if very large may
produce dulness, with increased conduction of the voice and
breath sounds, in the interscapular or upper sternal regions. A
venous hum heard over the manubrium sterni when the head is
fully retracted is supposed to indicate pressure on one of the
venous trunks of the mediastinum. Traction diverticula of the

22—2

340 CLINICAL APPLIED ANATOMY.

oesophagus are believed to be initiated by disease of these glands.
The inflamed glands have been known to perforate any of the
following structures, which are in close relation with them :
trachea, main bronchi, oesophagus, pericardium, aorta, pulmonary
artery, pulmonary vein, or thoracic duct. They may produce
chronic mediastinal suppuration. By opening in two directions
they have given rise to communications between the oesophagus
and the air tubes, or the air tubes and the mediastinum.

CHAPTER XVI.

DISEASES OF THE ALIMENTAEY TKACT, PEEITONEUM,
AND DIGESTIVE GLANDS.

The Lips.

The lips are well supplied with blood from the coronary arteries
of the facial, and this, together with their mode of development,
may account for the frequency with which they are the site of
angeiomata or naevi. Their exposed position renders them liable
to injury and subsequent inflammation, and should a fissure be
produced, the contraction of the circular fibres of the orbicularis
oris frequently interferes with healing because of the want of
rest thereby induced, in a manner similar to that caused by the
action of the external sphincter in cases of anal fissure.

The presence of many and large mucous glands explains the
incidence of mucoceles or retention cysts.

A carbuncle occurring on the upper lip is always a serious
affection, because of the possibility of thrombosis spreading from
the facial to the ophthalmic vein through the communication at
the internal canthus of the eye, and so backwards to involve
the cranial sinuses, particularly the cavernous, whereby severe
cerebral symptoms may be produced.

A primary syphilitic infection may occur on either lip from
contact.

Carcinoma, in the form of epithelioma, occurs almost exclusively
in the lower lip, a reason for this fact being that the lower lip is
the one which is irritated in the use of a pipe.

The lymphatic glands which are affected in inflammation and
epithelioma of the lips are first the submental and submandi-
bular, and afterwards the deep glands along the carotid sheath,

342 CLINICAL APPLIED ANATOMY.

and particularly those near the bifurcation of the common
carotid.

Wounds of the lip may bleed profusely from the coronary
branches of the facial artery, but the haemorrhage can be readily
controlled temporarily by compressing these vessels between the
finger and thumb. The arteries lie closer to the mucous mem-
brane than the skin surface. In suturing it is important to
remember that care must be taken to approximate the edges of
the wound accurately, so as to bring the red margin of the lip
exactly into line.

Hare-lip. — A common congenital deformity is that known as
hare lip. In the development of the face the median fronto-nasal
process as a whole should become joined with the bilateral maxil-
lary processes, the deeper bony parts articulating with one another
and the superficial cutaneous portions fusing. Failure of the
junction of the skin edges of the lower part of the cleft between
the above-mentioned processes constitutes hare-lip. This may
vary in degree from a slight notch in the red margin of the upper
lip, to a cleft extending right up into the anterior naris. As a
rule, in a hare-lip the red margin is continued up on the sides of
the gap. Moreover, the cleft may be unilateral or bilateral ; if
bilateral, the median portion, consisting of the skin covering the
premaxillary bones, may be carried forwards on the end of the
vomer. The premaxillary bones contain the incisor teeth, and
in dealing with this part during the closure of the hare-lip,
it has to be remembered that if the bone is forced back, there is
a tendency for these teeth, when they appear, to be rotated back-
wards in such a manner that they will not close properly upon the
lower incisors. Hare-lip may be associated with a cleft palate.

Median hare-lip is extremely rare. In this variety the notch
between the internal nasal prominences of the fronto-nasal
process remains unobliterated, and the cleft may be prolonged
by a furrow which runs on to the tip of the nose.

After closure of a hare-lip there is a possibility that asphyxia
may arise, for the dressing still further diminishes the opening of
the anterior nares.

CLEFT PALATE. 343

The Mouth.

Cleft Palate. — A cleft may involve both the soft and the hard
palates, or the soft palate alone. Very rarely, in the congenital
form, the hard palate is cleft without the soft. The cleft is
practically median until it reaches the spot where the inter-
maxillary suture divides laterally into that between the
premaxillary bone and the maxilla. It is uncommon to get a
complete cleft of the palate unaccompanied by a hare-lip, though
it is extremely frequent for a hare-lip to be present without a
cleft of the palate.

The higher the arch of the palate, the easier as a rule is the
usual operation for closure, on account of the greater breadth of
the muco-periosteal flap that can be separated. The attachment
of the velum palati to the ridge on the posterior aspect of the
palate bone indicates the necessity for a free division at this spot,
so as to allow the two freshened edges of the soft palate to be
brought together by sutures without tension.

The Gums and Teeth.

An epulis usually has its origin from the lining membrane of
the alveolus of a tooth, and although the prominence of the growth
appears upon the gum, its pedicle lies hidden within the tooth
socket. In the majority of cases it is therefore necessary to
remove the tooth, and cut out the epulis together with that part
of the socket from which it is growing.

An alveolar abscess is present when caries of a tooth causes
the formation of pus within an alveolus, and a knowledge of
the anatomical relations of the part explains many points in the
progress of the inflammation and its treatment. Purulent matter
will find its exit along the line of least resistance. It most
commonly therefore tracks upwards or downwards along the side
of the tooth, and elevating the mucous membrane of the gum,
forms a typical " gum-boil," which as a rule discharges itself into
the cavity of the mouth.

344 CLINICAL APPLIED ANATOMY.

On the other hand, the pus may find an exit through the sub-
stance of the bony tissue of the jaw. In the case of the mandible,
if it reaches the external surface of the bone, it raises the peri-
osteum and collects either between that membrane and the
osseous tissue, or, perforating the membrane, forms a cavity in
the superficial soft structures. It will thus be seen that an abscess
of this character consists of pus in two cavities with a narrow
track between. The one cavity, the alveolus, is small ; the other
cavity, external to the bone, may be many times greater (Fig. 48) .

In order to obtain a satisfactory evacuation of the purulent
fluid, it is desirable that the offending tooth should be extracted,
to drain the alveolar cavity, and that an incision should be made
from within the mouth, keeping close to the bone, to open the
external collection. By this internal incision a disfiguring scar
in the skin may be prevented. Unless the knife is kept practi-
cally in contact with the bone, there may be some danger of
wounding the facial artery, near the anterior border of the
masseter.

In the maxilla, pus may find its way through the bone in two
directions, either upwards into the antral cavity or inwards
beneath the muco-periosteum of the palatal process of the
maxilla. Pus formed in connexion with the second molar is
that which most commonly induces antral empyema, owing
to the fact that the fangs of this tooth may actually project
through the bony floor of the cavity and slightly raise its muco-
periosteum. Occasionally the roots of the first molar or second
bicuspid also perforate the floor of the antrum. Pus in the
antrum may find its exit by the side of the afiected tooth into
the mouth, or through the opening of the antrum into the
middle meatus of the nose, or occasionally through the anterior
wall of the cavity into the tissues of the cheek. It is only,
however, in a certain number of instances that the purulent
fluid will flow into the nasal cavity, because the aperture in the
natural state with all the bones and the mucous membrane
present, is really a small one, and may be readily occluded by
the swelling of the soft tissues. Further, the opening lies at

Alveolar Abscess.

Fig. 48. — Diagram to illustrate how pus may track from an alveolus.

[ To face page 344.

GLOSSITIS. 345

nearly the highest point of the cavity, and unless the head is
inclined to the opposite side, pus must fill the antrum before it
will overflow into the nose.

In incising an abscess beneath the muco-periosteum of the
hard palate, the presence of the somewhat large anterior palatine
artery, lying in close apposition with the inner border of the
alveolar process, should be remembered, as haemorrhage is likely
to be troublesome if the vessel is injured.

The alveolar processes of the maxilla and the mandible may
be expanded by cystic or solid new growths. Cysts may be
derived from the original epithelial tooth elements, while the
common new growth is that of the character of a myeloma. In
both there wdll be a tendency for a considerable thinning of the
compact bone, frequently giving rise to a characteristic
parchment- like crackling.

The Tongue.

Wounds of the Tongue. — A deep, incised wound of the tongue,
caused most commonly by the closure of the teeth upon it, is apt
to bleed rather freely, on account of the vascularity of the organ.
If the ranine artery be cut across, it will be needful to apply a
ligature, but in the majority of cases a stitch inserted deeply
into the substance of the tongue by means of a fully curved
needle will control the haemorrhage by the pressure of the two
surfaces of the wound one upon the other.

Glossitis. — The exposed position of the surface of the tongue
and its liability to irritation and injury, either from the passage
of food substances over it or from its oft-repeated movements
against the teeth, renders superficial inflammation extremely
common.

Dyspe/ptic ulcers are apt to occur at or near the tip of the
tongue, probably from the incessant worrying of this portion of
the mucous membrane by contact with the none too clean and
often roughened posterior surface of the incisor teeth.

The ordinary superficial dental ulcer of the tongue is seen more

346 CLINICAL APPLIED ANATOMY.

frequently on the lateral margin of the organ, and corresponds
to the position of a jagged bicuspid or molar, and it is here
again that epithelioma most frequently originates.

The small ulcers seen upon the frsenum of the tongue in some
cases of whooping-cough may perhaps be explained by the
traction of this band of tissue across the two lower central
incisors during a paroxysm.

Interstitial glossitis of a gummatous character is most com-
monly found in the middle line of the tongue towards the base,
which is possibly due to the fact that there is little if any
arterial anastomosis from one half of the tongue to the other,
the practically extra-vascular area permitting the development
of the infective granuloma and its subsequent caseation.

Epithelioma of the Tongue. — Unfortunately this is by no
means an infrequent disease, and a thorough knowledge of the
anatomical considerations concerning it is of the utmost impor-
tance in its early and radical treatment.

The neoplasm commences as a rule in that part of the tongue
which is most subjected to irritation : hence, as has been men-
tioned, the side of the tongue is one of the most frequent sites.
The disease spreads locally in the substance of the organ, and if
left untouched, sooner or later involves the floor of the mouth
and subsequently the mandible. This local spread accounts for
the fixation of this naturally freely moveable organ, and w^hen
the loss of mobility is well marked, and therefore protusion
greatly interfered with, the possibility of a complete extirpation
of the disease is extremely doubtful.

The lymphatic glands are apt to be early enlarged. The sub-
mandibular and the deep carotid glands are those which are first
the sites of secondary deposits. The impossibility of determining
the actual implication of the glands in the early stages of the
disease renders it highly desirable, if not absolutely necessary,
that all the lymphatic nodes of the region should be dissected
out at the time of the operation upon the tongue, or very soon
afterwards. The submandibular glands lie in close connection
wdth, and even sometimes partially buried in, the submandibular

LINGUAL CAECINOMA. 347

salivary gland. Hence it is not altogether easy to thoroughly
eradicate them without at the same time extracting the salivary
gland. No hesitation should be felt in doing so as the other
glands are amply sufficient to keep the mouth moist, and the
wound does not as a matter of experience become infected from
the mouth along that part of Wharton's duct which is left
behind.

The same incision which is made for the removal of the glands
before excision of the tongue can be utilised for ligature of the
lingual artery. If this vessel is tied where it lies under cover of
the hyo-glossus muscle, it should be recollected that its direction
is much more nearly vertical than horizontal, and great care
must be taken not to miss the artery and pass through the
middle constrictor, and so open into the pharynx and provide a
pathway for infection into the cervical wound. Ligature of
the lingual artery beneath the hyo-glossus does not cut off
the blood supply to the dorsum of the tongue near its base,
seeing that the dorsalis linguae branch arises behind the pos-
terior border of the hyo-glossus. It is well, therefore, if the
tongue or half of it is to be removed far back, to ligature the
lingual soon after its origin from the external carotid. In cases
of primary or secondary haemorrhage from the lingual when it
has been tied in the floor of the mouth, arrest of the bloodflow
may be easily brought about temporarily by drawing forward
the base of the tongue with the finger and pressing it against
the body of the mandible. This temporary arrest may need to
be followed by ligature of the external carotid. The artery
should be secured distal to the origin of the superior thyroid
branch, so as to eliminate the free communication between the
inferior and superior thyroid arteries.

The Tonsils.

Tonsillitis. — The palatine tonsils are placed in an extremely
exposed position, for they may be infected both by the passage
of air or food over them. The air which is unnaturally drawn

348 CLINICAL APPLIED ANATOMY.

in through the mouth may be highly charged with bacteria, and
these micro-organisms may pass directly on to the surface of
the tonsil, covered with its mucilaginous secretion. Few, if any,
of these micro-organisms are deposited in their passage through
the mouth. If they had passed over the mucous membrane of
the devious passages of the nose, few would have entered the
pharynx. Again, the passage of food through the fauces, guarded
laterally as it were by the tonsils, explains the liability for these
organs to meet with injury and infection.

Eapid absorption occurs from the lymphoid tissue, and the
lymph carrying septic material passes to the glands of the
concatenate chain, and these filters arrest the progress of the
bacteria. Thus it happens that they are so frequently the site
of tuberculous infection. One of the highest of these glands,
lying immediately under cover of the angle of the jaw, when
enlarged in tonsillitis, has been sometimes mistaken for the
tonsil itself.

The enlargement of the tonsil induced by acute inflammation
may seriously obstruct the entrance to the pharynx ; hence it is
that severe pain is caused by the act of deglutition, partly owing
to the movement of the pillars of the fauces and partly to the
pressure of the bolus of food upon the inflamed structures.

The sensory nerve supply of the tonsil is derived from the
glosso-pharyngeal nerve, which runs downwards and forwards
just external to it. The tonsil and the posterior third of the
dorsum of the tongue are both supplied by the glosso-pharyngeal
nerve, which may explain the chronic furring of the tongue in
cases of chronic tonsillitis, but this is more likely to be due to
the mouth breathing.

When acute tonsillitis terminates in suppuration, the purulent
matter should be evacuated. There is very little, if any, danger
of wounding any important vessel in this small operation. It is
generally stated that the internal carotid artery is not far
distant, but as a matter of fact even in children the amount of
space between the tonsil and the vessel is very appreciable, and
injury of this arterial trunk is very unlikely to occur unless the

DIVEETICULA OF THE CESOPHAGUS. 349

point of the knife is plunged almost directly outwards. The
vessel which in point of fact lies closest to the tonsil is the main
trunk of the facial artery, and in cases where external pressure
is applied just below the angle of the mandible, to push the
tonsil inwards during the operation of tonsillotomy or ton-
sillectomy, this artery may possibly be in some degree of danger.
The actual vessels from which blood flows after tonsillotomy are
the tonsillar branches of the ascending pharyngeal, of the facial,
of the dorsalis linguae, and sometimes branches from the internal
maxillary.

In order to engage the tonsil satisfactorily in the ring of a
guillotine, it is well to remember that the front portion of the
organ is overlapped to a certain extent by the anterior pillar of
the fauces, containing the palato-glossus muscle, and therefore
the posterior portion of the tonsil should be first caught by the
instrument.

Diseases of the (Esophagus.

Malformations and Diverticula of the (Esophagus. — A com-
plete interruption of the oesophagus a short distance above the
bifurcation of the trachea may be met with. The upper end of
its lower segment then opens into the trachea. This malforma-
tion does not, as was once supposed, indicate a failure of the
buccal invagination of epiblast to fuse with the fore-gut, but is
probably due to obliteration of part of the gullet by traction of
the outgrowing lung bud, which springs from the alimentary
tract in this situation. Congenital strictures may occur in the
same situation and are due to the same cause.

Pressure pouches occur in the mid-line posteriorly at the junc-
tion of the oesophagus and pharynx. These diverticula are at
first lodged in the retro-pharyngeal space but later present them-
selves at the left side of the neck. The part of the oesophagus
from which ihey arise is weakened owing to the divergence of
the longitudinal muscular fibres towards the front in the form
of two lateral bands which become attached to the back of the
cricoid cartilage. Although known as pressure pouches of the

350 CLINICAL APPLIED ANATOMY.

oesophagus it is possible that some of these diverticula really arise
in the pharynx and are due to defective closure of pharyngeal
clefts.

Traction diverticula are usually found on the anterior wall of
the oesophagus, near the tracheal bifurcation. They are
attributed to the contraction of inflamed and adherent bronchial
glands. Inflammatory adhesion of the oesophagus to the right
lung has been known to have the same effect. (Esophageal
diverticula are prone to ulceration, and thus communications
may be established between the oesophagus on the one hand and
the trachea, bronchi, pleura, pericardium or mediastinal spaces
on the other.

A perioesophageal abscess lies in the surrounding mediastinal
tissue which is continuous above with the retropharyngeal space.
The abscess may arise in connexion with caries of the vertebrae,
suppurating lymph glands or inflammations and perforations of
the oesophagus itself. The natural tendency of the abscess is
to open into the oesophagus or pharynx, but it sometimes
perforates the trachea or may be guided by the connective tissue
planes towards the contiguous pleural sacs. The mediastinal
abscess of caries often presents posteriorly, following the con-
nective tissue sheaths of the posterior branches of the intercostal
arteries. These sheaths are continuous with the mediastinal
tissues surrounding the aorta. Eetropharyngeal abscesses some-
times track through the thorax into the abdomen. By pressure
of mediastinal abscesses on the vagus or air tubes a dangerous
form of paroxysmal dyspnoea may be induced.

There are three places where the oesophagus is somewhat
constricted and at which malignant disease is most likely to
commence. The first place is quite at the commencement, oppo-
site the cricoid cartilage and six inches from the incisor teeth.
The second place is supposed to indicate the level at which the
lung bud originally arose from the gullet ; it is a short distance
above the point where the left bronchus crosses the latter and
lies about nine inches from the incisors. The third constriction
is at the oesophageal opening of the diaphragm, at least fifteen

MALIGNANT DISEASE OF THE CESOPHAGUS. 351

inches from the teeth. The actual opening of the oesophagus
into the stomach is an inch lower down. The oesophagus pierces
the diaphragm at the level of the tenth dorsal vertebra, at a point
immediately to the left of the tip of the ninth dorsal spine.

In the neck the oesophagus is loosely connected by areolar
tissue with the posterior membranous wall of the trachea; the
recurrent laryngeal nerve of each side ascends in the groove
between the two. The carotid sheaths and the lobes of the
thyroid gland lie laterally, the relation being more intimate on
the left side owing to the deviation of the oesophagus to the left
at the root of the neck. A malignant growth of the cervical
portion of the oesophagus may cause oedema of the larynx,
simulating an inflammatory condition, or actually invade it. The
trachea may be compressed or perforated ; one or both recurrent
nerves may be paralysed ; the thyroid gland may be invaded, or,
more rarely, the growth may ulcerate into the adjacent blood
vessels or give rise to suppuration in the prevertebral connective
tissue, the layers of which separate the oesophagus from the
vertebral column and the longus colli muscles.

The thoracic portion of the oesophagus traverses the superior and
posterior mediastina. The trachea lies in front above, but lower
down the air tube deviates to the right and the left bronchus
crosses the gullet. Either this bronchus or the lower part of the
trachea may be compressed or perforated by a new growth in
this situation. Below the trachea, the pericardium, and lower
still the diaphragm, are in anterior relation and are sometimes
invaded. The lateral relations of first importance in the thorax
are the lungs and pleurae. The oesophagus is in much more
extensive relation with the right pleural sac than with the left,
because the thoracic aorta intervenes between it and the latter.
The former sac not only forms a continuous lateral relation, but
below the level of the eighth dorsal vertebra becomes posterior
as well. There is therefore a greater probability of invasion of
the right pleural sac and lung than of the left. Gangrenous
processes may be the outcome of such invasion, since the food
passages easily convey infections. The left pleural sac is in

352 CLINICAL APPLIED ANATOMY.

relation with the oesophagus in two positions, in the superior
mediastinum and in the posterior mediastinum just before the
tube traverses the diaphragm.

The relations of the thoracic aorta to the oesophagus vary con-
siderably at different levels. The transverse aorta crosses it to
gain its left side. The descending aorta at first lies to the
left, but in the lower part of the thorax the relations of the two
are gradually reversed, so that the oesophagus passes in front
and finally lies even to the left of the aorta. Of the large
arteries arising from the aortic arch only the left subclavian
comes into relation with the oesophagus. Ulceration of a growth
into the aorta or subclavian is rare. Occasionally the thoracic
duct, the azygos veins or the sympathetic chain are implicated.
The thoracic duct at first lies to the right, being separated from
the oesophagus by the aorta, higher up it lies behind and finally
crosses to the left as it enters the superior mediastinum. The
left recurrent laryngeal nerve lies between the oesophagus and
the transverse aorta. It may be involved here by cancer of the
oesophagus.

When cancer invades the middle and lower parts of the tube the
mediastinal and lumbar glands become enlarged ; when the upper
third is involved the glands of the mediastinum and those at the
root of the neck become implicated. A gland which lies in the
posterior triangle just above the left clavicle is of great significance
in this respect, but the same gland may be enlarged when the malig-
nant disease involves the stomach, pleura or lungs. Enlarged
glands may actually obstruct the oesophagus at some distance from
a primary carcinomatous ulcer which is causing no symptoms.

Fibrous strictures of the oesophagus may result from the
action of corrosive poisons. They are found at the upper or
lower ends as a rule. At these points the tube is narrow and
the passage of fluids somewhat delayed, whilst their passage
along the rest of the gullet is rapid.

Foreign bodies impacted in the oesophagus tend to become
fixed where the tube is narrow, that is to say at either end or
at a point nine inches from the incisor teeth, just above the

GASTEIC ULCEE. 353

position of the left bronchus. The subsequent formation of a
mediastinal abscess or ulceration into the aorta, pericardium,
left bronchus, trachea, pleura or lung tissue are sufficiently
explained by the relations of the gullet to these structures.

Rupture of the oesophagus is rare and is practically limited to
the lo^Yer third of the tube. The rent, which is usually longi-
tudinal, may open directly or indirectly into either pleural
cavity, causing pneumothorax. Mediastinal emphysema, sup-
puration or haemorrhage may also occur. The lower part of the
gullet differs from the upper in that it consists of involuntary
muscular fibres and is firmly fixed to the diaphragm, also simple
ulceration usually occurs in the lower third of the tube. All
these factors may favour rupture during the act of vomiting.

Idiopathic dilatation of the oesophagus has been variously
attributed to pressure by a dilated aorta or hypertrophied heart
or spasm of the cardiac orifice. It may, however, occur without
evidence of the presence of any of these conditions, and is
possibly due to paralysis of the longitudinal muscular fibres and
consequent inability to open the cardiac sphincter.

Diseases of the Stomach.

Gastric Ulcer. — Since quite two-thirds of the stomach lie under
cover of the liver and left costal arch only a small portion of the
stomach, which includes the pylorus, can be palpated. The area
of superficial tenderness may afford some indication of the position
of the ulcer. The stomach is innervated from the seventh, eighth
and ninth dorsal segments. The seventh segment supplies the
cardiac end and is distributed to a skin field which includes the
ensiform region, extending round to the back across a spot oppo-
site the eighth and ninth dorsal spines, below the lower angle of
the scapula. Superficial tenderness may be found in both these
regions when the cardia is the site of ulceration. The ninth
segment innervates the region of the umbilicus. The eighth
segment is intermediate in position. When this segment is
involved a tender spot may be found in front or in the infra-
axillary region. As a general rule the nearer the superficial

C.A.A. 23

354 CLINICAL APPLIED ANATOMY.

tenderness is to the ensiform cartilage the nearer the ulcer to
the cardiac orifice. (See Figs. 20—23, p. 226.)

The idea that the stomach is a flaccid bag, suspended by the
attachment to it of the oesophagus and the gastro-hepatic omentum,
is erroneous and misleading. When empty the viscus appears as
a contracted pyriform tube of which the cardiac end is the larger.
The tube is somewhat bent on itself at the junction of its cardiac
and pyloric segments. The long axis of the cardiac portion is
directed from the oesophageal opening, downwards, forwards and
to the right, that of the pyloric portion is directed more trans-
versely to the right to terminate in the duodenum. When food
is ingested, the more flaccid cardiac portion probably relaxes
quickly to receive it, whilst the relaxation of the thicker pyloric
segment is delayed ; finally the whole organ, wdth the exception
of its terminal inch, which may be called the pyloric canal,
becomes further enlarged. This explains the early onset of pain
after food when the ulcer is in the cardiac portion, and the delay
of onset when the pyloric portion is involved. The sharp angle in
the lesser curvature, which corresponds to the junction of the flaccid
cardiac and tonically contracted pyloric segments may have some
influence in determining the occurrence of ulcers near this part
of the lesser curvature. When hour-glass stomach occurs as the
result of ulceration, the stricture is usually rather to the pyloric
side of the middle of the viscus. The position of such a stricture
may represent the line of junction between the cardiac chamber
and the more contracted pyloric segment. The ulcers and cica-
trices which result from the swallowing of corrosive fluids also
tend to involve the pyloric segment of the organ. This may be
explained by the fact that such fluids pass quickly through the
cardiac portion to remain longer in contact with the pyloric
segment, which lies at a lower level and offers more resistance
to their passage.

The stomach when distended expands away from the lesser
curvature, which remains more or less fixed by the attachment to
it of the oesophagus, the duodenum and the left pancreatico-
gastric fold. The right pancreatico-gastric fold, carrying the

GASTEIC ULCEE. 355

hepatic artery, in a similar manner serves to anchor the duo-
denum and so indirectly fixes the right end of the lesser curvature
of the stomach. As the stomach expands it completely fills a well-
defined space in the upper and left part of the abdomen known as
the stomach chamber. This chamber has a sloping floor on which
the stomach rests, a dome-like roof against which the anterior
surface abuts, and an anterior wall which is in contact with the
anterior surface and greater curvature. When the stomach is
empty a part of the transverse colon near the splenic flexure turns
up into the stomach chamber.

The inflammation which accompanies gastric ulceration may
extend to surrounding structures, and the stomach thus contract
adhesions to different parts of the stomach chamber. Adhesions
readily form between the under (posterior) surface of the stomach
and the shelf on which it rests, since in this position they are
well supported and not easily disturbed by gastric or respiratory
movements. Adhesions between the stomach and the dome or
the anterior wall of the stomach chamber are formed with less
facility and more easily ruptured since they are constantly exposed
to traction in consequence of alterations in the size of the stomach
caused by the ingestion of food or fluid, and also by the respiratory
excursions of the diaphragm, liver and anterior abdominal walls.
Consequently, although ulcers of the posterior wall are more
common, ulcers of the anterior wall perforate more frequently.
The latter ulcers, owing to the difficulty with which firm adhesions
form, are sometimes spoken of as " undefended."

The structures which form the stomach bed are the front of the
left kidney and its adrenal body, the gastric surface of the spleen,
the upper surface of the pancreas, the transverse colon and its
mesocolon. Interposed between these structures and the posterior
wall of the stomach is the lesser sac of the peritoneum, except
over a small area near the cardiac end, where the stomach is in
direct contact with the diaphragm above the left adrenal body.
Adhesions of the posterior surface of the stomach partly obliterate
the lesser sac and usually bind the stomach to the pancreas, but
sometimes the spleen or other structures, such as the lymphatic

23—2

356 CLINICAL APPLIED ANATOMY.

glands along the top of the pancreas and in the gastro-splenic
omentum, become adherent. By an extension of the destructive
process the pancreas may become exposed in the floor of an ulcer
and eroded or inflamed or even suppurate. The same may happen
in the case of the spleen. Posterior ulcers rarely perforate directly
into the lesser sac. The roof of the stomach chamber, to which
ulcers of the anterior wall may adhere, is formed by part of the
under surface of the liver and the left cupola of the diaphragm.
The anterior wall of the stomach chamber, against which part of
the anterior surface and greater curvature of the distended stomach
rest, is formed by the anterior abdominal wall between the costal
margin on the left side and the liver on the right. Adhesions
may occur in this area also. Perforation of an ulcer of the
anterior wall of the stomach must involve the greater sac unless
protective adhesions have formed and the perforation occurs
into them.

It is interesting to note that a part of the under surface of the
heart, near the apex, is only separated from the stomach by the
pericardial sac, the left cupola of the diaphragm, and the peri-
toneum ; in rare instances an ulcer of the anterior wall of the
stomach has been known to perforate the pericardium and even
the heart itself. Adhesions in the region of the pylorus have been
known to obstruct the bile ducts, or attach the pylorus to the gall-
bladder, inducing attacks of cholecystitis and colic.

The gastric haemorrhage which results from ulceration may be
arterial or venous. Haemorrhage which proves fatal is nearly
always arterial, a large vessel being involved. The larger vascular
trunks in the wall of the stomach lie in the submucous tissue
beneath the mucous membrane. The large arteries which form
the vascular circle along the borders of the stomach are sometimes
attacked, and erosions or small aneurysms may result. The
arteries of the lesser curvature, particularly the coronary, may
suffer in this way. The pancreatico-duodenal and the right gastro-
epiploic arteries are, from their position, more likely to be per-
forated by ulcers of the pylorus or duodenum than of the stomach.
The splenic artery, although not directly applied to the stomach

GASTEIC CAECINOMA. 357

wall, lies in the bed of the stomach chamber, and may be opened
by ulcers on the posterior wall which have contracted adhesions.
The coronary veins may be eroded, or even the splenic or portal
trunks, although at first sight, on account of the interposition of
the pancreas, erosion of the two latter would appear impossible.
Haemorrhage from veins is uncommon, and when attacked by a
gastric ulcer they are much more likely to be concerned in the pro-
duction of portal pyaemia or secondary abscesses. As rarities may
be mentioned perforation of the hepatic artery, of the abdominal
aorta, and even of the left ventricle of the heart.

A gastric perforation is occasionally circumscribed by adhesions
which have formed as the ulcer approached the peritoneal surface.
In such cases a more or less localised abscess may result, and the
patient escape general peritonitis. Such localised abscesses may
lie in the dome of the stomach chamber between the stomach
and left wing of the diaphragm, or between the stomach and
its bed. They may come forwards and present in the epigas-
trium, being limited below by omental adhesions to the anterior
abdominal wall. Fistulae are rarely formed as the result of simple
ulceration. They may appear in the epigastrium or unite the
stomach with the colon, small intestine, or even gall-bladder.
Earely an adherent ulcer perforates into the subperitoneal tissues,
giving rise to suppuration or emphysema.

The cicatrices left by ulcers may produce a bilocular or hour-
glass stomach, and may, if situated in the pyloric region, give rise
to obstruction to the exit of contents and to dilatation.

Carcinoma of the stomach arises from the epithelium of the
gastric glands, and so may be either columnar- or spheroidal-
celled. It is most frequent in the pyloric region, but may
originate at the oesophageal opening or in some other part. The
pylorus and adjacent part of the greater curvature are the
only portions accessible to palpation. The transpyloric line
(Fig. 49, p. 362), which bisects the distance from the top of the
manubrium sterni to the pubic symphysis, indicates the level of
the pylorus, but the weight of a tumour or the drag of a dis-
tended stomach may dislocate the pylorus considerably. The

358 CLINICAL APPLIED ANATOMY.

tumour may exhibit considerable mobility or contract adhesions.
The adjacent aorta may communicate pulsation to it. Being
muscular it may sometimes be felt to harden and relax, and
at times gastric contents are felt to bubble through it. The
peristalsis of the stomach may be distinguished from peristalsis
of the transverse colon by the fact that the wave of the former
passes from left to right, whilst that of the latter passes from
right to left. In some cases the direction of gastric peristalsis is
reversed.

The arrangement of the lymphatic vessels and glands of the
stomach has an important bearing on the spread of gastric
carcinoma. The lymphatics commence in the submucous coat
and follow the track of the vessels in the subserous tissue. Three
distinct lymphatic areas may be recognised, the superior gastric,
the inferior gastric, and the area of the fundus. The superior
gastric lymphatics drain the upper halves of both surfaces of the
stomach from the pylorus to the junction of the central third
with the fundus. Their efferent trunks follow the coronary vein
along the lesser curvature, lying between the two layers of the
lesser omentum ; they traverse the superior gastric glands which
lie in this situation, and near the cardiac orifice turn backwards,
in the pancreatico-gastric fold, to enter the glands of the coeliac
group. They leave the stomach where the coronary artery reaches
the lesser curvature. The inferior gastric lymphatics drain the
lower halves of the pyloric and central regions. They traverse the
inferior gastric glands of the greater curvature, and their trunks,
accompanying the right gastro-epiploic vessels, pass below the
pylorus into the pancreatico-duodenal fold to reach the coeliac
glands. The lymphatics of the fundus accompany the vasa brevia
of the splenic artery in the gastro-splenic omentum, and pass to
the glands near the hilus of the spleen. These glands in turn
discharge into the cceliac glands. In the lesser omentum a few
lymphatic trunks pass directly from the pylorus to the glands in
the portal fissure.

Carcinoma of the pylorus involves both upper and lower
lymphatic areas. It extends chiefly along the lesser curvature,

GASTEIC CAECINOMA. 359

towards the point where the lymphatic trunks leave the stomach.
It shows little tendency to pass beyond the pylorus to the
duodenum, the lymphatic communication not being at all free in
this situation. Extension along the greater curvature is slight,
since the lymphatic trunks soon pass away to the coeliac glands.
The glands in the portal fissure may be directly implicated and
compress the portal vein and bile ducts.

Carcinoma of the greater curvature infects the inferior gastric
glands and may cause diffuse infiltration of the great omentum
or perforate the transverse colon, causing a gastro-colic fistula.
Sometimes it compresses the vessels of the transverse colon,
causing local necrosis of this portion of the bowel.

Carcinoma of the cardiac or'ifice can only infect one or two
glands of the lesser curvature, since the lymphatics of this region
soon reach the coeliac glands. The growth may invade the
oesophagus and spread along it in longitudinal columns corre-
sponding to the course of the lymphatics. There is a free com-
munication between the subserous and submucous lymphatics of
the stomach and the oesophagus.

Enlarged coeliac glands sometimes form a nodular tumour.
They are in a position to receive pulsation from the aorta,
occlude the inferior vena cava, or invade the spinal column.
They are early infected in gastric carcinoma, and any radical
operation should include their removal. Their ducts join with
those from the intestines and discharge into the receptaculum
chyli which lies on the right side of the second lumbar vertebra
under cover of the right crus of the diaphragm. By backward
propagation the lumbar, mesenteric, sacral, iliac and even the
inguinal glands may be involved. Forward infection invades
the thoracic duct, the glands of the j^osterior and superior
mediastina and even those at the root of the neck, particularly
one on the left side above the clavicle, known as Virchow's gland.

Miliary carcinomatous deposits may occur on the under sur-
face of the diaphragm, and in the superficial lymphatics of the
liver, being derived from the lymphatics of the portal fissure.
The diaphragm may be traversed and the right pleura invaded

360 CLINICAL APPLIED ANATOMY.

Large secondary growths in the liver are due to infection carried
by the portal vein direct.

Carcinoma of the stomach has a tendency to become adherent
to neighbouring parts, and invasion through the medium of the
adhesions may occur. The pyloric branch of the hepatic artery
is sometimes eroded.

The gastric growth soon ulcerates through the mucous mem-
brane, and presents as a foul ulcer owang to its exposure to the
gastric contents. A diffuse infiltration of the stomach wall may
occur, giving rise to what is known as the " leather bottle
stomach." Growth at the pylorus is in a position to cause
obstruction, and so lead to dilatation, w^hilst growth at the cardia
may hinder the entry of food into the stomach, and considerable
atrophy of the organ result.

Dilatation of the stomach is due to various causes. Acute
dilatation is a form which comes on abrupt^, and is very fatal,
but is fortunately rare. In atonic dilatation the muscular wall is
at fault. Habitual over-distension with food or drink may have
the same result. Obstructive dilatation may be due to changes
in the walls of the pyloric portion, or in the duodenum or
to pressure from without. The pyloric sphincter involves nearly
an inch of the stomach wall adjacent to the pyloric orifice, and
is capable of great dilatation. Foreign bodies wdth a diameter
of over three-quarters of an inch have passed through it.
Malignant disease, cicatrices, and benign growths may narrow
its lumen. It is sometimes the seat of congenital hypertrophy,
which also obstructs the exit.

Since the pylorus rests on the neck of the pancreas and is
overlapped by the liver, it is not surprising that it is occasionally
obstructed by tumours of these organs. It also lies in close
relation with the under surface of the gall bladder, and as the
result of cholecystitis or of pyloric ulceration the two may
become adherent. The pressure exerted by a movable and
displaced kidney upon the duodenum or pylorus may also give
rise to intermittent obstruction to the exit of gastric contents.
Obstruction may be caused by tumours of the omentum,

GASTEIC DILATATION. 361

enlarged mesenteric or retroperitoneal glands, or even by
aneurysms of the abdominal aorta or coeliac axis.

Very diverse estimates as to the normal capacity of the
stomach are current. It may perhaps be fixed as being from
thirty-five to forty ounces in the adult. In children up to six
months of age the gastric capacity may be approximately stated
to be an ounce more than the age of the child in months ; at
birth it is barely an ounce, at one month the capacity is two
ounces, and at six months it is seven ounces. At twelve months,
however, the capacity is but nine ounces, and at eighteen months
it is twelve ounces.

Dilatation of the stomach is inferred from an increase in its
superficial area, as determined by physical examination. It is
important to remember that when the stomach is contracted a
part of the transverse colon may lie in front of it. Sometimes
the actual outHne of the stomach can be seen ; at others it must
be determined by auscultatory percussion. Inflation is often
necessary, and the valvular mechanism of the cardia, coupled
with the obstruction at the pylorus, renders this easy of accom-
plishment by eftervescing mixtures or by an air pump and
stomach tube. Since the cardiac end of the dilated stomach
accurately fits the left dome of the diaphragm, the fundus of
the distended stomach rises to the same level as this dome, and
lies a little above and internal to the position of the cardiac
impulse. The proximity of the stomach to the heart is held
accountable for the palpitation and dyspnoea sometimes produced
by gastric distension. The cardiac sounds may be echoed by
the air-containing stomach, and its encroachment on the base of
the lung may simulate pneumothorax in childhood.

The greater curvature of the stomach emerges from beneath
the left costal margin at the level of the ninth costal cartilage
(corresponding to the position of the gall bladder on the
opposite side). The lower border of a normal stomach when
inflated should not extend lower than a line joining the tips of
the tenth costal cartilages, or two inches above the umbilicus.
(Fig. 49, p. 362.)

362 CLINICAL APPLIED ANATOMY.

The position of the pylorus is best defined by the transpyloric
line. This is a horizontal line which bisects the distance between
the episternal notch and the top of the pubic symphysis. The
pylorus normally lies in this line, being practically mesial if the
stomach is empty but lying two or three inches to the right if
the viscus is distended.

The weight of the dilated stomach tends to depress that
part of the stomach bed which is formed by the transverse
colon and mesocolon. The stomach may thus indirectly exercise
enough pressure on the duodeno-jejunal flexure or the terminal
portion of the duodenum to obstruct the passage of its own
contents.

Prolapse of the stomach, or gastroptosis, may also be a cause
of dilatation, a sharp bend being formed at the superior duodenal
flexure through the agency of the peritoneal ligaments attached
at this spot. The stomach is normally retained in its position
in the stomach bed not only by the support of the muscular
walls of the abdomen and the structures which form the bed, but
also by strong ligamentous bands. At each end of the lesser
curvature vertical and horizontal ligamentous supports are
attached. The left support is formed by the firm attachment
of the cardiac end to the diaphragm in the neighbourhood of the
CBSophageal opening, by the adjacent gastro-phrenic omentum
which passes vertically, and by the left pancreatico-gastric fold,
which is horizontal. The pancreatico-gastric fold is continuous
with the gastro-phrenic omentum and conveys the coronary
artery to the stomach. The right support is also a double fold ;
this is attached not to the stomach but to the first curvature of
the duodenum. It consists of the vertical hepato-duodenal
ligament, which is the right free edge of the lesser omentum
and the horizontal pancreatico-duodenal fold which passes from
the region of the head of the pancreas forwards to join the
duodenum at the same point as the hepato-duodenal ligament,
the two becoming continuous. The central portion of the lesser
omentum is of extreme tenuity and obviously of no importance
as a gastric support. The main factors are the strong ligaments

Topography op Abdomen.

'^ Liver. M

_..iac Meso-
colon begins.

Fig. 49.— Diagram showing the disposition of the liver, the stomach, the large
intestine and the lines of peritoneal attachment in the regions of the
abdomen. M.L., middle line; L.L., lateral lines ; Disc line represents the
level of the disc between the first and second lumbar vertebrae. (From Ellis's
Anatomy, after Christopher Addison.)

[To face page 362.

DUODENAL ULCEE. 363

already described. The two horizontal portions of these liga-
ments are easily demonstrated by opening the lesser sac below
the stomach and turning that viscus upwards. The folds can
then be seen to spring from the posterior abdominal wall in the
neighbourhood of the coeliac axis, and skirting the orifice of
the Spigelian recess of the lesser sac of the peritoneum, pass
forwards, just above the pancreas, to the cardiac end of the
stomach and to the duodenum about an inch beyond the pylorus.
The coronary and the hepatic arteries can be felt in the substance
of the folds.

The sharp V-shaped bend which develops in the lesser curva-
ture of a prolapsed stomach is due to its being slung up by its
two ends. The lesser curvature in such cases, instead of lying
under cover of the liver, may be distinctly visible, and sometimes
a part of the pancreas can be felt above it, simulating a malig-
nant tumour. In extreme prolapse the stomach may form a
prominence below the level of the umbilicus.

Diseases of the Intestine.

Duodenal Ulcer. — The first part of the duodenum is the
commonest site for ulcers. This part of the bowel begins at the
pylorus, opposite the first lumbar vertebra. With the stomach
empty, the duodenum is directed first to the right and then back-
wards beneath the liver, but with the stomach full it passes
directly backwards. It is therefore very movable. Its relations
have important bearings on the complications which may arise.
The quadrate lobe of the liver lies above and in front of it. The
head and neck of the pancreas support it. Behind it the portal
vein passes upwards to the liver, and the gastro-duodenal artery
and bile duct pass downwards, the artery lying about an inch to
the right of the pylorus. The termination of this part of the
duodenum lies immediately to the right of the inferior vena
cava. The relations to the peritoneum are exactly like those of
the stomach. A diverticulum of the lesser sac passes to the
right behind the bowel, whilst the remainder of its circumference

364 CLINICAL APPLIED ANATOMY.

is in relation with the greater sac. Duodenal ulcer, however,
like gastric ulcer, does not tend to perforate into the lesser sac
and probably for similar reasons, i.e., the formation of adhesions
which obliterate the small posterior diverticulum. Ulcers of the
first part have, however, a great tendency to perforate anteriorly
into the greater sac and to produce either general peritonitis or
a localised collection of pus in the right kidney pouch or
subphrenic space. Various vessels have been known to be
eroded. Posteriorly the portal vein, the hepatic artery, or its
gastro-duodenal branch may suffer. The superior pancreatico-
duodenal branch of the latter has been perforated, and ulceration
has been known to extend sufficiently to the left to open branches
of the splenic artery, and even the aorta. (Fig. 52, p. 416.)

The second part of the duodenum is sometimes the site of
ulceration, which is usually above the level of the biliary papilla.
This part lies on the right side of the spine, and reaches as low
as the third or even the fourth lumbar vertebra. The transverse
colon crosses its middle ; it comes into contact above with the
neck of the gall bladder and below with the coils of small
intestine ; any of these may be opened by an ulcer, and a bi-
mucous fistula result. Posteriorly it is in relation with the
inner part of the right kidney, with its vessels and ureter; but
these are not known to suffer. Moulded on its right or convex
aspect is the duodenal impression of the liver, and below this the
hepatic flexure of the colon. Its concave left aspect is closely
applied to the head of the pancreas, and is in intimate relation
with the bile and pancreatic ducts, the papilla of Vater, or
common orifice of these ducts, being found three and a half or four
inches beyond the pylorus. Ulcers near the papilla are of especial
importance, since they may cause complete cicatricial occlusion
of both the bile and pancreatic ducts, giving rise to very
characteristic symptoms. The inferior vena cava is in close
relation with the duodenum behind the head of the pancreas.
The second part of the duodenum is only covered by peritoneum
in front and on its convexity. When there is no transverse
mesocolon, the transverse colon may be in direct contact over a

DUODENAL CAECINOMA. 365

considerable area. The bearing of the peritoneal and colic
relations on the possibility of perforation into the greater sac
and into the transverse colon is obvious.

As the result of duodenal ulceration cicatricial stenosis may
occur, or the presence of dense external adhesions may cause
considerable obstruction.

Pressure on the duodenum sometimes leads to obstruction.
The pressure may be due to a movable right kidney, and is then
intermittent. A stomach much distended with fluid may exercise
pressure on the terminal portion of the duodenum which lies
behind it. Collapse of the small intestine may cause the superior
mesenteric vessels to become tightly drawn across the transverse
portion of the duodenum, and may thus obstruct it.

Malignant disease of the duodenum is very uncommon. A
carcinoma of the first part appears as a movable tumour, with
symptoms very like those of pyloric cancer. If the obstruction
is considerable no regurgitation of bile is possible. Carcinoma
is more likely, however, to arise in the neighbourhood of the
papilla of Vater. The tumour is then fixed, even in its early
stages, for this part of the duodenum is not movable, being
retroperitoneal. Obstruction of the biliary and pancreatic ducts
will complicate the intestinal obstruction which results. Eetro-
peritoneal growths arising in the lymphatic glands sometimes
encircle and infiltrate the retroperitoneal portion of the duodenum,
and may compress the bile duct and pancreatic duct at the same
time.

Malformations of the duodenum are rare. When the duodenum
is prolapsed, traction by the bile duct may draw out a small
diverticulum. Diverticula may also arise from ulceration and
yielding of the wall. A diverticulum sometimes projects above
the biliary papilla and passes towards the head of the pancreas ;
this has been attributed to the influence of one of the outgrowths
from which the pancreas is developed. External adhesions at
the base of an ulcer may also drag out the duodenal wall in the
form of a pouch.

Rupture of the duodenum usually results from the passage

366 CLINICAL APPLIED ANATOMY.

of a wheel across the abdomen, whereby this portion of the bowel
is subjected to a shearing force. Being fixed on the front of the
spine, it cannot slip away, and is lacerated. The rent may be
entirely extraperitoneal.

Malignant disease of the small intestine is rare. "When a
distinct tumour is present, and this is more likely to be the case
with sarcoma than with carcinoma, the length of the mesentery
may allow the growth to gravitate towards the lower part of the
abdomen. It may become adherent in this position, and by
ulceration a fistulous communication may be established with
some part of the colon, the urinary bladder, or other hollow
viscus. Pedunculated growths in the interior of the jejunum
or ileum sometimes give rise to extensive chronic intussusceptions,
an occurrence which is favoured by the length and freedom of
the mesentery.

Malignant disease of the colon usually occurs in the form
of an annular carcinomatous infiltration leading to stricture.
Occasionally it is in the form of a tubular infiltration. In both
cases the interior, being exposed to the passage of the bowel
contents, tends to ulcerate and become septic. Malignant disease
is prone to arise in those parts of the colon which present abrupt
bends or are exposed to pressure by bony edges. It is often
met with on the brim of the true pelvis, or opposite the crest
of the ilium ; it is less common at the splenic or hepatic flexures,
in the transverse colon or the caecum. (Eig. 49, p. 362.)

The growth opposite the brim of the true pelvis lies at the
junction of the iliac and pelvic portions of the colon. It may
become adherent to the left iliac vein, causing oedema of the left
leg, or compress the left ureter, giving rise to left renal colic
and hydronephrosis. Since the ovarian fossa and ovary are
close by, it is not surprising that the growth may become
adherent to the latter. Haemorrhoids may occur from obstruc-
tion to the veins in the bowel wall. Perforation at the site of
the growth will give rise to a pelvic abscess or a spreading general
peritonitis.

The growth opposite the iliac crest on the left side occurs at

INTESTINAL CAECINOMA. 367

the point of junction of the descending and iliac portions of the
colon.

Carcinoma at the splenic flexure cannot as a rule be palpated,
since this part of the colon is deeply situated under cover of the
ribs. Any tendency to prolapse of the growth is counteracted
by the phrenico-colic ligament. The growth is in close relation
with the spleen and the front of the left kidney.

Similar considerations apply to growth at the hepatic flexure.
The growth lies deeply, and the hepato-colic ligament which is
occasionally present may keep it up. It is in relation with the
right lobe of the liver, the gall bladder, and the duodenum.

Carcinoma of the transverse colon is usually associated with
prolapse of this part. The average length of this segment of
the large bowel is twenty inches, and the length of the mesocolon
is five inches from origin to attachment. The prolapsed growth
tends to become adherent to the pelvic colon, the urinary bladder,
or the uterus. Occasionally it becomes adherent to the stomach,
to the lower border of which the transverse colon is closely
applied.

Carcinoma of the caecum is rare, and commences in the neigh-
bourhood of the ileo-caecal valve. It may become adherent to
the external iliac vein or the right ureter. Carcinomata of the
ascending or descending colon or caecum occasionally ulcerate
into the retroperitoneal tissue, since these parts of the bowel
may be devoid of a complete peritoneal investment. Carcinoma
at the junction of the iliac and pelvic segments of the colon
may do the same.

Secondary deposits may be expected in the lymphatic glands
and also, since this part of the bowel belongs to the portal
area, in the liver. In some cases the general circulation is
invaded, and metastatic deposits occur in the lungs, bones, and
other parts. Involvement of the glands is slow. The lym-
phatics of the ilio-pelvic colon terminate in glands around
the inferior mesenteric artery. The lymphatics of the trans-
verse colon and its two terminal flexures are numerous, and
pass alongside the middle colic artery to the glands of the

368 CLINICAL APPLIED ANATOMY.

superior mesenteric chain. They communicate freely with the
lymphatics of the great omentum, and so come into relation with
the lymphatics of the lower border of the stomach. The lymphatics
of the ascending and descending colon also gain the superior
mesenteric chain. The glandular apparatus of the descending
colon is very poorly developed, which may account for the slow^-
ness with which glandular infection occurs when the disease is in
the lower parts of the bow^el.

Malignant disease of the rectum is more common than in any
other part of the alimentary tract. It may either originate in
the glandular epithelium of the crypts of Lieberkiihn or in the
squamous epithelium of the anal canal. Squamous epithelium
extends up to the lower ends of the columns of Morgagni, and,
according to some authors, along these columns also. Local
extension of rectal growths is liable to involve important pelvic
structures, for the prostate, urinary bladder, vesiculae seminales,
and terminations of the vasa deferentia, lie in the closest contact
with the anterior rectal wall. In the female, the vagina and
uterus are apt to be invaded, and fistulous communications may
be thus established. By backward extension rectal growths
become adherent to the sacrum and coccyx.

Ulceration of the Small Intestine. — Tuherculoiis ulcers com-
mence in the Peyer's patches or the solitary follicles. These
ulcers tend to extend transversely round the bowel, following
the course of the lymphatic vessels. The lymphatic collecting
trunks in the mesentery sometimes become caseous, and can be
traced to the mesenteric glands, which may also be infected.
Since both the Peyer's patches and the solitary follicles are best
developed in the lower ileum, the ulcers are best marked in this
region. They are especially common just above the ileo-csecal
valve, owing to the obstruction offered by that structure to the
onward passage of the intestinal contents.

Typlioid ulcers also originate in the lymphoid structures, and
are best marked in the lower part of the ileum. They are
produced by sloughing or necrosis of Peyer's patches and
follicles, and have not the same tendency to extend transversely

INTESTINAL OBSTKUCTION. 369

that tuberculous ulcers exhibit. An important collection of
lymphatic glands lies around the termination of the superior
mesenteric artery at the ileo-caecal angle. These glands are
involved secondarily to ulceration of the lower part of the
ileum, and by suppuration may give rise to peritonitis, since
they are immediately beneath the peritoneum.

In summer diarrhoea and various infectious fevers other than
typhoid, considerable swelling and even ulceration of the
lymphoid tissue of the intestine may occur.

Ulcers of vascular origin, girdling the intestine, are sometimes
met with as the result of embolism, thrombosis, syphilis, and
amyloid disease. The distribution of the arterial twigs which
supply the intestine is the basis of the transverse arrangement
of these ulcers.

Ulceration of the Large Intestine. — Although there are no
Peyer's patches in the large bowel, lymphoid tissue is plentiful,
particularly in the caecum and vermiform appendix. Ulcers
may arise in this tissue in many infective conditions, such as
typhoid fever, tuberculosis, and dysentery. So-called stercoral
ulcers are particularly apt to form in the caecum as the result of
chronic obstruction of the bowel, and certain metallic poisons,
like mercury and antimony, may, during the process of excretion
by the colon, originate ulceration.

Intestinal Obstruction.
{Other than that due to Malignant Disease.)

Strangulation by a band is an accident which is almost
exclusively limited to the small intestine, this part of the bowel
being more easily ensnared than the colon owing to its greater
mobility, smaller calibre, and coiled arrangement.

Bands are usually adventitious structures which have resulted
from past inflammation or operation. They occur most fre-
quently in the lower part of the abdomen, in connection with the
vermiform appendix, the hernial orifices, the Fallopian tubes, and

C.A.A. 24

370 CLINICAL APPLIED ANATOMY.

the mesenteric glands. The parts of the small intestine most
likely to become entangled are those which lie in relation with
these structures.

A Meckel's diverticulum sometimes acts as a band, producing
obstruction. The diverticulum, which is the remains of the
vitelline duct, usually arises from the small intestine within three
feet of the ileo-csecal valve. It may retain its connection with
the umbilicus, or its extremity may be free or acquire adhesions
to other structures.

Strangulation in a peritoneal slit is sometimes observed.
The aperture is usually in the lower part of the mesentery of
the ileum, and is surrounded by an arterial arch formed by
the ileo-colic branch of the superior mesenteric artery and the
lowest of the vasa intestini tenuis. Slits may also occur in other
broad peritoneal folds, such as the great omentum, the broad
ligaments, the falciform ligament, the phrenico-colic ligament, or
even the mesentery of the appendix.

Diaphragmatic hernia may be congenital, or acquired.
The congenital variety is due to persistence of the original
communication between the pleural and peritoneal cavities.
The opening is in the dorso-lateral region of the diaphragm,
and usually occurs on the left side, since the presence of
the liver on the right side aids the closure of the right
communication. The serous membranes of the two cavities
being continuous, the extruded viscera lie free in the
pleural cavity. The stomach usually passes into the cavity,
dragging in the colon and spleen by virtue of their omental
connections. The liver and pancreas sometimes enter as well.
The displacement of the stomach may lead to acute torsion of
the small omentum and partial strangulation.

The acquired forms may be traumatic or spontaneous.
Traumatic hernia is due to wounds or ruptures of the diaphragm.
Spontaneous diaphragmatic hernias have definite sacs. They may
pass through the oesophageal opening or between the sternal and
costal portions of the diaphragm, never, it is said, through the open-
ings for the aorta or vena cava. In enteroptosis, the oesophageal

DUODENAL HEENIA. 371

opening of the diaphragm may be so displaced downwards that
it actually encircles part of the stomach below the oesophagus.

Duodenal hernia may occur in two forms, the right and the
left. Of these the left hernia occupies a peritoneal fossa which
lies to the left of the duodeno-jejunal junction. The mouth of
the sac contains in its left margin the inferior mesenteric vein
and usually the left colic artery. These two vessels form by
their intersection the vascular arch of Treitz. The hernial sac
burrows in the retroperitoneal tissue in a direction outwards or out-
wards and upwards. In extreme instances the whole of the small
intestine may lie in the sac. When the opening of the sac is in
view only the issuing coil of intestine can be seen ; the entering
coil being entirely concealed, appears to gain the interior by
perforating the sac wall. As the hernia extends in the retro-
peritoneal tissue it passes behind the attachment of the ascend-
ing and descending colon to the parietal peritoneum, so that the
colon becomes closely applied to the front of the sac. Behind the
sac lie the psoas and the kidney with the renal vessels. The com-
pression to which the inferior mesenteric vein is exposed at the
mouth of the sac may give rise to haemorrhoids and bleeding
from the bowel.

The right duodenal hernia is so called because it lies to the
right of the spine. The orifice of the sac lies behind and to the
left, on the lumbar vertebrae. The hernia appears to originate
in a small fossa in the mesentery of the upper part of the
jejunum, lying immediately below the transverse portion of the
duodenum. The orifice of the sac lies within the concavity of
the curve formed by the superior mesenteric artery as that
vessel arches downwards and to the right. The aperture may
be dragged downwards to the right iliac fossa by the weight of
the intestine, and so confounded with hernial orifices in this
region. As the hernia develops it establishes relations with the
back of the ascending and transverse colon.

Hernia into a fossa about the caecum is either ileo-csecal
or retro-colic. The ileo-colic fossa is not known to be the site
of hernia. The ileo-csecal fossa lies between the mesentery of

24—2

372 CLINICAL APPLIED ANATOMY.

the appendix behind and the ileo-caecal fold in front. Small
intestine may become entangled in this fossa, and the appendicular
artery then lies behind the mouth of the hernial sac. Hernia
into the retro-caecal fossa usually goes by the name of retro-colic,
since the sac lies behind the lower part of the ascending colon.
The outer boundary of the fossa is known as the retro-colic fold
or suspensory Hgament of the caBCum. The inner boundary is a
downward prolongation of the mesentery of the small intestine
towards the iliac fossa, which is sometimes called the inferior
ligament of the caecum, and may reach to the inguinal canal
or the broad ligament.

Intersigmoid hernia lies in a pouch behind the root of the
mesentery of the pelvic colon. The common iliac artery and
the ureter lie behind the mouth of the fossa.

Hernia into the foramen of Winslow has been met with.
Some part of the small intestine or colon passes through the
foramen into the lesser sac of the peritoneum, and is strangu-
lated. The stomach lies in front of the sac, and the presence of
the hepatic artery, portal vein, and bile duct in the constricting
ring may render relief of the condition impossible.

Gross congenital malformations of the peritoneum are often
associated with the different forms of internal hernia. Indeed,
the occurrence of hernia into the foramen of Winslow is impos-
sible apart from such abnormalities. Either the caecum and
ascending colon fail to migrate in the usual manner towards the
right iliac fossa, or an abnormal length of mesentery, or a
mesentery common to great and small bowel is present.

A yoIyuIus or twist is only likely to occur in those parts
of the bowel which are provided with a long fan-shaped mesentery.
This condition is normally fulfilled by the pelvic colon and the
coils of small intestine, but as an abnormality the ascending
colon may have an unusually long mesocolon, or there may be
a common mesentery for the small intestine, caecum, and a
variable length of the colon. The pelvic colon is the part
usually twisted; the mesentery is of the required shape, and
the bowel is constantly changing its position with the varying

INTUSSUSCEPTION. 373

distension of the bladder and rectum. A volvulus occasionally
involves the small intestine.

The caecum may be obstructed in consequence of its becoming
acutely flexed on the colon ; the colon and caecum may become
twisted round their longitudinal axis, or the ascending, trans-
verse, and descending colon may form one large volvulus.
Strangulation is not so acute when the intestine is merely bent
at an angle instead of becoming twisted on its mesenteric axis.
In acute strangulation the vessels are obstructed, the bowel
becomes greatly congested and swollen, and the peritoneal coat,
which is the least distensible, is apt to tear. Peritonitis is an
early complication.

Intussusception usually occurs in the neighbourhood of the
caecum, but it is also found in the jejunum, ileum, colon, and
rectum. It appears most likely to occur where a part of the
intestine which is more or less free joins a part which is com-
paratively fixed ; consequently the favourite sites for intussuscep-
tion are the caecal region, the lower end of the ileum, where
that becomes comparatively fixed before entering the colon, and
the junction of the pelvic colon with the rectum. In the ileo-
caecal variety, which up to recent time has been held to be the
commonest, the ileo-caecal valve, followed by the small intestine,
becomes prolapsed into the colon. In the ileo-colic form the
lower part of the small intestine becomes prolapsed and engaged
in the jaws of the valve. This form rarely attains a great size
of itself, but the end of the ileum, tightly gripped in the jaws of
the valve, is apt to form the starting-point of a new intussus-
ception of the ileo-caecal form. A compound intussusception
results, and this is now said to be the commonest variety.
Another form of compound intussusception may arise when an
enteric invagination reaches the valve, and, being unable to pass
through it, pushes it on in front. Whenever the ileo-caecal valve
is prolapsed the caecum and appendix become drawn into the
receiving sheath, the general rule being that intussusceptions
increase at the expense of the receiving sheath. The mesentery
being also drawn into the sheath by the portion of intestine to

374 CLINICAL APPLIED ANATOMY.

which it is attached, intense engorgement of the intussuscepted
bowel occurs, leading to the passage of blood and mucus, and some-
times to sloughing of the intussusceptum. The traction on the
mesentery also confers a characteristic curve on the intus-
susceptum, and may cause its orifice to be tilted against the
side of the receiving layer. Complete obstruction of the bowel
or sloughing of the receiving layer at the point of pressure may
result. The tumour, consisting as it does of muscular bowel,
may sometimes be felt to harden and relax during examination.
The highly cedematous and inflamed apex of an enteric intus-
susception may easily be mistaken for the ileo-caecal valve. A
polyp is often the starting-point of an intussusception in the
adult, and in childhood inflamed Peyer's patches or invaginated
saccules of the colon are believed to act in a similar manner.

Intussusceptions during their progress follow the direction of
the colon, and in some cases protrude from the anus. For an
intussusception arising in the csecal region to do this it is
obvious that either an extensive mesocolon must be present,
or the colon and its mesentery must be stripped away from the
posterior abdominal wall.

A moment's reflection will show that the easiest way to reduce
a tight intussusception is by compression from below aided by
traction of the outer layer downward over the intussusceptum,
thus causing reduction by gradually unrolling the outer tube in
the reverse way to that in which the invagination was brought
about. Upward traction on the intussuscepted layer causes the
unfolding to occur at the apex of the entering tube ; this process
is resisted, and tends to throw the inner tube into folds, further
wedging it in the bowel. But intestine prolapsed through the
ileo-caecal valve usually has to be reduced by upward traction.

Obstruction of the Bowel by Gall Stones. — A gall stone large
enough to become impacted in the bowel must of necessity have
entered it by ulceration, and not by passage along the bile ducts.
The relations of the gall bladder render it possible for a stone
to enter either the duodenum or the colon in this way, but entry
into the duodenum is by far the commoner and more serious

STEICTURE OF INTESTINE. 375

occurrence. Once in the lumen of the bowel the point of
impaction is largely determined by the size of the stone, for
there is a gradual diminution in the calibre of the intestine from
the duodenum to the ileo-caecal valve. The ileo-csecal valve
itself may offer considerable resistance to the passage of a stone.
A stone in the colon may become impacted in the pelvic segment
or near the anus, the calibre of the pelvic colon and rectum
being much less than that of the upper portions of the large
bowel. Comparatively small stones may induce obstruction by
setting up spasm of the muscular coat of the bowel. A gall
stone by its weight may drag down the coil of small intestine
which contains it, and even be felt in the pouch of Douglas.

Impaction is not the only way in which gall stones produce
obstruction. A volvulus may result from their presence in the
bowel. Adhesions of the gall bladder may obstruct the bowel
or the obstruction may be due to acute peritonitis.

Cicatricial strictures of the intestine arise in various ways
Tuberculous ulcers tend to encircle the gut, and strictures
may result in the lower part of the ileum, where lymphoid
tissue is very abundant and tuberculous ulcers, consequently,
are commonest. Dysenteric ulcers frequently cause stricture.
Strictures are met with in the rectum, pelvic colon, and some-
times at the hepatic and splenic flexures, all of which are
positions in which the bowel wall presents sharp bends. Cicatrices
may also occur in those parts of the bowel which have been
strangled in hernial orifices.

Compression by adhesions usually affects those segments of
the intestine which are the least movable, such as the ascending
and descending colon and the hepatic and splenic flexures.

Congenital Obstructions of the Food Passages.

Congenital occlusion of the oesophagus, gives rise to vomiting,
choking, inanition, and hunger in the new born. The obstruction
cannot be due to a failure of the oral depression to meet the
anterior end of the primitive gut, for it lies below the pharynx.

376 CLINICAL APPLIED ANATOMY.

which is itself a derivative of the fore gut. The occlusion is
usually just below the level of the cricoid cartilage, and is deter-
mined by the outgrowth of the lung bud from the primitive
intestinal tube. A fistulous communication between the oeso-
phagus and trachea frequently exists below the obstruction.
Earely the oesophagus is stenosed just above its entrance into
the stomach.

Hypertrophic stenosis of the pylorus is probably a congenital
condition, and is characterised by a great hypertrophy of the
muscular coat of the pylorus and pyloric canal.

Occlusion or obstruction of the duodenum is sometimes found
in the neighbourhood of the common bile duct, and may be due
to the outgrowth of the liver, or pancreas buds in this position.

Stenosis of the duodeno -jejunal flexure is rare. It has been
attributed to developmental changes in the peritoneal folds of
this region.

Occlusion or stenosis of the ileum may be found at the site of
Meckel's diverticulum. This diverticulum arises within three
feet of the ileo-csecal valve, and is the residue of the vitelline
duct. It may or may not retain its connexion with the umbilicus.

Multiple congenital strictures of the small intestine occur
rarely. No satisfactory explanation of these has been offered.

Congenital dilatation of the colon is associated with obstinate
constipation, and may be met with without organic obstruction
of the rectum or anus.

Malformations of the rectum include congenital strictures,
imperforate conditions, absence of the anus or the rectum, or
both those structures, and openings of the rectum in abnormal
situations.

An obstruction may be found at the junction of the anus and
rectum in the form of a membranous fold. The fold is probably
a remnant of the cloacal membrane. The anal valves, which lie
at the lower ends of the columns of Morgagni, represent the
cloacal membrane, the fusion of anus and rectum corresponding
to the white line in this situation.

Congenital strictures of the rectum sometimes assume a

APPENDICITIS. 377

cylindrical form. These may arise in connexion with the out-
growth of the allantois from the bowel, an explanation which
brings them in line with similar strictures of the oesophagus,
duodenum, and ileum.

Occasionally the rectum ends blindly two inches or more
above the anus. The mere persistence of the cloacal septum is
insufficient to account for so much separation of the two tubes.
In such cases either a part of the rectum has been obliterated,
and may still be represented by a fibrous cord, or the condition
may be due to a complete failure in the down-growth of the
post-allantoic portion of the gut.

If the rectum retains its connexion with the allantois, and the
anal canal is not formed, the bowel may open into the bladder or
upper part of the vagina. Abnormal communications with the
urethra, or openings in the region of the vulva, indicate that the
bowel has retained its communication with the front part of
the uro-genital sinus. Communication of the rectum with a
spina bifida suggests the persistence of a neurenteric canal.

Discharge of bowel contents from the umbilicus are in some
cases due to a wound of a prolapsed coil of intestine during
division of the umbilical cord. In other instances a Meckel's
diverticulum is present and patent.

It has been suggested that a coil of bowel is sometimes ensnared
in the umbilical ring during foetal life and so obliterated.

APPENDICITIS.

The situation of the local tenderness and the local swelling
caused by appendicitis will depend upon the position which
the appendix happens to occupy.

The spot at which the vermiform appendix springs from the
inner and back part of the caecum may be indicated with sufficient
accuracy by taking a point one inch below the intersection of the
right Poupart and the intertubercular planes. (Fig. 49, p. 362,
also Fig. 54, p. 429.) The "lie" of the appendix itself is
inconstant, and cannot be predicted with accuracy.

378 CLINICAL APPLIED ANATOMY.

In most cases the appendix lies internal to the long axis of the
caecum, but sometimes it is behind or to the outer side of it.
When it is to the inner side of the caecum it may lie under cover
of the lower end of the ileum and mesentery of the small
intestine, or be coiled up on the pelvic brim, or hang over into
the cavity of the true pelvis. If it is behind the ileum and its
mesentery, which is not an uncommon position for it to occupy,
these structures will have to be raised in order to expose it, and
the peritonitis which results from its inflammation is very apt
to spread widely amongst the coils of the small intestine. In such
cases the local swelling and tenderness will be felt in the right
iliac fossa internal to the position of the caecum. Inflammation
of an appendix which lies coiled on the pelvic brim is in a
favourable position to infect both the pelvis and the right iliac
fossa ; the inflammatory mass should be felt superficially just
above Poupart's ligament. If the appendix hangs down over
the brim of the true pelvis, the peritonitis which results from its
inflammation involves the structures in the pelvis, and the
inflammatory mass may only be detected by rectal or vaginal
examination.

"When the appendix is not internal to the long axis of the
caecum, it may be found in a retrocaecal pouch, or may extend
upwards behind the ascending colon or lie in the sulcus between
the caecum and the right flank. An appendix in a retrocaecal
pouch may give rise to a localised and deep-seated abscess which
is diflicult to find. The difliculty is even greater when the
appendix is actually bound down behind the ascending colon.
In such cases it has probably become entangled during the
descent of the caecum, and imprisoned by the normal adhesion
of the mesocaecum to the abdominal wall. The fact that all the
longitudinal bands of the colon converge to the root of the
appendix may afford considerable assistance to the surgeon in
his search for an abnormally placed appendix. When the
appendix lies behind the caecum or colon, tenderness on deep
pressure may often be found, not on the front of the abdomen,
but immediately above the iliac crest posteriorly. In such cases

APPENDICITIS. 379

the retroperitoneal connective tissue may become invaded during
the course of the disease. When the appendix hes in the
peritoneal sulcus between the caecum and the flank, the inflam-
matory mass may be found in the right loin, and is favourably
placed to infect the right kidney pouch of the peritoneum and
extend into the right subdiaphragmatic region.

In rare instances the caecum fails to complete its migration
from the umbilical region to the right iliac fossa. In such cases
the abscess resulting from appendicitis may lie in the region of
the umbilicus or neighbourhood of the right kidney. If the
descent of the caecum fails to stop at the proper point both
caecum and appendix may be found in the true pelvis. When
the caecum is loosely attached to the abdominal wall the appendix
may wander into the left iliac region. It has also been found in
the sacs of umbilical, inguinal, or femoral herniae. Inflamma-
tion of an appendix in any of these abnormal situations may
give rise to great difficulties in diagnosis.

The vermiform appendix is essentially a lymphoid organ. It
abounds in lymphatic tissue and closely resembles the tonsil.
This, together with the fact that it is a blind tube, explains its
proclivity to inflammation and perforation. In common with
other lymphoid aggregations, a certain amount of atrophy occurs
after middle life. Appendicitis is most common before this
retrogression occurs. The narrow lumen of the tube is easily
obliterated as a consequence of inflammation, and retention cysts
may arise as a consequence.

The lymphatics of the appendix, which arise in the lymph
sinuses surrounding the lymphoid nodules, after traversing
some insignificant glands in the meso-appendix, terminate
in a group of glands near the ileo-caecal junction, round the
terminal branch of the superior mesenteric artery. These
glands may form part of the inflammatory swelling in appen-
dicitis. Suppuration in them is quite the exception. A group
of retroperitoneal glands along the inner border of the ascending
colon is frequently enlarged as well, as also are some glands
which lie alongside the right iliac arteries. An anastomosis

380 CLINICAL APPLIED ANATOMY.

between the lymphatics of the appendix and those of the
right ovary has been described but needs confirmation. The
appendix receives its blood-supply from the appendicular artery.
This small vessel is derived from the terminal branch of the
superior mesenteric, and usually passes behind the termina-
tion of the ileum to reach the meso-appendix. Kunning along
the free edge of this fold it distributes a series of branches to
the wall of the appendix. The meso-appendix is not continued
quite to the tip of the appendix, and where it terminates the
appendicular artery continues its course in close apposition to the
muscular wall. The base of the appendix also receives twigs
from the caecal arteries, and, in the female, the ovarian artery is
said to supply a small branch, but, like the intercommunication
between the appendicular and ovarian lymphatics, the presence
of this is not satisfactorily established. There can be no doubt
that the chief factor in the production of gangrene is virulence
of inflammation, but it has been supposed that obstruction of
the appendicular artery by twists or adhesions may be a con-
tributing cause. The great frequency of gangrenous processes
near the tip of the organ may be due to the greater ease with
which the terminal portion of the appendicular artery is involved
by extension of the inflammation, the vessel being here in closest
contact with the muscular wall.

The nerves of the appendix are derived from the superior
mesenteric plexus. This plexus consists of branches from the
coeliac plexus, the semilunar ganglia, and the vagus. Neverthe-
less, the wall of the appendix, like other parts of the intestine,
is quite insensitive. Consequently absence of pain in appendicitis
does not indicate that serious mischief is not in progress. In
the early stages of appendicitis pain is often vaguely referred to
the region of the umbilicus. This pain is supposed to be due to
the drag exercised by the contracting caecum and appendix on
their peritoneal attachments to the posterior abdominal wall, for
it is well known that tension on the root of the mesentery or
mesocolon can elicit pain of this nature. This supposition is
supported by the fact that the umbilical pain soon ceases,

APPENDICITIS. 381

presumably owing to paralysis of the gut induced by increasing
inflammation. The occurrence of deep-seated local pain in
appendicitis indicates inflammation of the sensitive parietal
peritoneum or retroperitoneal tissues. Absence of this deep
tenderness may be of serious prognostic import, indicating a
profound toxaemia. Cutaneous hyperaesthesia, if present, for
it is exceptional, corresponds in distribution to the tenth, eleventh,
and twelfth dorsal segmental areas. It is a true reflected
tenderness, and is not derived from the visceral peritoneum,
which appears to be unable to originate sensory impulses.

The mass which is felt in the abdomen in cases of appendicitis
may consist of inflamed caecum and small intestine, the appendix
itself, inflamed omentum, enlarged glands, faecal matter, and
pus. The disposition of the great omentum over the front of
the intestinal coils accounts for the frequency with which it
forms part of the wall of an appendix abscess.

Venous thrombosis may arise as a complication of appendicitis.
The veins of the appendix are radicles of the portal system, and
may be the starting-points of portal thrombosis or portal
pyaemia. The proximity of the appendix to the right iliac veins,
across which it may lie, sometimes leads to thrombosis or
infection of these vessels, and in such cases thrombosis of the
right femoral vein, extension of clot to the opposite common iliac
vein, systemic pyaemia or pulmonary embolism, are dangers to be
feared.

Arteries are rarely eroded during the course of the inflamma-
tion. If they are, haemorrhage into the peritoneal cavity or into
the bowel may occur. The right iliac arteries, the deep circumflex
iliac, and the colic branches in the wall of the gut have been
known to be the source of haemorrhage in such cases.

The tracks followed by the pus when suppuration is localised
and intraperitoneal, or becomes extra,peritoneal, are described
subsequently. (See page 883.)

In the attempt to avoid hernia as a sequel to operations on
the appendix, advantage is taken of the arrangement of the
muscular layers of the abdominal wall. The rectus sheath may

382 CLINICAL APPLIED ANATOMY.

be opened, and that muscle pulled aside, so that when allowed
to return it covers the incision in the posterior wall of the
sheath, or access may be gained by separating the external
oblique, internal oblique, and transversalis muscles in the
direction of their fibres which decussate with each other. In all
cases it is important to bear in mind that the outer edge of
the rectus usually extends in the adult to within two inches of
the anterior superior iliac spine.

Diseases of the Peritoneum,
acute peritonitis.

Acute peritonitis is usually the result of infection which has
spread from some viscus which is invested by the visceral or
abuts against the parietal layer of the membrane. In the female
the orifices of the Fallopian tubes allow infection to spread from
the genital passages. In some cases peritonitis results from
blood-borne infection, and it may also follow penetrating wounds
of the sac. The extension of the serous membrane into the
dome of the diaphragm renders the sac liable to penetration by
wounds of the lower part of the thorax, and its extension around
the rectum and along the upper third of the posterior vaginal
wall exposes it to injury in these situations. The membrane
may also be infected along a patent funicular process.

The most vulnerable part of the visceral layer is that which
invests the small intestine and appendix. The pelvic portion is
more resistant to infection. It is exceptional for infection to
spread through the parietal portion of the greater sac from
without, but this sometimes happens, particularly in the region
of the diaphragm. The lymphatic channels are better developed
in this situation. The parietal portion of the lesser sac is liable
to infection from the subjacent pancreas.

The great absorptive power of the peritoneum accounts for the
rapidity with which toxic symptoms arise in peritonitis. The
area of the membrane is said to be equal to that of the whole
integument of the body, and it is looked upon as a large
lymphatic space, although it is doubtful if its direct connexion

INTEAPEEITONEAL SUPPUEATION. 383

with lymphatics hy means of stomata is so free as was at one
time supposed. Unfortunately it matters little whether the
toxic absorption is due to the agency of lymphatics or the blood
vessels with which the membrane is freely supplied.

The nervous connexions of the peritoneum are important. It
receives branches from the lower seven intercostal trunks through
the great abdominal plexuses of the sympathetic. The same
nerves innervate the abdominal muscles and lower intercostals.
The movements of these muscles are therefore restricted in
peritonitis, as also is that of the diaphragm.

The visceral layer of the peritoneum appears unable to trans-
mit painful sensations, but the parietal layer is extremely sensi-
tive. The pain of peritonitis is due to implication of the parietal
peritoneum, and is as a rule deep seated and not referred to
cutaneous areas.

INTRAPERITONEAL SUPPURATION.

(Fig. 50, p. 384.)

For the consideration of localised abscesses and the tracks
followed by purulent collections within the peritoneum, it is
convenient to divide the peritoneal cavity into certain regions.

1. The Subdiaphragmatic or Supramesocolic Eegion, which is
included between the transverse mesocolon below and the dia-
phragm above. This space may further be subdivided into a
part below the right wing of the diaphragm, a part below the
left wing, and a part below the right lobe of the liver in the
region of the right kidney.

2. The Lumbar Eegions, situated laterally, and containing the
ascending and descending portions of the colon. These regions
are effectually separated by the prominence of the lumbar spine.

3. The Submesocolic Eegion, between the transverse meso-
colon above and the mesentery of the small intestine below.
This region is continuous laterally with the right lumbar region,
of which it is virtually a part.

4. The Submesenteric Eegion, intervening between the mes-
entery and the true pelvis. It bears the same relation to the

384 CLINICAL APPLIED ANATOMY.

left lumbar region that the submesocolic region bears to the
right.

5. The Lesser Sac of the Peritoneum. This is a diverticulum
of the greater sac arising in the region of the right kidney.

6. The Eegion of the Pelvis.

The mesocolon and mesentery constitute peritoneal partitions
of which the mesocolon is more complete and important. The
transverse mesocolon is attached to the posterior abdominal wall
at the level of the second lumbar vertebra. Traced from right
to left across the abdomen it first ascends as it crosses the lower
part of the right kidney, the second part of the duodenum, and
the head of the pancreas, after which it runs to the left with less
upward inclination, along the anterior border of the body of the
pancreas. The projection of the lumbar spine and a small
upward prolongation of the superior layer of the mesocolon in
this region sharply separate the right and left halves of the fold.
Consequently extravasations of fluid above the right half are
directed downwards towards the depression around the upper
part of the right kidney.

The root of the mesentery springs from the posterior abdominal
wall along an oblique line which extends from the left side of the
second lumbar vertebra to the right iliac fossa. Starting at
the duodeno-jejunal flexure, the line of attachment crosses the
front of the terminal part of the duodenum, the aorta, the inferior
vena cava, the right ureter, and the right psoas muscle to reach
a variable point in the right iliac fossa. The direction may be
indicated on the surface by drawing a diagonal line from a point
on the transpyloric line, an inch to the left of its middle point,
to the right iliac region. The mesentery is not so efficient in
separating the submesocolic from the submesenteric regions as
the transverse mesocolon is in cutting off the subdiaphragmatic
space from the regions below.

Subdiaphragmatic Region.— The viscera in relation with this
part of the greater sac are the stomach, spleen, liver, gall
bladder, bile ducts, part of the duodenum, and upper part of the
right kidney. An abscess in this region may be due to disease

Intra-pkritoneal Suppuration.

L. Live

Transpyloric 1
plane. ~- — ►V

A5ce,noling
Colon.

plane,
Disc line.

Crest of Ilium.

Inter- /'' ^l
tubercular/
plane. ^ '

Stomach .

Splenic (Flexure
^ of Colon.

Caecum.-

Root of

Append i

Margin' of
Psoas Muscle.

Jrctrpsverse Meso-
)lon ends.

-Crest of Ilium.

interior
Suoerior
iiacopin

liac Meso-
colon begins.

Iliac
Colon.

Fig. 50. — The shaded areas indicate the conimon positions of intra-peritoneal
abscesses. The heavy arrows indicate the directions in which such abscesses
tend to track. Abscesses among the coils ol" small intestine have been
omitted.

The diagi-am is founded on one drawn by Christopher Addison to illustrate the
topography of the abdomen (see page 362).

[To face jxige 884.

SUBDIAPHEAGMATIC ABSCESS. 385

or injury of any of these structures. But the area may also
become infected by pus which has travelled up alongside the
ascending or descending colon. Conversely, the track of infection
may pass from above downwards towards the pelvis.

A subdiaphragmatic abscess may lie between the liver and the
diaphragm in the right cupola, around the spleen in the left
cupola, or around the kidney in the right kidney pouch. The
falciform ligament sometimes forms the right or left boundary
of an abscess beneath the diaphragm. The area of percussion
dulness or of tympanitic resonance when gas is present may be
sharply limited by the position of the ligament. The latter is a
crescentric fold, the remnant of the ventral mesentery of the
embryo. Its convex border is attached to the under surface of
the diaphragm, near to the right limit of the pericardium, and
to the anterior abdominal wall an inch or more to the right of
the middle line. Its concave border is attached to the superior
and anterior surfaces of the liver. The fold extends downwards
to within one or two inches of the umbilicus, and the round
ligament lies in its free edge.

An abscess under the right wing of the diaphragm will tend to
raise the diaphragm and depress the liver. Hence on the one
hand, respiratory movements are restricted and the right lung
becomes partly collapsed, whilst on the other the liver is
depressed. Subdiaphragmatic friction, simulating pleural friction
may be heard, and pain, tenderness, and even oedema of the
right axillary region may be present.

An abscess under the left iving of the diaphragm lies in the
greater sac, occupying part of the stomach chamber, and also
the space between the spleen and the chest wall. Such abscesses
are sometimes termed perisplenic. The retention of pus in
this situation is considerably assisted by the presence of a well
marked phrenico-colic fold. This fold is continuous with the
left part of the great omentum, from which it is derived, and
extends outwards from the splenic flexure of the colon to the
diaphragm. Thus, when the patient is supine, there is a natural
well in the left subdiaphragmatic region, containing the spleen

C.A.A. 25

386 CLINICAL APPLIED ANATOMY.

and a portion of the stomach, and corresponding to the well
around the upper part of the right kidne3\ This well is ready
for the reception of any fluid which may trickle into it. The
physical signs produced by a collection of fluid here are similar
to those already described as accompanying right-sided collections,
with the exception that the left lobe of the liver alone may be
depressed and the cardiac impulse may be displaced upwards.
The subdiaphragmatic friction sound may have a cardiac or
respiratory rhythm.

A siLhdiaphragmatic abscess which lies beneath the liver, and
is consequently sometimes termed subhepatic, occupies a peri-
toneal well, known as the right kidney pouch. This belongs to
the greater sac, and its boundaries are as follows. Above and
in front, the right lobe of the liver and its ligaments ; below,
the hepatic flexure of the colon and its attachment to the
posterior abdominal wall; internally, the peritoneum covering
the descending duodenum and lumbar spine, and stretching
forwards to the foramen of Winslow ; externally, the parietal
peritoneum of the lumbar region. The peritoneum covering
the right kidney forms the floor of the pouch. This well has
proved capable of holding nearly a pint of fluid before it over-
flows into other parts of the peritoneal cavity. With the patient
supine, the right lumbar region slopes from below towards it ;
the right half of the transverse mesocolon forms an inclined
plane directed to it, and the gall bladder and bile ducts lie in
intimate relation with it. Fluid collections in this situation
may travel from the appendix along the lumbar region, or from
the pylorus and duodenum, being directed by the prominence of
the lumbar spine and inclination of the transverse mesocolon, or
may be the result of lesions of the gall bladder and its ducts.
Abscesses in the liver and right kidney or in connection with
malignant growth of the hepatic flexure of the colon may also
be found in this part of the peritoneal sac. A large collection
of fluid here may so push up the liver and impede the action of
the diaphragm as to simulate a collection between the liver and
the diaphragm, but the edge of the liver would be raised in

LUMBAE ABSCESS. 387

the former case and depressed in the latter. The subdia-
phragmatic region may be almost entirely shut off from the rest
of the peritoneal cavity in consequence of adhesion of the great
omentum to the anterior abdominal wall. The upper part may
also be shut off by adhesions between the abdominal wall and
the liver or stomach.

The Lumbar Regions. — These regions communicate below
with the pelvis. With the body supine they form inclined
planes leading from the pelvic brim to the subdiaphragmatic
space. Their separation from the latter is very incomplete.
On the left side the phrenico-colic fold, and on the right a
similar but more variable fold may form more or less effectual
barriers. As the result of appendix suppuration pus may track
upwards in the right loin, between the colon and the parietes,
and infect the right kidney pouch or extend between the liver
and the diaphragm. Even suppuration of pelvic origin may
travel the same way. Conversely, suppuration in connexion
with perforated pyloric or duodenal ulcers may be directed by
the mesocolon and prominence of the spine into the kidney
pouch, and then travel downwards in the right lumbar region
simulating appendicitis. Lesions of the gall bladder may produce
a similar result.

When perforation of the anterior wall of the stomach has
given rise to a collection of fluid in the greater sac around the
spleen, a well developed phrenico-colic fold may effectually
seal off the infection from the left lumbar region. A badly
developed fold may allow the lumbar region and even the pelvis
to be infected. Pelvic collections and infections may travel
upwards by the same route, following the descending colon.

The Submesocolic Region lies between the transverse meso-
colon and the mesentery of the small intestine. Its apex lies at
the point of convergence of these folds near the second lumbar
vertebra. The prominence of the spine causes this region to
slope away towards the right loin, with which region it is
virtually continuous. The combined areas contain coils of small
intestine, the caecum, ascending colon, lower part of the right

25—2

388 CLINICAL APPLIED ANATOMY.

kidney, part of the right ureter, and often the vermiform
appendix.

The Submesenteric Region is related to the duodeno-jejunal
junction, the greater part of the small intestine, the left part
of the transverse colon, the lower part of the left kidney, the
left ureter, the lower part of the abdominal aorta, and the
common iliac arteries. The appendix when it lies behind the
termination of the mesentery, is also in relation w^ith it. This
region communicates freely with the left lumbar region and with
the pelvis.

The Lesser Sac may be looked upon as a diverticulum from
the subdiaphragmatic area of the greater sac. The viscera in
anterior relation to it are the stomach, first part of the duodenum,
and Spigelian lobe of the liver. Behind it are the pancreas, the
left kidney and suprarenal body, and the transverse colon. This
sac varies much in size in different bodies. The variation is
particularly marked in the degree to which the cavity extends
downwards between the layers of the great omentum. The sac
reaches laterally from the hepatic to the splenic flexures of the
colon, and is bounded below by the transverse mesocolon. Like
the greater sac the cavity is potential rather than real, and the
same applies to the foramen of Winslow, the boundaries of
which are normally in contact. A diverticulum of the lesser
sac clothes the back of the commencing duodenum for about an
inch, so that it is possible for duodenal ulcers to open into it.
Clinically, fluid collections in the lesser sac are exceptional. It
often becomes obliterated by inflammatory lesions before there is
any actual perforation. It may be invaded from the stomach,
the duodenum, the liver, the pancreas, the left kidney, the
suprarenal capsule, the transverse colon, and possibly the spleen.
The cystic bile duct has been known to perforate into the sac
through the posterior layer of the lesser omentum.

When an effusion occurs a swelling is seen on the left hypo-
chondriac, epigastric and umbilical regions, of somewhat rounded
outline, and varying from time to time according to the condition
of the overlying stomach. The colon lies below the swelling,

EETEOPEEITONEAL SUPPUEATION. 389

and an area of dulness may be found over the ribs posteriorly,
owing to the upraising of the diaphragm in this region.

The Pelvic Region is often the site of intraperitoneal abscess.
It may be invaded from any of the viscera which it contains.
It is also open to invasion from the lumbar regions as already
explained, and in cases of sudden perforation of the stomach
the great omentum may direct the stomach contents directly to
the pelvis. The region is accessible to examination by the
rectum or vagina. The proximity of the abscess to the bladder
may lead to painful micturition or retention of urine, and even to
exfoliation of parts of the mucous membrane of the bladder. Its
relation to the rectum may cause tenesmus. The abscess may
discharge into bladder or bowel. It is often shut in above by
matted coils of intestine and by the great omentum.

RETROPERITONEAL SUPPURATION.

Eetroperitoneal abscesses may lie in the retroperitoneal con-
nective tissue or beneath the deep fascia of the abdomen.
Abscesses in the areolar tissue are usually derived from the
appendix, but may originate in the caecum, lymphatic glands or
the tissue around the uterus or rectum. When the appendix is
closely bound down to the abdominal parietes by developmental
or inflammatory adhesions it is in a favourable position to infect
the planes of connective tissue. The pus may spread freely and
track in various directions. Upward extension involves the
retroperitoneal tissue of the lumbar region, and may give rise
to perinephritic abscess. The posterior, non-peritoneal, surface
of the liver may be invaded, and even the subpleural tissue
giving rise to infection of the pleural sac. In other cases the
abscess spreads inwards towards the spine surrounding and
eroding the bodies of the vertebrae. - Sometimes the pus makes
its way along the inguinal canal or even along the femoral
sheath. It may invade the connective tissue planes of the
pelvis, and has been known to pass through the obturator
foramen into the buttock. Perforation of the psoas fascia may

390 CLINICAL APPLIED ANATOMY.

allow appendix suppuration to extend into the psoas sheath. The
hip-joint, over which the muscle passes, may be invaded, and the
elongated bursal space, which lies between the vastus internus
and the inner aspect of the femur, is sometimes infected, giving
rise to periostitis and necrosis, which may show itself in the
popliteal region. The pus may also be directed into the thigh
under the iliac fascia. Psoas abscess dependent upon caries is
described elsewhere.

Abdominal Hernia.

An abdominal hernia is the protrusion of an abdominal viscus
from the abdominal cavity. As a rule such a hernia consists of
a sac, composed of peritoneum, and contents, which may be any
of the abdominal viscera.

Except in quite rare instances there is no rupture or tearing
in the causation of a hernia, and therefore the term " ruptare "
to designate this condition is not a scientific one.

Certain anatomical peculiarities heighten the likelihood of a
protrusion at particular regions of the abdominal w^all. These
may be termed weak spots. In addition to the area being a
weak one, from the want of the thickness of the structures in
the region, there is also the possibility of a congenital pouch of
peritoneum persisting after birth, into which viscera may
descend, and some believe that this finger-like process of serous
membrane is the most important factor in the production of a
hernia.

The three common weak spots at which hernise most usually
protrude are the inguinal region, the femoral region, and the
umbilical region. All other hernise are comparatively rare, and
will only be briefly alluded to.

Inguinal Hernia. —In the male the testis, accompanied by its
cord, passes from the abdomen into the scrotum. In the female
the round ligament of the uterus traverses the abdominal wall
and occupies the same position as the upper part of the spermatic
cord does in the male. A weak spot is therefore left in this

INGUINAL HERNIA. 391

region. Both of these structures are normally accompanied by
a patent process of peritoneum in the foetus, which should close
some few weeks before birth ; in many instances, however, it
remains as an unclosed tube, ready to receive bowel or omentum
when the intra-abdominal pressure is raised sufficiently high.

The serous sac, continuous with the parietal peritoneum lining
the anterior abdominal wall, finds its way through the parietes
in an oblique manner. It commences at the region known as
the deep (or internal) abdominal ring. In the foetus and young
infant this is situated almost immediately above the crest of the
OS pubis, but as growth proceeds, and particularly when adult
life is reached and the pelvis developed, it gradually recedes
upwards and outwards, till at last it is found a finger's breadth
above the middle of Poupart's ligament. This so-called "ring"
is in reality a slit-like depression in the fascia transversalis,
readily seen from the abdominal aspect if the parietal peritoneum
is stripped oil external to the deep epigastric artery.

The neck of the sac then passes along the inguinal canal, which
passage is oblique, running downwards and inwards, and of very
short length in the young subject, but measuring from one and
a half to two inches in the adult. The boundaries of this passage
are of great importance, and should be thoroughly understood
before undertaking an operation upon an inguinal hernia.

Anteriorly, that is superficially, there are placed the skin ; two
layers of superficial fascia, one containing fat, superficial epigastric
vessels and some cutaneous nerves, and the other, the deeper,
being of a more fibrous texture ; then the aponeurotic fibres of the
external oblique muscle, running in the same direction as the
canal itself ; and in front of the outer half of the passage, and
therefore covering and protecting the deep abdominal ring, the
arching muscular fibres of the internal oblique and a few of the
transversalis arising from the external half of Poupart's liga-
ment. These fibres are of much moment, seeing that they arch
over the cord or the round ligament, and becoming the conjoined
tendon, are inserted into the crest of the os pubis, deep to the
cord or round ligament. Thus, when they contract, they tend to

392 CLINICAL APPLIED ANATOMY.

straighten and therefore approximate to Poupart's ligament and
close the canal, thus having almost a sphincter-like action.

Posteriorly, that is deeply, there is found in the outer half
of the canal the fascia transversalis, whilst in the inner half
both fascia transversalis and conjoined tendon are seen, and
in front of the latter at the most internal part is the triangular
fascia.

The roof of the canal is formed by the arching fibres of the
internal oblique and transversalis muscles, while the floor is
really a groove produced by the fusion of the fascia transversalis
with the posterior part of Poupart's ligament.

The congenital pouch of peritoneum having passed the whole
length of the inguinal canal, emerges through the superficial
(or external) abdominal ring. This again is no true " ring,"
being a triangular opening bounded by an inner and an outer
pillar, derived from the aponeurosis of the external oblique
muscle, and below by the crest of the os pubis. Of the two
pillars, the inner is flat, and is attached to the front of the
symphysis pubis, while the outer is rounded and is inserted
into the spine of the os pubis. The size of this slit in the
external oblique varies in different individuals.

Except in very stout adults or young infants the superficial
ring can be palpated by a finger placed directly over it, immedi-
ately above the crest of the os pubis, a fact which is not usually
fully recognised. By invaginating the scrotum until the pubic
spine is felt, the tip of the finger may be readily made to enter
the ring, and if the manoeuvre is carried out with care, no pain
need be occasioned to the patient. There are two facts which
may be gleaned from this method of examination; one, the
approximate size of the superficial ring, a knowledge of which
is not of much practical moment as it has but little bearing
upon hernia; the other, whether there is any protrusion
descending the inguinal canal and impinging upon the top of
the examining finger, a matter of considerable moment in the
diagnosis between an inguinal and a femoral hernia.

In the female, the spine of the os pubis may be defined by

INGUINAL HERNIA. 393

following up the inner border of the adductor longus tendon,
made tense by abduction of the slightly flexed thigh.

A hernia which emerges from the inguinal canal is spoken of
as a complete inguinal hernia. It is usual to give a somewhat
elaborate description of the coverings of such a protrusion,
but it is difficult, and of little practical importance, to make
out these layers separately. In cutting down upon a hernial
sac what is really desirable is to be able to distinguish the sac
itself, rather than to differentiate the different layers which
cover it.

In the older operative procedures, with the incision made
through the scrotum, the skin is the first layer, and then follows
the dartos tissue, then the layer derived from the deep portion
of the superficial fascia, covering the superficial abdominal ring
itself and called the intercolumnar fascia, after which the
cremasteric fascia and muscle will be exposed, then the infundi-
buliform fascia derived from the fascia transversalis, beneath
which is a somewhat fatty layer composed of extraperitoneal
tissue covering the sac itself.

In the present-day method of exposing the hernial sac by an
incision parallel wdth the inner half of Poupart's ligament and a
finger's breadth above it, the following structures will be divided
before the sac is laid bare : — The skin, two layers of superficial
fascia (in which some small blood vessels may be cut), the
aponeurosis of the external oblique, and, when this is cut,
the interior of the canal will be exposed, and lying within it
the ilio-inguinal nerve running down upon the neck of the sac,
which itself is covered by the cremasteric and infundibuliform
fasciae, the spermatic cord being placed in the great majority of
cases posterior to the sac.

The sac may be recognised chiefly by its colour, which is in
most instances a characteristic slaty-blue when strangulation is
present, and of a bluish- white opaque look in non- strangulated
cases. Sometimes typical arborescent vessels may be observed
on its outer aspect, and it is important to recollect that the
external surface of the sac is rough, and that it is not until

394 CLINICAL APPLIED ANATOMY.

the interior is exposed that the smooth aspect of the peritoneum
is seen.

The somewhat rare form of direct inguinal hernia is one in
which the protrusion takes place wdthin Hesselbach's triangle,
the boundaries of which are, externally, the deep epigastric
artery ; internally, the outer border of the rectus abdominis ;
and, below, the inner half of Poupart's ligament. It is difficult or
well-nigh impossible to diagnose without dissection the difference
between an indirect (or oblique) and a direct inguinal hernia.
If the finger can be introduced into the inguinal canal and the
pulsation of the deep epigastric artery felt, the protrusion of the
hernia, on the patient coughing, internal to this artery proves
its direct course. It is important to remember that in a con-
siderable proportion of large, indirect, inguinal herniae the neck
of the sac drags the deep epigastric artery downwards and
inwards, till at last the deep and the superficial rings are almost
directly the one behind the other, the hernia in such a case
simulating a direct one very closely.

Femoral Hernia. — Behind the innermost part of Poupart's
ligament and a little below and external to the spine of the
OS pubis is a potential opening, made patent by the scalpel or
by the protrusion of a femoral hernia. This is the so-called
"femoral ring," and is the upper or abdominal entrance into
the femoral canal. It has an oval shape, with the long axis
transversely placed, and in the erect position its plane is nearly
horizontal.

Its boundaries are, internally, Gimbernat's ligament, which is
in reaUty the triangular internal attachment of Poupart's liga-
ment; externally, the common femoral vein, separated by the
septum of the femoral sheath ; in front is Poupart's ligament
itself ; and behind is the pectineus muscle covered by the
pectineus fascia, while deep to the muscle is the horizontal
ramus of the os pubis.

The femoral ring opens into the femoral canal, which is the
most internal division of the femoral sheath, and is composed
anteriorly, of the transversalis fascia, and, posteriorly, of iliac

FEMORAL HERNIA. 395

fascia. The canal itself contains the lymphatic vessels passing
from the superficial femoral lymphatic glands to the deep external
iliac lymphatic nodes, and sometimes a lymphatic gland itself
is actually placed in the canal. The boundaries of the canal
are, anteriorly, the fascia transversalis, posteriorly, the fascia
iliaca, externally, the septum separating the space from that for
the vein, and, internally, the meeting of the fascia transversalis
with the fascia iliaca.

Superficial to the femoral canal, and in a sense forming its
lower aperture or exit, is found the so-called saphenous opening
— a term which is w^holly a misnomer, for there is no true
opening, and it is not, therefore, an obvious one. The pseudo-
opening lies at the upper and inner part of the thigh, a couple
of fingers' breadth below and external to the spine of the
OS pubis. It is formed between two layers of the fascia lata
of the thigh, known as the iliac, or anterior, and the pubic,
or posterior, portions. It gives passage to the internal saphenous
vein. The upper edge of the opening has its upper extremity
attached to the anterior aspect oi Gimbernat's ligament and the
lower border of Poupart's ligament, and is fairly defined and
somewhat sharp.

Again, as in the case of an inguinal hernia, the actual
coverings of a femoral hernia are not of much moment. They
may be mentioned here as the skin, superficial fascia, cribriform
fascia (probably the deeper layer of the superficial fascia), fascia
transversalis, extraperitoneal tissue, followed by the sac itself.

Whilst the sac of a femoral protrusion is traversing the
femoral canal, it necessarily takes a vertical direction, and lies
to the inner side of the femoral vein, and its neck is external
to the spine of the os pubis. In the male, the spermatic cord is
above, that is on a higher level than the femoral ring, the deep
epigastric artery is on the outer side and above. The pubic
branch of this vessel passes downwards and backwards on the
outer side of the femoral ring to anastomose on the upper
surface of Gimbernat's ligament with a similar branch derived
from the obturator artery. In about two cases out of every

396 CLINICAL APPLIED ANATOMY.

seven this anastomosis is so large as to form the origin of the
main portion of the obturator vesseL When this " abnormal "
origin of the obtm'ator artery is present, in 10 per cent, of the
instances the vessel runs over the anterior or upper margin of the
femoral ring, and then down along its inner border to reach
the obturator foramen. In another 37 per cent, it passes across
the femoral ring, and in 53 per cent, it arrives at the obturator
aperture by skirting the external side of the femoral opening.
Thus it will be seen that if a femoral hernia becomes strangu-
lated, the artery will be liable to injury, if the knife be used,
in at least 10 per cent, of all cases where its abnormal origin
is present. Moreover, if the neck of the hernial sac in its
descent pushes the artery over, when lying across the ring, to
the inner side it will again become placed in a position of
danger.

In the strangulation of a femoral hernia the edge of Gimber-
nat's ligament tends to exercise a sharp cutting pressure upon
the sac and its contents ; hence the very rapid damage which the
intestine is likely to undergo.

When a femoral protrusion has left the femoral canal, it most
frequently tends to descend the front of the thigh, rather than
to ascend superficial to Poupart's ligament. The upward course
is induced probably by the attachment of the deep layer of the
superficial fascia to the fascia lata being very firm.

A femoral hernia is not infrequently sacculated by the pressure
of fibrous bands derived from the cribriform fascia.

Umbilical Hernia. — During the process of development the
two lateral halves of the parietes of the abdomen approach one
another and ultimately coalesce, save for the aperture through
which pass the umbilical vessels. This opening is closed by
scar-tissue subsequent to the separation of the cord.

The anatomy of the umbilicus in the first few weeks after
birth shows an arrangement of fibres of semi-elastic tissue in
the form of a sphincter. These tend to become less elastic and
more fibrous, so that they gradually contract, and, as it were,
cut through the structures which originally traversed the

UMBILICAL HEENIA. 397

opening. At the same time the vessels become obHterated and
themselves converted into a mass of scar- tissue, at first weak,
but later of considerable denseness and firmness.

In adult life the umbilicus shows tw^o sets of fibres about it,
one decussating across the middle line, and the other of circular
direction around the aperture or pseudo-aperture itself. These
form the so-called ring, w^hich is stronger at its lower than at
its upper part. The scar-tissue in the upper margin of the
opening is less firm than in the lower, owing to the fact that in
the former region there are only the remains of the umbilical
vein, while in the latter are found the obliterated urachus and
the arteries.

If the two halves of the abdominal wall fail to unite in any
marked degree in the region of the umbilicus, a true " congenital "
umbilical hernia will result.

Dilatation of the scar-tissue at the umbilicus after the fall of
the cord constitutes an acquired umbilical hernia, '• infantile "
when in a young subject, " adult " after infancy.

The tissues covering an acquired umbilical hernia become
rapidly stretched, and there is a tendency for the peritoneum
forming the sac to become fenestrated. The contents of such a
hernia are often irreducible owing to adhesions, partly within
the sac, but partly, also, to the external tissues, if the sac is
fenestrated.

Diseases of the Salivary Glands.

Wounds of the Parotid Region. — The parotid gland contains
within its substance very important structures. The formation
of the temporo-maxillary vein in the upper part of the gland
by the union of the superficial temporal and internal maxillary
veins, and its course somewhat superficially downw'ards through
the gland, renders this venous trunk particularly liable to injury
in punctured w^ounds of this region. Deeper than the vein
lies the external carotid artery breaking up into its terminal
branches, the superficial temporal and the internal maxillary.
It again may be damaged but much more rarely. Deepest of all

398 CLINICAL APPLIED ANATOMY.

in the parotid, entering the gland soon after its exit from the
stylo-mastoid foramen, is the facial nerve, which traverses the
parotid in a direction towards its anterior margin becoming
more and more superficial. It is this structure which is most com-
monly divided, resulting in partial, or possibly total, temporary
or permanent paralysis. In the uppermost part of the gland is
found the auriculo-temporal nerve, and incisions in this region
may damage it.

A wound of the gland substance, but more especially of its
duct, is prone to be followed by a salivary fistula. Stenson's duct
emerges from the anterior border of the gland and runs across
the cheek, inclining slightly downwards. The middle third of a
line drawn from a point half-way between the bottom of the
concha and the lobule of the ear, to a point half-way between the
ala of the nose and the red margin of the upper lip, represents
very accurately the course of the duct. It is well to remember
that it first lies on the masseter, and at the anterior margin of
the muscle it makes a sharp bend inwards, perforates the
buccinator and opens on the mucous membrane of the cheek,
opposite to the second upper molar tooth, having a length in
the adult of about two inches. Thus any attempt to pass a probe
from the mucous opening should be preceded by eversion of the
cheek to straighten the duct. An incised wound across the line
of the duct may sever it, and thus establish a salivary fistula.

Parotitis. — The parotid gland is invested by a complete
capsule of deep cervical fascia, and is divided into lobes by
processes of the fascia passing into its interior. It is thus that
inflammatory products formed within are tightly bound down and
cause considerable suffering to the patient. The swelling of the
gland interferes with the proper movements of the mandible, and
the motion of this bone induces great pain by the pressure of the
condyle upon the inflamed gland tissue. Seeing that there is
very little tissue intervening between the parotid and the internal
jugular vein behind, it is possible that any cerebral symptoms
in the course of mumps may be due to cerebral hyperaemia
caused by pressure.

PAEOTITIS. 399

There is no anatomical connexion between the parotid and
the testis or the ovarj^ and therefore metastatic inflammations in
these organs must be dependent rather upon a general infection.

Parotitis, if not of the specific variety, may be induced by the
extension of septic organisms from the mouth along the duct to
the parenchyma of the gland. This may happen particularly
in enteric fever, and during convalescence from laparotomy,
especially where there is neglect of the proper care to keep the
teeth, gums, and tongue clean.

Suppuration within the capsule of the gland is not uncommon.
The pus formed will track in the line of least resistance. Most
usually the line followed is forwards on to the cheek, backwards
and upwards through the cartilaginous portion of the external
auditory meatus, or inwards towards the pharynx, where there
may sometimes result a retropharyngeal abscess. This latter
situation is probably gained by the weak spot in the capsule in
the space between the anterior aspect of the styloid process and
the posterior border of the external pterygoid. For the same
reason, a collection of pus primarily originating in the retro-
pharyngeal tissues may find an exit through the substance of
the parotid. A parotid abscess may also advance into the
temporal fossa, into the tissues of the neck, or into the temporo-
mandibular joint cavity.

In opening a parotid abscess, care must be taken not to wound
the structures contained within it. If an incision is made
directly into the abscess cavity, it should be so planned as to lie
nearly horizontally, and as low dow-n as possible, so as to avoid
injury to the facial nerve or the parotid duct. Such an abscess
may be conveniently and safely opened by cutting on to the cap-
sule of the gland by an oblique incision, downwards and forwards,
and then opening into the abscess cavity by thrusting a director
onwards into it, and subsequently enlarging the opening by a
pair of sinus forceps.

Parotid Tumours. — Certain peculiar innocent growths are
found in connexion with the parotid, these tumours being
mixed in character, one component frequently being cartilage.

400 CLINICAL APPLIED ANATOMY.

This is possibly explained by the fact that islets of embryonic
cartilage from the first or mandibular arch may remain enclosed
within the gland. These innocent growths of the parotid merely
displace the contained structures, and although they may reach
a considerable size, seldom interfere with the functions of
the vessels or the nerves. Excision of such growths is fairly
easy, many being encapsuled. Temporary facial paralysis may
follow.

Malignant tumours of the parotid, particularly sarcoma, quickly
infiltrate the tissues and soon implicate the facial nerve, pro-
ducing paralysis. Such growths are extremely difficult to remove
as may be readily understood when the structures contained
within the gland are remembered.

The anterior auricular lymphatic glands may lie upon or within
the sheath of the parotid. When enlarged they may simulate a
parotid tumour. If lying superficial to the capsule they are
readily excised. If residing within the capsule, it may even be
necessary to divide some gland tissue before they are exposed,
and care must be taken while dissecting them out, especially when
dealing with the deeper parts of the wound.

Parotid Calculi. — The duct of the parotid may be the site of a
calculus. This may lead to a fluid swelling occupying the region
of the gland, filling up the sulcus between the ramus of the jaw
and the internal auditory meatus, and passing forward on to the
cheek. Occasionally the concretion may be palpated in the line
of the duct on the cheek, but it is much more readily demonstrated
by a probe passed into the duct through its buccal aperture. If
the cheek is drawn outwards and somewhat everted, a small papilla
may be observed opposite the second upper molar tooth, and with
a little dexterity a fine eye probe can be guided into the opening
on its summit. This, if made to pass along the lumen of the duct,
will strike the calculus. Excision of the stone should always be
made from the buccal surface to avoid the formation of a salivary
fistula.

Submandibular Gland.— This salivary gland is much less often
the seat of disease than is the parotid, The duct (Wharton's duct)

DISEASES OF THE LIVER 401

arises from the deep portion of the gland lying upon the hyo-
glossus muscle, deep to the mylo-hyoid. The duct runs forwards
and some^^hat inwards, close beneath the mucous membrane of
the floor of the mouth, on which it makes a distinct ridge, to open
on a papilla by the side of the frsenum linguae. A calculus in this
duct can be easily jjalpated, or even seen, from within the mouth.
The duct is not readily dilated by retained secretion, and there-
fore its blockage by a concretion is apt to be accompanied by
much pain. Consequently a ranula is seldom a dilatation of this
duct, but is much more generally a retention cyst of one of the
mucous glands of the floor of the mouth. The calculus can be
easily excised by an incision made into the duct on the floor of
the mouth.

The submandibular gland covers that part of the hyoglossus
muscle which overlies the lingual artery, and therefore it will
require displacing upwards to expose the lingual triangle formed
by the two portions of the intermediate tendon of digastric muscle
and the hypoglossal nerve.

Diseases of the Liver.

Deformities and Displacements. — The deformity of the liver,
which is of most clinical interest, is the presence of a linguiform
lobe, known as Eiedel's process. This is an elongated projection
which springs from the edge of the right lobe, close to the
gall bladder. In some instances it is congenital; in others it
appears to have been drawn down by the weight of a distended
gall bladder, which is attached to its deep surface. The lingui-
form lobe projects downwards in front of the right kidney, and
if its connexion with the liver escapes recognition it may be
confused with the kidney, a growth of the colon, or an intus-
susception. Biliary colic may exist with a linguiform lobe, owing
to traction on the bile duct.

Various distortions of the liver are met with, as the result of
tight lacing and the use of tight belts, the precise deformity varies
with the level at which the compression is applied.

C.A.A. 26

402 CLINICAL APPLIED ANATOMY.

Downward displacement, or ptosis of the liver, may occur
alone or be associated with general enteroptosis. The liver is
supported by the combined action of its ligaments, its attach-
ment to the diaphragm by means of the inferior vena cava and
extensive posterior non-peritoneal surface, and by the action of
the muscular portion of the abdominal wall. The liver, being
plastic, undergoes considerable modification of shape when
displaced. The displacement may cause obstruction of the
structures which enter the portal fissure, and also in rare
cases the inferior cava may become distorted. The traction
of a displaced liver may induce various nervous symptoms, such
as pain in the shoulder, dyspnoea, etc.

Rupture of the Liver. — The liver is bulky and occupies a
considerable portion of the upper part of the abdominal cavity ;
moreover it is heavy, friable, and subjacent to yielding ribs.
Consequently it is more often ruptured as the result of falls and
contusions than any other abdominal organ. The liver substance
bleeds freely when torn or penetrated, for the portal and hepatic
veins are not provided with valves, and the latter in particular
are held open by their intimate relation to the liver substance. If
the rupture involves the posterior, non-peritoneal surface, the
blood will escape into the retroperitoneal tissues, instead of
into the peritoneal cavity. In some cases the liver has been
extensively damaged without laceration of Glisson's capsule,
the blood then remains confined. Damage to the liver is
often associated with fracture of the ribs or costal cartilages
which overlie it. Posteriorly, in the scapular line the liver is
subjacent to the five right lower ribs, the eighth to the twelfth ;
in the axillary region it is also under cover of five right ribs,
the seventh to the eleventh ; in front it is under cover of five
right costal cartilages, the fifth to the ninth.

Penetrating wounds of the liver may be in such a position
that they also traverse the pleural sac, the lung, the diaphragm,
and the peritoneal cavity. Wounds of this nature may be
situated in the sixth or seventh intercostal spaces antero-
laterally, or in the eighth, ninth, or tenth spaces posteriorly.

ICTEEUS NEONATOEUM. 403

Catarrhal Jaundice is usually considered to be an infective
inflammation of the common bile duct, extending from the
duodenum. Occlusion of the common duct by inflammatory
swelling of its lining membrane is favoured by the following
anatomical conditions — the terminal portion of the duct traverses
the duodenum very obliquely; the walls of the duct are thick
and do not easily stretch ; its lumen is narrow, and in addition,
the pressure under which bile is secreted is very low.

In a very large percentage of cases the common bile duct
is completely embraced in the head of the pancreas, and in the
remainder it lies in a deep groove in the gland. It is therefore
possible that inflammatory swelling of the head of the pancreas may
be the cause of some of the cases of so-called catarrhal jaundice.

Slight jaundice is easily recognised in the ocular conjunctiva.
When looking for it in this situation the presence of yellow sub-
conjunctival fat in the parts remote -from the cornea should
be borne in mind, and attention particularly directed to the
conjunctiva immediately surrounding the cornea where the fat
is absent.

Jaundice in the Newly-born is usually transitory and in all
probability due to inspissation of the bile and slight catarrh
of the duct. There are, however, graver forms. Obliteration
of some part of the bile passages may be present. There
appears to be no special site for this, for the stenosis may
be found anywhere in the course of the bile ducts from their
commencement in the liver to their termination in the duode-
num ; at the same time the gall bladder may present inflamma-
tory changes and multilobular cirrhosis be present. In other
instances the jaundice is due to obstruction of the ducts by
perihepatitis, for Glisson's capsule becomes invaginated into the
liver at the portal fissure, and so comes into close relation with
the ducts, and when inflamed may compress them. Another
variety is that in which the umbilical vein, becoming infected
at the umbilicus, gives rise to a portal pyaemia. General pyaemia
may also result, since, at this age, the ductus venosus connects
the portal and systemic venous systems.

26—2

404 CLINICAL APPLIED ANATOMY.

Passive Congestion of the Liver.— The Uver is peculiarly
liable to suffer in all conditions of venous back pressure because
the hepatic veins are large, open into the inferior vena cava
quite close to the right auricle, and are quite destitute of valves.
Hence the passively congested, or nutmeg, liver occurs as the
result of valvular disease of the heart, obstruction of the pul-
monary circulation, adhesion of the pericardium, constriction
of the inferior vena cava by mediastinitis, displacements of the
heart which bend the inferior vena cava, or pressure on that
vessel by enlarged glands or aneurysm. A moderate degree of
passive congestion is also seen in the livers of persons who have
died slowly with heart failure.

In a nutmeg liver the injected areas correspond to the intra-
lobular and sublobular branches of the hepatic veins, the first-
named branches occupying the centres of the lobules. The pale
areas consist of cells which have degenerated in consequence
of the stasis of the circulation. General pressure on the bile
capillaries accounts for the moderate degree of bile staining often
present.

The jaundice which results from passive congestion of the liver
is frequently associated with dropsy of cardiac origin, which
indeed often precedes the jaundice. It is often noticeable that
the jaundice is much more intense in the upper parts of the
body than in the lower cedematous parts, the explanation being
that both the fluid in oedema and the pigment of jaundice tend
to accumulate in the lymphatic interspaces, and when these are
already occupied by stagnant dropsical fluid, it is difficult for the
bile pigment to exude into them.

The venous congestion of the liver, coupled with a certain
amount of resistance offered by its capsule, causes the organ to
become tender to the touch.

The congested liver is enlarged. This is detected by deter-
mining the position of the lower edge, after ascertaining that the
upper level of percussion dulness is not below its normal situa-
tion. The upper limit of dulness to light percussion corresponds
to the line indicating the lower limit of the lung. It is found at the

CIEEHOSIS OF THE LIVEE. 405

sixth rib in the nipple Hne, the eighth rib in the axilla, and the
tenth dorsal spine posteriorly. In the recumbent position the
liver only comes from mider cover of the ribs in the epigastrium,
its edge passing from the ninth right to the eighth left costal
cartilage. The edge can rarely be felt unless the organ is
enlarged, but when felt can readily be recognised by its sharpness
and the notches corresponding to the fundus of the gall bladder,
and the position of the round ligament. A tendinous intersection
in the rectus is apt to be mistaken for the liver, so it is well to
keep to the outer side of this muscle w^hen seeking for the liver
edge. The position of the liver in the dome of the diaphragm
causes it to move freely with the respiratory movements.

Infarction of the liver is rare. The organ is practically supplied
with blood from two sources, the hepatic artery and the portal
vein, and the capillaries of both these vessels communicate freely
with the hepatic veins. When infarcts do occur they are small
and present a nevoid appearance. They have been met with in
thrombosis and embolism of the portal vein, embolism of the
hepatic artery and retrograde embolism of the hepatic veins.

Cirrhosis of the liver is believed to be due to the action of
some toxic or infective agent. Most of the blood which traverses
the liver is brought from the digestive tract by the portal vein,
and this vessel is supposed to be the common track of invasion.
The hepatic arteries afford another means of access to the liver
and may be responsible for the production of interstitial cirrhosis
in certain of the infectious fevers. The pigmentary cirrhosis of
bronzed diabetes is often associated with endarteritis of the
hepatic arteries, which has led to the belief that infection by
this route may cause the disease. The bile ducts afford a third
means of invasion, and by some authors the form of cirrhosis
designated monolobular or biliary is held to arise in consequence
of an infection which ascends these from the duodenum. In
multilobular cirrhosis of the liver, which is the common form of
the disease, the new fibrous tissue spreads from the portal canals.
Branches of the hepatic artery, portal vein and bile duct lie in
company in these spaces, but the vein chiefly suffers compression

406 CLINICAL APPLIED ANATOMY.

the artery and duct mostly escaping, in consequence the cirrhotic
process is beUeved to be more intimately associated with the
vein than with the artery or duct. The new fibrous tissue is
permeated by branches of the hepatic artery, and that vessel
becomes enlarged. The portal vein is also enlarged as the result
of the obstruction. The portal congestion may be considerably
relieved by the opening up of communications which exist between
the portal and general venous systems (Fig. 47, p. 338) or by
operative measures designed to the same end. Portal radicles
anastomose freely with the retroperitoneal venous plexus, and this
in turn communicates with the lumbar and renal tributaries to
the inferior vena cava. The anastomosis between the two systems
takes place behind the pancreas, duodenum, and colon, where
these are directly applied to the posterior abdominal wall without
the intervention of the peritoneum. Communications also occur
between the same systems in the roots of the various mesenteries.
A plexus of tortuous veins may often be found between the
layers of the coronarj^ ligaments of the liver, communicating on
the one hand with the veins of the liver and on the other with the
phrenic and intercostal tributaries to the azygos veins. Some
small veins which are constantly present descend from the left
division of the portal vein along the round ligament to the um-
bilicus and there form connexions with the epigastric veins and
the superficial veins of the abdominal wall. When these veins
are much enlarged the venous circle of the umbilicus becomes
engorged, giving rise to the snake-like appearance known as the
caput MeduscE. A venous hum may at times be heard between
the umbilicus and the liver, and is attributed to enlargement of
the veins descending from the liver. At the cardiac end of the
stomach the gastric tributaries to the portal system anastomose
with the oesophageal tributaries to the azygos veins, and these
communications may become enlarged and varicose. At the
lower end of the intestinal tract the portal system effects another
communication with the systemic veins, for the superior hsemor-
rhoidal tributary to the inferior mesenteric vein joins the middle
and inferior haemorrhoidal tributaries to the internal iliac veins.

CIERHOSIS OF THE LIVER. 407

Engorgement of the various tributaries to the portal vein
has been supposed to produce the various signs and symptoms of
cirrhosis of the liver in a purely mechanical way. On this
assumption, congestion of the gastric tributaries is responsible for
dyspepsia, nausea, and haematemesis ; congestion of the splenic
vein for splenic enlargement and anaemia; congestion of the
superior mesenteric vein for ascites ; and congestion of the
hsemorrhoidal vein for haemorrhoids. The matter, however, is
not so simple as this, although it is certain that the splenic
enlargement may very much diminish when the portal system
is depleted by the result of haemorrhage from the oesophageal,
gastric or haemorrhoidal veins, or by profuse diarrhoea. Throm-
bosis of the portal vein, on the other hand, may be followed by
great increase in the size of the spleen and ascites.

The ascites in some cases has been supposed to be due to
thrombosis of small radicles of the portal vein or of its compen-
satory communications. This, however, remains to be proved.
The effusion is possibly due to a further catarrhal swelling of the
liver cells, which strangles the small portal radicles owing to the
resistance of the fibrous tissue in which the lobules are enmeshed.

The accumulation of fluid in ascites exercises pressure on the
large renal and iliac trunks, causing albuminuria and oedema of
the legs, which sometimes extends to the lower part of the
abdominal wall, but similar results may arise from the
cardiac degeneration which so often accompanies cirrhosis.

The effusion also interferes with the action of the diaphragm,
leading to dyspnoea, collapse of the lung bases and irregularity
in cardiac action. The shifting dulness of ascites may be simu-
lated by a loaded colon if that be provided with a long mesentery,
but may be distinguished by the fact that the gain of resonance
in the uppermost flank is not accompanied by a corresponding
loss of resonance in the flank which is lowermost.

The inferior vena cava, although embedded in a depression at
the back of the liver, is rarely exposed to much compression.

The indications of enlargement of the liver have been con-
sidered already. The normal vertical extent of liver dulness

408 CLINICAL APPLIED ANATOMY.

may be given as four inches in the right nipple Hne and four
and a half to five inches in the axilla.

Abscesses of the Liver. — The routes by which pyogenic in-
fection may reach the liver are the portal vein, the bile ducts,
the hepatic artery and the lymphatics. Ulceration of any part
of the intestinal tract from the cardiac end of the stomach to
the anus, or inflammation of the umbilical vein in infancy may
give rise to portal infection and multiple abscesses. Eadicles of
the portal vein may also be infected by abscesses of the spleen
or mesenteric glands, by inflammation of the gall bladder or
large bile ducts, or by retroperitoneal suppuration through their
communications with the subperitoneal venous plexus.

Infections of the gall bladder and large bile ducts may extend
directly to the liver along the biliary passages, the retrograde
extension being much facilitated when biliary stasis is present.
Multiple small abscesses like those of portal pyaemia result.

Liver abscesses may also be part of a general pyaemia. The
infection in such caces is carried by the hepatic artery. To
reach this vessel the infective emboli must first traverse the lung,
but do not necessarily lodge here on account of the large size of
the pulmonary capillaries compared with those of other parts
of the body.

When abscesses in the neighbourhood of the liver invade it
from without, they probably follow the course of the lymphatic
spaces.

Tropical abscess is usually solitary and situated in the upper
part of the right lobe. The direction in which these abscesses
tend to rupture is determined by their anatomical relations.
Owing to the common situation of the abscess, it usually bursts
upwards into the lung or pleural sac, for it is in close contact
with the dome of the diaphragm, and in addition many of the
lymphatics of the liver pass towards the diaphragm between the
layers of the coronary ligament. A considerable number of
abscesses burst into the peritoneum, and some, extending from
the under surface of the liver in the region of the right kidney
pouch, may open into the stomach, duodenum, colon, or even the

TEOPICAL ABSCESS OF THE LIVEE. 409

inferior vena cava or bile ducts. The j)ericardium is perforated
in some instances, or pus, burrowing between the layers of the
coronary ligament, may travel down behind the peritoneum and
reach the pelvis of the right kidney.

Pain on the top of the shoulder may occur in liver abscess.
The pain is localised in the angle between the clavicle and
acromion process. The phrenic nerve which is distributed to
the diaphragm and in part to the liver, arises chiefly from the
fourth cervical root, and filaments from the same root help to
form the supraclavicular branches of the cervical plexus. This
anatomical fact may account for the peculiar localisation of the
referred pain.

The base of the right lung is hollowed out and fits on the
convex surface of the liver like a cap, the diaphragm and pleura
intervening. A large abscess, projecting from the upper part of
the right lobe of the liver posteriorly, may give rise to a dome-
shaped area of dulness which encroaches on the pulmonary
resonance. If fluid is effused in the intervening pleural sac the
characteristic outline of the dulness is obscured. A dull area of
similar outline may be found in the axilla when the abscess is
situated more laterally. The normal lower border of pulmonary
resonance is a horizontal line which corresponds to the sixth
costal cartilage in front, the sixth rib in the nipple line, the
eighth rib in the axilla, the tenth rib in the scapular line, and
the tenth dorsal spine posteriorly. When the liver is enlarged
in the upward direction the base of the lung is pushed upwards,
but the level of the lower border of the pleural sac remains prac-
tically unchanged. The lower limit of the pleura extends from
the mid-line in front across the seventh costal cartilage ; it
reaches the eighth rib in the nipple line, the lower border of the
tenth rib in the axilla, and the level of the twelfth dorsal spine
behind. The fixed position of the lower limit of the pleura under
all circumstances is accounted for by the presence of the strong
phrenico-pleural ligament which passes between the point of
attachment of the diaphragm to the adjacent costal cartilages
and the lower limit of the pleural sac.

410 CLINICAL APPLIED ANATOMY.

Abscesses in the usual position in the right lobe are best
reached by the transpleural route.

Tuberculosis of the Liver. — The routes by which tubercle
bacilli may reach the liver are the same as those already men-
tioned as giving access to pyogenic infections. Miliary tuber-
culosis is due to infection which is carried to the Hver by the
hepatic artery. Tuberculous pericholangitis, curiously enough,
is probably a portal infection, the bile ducts being invaded from
the portal radicles which lie alongside the ducts in the portal
canals. Tuberculous infection of the liver along the lymphatics
is rare, for the liver is not interposed in the lymph stream from
the intestines to the thoracic duct.

Syphilis of the Liver. — The liver is more likely than any
other viscus to be the site of gummata in acquired syphilis.
They mostly lie on the anterior surface, this being exposed to
slight injuries ; and in the right lobe, which, being the larger,
offers a wider field for infection. Gummata in the region of the
portal fissure may compress the bile ducts and portal vein,
giving rise to jaundice, ascites, and splenic enlargement, but
these symptoms are uncommon. Fever may be present.
Gummata are usually accompanied by perihepatitis, and if this
is extensive, the action of the diaphragm may be interfered with,
and partial collapse of the base of the right lung occur. At the
same time pain may be reflected along the phrenic nerve to the
branches of the cervical plexus, which supply the point of the
shoulder. In such cases the condition is apt to be confounded
with subdiaphragmatic suppuration or basal pneumonia.

Carcinoma of the liver is usually secondary to some part of
the alimentary track which is drained by the portal vein.
Venous transfer is unusual in carcinoma, but growths in the
intestine are prone to ulcerate, and may open up the portal
radicles in this way. Moreover, as already pointed out, the liver
lies off the track of the main lymphatic stream from the in-
testines. Carcinoma may reach the liver by other routes, for it
is sometimes secondary to growths in the breast, or may extend
from the gall bladder or pylorus by direct continuity.

GALL BLADDEE AND BILE DUCTS. 411

Carcinoma of the liver can extend along the lymphatics of the
round ligament, and so may give rise to secondary nodules at
the umbilicus. It may also infect the glands in the portal
fissure, and so produce jaundice and ascites.

Sarcoma, which is of rare occurrence primarily within the
portal area, is equally rare in the liver as a secondary growth.

Diseases of the Gall Bladder and Bile Ducts.

The bile duct opens into the duodenum on the tip of a small
nipple-like projection, which is sometimes known as the papilla
of Vater. Within the papilla, whilst traversing the duodenal
wall, the duct presents a terminal dilatation which usually, but
not always, receives the termination of the main duct of the
pancreas. The dilated portion of the duct is known as the
ampulla of Vater. The papilla is situate on the inner and
posterior, aspect of the descending portion of the duodenum,
about four inches from the pylorus. Infection from the duo-
denum can gain access to the common duct through the papilla,
and ascend through the cystic duct to the gall bladder, or through
the hepatic ducts to the liver. The pancreatic duct may be
infected at the same time on account of its relation to the
ampulla.

The cystic duct near its junction with the gall bladder
describes an S-shaped curve, and this, together with the dupli-
catures of mucous membrane which form Heister's valve, accounts
for the ease with which it is obliterated by inflammatory changes
in its mucous membrane. When the cystic duct is obstructed in
this way, the gall bladder becomes distended with the mucous
secretion of its own glands.

The fundus of the gall bladder usually projects against the
abdominal wall at the upper part of the right linea semilunaris,
and when the viscus is distended, may be felt as a rounded and
superficial tumour at the outer border of the right rectus muscle,
just internal to the ninth costal cartilage (Fig. 49, p. 362). Unless
it is firmly fixed by inflammatory lesions, the gall bladder follows

412

CLINICAL APPLIED ANATOMY.

the respiratory excursions of the liver. When inflamed, even
though its outhne cannot be distinctly felt, its position may often
be discovered by the local tenderness elicited by its descent

neck

gall bladder

right hep. duct
left hep. duct
hep. duct

omental stage
com. bile duct

pancreatic duct

Fig. 51— The Gall Bladder and Bile Ducts viewed from the
Eight. [HuglieH and Keith.)

against the fingers if a full inspiration be taken. A greatly
distended gall bladder forms a pyriform tumour which can be
moved laterally and also antero-posteriorly, but cannot be
separated from the liver above, or restrained from following its up

GALL STONES. 413

and down movements. This is owing to the fact that the stalk of
the gall bladder is closely connected to the liver by its duct, and
also that, except in rare cases where a mesentery to the gall
bladder exists, the uj^per sm-face of the gall bladder is closely
attached by connective tissue to the fossa of the liver in which it
lies. Owing to the restraint exercised by its attachments to the
liver a greatly distended gall bladder may assume a forward
curve, and then its shape has been likened to a cucumber. The
transverse colon or even coils of small intestine may ride up over
the fundus of the gall bladder and lie between it and the liver.
In such cases, a resonant area may separate the fundus from
the liver dulness. Inflation of the stomach tends to carry the
enlarged gall bladder upwards and to the right, owing to the
pressure exerted on it by the pylorus and first part of the
duodenum, whilst inflation of the colon usually displaces it
upwards.

The nerves of the gall bladder are derived from the eighth
and ninth dorsal segments of the cord, through the great
splanchnic nerve and the coeliac plexus. When the gall bladder
is inflamed, superficial tenderness may be present over an area
corresponding closely to the fundus, and another in the right
subscapular region at the level of the eleventh dorsal spine;
the former is the site of maximum tenderness of the ninth
segmental area, the latter is situated in the eighth dorsal
segmental field. These tender areas are often met with in cases
of gall stones. (Figs. 20-23, p. 226.)

Large gall stones may pass direct from the gall bladder into
the bowel by a process of adhesion and ulceration. Since the
under surface of the gall bladder lies in direct contact with the
duodenum and the transverse colon, it is into one of these that
the stone is likely to be discharged. Occasionally it makes its way
into the neighbouring pylorus. The fundus of the gall bladder
being directly applied to the anterior abdominal wall may become
adherent to it, and ulcerate into its deepest layer. The purulent
contents may then be extravasated into the connective tissue
which ensheaths the round ligament of the liver and point in

414 CLINICAL APPLIED ANATOMY.

the neighbourhood of the umbilicus. Gall stones have bfeen
discharged this way.

The resistance to the passage of gall stones along the ducts is
greatest where the cystic duct unites with the hepatic to form
the common duct, and where the latter opens into the duodenum.
The common duct, where it lies in the edge of the lesser
omentum, is normally about the size of a crow quill. When
obstructed at its duodenal end it has become so dilated as to be
mistaken for the gall bladder itself. The cystic and common
ducts, being comparatively narrow tubes, may become the sites
of stricture. The stricture is more commonly found in the
cystic duct owing to the anatomical characters which have
already been described as favouring its occlusion. In cases of
obstruction, the liver may become honeycombed with dilated
ducts and much increased in size.

The lymphatic glands which receive the lymphatics of the gall
bladder and bile ducts share in their inflammation, and may
become so enlarged and hard that they have been mistaken for
gall stones or malignant growths. A gland which lies on the
cystic duct near the neck of the gall bladder is nearly always
enlarged. This is the cystic gland, and it receives the lymphatics
from the gall bladder. Another fair sized gland is usually found
near the junction of the cystic and hepatic ducts, and it is
succeeded by a chain of glands which lie along the common
duct in the edge of the lesser omentum. These compose the
" satellite chain of the bile duct," and the lymph which they
transmit finally reaches the glands at the upper border of the
pancreas.

Pylephlebitis may result from gall stones. The portal vein is
in least intimate relation with the common bile duct in the
middle of its course. Above and below it is in close relation and
in some cases is actually applied in spiral fashion to the upper
part of the common bile duct on the right side of the latter.
The portal vein may be infected by ulceration into it of a gall
stone, or by infection of the small radicles it derives from the
gall bladder.

PANCEEATITIS. 415

The peritoneal adhesions set up by inflammations of the gall
bladder may involve the duodenum, transverse colon or pylorus,
all of which are adjacent. Gastric pain and dilatation, or pain
in the region of the colon, may result.

The part of the peritoneum first infected as the result of
inflammation or rupture of the gall bladder is the right kidney
pouch, which lies above the transverse meso-colon. The
omental stage of the common bile duct has been known to
rupture into the lesser sac, which is rendered possible by the
position of the duct in front of the foramen of Winslow.

A stone lodged in the lower part of the ampulla of Vater may
ulcerate through the duodenal wall into the bowel, or cause a
retroperitoneal perforation. Earely it infects the peritoneum in
this region. Stones in this neighbourhood are in a position to
obstruct also the pancreatic duct or cause regurgitation of bile
into it.

Diseases of the Pancreas.

Inflammation of the pancreas, whether acute or chronic, is
usually a consequence of infection of the duct. The inflammation
may spread to it from the duodenum or from the bile duct in com-
mon with which the pancreatic duct usually opens. A gall stone
impacted at the lower end of the bile duct may impede the outflow
from the pancreatic duct and lead to infection, or if near the
orifice of the biliary papilla, may actually cause bile under
pressure to regurgitate into the pancreas and set up acute
inflammation in this way. On the other hand the swelling of
this gland when acutely inflamed may cause compression of the
common bile duct. Drainage of the bile ducts is sometimes
adopted as a means of indirectly draining the ducts of the
pancreas, but can only be effectual when both open into the
ampulla of Vater.

It is probable that in some cases the pancreas is infected by the
blood stream. The only direct connexion between the parotid
gland, the pancreas and the testicle, is vascular, and all these
structures may be inflamed in mumps. It is possible that the virus

416

CLINICAL APPLIED ANATOMY.

of other infective diseases, such as typhoid fever, may really
gain access to the gland in this manner.

Extension of inflammation from closely related structures
sometimes produces a localised pancreatitis. Gastric and
duodenal ulcers, tumours of the pylorus and other organs,
disease of the lumbar vertebrae and aneurysms of the aorta or
cceliac axis may in this way set up an inflammation.

The depth at which the pancreas lies in the abdomen and the

cystic duct
for. of Winslow,
supra-renal
1st stage daod.
rt. kidney
com. bile duct
2nd stage
duct of SantorinI

hepatic duct

com. bile duct
hep. art.

A^ pancreas

pancr. duct (Wirs.)
opening

jejunum

3rd stage duod.

Fig. .52. — The Head of the Pancreas, Duodenum, and Common
Bile Duct. {Hughes and Keith.)

presence in front of it of the stomach, render it difficult or
impossible to recognise moderate degrees of enlargement of the
gland. Indeed, it is usually impossible to feel the gland at all.
Acute pancreatitis usually shows itself as an acute peritonitis in
the upper part of the abdomen, involving the lesser sac, which
covers the front of the gland, or that part of the greater sac which
is in contact with its lower border. The pancreas is in close
relation with the great nerve plexuses of the abdomen, which may
explain the extreme pain and collapse which is so characteristic
of acute inflammation.

PANCEEATIC CALCULI. 417

The splenic vein lies along the back of the gland and receives
tributaries from it, so it is surprising that portal thrombosis is
not more commonly associated. The fat necrosis which accom-
panies acute pancreatitis is attributed to the escape of the
fat-splitting ferment into the tissues of the immediate neigh-
bourhood, but sometimes is observed in remote situations, in
which cases the ferment may have been carried by blood vessels
or lymphatics.

In hsemorrhagic pancreatitis the bloody infiltration is liable to
extend beyond the pancreas in the retroperitoneal tissues,
involving in this way the roots of the mesentery and transverse
mesocolon, the colic retroperitoneal tissue and the perinephritic
tissue also.

Sclerosing inflammation of the pancreas leads to compression
of the termination of the common bile duct and also of the
pancreatic duct. It is rare for the portal vein to be implicated
since it is not in the substance of the gland. In the interacinous
form of the disease the gland is much more closely permeated
with connective tissue than in the interlobular form, and
consequently the interacinous cell islets are more likely to
be destroyed. It is possible that the destruction of these cell
islets in the tail of the organ has some influence in inducing
diabetes.

Calculi in the pancreas lead to dilatation of the duct of Wirsung,
so that it can easily be traced through the gland. They may be
associated with pancreatitis. When dilated, the pancreatic duct
has been known to form fistulous communications with the lesser
sac, or the stomach, or duodenum. When an accessory duct of
the pancreas is present, it usually opens into the duodenum
three-quarters of an inch above and somewhat ventral to the
main pancreatic duct. The accessory duct is very variable,
and so not of great clinical importance. When present it may
compensate for a blockage of the main duct.

Abscess of the pancreas may form as the result of inflam-
mation or injury. Such an abscess may bulge into the lesser
sac and, pushing forwards the lesser omentum, present between

C.A.A. 27

418 CLINICAL APPLIED ANATOMY.

the liver and the stomach ; or it may push the stomach
forwards or present below it, above the transverse colon.
Following the connective tissue planes it may insinuate itself
between the layers of the transverse mesocolon and, reaching the
lumbar region, surround the kidneys. The duodenum, colon and
stomach are the parts of the intestinal tract into which a pan-
creatic abscess is most likely to perforate, particularly the two
latter on account of their close relationship to the head of the
gland.

Pancreatic cysts may arise when the main duct is obstructed
by a pancreatic calculus, or by a gall stone in the ampulla of
Vater, or by external pressure. The relations of the pancreas to
the peritoneum have considerable influence in determining the
directions in which cysts may extend and present themselves. The
greater part of the head and body of the gland is in immediate
relation with the lesser sac. Consequently pancreatic cysts
usually project into the lesser sac, either pushing the stomach
in front of them or presenting above, between it and the liver,
or below, between it and the transverse colon. But pancreatic
cysts may project into the greater sac ; thus a cyst arising to
the right of the foramen of Winslow may bulge in the right
hypochondrium, simulating a cyst of the kidney or suprarenal
body or a distended gall bladder. A cyst springing from the
head of the gland below the transverse mesocolon may present
below the hepatic flexure of the colon and be mistaken
for a renal or colic tumour; the root of the mesentery will
prevent such a cyst from encroaching on the left half of the
abdomen. It is possible for a cyst arising from the uncinate
process of the gland to appear to the left of the root of the
mesentery, below the transverse colon, where it may simulate a
tumour of the left kidney, or one arising from the colon in this
situation or from the small intestine. If large it may even simu-
late an ovarian cyst. Cysts in some cases burrow between the
layers of the mesentery or of the transverse colon when they
spring from the gland opposite the point of reflection of the peri-
toneum to form these folds. When cysts arise from the posterior

Topography of Abdomen.

Ik , .. f^'d line

Laceral Ime i Lateral Tne

Transpyloric

The disc bebwee^
Che i^'^ and z'^"
Lumbar Verbebr,^

t-.ter tubercular
plane.

Fig. 53.— Diagram showing the disposition of the deep organs in the regions of
the abdomen. (From Ellis's Anatomy, after Christopher Addison.)

{To face "page 419.

CAECINOMA OF THE PANCREAS. 419

part of the gland, retroperitoneal extension may occur, the cyst
invading the lumbar region.

Pancreatic cysts, from their position, may transmit the pulsation
of the aorta, or compress the inferior vena cava or the portal
vein. They have been known to cause obstruction of the small
bowel. They must be distinguished from encysted fluid in
the lesser sac of the peritoneum, such as may result from
crushing of the pancreas against the vertebral column.

Carcinoma of the Pancreas. — Since the head of the pancreas
is the usual seat of cancer in this organ, pressure symptoms are
pronounced. The intimate relation of the common bile duct to
the head of the gland accounts for its early obstruction with the
production of jaundice, distension of the gall bladder, swelling of
the liver from retained bile, and rarely, attacks of colic indis-
tinguishable from those due to gall stones. The infiltrated pan-
creas is not easily felt, and is usually concealed by the distended
gall bladder. Occasionally, however, it can be recognised as a deep-
seated tumour above the umbilicus, for it lies in front of the
second lumbar vertebra, whilst the umbilicus corresponds to the
body of the fourth. The tumour may transmit the pulsations of
the aorta, which lies behind it, and may ultimately give rise to com-
pression of the portal vein, the splenic vein, or the inferior vena
cava, all of which are also in posterior relation with the gland.
Ascites, swelling of the spleen, or dropsy of the legs and lower part
of the abdomen, may thus be produced. The intimate relation of
the duodenum to the head of the pancreas accounts for the occasional
invasion of this part of the bowel. The transverse colon which
crosses the head of the pancreas, is sometimes infiltrated. The
pylorus also is not far distant from the head of the gland, but it
is more common for cancer of the pylorus to become adherent
to the pancreas than for cancer of the pancreas to invade the
pylorus. The cancer being in portal territory secondary growths
may be expected in the liver, but the patient often dies before
metastasis occurs. The chain of lymphatic glands along the
pancreas also becomes involved. When malignant disease
invades the tail of the pancreas, which is uncommon, it is not

27—2

420 CLINICAL APPLIED ANATOMY.

favourably situated to produce pressure symptoms, but left
hydronephrosis may occur from compression of the upper end
of the ureter. A growth in the tail of the pancreas can some-
times be excised, but a growth in the head has such intimate
relation to important structures that excision is practically out
of the question.

CHAPTEK XVII.
DISEASES OF THE UEINAEY SYSTEM.

Diseases of the Kidney.

Congenital Abnormalities. — The renal bud, arising as it does
from the dorsal aspect of the Wolffian duct near the cloaca, may
be said to have a pelvic origin. In the process of growth it
assumes a position behind the peritoneum of the lumbar region.
The kidney sometimes remains in the pelvis between the rectum
and bladder, in other instances it lies on the sacral promontory
below the bifurcation of the aorta, or may be found on the
sacro-iliac synchrondrosis, on the venter of the ilium, or abnor-
mally low in the lumbar region. In all such cases the kidney is
firmly fixed and the vessels are short, being derived from the
arterial and venous trunks in the immediate neighbourhood, the
vessels wandering into the organ during development. Fusion
of the renal buds may occur, giving rise to a solitary kidney,
which is usually of abnormal shape. The horse-shoe form is
commonest, the kidneys being united across the spinal column
by their lower poles. Occasionally the fused renal mass lies on
one or other side of the spine.

The suprarenal bodies do not participate in displacements of
the kidneys, but are usually found in their normal positions.

Congenital cystic kidneys consist of a congeries of retention
cysts, which largely replace the renal substance. The cysts
vary up to three-quarters of an inch in diameter, and are
supposed to be cystic dilatations of Wolffian remanants included
in the kidney substance proper. Minute masses of tissue having
the structure of the suprarenal body are also occasionally
found embedded in the kidney. These are known as " adrenal
rests."

422 CLINICAL APPLIED ANATOMY.

Injuries to the Kidney. — The kidney being retroperitoneal,
it is possible for it to be extensively lacerated as the result of
blows, falls and other injuries, without the peritoneum being
involved. Being supported by the bodies and transverse pro-
cesses of vertebrae, and also by the last rib, it may be crushed
against these bony points by violence applied in front. The
impressions left in a hardened kidney by the twelfth rib and
transverse processes of the first and second lumbar vertebrae
show how intimate the relation is. If the proper capsule of the
kidney is torn, the extravasated blood is mainly checked by the
renal fascia which forms the outer boundary of the fatty capsule ;
if the blood escapes through this, there is but little obstacle to
its wide dissemination in the connective tissue planes of the
abdominal wall. Extravasated urine is usually present, as well
as blood, and may be in large quantity if the renal pelvis is
torn. Haematuria often occurs. Kents of the peritoneal covering
when present add much to the gravity of the condition.

In acute flexion of the spine the kidney may be squeezed
between the ilium and the lower ribs.

The kidney may be injured from behind by a penetrating
wound without implication of the peritoneum, but this is very
unlikely when the wound penetrates from in front.

Perinephritic abscess is situated in the retroperitoneal tissue
in which the kidney lies, and must be distinguished from localised
intraperitoneal suppuration in front of the kidney. Perine-
phritic abscesses may be primary, such as occur from injury
or during the course of certain infectious diseases, or may arise
by extension of suppuration in the neighbourhood. The infec-
tion may extend from a lesion of the kidney, such as calculus,
tuberculosis, or abscess, or may originate in the bones of the
spine, or arise in connexion with the vermiform appendix,
colon, pancreas, or duodenum. In the case of the vermiform
appendix, the peritoneum will have been perforated in some
manner ; but with extension from the colon, pancreas and duo-
denum, this is not essential, since all these have areas free from
the serous membrane. Sometimes perinephritic infection spreads

MOVABLE KIDNEY. 423

from the pelvic connective tissue, or from above the diaphragm,
and conversely the pus of a perinephritic abscess may extend
into the pelvic connective tissue, or invade the subpleural tissue,
and so the pleura and lung. It rarely bursts into the peritoneum,
but may open into the colon, or present in the lumbar region.

Movable kidney may, or may not, be associated with general
prolapse of the abdominal viscera. The presence of a meso-
nephros as a cause of mobility is rare. More commonly the kidney
slips up and down behind the parietal peritoneum. Normally
the kidneys, being deeply situated in the loins, cannot be easily
palpated, save in very spare persons, but with care that the
abdominal muscles are well relaxed and bimanual palpation, the
difficulty may be got over. In the adult the right is three-
quarters of an inch lower than the left, but its lower pole
is above the level of the umbilicus, and an interval of an inch
and a quarter usually separates it from the iliac crest. (Fig. 53,
p. 419.)

The factors which keep the kidney in position are its fascial
capsule, the attachments of the renal vessels, the pressure which
the abdominal muscles exert on it through the medium of the
abdominal viscera, and possibly also the reflections of peritoneum
on its anterior surface. The fatty capsule of the kidney is an
infiltration of the retroperitoneal tissue with fat, and the outer
layers of this capsule are condensed into a firm fibrous layer known
as the renal fascia. These layers fuse along the outer border
of the kidney and above, but do not closely unite below it. The
renal fascia is firmly attached to the crura of the diaphragm, to
the aorta, and the posterior abdominal wall. The same connective
tissue surrounds the renal vessels, forming with them a strong
pedicle. The pressure exerted by the muscles of the abdominal
walls has an important influence in keeping the kidney in place,
and the anterior surface of the organ when hardened in situ
shows two inclined planes which slope from the middle towards
each pole. These planes indicate the direction of the pressure
exerted by the superjacent viscera, the upper plane corresponding
to pressure exerted from above, and the lower to supporting

424 CLINICAL APPLIED ANATOMY.

pressure from below. The bed on which the kidney Kes is an
inchned plane which, in the erect position, slopes downwards and
forwards towards the iliac crest. The bed is narrower and less
vertical in women. The kidney normally slides a short distance
down the inclined plane of its bed in inspiration.

Absorption of the retroperitoneal fat, yielding of the muscles
of the abdominal wall or pelvic floor, and disarrangement of the
planes in which pressure is exerted in consequence of tight
lacing, all conduce to the occurrence of movable kidney. The
greater frequency with which the right kidney is involved is no
doubt due to the superincumbent mass of the liver. The frequent
occurrence of movable kidney in the female sex is accounted for
by the shallow and more vertical kidney bed, coupled with the
influence of tight lacing and pregnancy.

The excursion of which a movable kidney is capable is
limited by the length of its vascular pedicle. When displaced
from its proper position, the corresponding loin may feel less
full and less resistani.

The symptoms which may accompany nephroptosis are deter-
mined by the relations and connexions of the kidneys. The
displaced organ may exercise either pressure or traction on
neighbouring parts of the intestinal tract. The descending
portion of the duodenum may become sharply bent by the
agency of peritoneal bands which pass from the anterior surface
of the kidney to the duodenum opposite the point of entrance of
the bile duct. The duodenum may be carried downwards with
the kidney, and become kinked by the traction exerted on it by
the hepato-duodenal ligament. The kidney may assume such a
position as to exercise direct pressure on the duodenum or
pylorus. By any of these agencies dilatation of the stomach may
be produced. Transitory jaundice may be induced by traction
on the bile duct or by pressure. The ureter may become
twisted, flexed, or otherwise obstructed, and the renal veins may
suffer in the same way. Thus hydronephrosis, renal congestion,
renal atrophy, and even renal thrombosis, may arise.

Pain may occur in various forms. In some instances it

NEPHRITIS. 425

occurs as renal colic ; in others it is referred to the spine and
termed " rachialgia ; " sometimes it is reflected along the nerves
of the corresponding abdominal segments, producing modifica-
tions of tactile sense, and in others it radiates down the outer
side of the thigh, or appears in the knee, the heel, or the sole of
the foot. The pains are in part due to a stretching of the renal
plexus, which is an offset of the solar plexus and accompanies
the renal vessels. The nerve supply of the kidney is derived
from the tenth, eleventh and twelfth dorsal and first lumbar
segments of the cord, through the splanchnic nerves. Kenal
pain may be referred along any of the sensory nerves derived
from these segments. In some instances, the displaced kidney
exercises direct pressure on branches of the lumbar plexus,
i.e., on the ilio-hypogastric, ilio-inguinal, genito-crural, external
cutaneous or anterior crural nerves.

Nephritis. — Infective or toxic matter may reach the kidney by
the blood stream, the ureter, or the lymphatics. Blood infection
is probably the cause of most cases of nephritis. The toxic
material may have been ingested or be the product of the activity
of bacteria in some other part of the system. The cortex of the
kidney contains the active secretory epithelium, and the blood is
chiefly distributed to this part. Consequently the stress of
inflammation falls chiefly on the cortex, involving the glomeruli
and the convoluted tubes. The blood supply of the convoluted
tubes is derived from the afferent vessels of the glomerular tufts.

The tough renal capsule resists the swelling of an acutely
inflamed kidney, and thus may ..produce further damage. The
favourable results of nephrotomy in acute nephritis may be
attributed to diminution of renal tension. The tension may
induce acute renal colic simulating that produced by calculus.
The practice of wet cupping the loin in acute nephritis is justified
by the free connexion which exists between the superficial vessels
of the kidney, the subperitoneal vascular plexus of Turner and
the lumbar vessels.

Infection which ascends the ureter usually gives rise to a
pyelitis before nephritis supervenes, and cystitis may precede

426 CLINICAL APPLIED ANATOMY.

both. The urinary tubules become directly infected from the
calyces into which they open. Ascending infections are gener-
ally suppurative, and occur in connexion with urethral strictures,
prostatic enlargements, and infections of the lower urinary
passages.

The kidney is occasionally infected by the lymphatic route.
The lymphatics of the ureter communicate directly with the
lymphatics which lie between the urinary tubules. Hence
infection can travel from the urinary bladder along the lymphatics
of the ureter to the kidney. Extension by this track explains
those cases in which the renal cortex is alone involved, the
pyramids and pelvis remaining free.

Tuberculosis of the kidney may be the consequence of
infection carried to the organ by the blood stream or reaching it
along the ureter, the ureteric lymphatics, or from structures with
which the organ lies in direct contact.

In miliary tuberculosis the tubercles are widespread and
originate in the small vessels. But tubercle bacilli brought to
the kidney may be excreted and may find a nidus in the glomeruli
or tubules during this process ; a chronic renal excretion tuber-
culosis may originate in this way. Presumably the number of
organisms carried to the kidney in such cases is not very great.
In the earlier stages of excretion tuberculosis the cortex is mainly
involved.

When infection ascends the ureter from below it naturally tends
to attack and erode the lower parts of the pelvis first, spreading
to other parts of the kidney later. Occasionally infection appears
to ascend the lymphatics which accompany the ureter and in such
cases the pelvis may at first escape.

The kidney has been known to be directly infected by a sub-
jacent psoas abscess. The direct anatomical connexion of the
kidneys, ureters, bladder, prostate, vesiculae seminales and
epididymis has much influence in determining the distribution of
tuberculous lesions, and particular attention should be paid to all
these structures when investigating a case of renal tuberculosis.

The tuberculous thickening of the ureter can sometimes be

RENAL CALCULI. 427

detected by palpation. Li old standing tuberculous disease the
kidneys become pyonephrotic and are matted to surrounding
structures. Their adhesion to the vena cava inferior on the right
side and to the aorta on the left may give rise to considerable
difficulty when excision is attempted.

Renal calculi usually lie in the pelvis of the kidney. The
calyces, which are diverticula of the pelvis, have narrow lumina,
so a stone lying in a calyx may be well concealed, and may
actually become embedded in the renal substance. The con-
traction of the pelvis, where it joins the ureter, offers a great
obstacle to the passage of calculi, which becoming wedged in the
narrow outlet give rise to partial or complete obstruction of the
passage. If the obstruction is complete and permanent the
kidney becomes atrophic ; if incomplete or recurrent hydro-
nephrosis will result. Irritation of the renal pelvis by the stone
accounts for the presence of albumen, pus and blood in the urine.

The kidney lies on the psoas and quadratus lumborum muscles,
and movements which necessitate the action of these muscles will
aggravate the pain, or sometimes elicit it if absent. Pain may
also be induced by making firm pressure on the front of the
pelvis of the kidney. A point on the anterior abdominal wall, a
finger's breadth internal to the tip of the ninth costal cartilage
fairly indicates the position of the pelvis. This point lies on the
transpyloric line. (Fig. 53, p. 419.) Another method of seeking
for the presence of calculus is to make forcible percussion of the
loin, upwards and inwards, just below the tips of the last two
ribs ; this procedure sometimes produces a sharp, darting pain.

Two varieties of pain may occur with renal calculus, one fixed
and localised, and the other intermittent and radiating. The
latter is renal colic. The fixed pain is usually in the position of
the kidney, but may be referred to some distant spot supplied by
a branch of the lumbar plexus. Thus it may be localised in the
testicle or the groin, being referred along the genito-crural nerve,
in the leg or inner side of the foot being referred to a branch of the
anterior crural nerve, or in the domain of the great sciatic nerve
posteriorly. The pain of renal colic, on the other hand, shoots

428 CLINICAL APPLIED ANATOMY.

round the lower part of the loin to the front of the abdomen, and
thence to the testicle, groin or inner side of the knee, following
the direction of the branches of the lumbar plexus. The pelvis
of the kidney and the ureter, where the pain originates, are
particularly associated with the eleventh and twelfth dorsal and
first lumbar segmental areas. (Fig. 20-23, p. 226.) Cutaneous
hypersesthesia may be expected to occur in these areas during
and after a paroxysm of colic. The skin of the scrotum, which
is supplied from sacral segments, does not become tender, but
the testicle does ; the implication of the latter may be explained
by the presence of filaments of the genito-crural nerve in the
tunica vaginalis, which is said to be the only serous membrane
supplied by a spinal sensory nerve.

The connexion of the vagus nerve with the renal plexus may
account for the nausea and vomiting which may be associated
with renal calculi.

The anterior and posterior arterial vascular areas of the kidney
are separated by the pelvis and do not anastomose. As a rule
three-quarters of the kidney belong to the anterior vascular area
and the remaining quarter to the posterior. The direction of the
axes of the posterior row of calyces indicates the plane of division
between the two territories. The veins are not arranged in the
same way, but all ultimately pass to the front of the pelvis. A
longitudinal column of renal substance, consisting of fused
columns of Bertini, and bearing large vessels, intervenes between
the anterior and posterior sets of pyramids. In incising the
kidney to search for stone it is well to keep behind this column.
The least damage to vessels is done by an incision parallel to the
posterior surface of the kidney a little behind its convex border ;
this will pass between the two vascular territories and open the
posterior calyces. It should be carried into them in front of the
posterior row of papillae to avoid section of the collecting tubules
of the pyramids.

Ureteric Calculus.— There are three narrow points in the
ureter at which a stone is liable to become arrested. Of these
one is just below the renal pelvis ; the second is at the pelvic brim

Structures which lie beneath the Spino-Umbilical Line.

Edge of rectus

abdominis (linea

semilunaris).

Ascending colon.
Crest of Ilium.

Ileo-csecal valve.

Anterior superior
iliac spine

Root of vermiform
appendix.

Edge of rectus

abdominis (linea

semilunaris).

Pelvis of ureter.

Transverse colon.

Terminal portion
of ileum.

Fig. 5i. — Diagram of the average position of the ileo-caecal valve, caecum, appendix,
and right ureter with relation to the line from the right anterior superior spine to
the umbilicus. (From Sir Frederick Treves's Cavendish Lecture, 1902. After Keith.),

The spino-umbilical line runs from the anterior superior iliac spine to the umbilicus.
The point where it crosses the outer edge of the right rectus is called
" Monro's point," and corresponds in position to the ileo-caecal valve. The base of the
vermiform appendix lies rather more than an inch below this. The ureter crosses
the spino-umbilical line at the point of junction of its middle and inner thirds.
The eleventh dorsal nerve enters the sheath of the rectus near Monro's point.
The genito-crural nerve lies close to the ureter.

[To face page 429.

CALCULUS IN THE UEETEE.

429

where the ureter describes a curve known as the flexura margi-
naHs ; the third is where the tube traverses the muscular wall of
the bladder. It is not as a rule possible to palpate the abdominal
part of the ureter. This part descends vertically from the kidney
in the umbilical region about an inch and a half from the mid-line.
The junction of the outer and middle thirds of a line joining the
anterior superior iliac spines corresponds to the flexura marginalis,

ext. iliac
oblit. hypo

obiit. hypog

uterine art

bladder

Fig. 55 — Diagrams of the Pelvic Course of the Ureter in the
Male (a) and Female (b). {Hughei< and Keith.)

int. iliac art.
ureter— 1st stage

2nd stage

utero-sacral
fold

or portion of the ureter which crosses the brim of the pelvis in
front of the bifurcation of the common iliac artery. It is said
that the first part of the pelvic portion of the ureter can be
palpated from the rectum in both sexes in the knee-elbow position.
In the female the terminal part of the tube passes above the
lateral fornix of the vagina, then crosses the side of the latter to
enter the bladder at a point corresponding to the middle of the
anterior vaginal wall. It can easily be palpated from the vagina.
The ureter is retroperitoneal in the whole of its course, and can

430 CLINICAL APPLIED ANATOMY.

be reached, without opening the peritoneum, from the kimbar
region, the iHac region, or the vagina. Calculi have also been
extracted from its lower end through the urinary bladder.

In hydronephrosis and pyonephrosis the pelvis of the kidney
is dilated. This is due to some obstruction to the exit of urine
from it. Whether one or both kidneys suffer will depend upon
the site of the obstruction. If the impediment is in the urethra
or at the neck of the bladder both kidneys will be involved.
Pelvic lesions outside the bladder, near the trigone, may also
involve both ureters. The ureters run in the pelvic connective
tissue, towards the base of the bladder, coming into fairly close
contact with the cervix uteri. They may both be obstructed by
pelvic cellulitis, carcinoma of the cervix uteri, or uterine prolapse.

Unilateral hydronephrosis may be due to obstruction of the
renal pelvis or of the ureter below this. It is particularly
associated with mobility of the kidney and is often intermittent
in such cases. An abnormal renal artery or vein may pass across
the upper part of the ureter and obstruct it, or the obstruction
may be due to an impacted calculus or pressure from without.
The relation of the first part of the pelvic colon to the left ureter
explains how the latter may become obstructed by a carcinoma in
this situation. The ureter as it passes into the pelvis follows the
course of the internal iliac artery and forms a posterior boundary
of the ovarian fossa ; consequently it is at times compressed by
malignant tumours of the ovary.

Enlargements of the Kidney. — The distinguishing charac-
teristics of renal enlargements are all based upon the anatomical
features and relations of the kidneys.

The outline of a renal swelling is rounded and has no sharp
edges, conforming to the normal contour of a kidney; it may
thus be distinguished from enlargement of the spleen.

The position of the colon with regard to the kidney is usually
maintained when the latter is enlarged. The presence of the
bowel in front of the swelling can sometimes be determined by
palpation and at others by percussion if the bowel happens to
contain gas, or has been artificially inflated from the rectum.

ENLAEGEMENT OF THE KIDNEY. 431

The hepatic flexure of the colon lies in front and to the inner
side of the lower end of the right kidney, whilst the splenic
flexure lies in front and to the outer side of the left, coming into
relation with it nearer the level of the hilus so that a consider-
able length of descending colon passes down in front of it. This
difference in the relation of the colon to the kidney on the two
sides accounts for the fact that colic resonance is more often
demonstrable over a left than a right renal swelling. Bowel
never passes between the spleen and the parietes, the colon lying
on the inner aspect of this viscus, and only under exceptional
circumstances does large or small intestine override the liver.

The kidneys lie closely applied to the spinal column on each
side and no area of resonance can be demonstrated between a
renal tumour and the spine, whereas theoretically it should be
possible to elicit a triangular area of pulmonary resonance, with
the apex downwards, between the vertebral end of a large spleen
and the spinal column. The thick muscular mass at the side of
the spinal column renders this sign, however, of but little use.

The close proximity of the kidneys to the spine also explains
the fact that there is no appreciable interval between a renal
swelling and the vertebrae of the lumbar region.

The directions in which an enlarged kidney is seen to project
are also determined by its surroundings. It cannot project
backwards because the bed on which the kidney rests consists of
the psoas, the quadratus lumborum and the diaphragm, and to
the resistance offered by these muscles is added the support
of the lumbar transverse processes, the last rib and the arcuate
ligaments. Extension of the tumour directly inwards is resisted
by the prominence of the vertebral bodies, whilst extension
upwards is prevented by the action of the diaphragm. The
kidney as a result tends to enlarge forwards and outwards, pro-
jecting forwards at or near the level of the umbilicus below the
position of the liver or stomach, and also extending towards the
flank. Although a renal enlargement, except in certain cases of
infiltrating malignant disease or of perinephritic suppuration,
does not bulge backwards, yet it can be felt to " fill the loin "

432 CLINICAL APPLIED ANATOMY.

and so contrasts with swellings of the gall bladder or spleen
which are more superficially placed. A word of warning, how-
ever, is necessary with regard to massive splenic tumours, for
these too tend to fill the loin and can be felt through the lumbar
muscles if of sufficient size.

The kidneys normally move slightly in respiration, following
the movement of the diaphragm. Eenal enlargements also show
the respiratory excursion unless fixed by adhesion. Owing to the
fact that the kidneys are not so closely related to the dome of
the diaphragm as the liver and the spleen are, the respiratory
excursion of the latter viscera and of the fundus of the gall
bladder, is more marked.

As a renal tumour increases it may obstruct the passage of
blood along the left spermatic vein in the male by stretching the
vessel in front of it. A gradually increasing varicocele may be
produced in this way. The right spermatic vein does not open
into the renal vein like the left, but joins the inferior vena cava
at a lower level, consequently it is not liable to be compressed by
an enlargement of the right kidney.

Diseases of the Bladder.

Cystitis. — Inflammation of the mucous membrane of the bladder
is most commonly the outcome of infection. Micro-organisms
usually reach the bladder in one of three ways : — First, ascend-
ing along the urethra, the distance being comparatively long in
the male and short in the female — though the same anatomical
fact may serve to explain the reason of the more complete and
prolonged retention of organisms within the bladder in the male
as compared with the female ; secondly, descending from a focus
within the kidney, as, for instance, in the secondary infection of
the bladder from a tuberculous pyelitis ; and, thirdly, although
rarely, through the blood stream.

The rugose condition of the mucous membrane makes it
difficult to dislodge the bacteria even by repeated and thorough
washings out.

HYPEETEOPHY OF THE BLADDEE. 433

The pain in acute cystitis is felt in the supra-pubic region
from the position of the bladder behind the symphysis in the
pelvis, but it is also referred to the end of the penis and to the
perineum, owing to the common nerve supply from the fourth
sacral.

Hypertrophy of the Bladder. — Hypertrophy of the muscular
coat of the bladder is, as a rule, the outcome of obstruction to
the passage of urine through the urethra. When it occurs the
detrusor uringe exhibits considerable enlargement of its fibres, so
as to produce distinct fasiculation. The firm, projecting ridges
of hypertrophied muscular fibres may often be felt by a sound
introduced into the bladder, and may even be mistaken for
calculi or growths.

The mucous membrane between these fasiculi of muscular
tissue is apt to bulge, from the pressure caused by the retained
urine, which bulging amounts in many cases to an actual hernia
of the membrane. Such protrusions are known as sacculi, and
they may occur at those parts of the bladder uncovered or
covered by peritoneum. If they attain a fair size, and particu-
larly if the entrance into them becomes narrowed, urine is apt
to stagnate within them, and calculi may be formed. In other
cases a sacculus may give way under pressure, and urinary
extravasation occur, possibly into the peritoneal cavity, or into
the cellular tissue of the pelvis or into that lying behind the
anterior abdominal wall, the so-called cavity of Eetzius.

Distension of the Bladder. — The empty bladder lies entirely
below the brim of the true pelvis, but when it becomes distended
it rises up into the abdomen, and may then reach as high as
the umbilicus. During this distension the reflection of the
peritoneum from its anterior surface by the urachus and the
obliterated hypogastric arteries is carried somewhat upwards,
and an interval is left between the level of the symphysis pubis
and the peritoneum, through which the organ can be tapped or
suprapubic cystotomy performed, without the peritoneal cavity
being traversed. In childhood the bladder is almost entirely out
of the pelvis proper.

C.A.A. 28

434 CLINICAL APPLIED ANATOMY.

Rupture of the Bladder. — Laceration or rupture of the bladder
may be caused by traumatism or over-distension. Gun-shot
injuries, fractures of the pelvis, rough usage of instruments,
particularly sounds or lithotrites, may all cause perforation of
the undistended or only shghtly filled organ. External violence
such as a kick or blow, coming upon the distended viscus, with-
out the intervention of the protection of the contracted recti
abdominis, may induce a rupture of that part of the bladder w^all
which is covered by peritoneum. Further, it is possible, though
not common, for over-distension to spontaneously cause a giving
way of the vesical wall, either where covered or uncovered by
peritoneum, and this is particularly liable to happen in those
cases w^here the distension occurs in a hypertrophied and sac-
culated bladder.

When the rupture is into the peritoneal cavity and sterile
water is injected into the bladder, this will find its way through
the rent into the larger space beyond. Hence it follows that if
a measured quantity is introduced, only a portion of this will be
withdrawn, thus establishing the fact of the perforation of the
vesical wall.

Retention of Urine. — Eetention of urine within the bladder
is caused by complete obstruction to its outflow along the
urethra, and is therefore due to pressure from without, disease
in the walls of the tube itself, or blockage from within.

One of the commonest causes of complete retention is organic
stricture of the urethra, the anatomical connections of which
are discussed later. Enlargement of the prostate gland is also
a not uncommon factor in producing retention, and is also sub-
sequently dealt with. Here the obstruction of the urethral
passage by a calculus may be alluded to.
■ Particularly in children, a calculus which is either formed in
the bladder or passed down the ureter from the kidney, is flushed
out by the flow of urine from the bladder into the urethra, and,
as a rule, is arrested in the narrowest part of that tube, that is to
say, just within the lips of the external meatus. In order to
extract the impacted stone it is well to remember that since

GONOKRHCEA. 435

the meatus is the narrowest part, the opening should be enlarged
in a direction upwards into the glans, and that the penis should
be seized on the proximal side of the stone, so that the calculus
may not slip into the higher and wider part of the urethra during
its removal.

If the urine cannot be withdrawn per urethram, the bladder
may be aspirated or tapped immediately above the symphysis
pubis, seeing that the retention of urine has distended the
bladder and elevated the peritoneal reflection ; or it is possible
to withdraw the urine by tapping through the rectum, above the
prostate and through the trigone at the base of the bladder,
which is also uncovered by peritoneum.

Specific Urethritis (Gonorrhoea). — Inoculation of the mucous
membrane of the urethra with the gonococcus occurs at the lips of
the meatus externus or just within the fossa navicularis. From
this starting place the whole length of the tube may become
involved by direct continuity of infection, and beyond it the
bladder and even the ureters and the kidneys may suffer from
the invasion. The openings of the glands in the mucous mem-
brane form convenient nesting places for the cocci.

The lymphatics of the urethra absorb the septic material, and
convey the organisms, both gonococci and staphylococci, to the
upper set of inguinal lymphatic glands, and sometimes also to
the lower set, thus inducing the formation of a bubo. The
gonococci reaching the prostatic portion of the urethra may
enter one or other of the common ejaculatory ducts, and may
travel along this tube, pass the entrance of the duct from the
vesicle and through the whole length of the vas, to eventually
reach the globus minor of the epididymis, there to cause in-
flammation or epididymitis. The vas itself is usually involved
in the inflammatory process and is thus thickened, and often the
surrounding tissues of the cord become oedematus. In some
instances, before the actual inflammation of the epididymus
occurs, pain may be experienced on defsecation, owing to the
hardened faeces pressing upon the lower end of the vas and the
seminal vesicle, both of which structures may have been already

28—2

436 CLINICAL APPLIED ANATOMY.

infected. Pain also in the inguinal canal may indicate an
inflamed condition of that part of the vas which lies therein.

The sub-mucosa of the urethral wall is abundant, hence the
marked swelling which occurs in urethritis, leading, not in-
frequently, to an obstruction of the channel and acute reten-
tion of urine. In relieving such retention by the use of a
catheter, one of a large size should be employed, so as to press
aside the swollen mucous membrane, and not to pierce the soft
tissue.

Stricture of the Male Urethra. — The urethra in the male
commences at the internal meatus at the neck of the bladder,
the lowest part of the trigone, and ends at the external meatus
at the termination of the glans penis. Between these two points
in the adult the prostatic portion measures a little more than
one inch, the membranous a little less than one inch, and the
penile about five inches. It is therefore obvious that a catheter
to reach the bladder by way of the urethra, and to project into it,
must be at least eight inches in length for the fully-developed
male.

The channel is narrowest at the external meatus, this being
a vertical slit. An instrument which will pass through this
aperture will traverse any portion of the rest of the normal
urethra, even the membranous part which comes second in
narrowness. Just within the external meatus is a wide area of
the urethra, owing to the fossa navicularis found in its floor, and
in the roof the lacuna magna, in which the tip of a small catheter
may be caught.

Numerous mucous glands open, in depressions or lacunae, into
the distal portion of the penile urethra. It is these pits
which are so liable to be hiding places for micro-organisms,
particularly the gonococcus, and casts of these sulci often appear
in urethritis, being washed out by the flow of urine.

In the bulbous portion of the urethra just below the anterior
layer of the triangular ligament may be seen the openings of
fcJae ducts of Cowper's glands, the glands themselves being
situated between the two layers of the ligament, on either side

STRICTUEE OF THE URETHRA. 437

of the membranous part of the tube. Only mucous glands
open into this latter part of the urethra.

The prostatic portion is wide, and on its floor is found an
elevation, on the summit of which there opens the sinus pocu-
laris, and on each of its sides the common ejaculatory duct.
The urethra terminates in the bladder at a spot which, in the
adult, is one inch behind the upper border of the symphysis
pubis, and three inches from the skin surface of the perineum.
The urethra is partially covered with voluntary muscles, the
bulbo-cavernosus around the bulbous part, and the constrictor
urethrse (deep transversus perinei) about the membranous
portion.

The passage of a catheter or other instrument along the healthy
urethral channel may be obstructed first by the narrowness of
the external meatus, and then by the actual curvature of the
tube. Thus it becomes desirable to draw up the penis over
the symphysis in the early stage of passing a catheter, so as to
convert the double curve of the passage into a single long one.
During its passage the tip of a catheter may lodge in the
lacuna magna, or against a possible fold of mucous membrane,
caught up as it were by the instrument. Its progress also may
be impeded by the spasmodic contraction of the peri-urethral
muscles. Frequently the point of the catheter may be run
against the superficial layer of the triangular ligament, not
properly engaging the entrance into the membranous portion of
the urethra. Beyond this spot there is little to interfere with
the onward passage of the instrument in the normal tube.
When, however, there is an enlargement of the prostate,
particularly when a so-called middle lobe is hypertrophied,
much obstruction at the entrance into the bladder may be
met with.

Organic stricture of the urethra is most common at the junc-
tion of the bulbous with the membranous portion of the urethra,
and this is accounted for by the fact that the urethra passes
through the anterior layer of the triangular ligament at this spot,
that annular ulcers of gonorrhceal origin are most frequently

438 CLINICAL APPLIED ANATOMY.

found here, and that the urethra is usually torn by injury in this
region. Stricture may also occur in the penile part, but it never
occurs in the prostatic portion.

Extravasation of Urine. — Extravasation of urine is most
usually caused by a giving way of the wall of the urethra. This
may be induced by, (1) a peri-urethral abscess, generally the
result of gonorrhoea, and usually on the proximal side of a
stricture, opening into the urethra, thus allowing urine to be
forced into the emptied cavity of the abscess during micturition,
and if the pressure is great the extravasation may be wide-
spread : (2) laceration of the urethra as the outcome of falls
astride, or blows upon the perineum. Here blood will pass from
the meatus independently of micturition, and should the patient
attempt to pass urine, some of it will invariably be extravasated
through the rupture ; (3) perforation of the wall of the urethra
by the forcible use of instruments ; (4) the giving way of the
dilated and perhaps even ulcerated wall of that portion of the
urethra immediately proximal to the site of a stricture ; (5) lacera-
tions of the urethra associated with fracture of the bones of the
pelvis.

If it is the membranous part of the urethra which has given
way, urine will pass into the substance of the compressor urethras
muscle between the two layers of the triangular ligament, and
theoretically, should be limited to this space, but usually trans-
gresses it in a superficial direction. Extravasation, however, is
far more common in front of, that is superficial to, the anterior
layer of the triangular ligament. Here there is a space which is
securely limited behind and at the sides, but open in front. It
is sometimes spoken of as the superficial compartment of the
urogenital triangle, and has the following boundaries, which
readily serve to limit the progress of extravasated urine, and
direct its advance in one direction only. Superficially are found
the skin and two layers of superficial fascia. The superficial
layer of this fascia is continuous with the subcutaneous tissue of
the thighs, scrotum, penis and the lower part of the anterior
abdominal wall. The deep layer of this fascia is distinctly

EXTEAVASATION OF UEINE. 439

membranous in character. It is definitely attached laterally to
the periosteum of the rami of the ossa pubis and the ischia, thus
preventing extravasated urine from finding its way into the
tissues of the thighs. Posteriorly it winds round the hinder
border of the transversus perinei muscles, to become blended
with the margin of the base of the triangular ligament, thereby
effectually hindering the escaped urine from passing back into
the perineum proper. In front, however, it is as it were un-
attached, and is continuous with the same layer covering the
scrotum, the penis, and the lower part of the abdominal wall.
From this anatomical arrangement it will be readily seen that
urine, extravasated by rupture of the bulbous portion of the
urethra, will find its way directly into the tissue beneath this
deep layer of the superficial fascia. Further, the urine will be
forced to extend forwards, being prevented from going backwards
or outwards by the attachment of the deep layer of the superficial
fascia, and upwards towards the pelvic cavity by the anterior
layer of the triangular ligament. It will therefore creep forwards
into the scrotal tissue, on to the penis, rising up on to the
anterior abdominal wall, and reaching, if allowed, as high even
as the level of the axilla. It will not descend from the hypo-
gastric region into the thighs more than to just below Poupart's
ligament, on account of the attachment of this deep layer of the
superficial fascia to the fascia lata two fingers' breadth below the
ligament. The urine readily induces an intense inflammation
with great swelling, and unless quickly drained out by free
incisions will cause sloughing. The incisions may be, and should
be, made deeply into the infiltrated tissue, without fear of doing
harm.

CHAPTEK XVIII.
DISEASES OF THE GENITAL SYSTEM.

Male.

the testis and epididymis.

Orchitis. — Inflammation of the testis may be due to the
invasion of the organ by bacteria, or to its injury by external
violence.

The body of the testis is most commonly the site of inflam-
mation due to the syphilitic virus. The investment of the body
of the testis by the peritoneum forming the tunica vaginalis
indicates the reason why a collection of fluid around the organ,
secreted by the serous membrane, is often seen in gummatous
orchitis. The presence of hydrocele in such cases also serves to
prevent the adhesion of the parietal and visceral layers of the
tunica vaginalis. Thus the process of inflammation but rarely
extends to the skin of the front of the scrotum, and hernia testis
in this condition is rare. The dense, firm, unyielding nature
of the tunica albuginea explains the severity of the pain felt
when acute orchitis is present.

Epididymitis, when occasioned by infection, is due to the
invasion by gonococci from the urethra along the vas to the
globus minor, or the deposit of tubercle bacilli, probably brought
by the blood stream.

Seeing that the epididymis is only partially covered with serous
membrane, its posterior aspect being destitute of it, it is easy to
understand why an inflammation of the epididymis may quickly
involve the overlying tissues, and lead to hernia testis.

New Growths of the Testicle. — In malignant growths of
the testicle it has to be remembered that the lym^^hatic glands
which are secondarily infected are those found in the lumbar

HYDEOCELE. 441

region near the kidney, because the testicle was originally de-
veloped within the abdomen in this region. Hence it follows
that it is not easy to determine whether or not these glands have
become involved in the early stages of malignant deposit in the
testis.

Imperfect Descent of the Testis. — The testis may be arrested
at any stage in its " descent " into the scrotum, or it may descend
but pass elsewhere than into the scrotum. The first abnormality
is termed arrest, whilst the second is known as ectopia.

There are several anatomical peculiarities which may lead to
arrest of the testis. Its blood-vessels may be too short, the vas
may not be long enough, the mesorchium, or fold of peritoneum
attaching the testis to the dorsal wall, may be so broad as to give
the testis so much play that it may never engage the deep ab-
dominal ring, or the testis may be tethered by intra-abdominal
adhesions.

Again, the testis or the epididymis or both may be too large
to permit of the passage of the gland along the inguinal canal or
through the superficial ring.

And, lastly, the pull of the gubernacular fibres may be too
feeble owing to their lack of development.

In ectopia testis the organ is most commonly found at the side of
the anus in the perineum. It is probably drawn there by a band
of gubernacular fibres, which can be felt fixed to the junction of
the rami of the os pubis and ischium. In other instances it is
drawn by gubernacular fibres into Scarpa's triangle, when the
spermatic cord can be felt passing through the superficial ring.

Hydrocele. — The processus vaginalis may remain patent in its
whole length, and peritoneal fluid draining into the po ich con-
stitutes a typical congenital hydrocele. In many of such cases
the actual communication with the general peritoneal cavity is
but small, and consequently it may be difficult to reduce the
fluid and impossible for abdominal viscera to descend — hence the
presence of a hydrocele and the absence of a hernia.

The processus vaginalis may be obliterated at any spot betw^een
its commencement in the parietal peritoneum and the summit of

442 CLINICAL APPLIED ANATOMY.

the testicle. Normally it becomes closed throughout the
whole length between these two points, and then a collection
of fluid in the tunica vaginalis, surrounding the testis, between
its parietal and visceral layers constitutes the common vaginal
hydrocele.

Failure in the complete obliteration in any portion of the
length between the site of the deep ring and the commencement
of the tunica vaginalis leaves a potential cavity which may
become distended with fluid. This will constitute the so-called
encysted hydrocele of the cord.

Supposing the processus vaginalis becomes closed at the site
of the deep abdominal ring but remains patent the whole way
below this, and its cavity becomes distended with fluid, there
is present what is termed an infantile hydrocele.

On the other hand, given that the processus vaginalis becomes
obliterated about the region of the superficial abdominal ring or
slightly below it, remaining patent and in communication with
the abdomen on the proximal side, fluid trickling into this portion
will constitute a funicular hydrocele.

In tapping a common vaginal hydrocele it is important to
remember the relationship of the body of the testis to the fluid.
In by far the larger number of instances the testis lies below
and behind, and the trochar and cannula introduced from the
front to a depth not greater than half an inch should not touch
the anterior surface of the organ. Occasionally, however, the
testis is placed in front of the tunica vaginalis, in a position
liable to injury, but its presence at this spot may be determined
by the position of the shadow cast when testing for translucency.

THE SPERMATIC CORD.

Inflammation of the Cord. — In considering the question of
inflammation of the spermatic cord it may be well to note the
various structures which enter into its composition.

The first is the vas, together with its artery, usually derived

INFLAMMATION OF THE COED. 443

from the inferior vesical, and its veins, which empty themselves
into the vesical plexus, these vessels being derived from and
terminating in an altogether different region to those belonging
to the testicle, although there is a definite anastomosis between
them. Then follow in order of importance the spermatic vessels,
the artery being derived from the abdominal aorta, immediately
distal to the renal arteries, while the veins empty themselves
on the right side into the inferior vena cava and on the left
into the left renal vein. Next there are the spermatic nerves,
derived from the renal and aortic plexuses ; hence it is that
severe pressure upon the testicle is apt to induce serious collapse,
and that a calculus in the kidney may be associated with pain
referred to the testis. The spermatic lymphatics found in the
cord pass up to the lumbar lymphatic glands. In addition to
the above there are also in the cord the remains of the guber-
naculum testis in the form of unstriped muscle fibres, and the
obliterated portion of the processus vaginalis.

Inflammation of the cord may occur either through the vas or
the veins.

A vas which is transmitting bacteria is liable to have its own
walls infected, and the inflammation may spread beyond into the
tissues surrounding it. Therefore in certain cases, particularly
those of tuberculosis, the vas itself is thickened from the actual
tuberculous deposit in its walls, and not infrequently becomes
nodular to the touch ; whilst in cases of gonococcic invasion the
parts external to the vas itself sometimes become markedly
infiltrated and indurated, and in some of these instances a true
phlebitis of the spermatic veins may result.

On the other hand a blow upon, or stretching of, the spermatic
cord may give rise to some extravasation of blood and subsequent
inflammation. Occasionally the vas itself may be ruptured,
either in the inguinal region or in the extra-peritoneal tissue of
the iliac fossa, and this may give rise to a dribbling of blood
from the urethra altogether apart from micturition, owing to the
direct connection of the vas with the prostatic portion of the
urethra by way of the common ejaculatory duct,

444 CLINICAL APPLIED ANATOMY.

THE PROSTATE GLAND.

Prostatitis. — The prostate is situated at the meeting place
of the genital and the urinary tracts; hence it follows that
there are three sources through which it may become infected
and inflammation result. First, by way of the urethra, and
particularly by the gonococcus ; secondly, along the excretory
tube of the testicle and through the common ejaculatory duct,
and especially by the tubercle bacillus : lastly, along the ureter
through the bladder and the first part of the urethra, either by
septic or tuberculous organisms. The orifices of the numerous
glands of the prostate and the wider aperture of the sinus
pocularis afford convenient nesting-places for the bacteria derived
from any one of these channels.

Inflammation of the prostate leads to severe pain, on account
of the denseness of its capsule, and frequently to retention of
urine, because of the obstruction to the urethral passage from
the bulging forwards of the floor of the tube.

Pus within the substance of the prostate most commonly
finds its way into the urethra or into the bladder, through the
lower part of the trigone ; occasionally into the rectum, in front
of which the prostate lies, only separated by its capsule and
some loose cellular tissue ; still more rarely, through the skin of
the perineum.

In opening a prostatic abscess from the perineum it is important
to warn the patient that urine will almost certainly flow through
the wound, seeing that if the abscess has already partially
evacuated itself into the urethra, the wound in the j)erineum
will constitute a direct tract from the urethral passage to the skin.

Enlargement of the Prostate.— It would be out of place to
discuss the various theories as to the exact etiology and histology
of enlargement of the prostate. It will be sufficient to show how
this enlargement anatomically alters the outflow of urine.

The two lateral masses of the prostate — often called lobes —
are united together by a thin commissure anterior to the urethra,

ENLAEGEMENT OF THE PEOSTATE. 445

but more firmly behind that channel, the urethra itself traversing
the organ. Hence it follows that any increase in size of the
prostate must necessarily lead to alterations in the direction and
size of the urethra.

But while this is true, it is the projection of the enlarged
prostate into the vesical cavity which, as a rule, causes most
inconvenience, and the subsequent serious results. In enlarging,
the tissue increases in the line of least resistance, and not infre-
quently this is towards the interior of the bladder. Hence there
projects upwards a so-called middle lobe which is in reality an
asymmetrical outgrowth of a lateral lobe. This tends to block
the exit from the bladder, and particularly so when the patient
strains during the act of micturition. It may very easily lead
to complete retention of urine, necessitating speedy relief.

The passage of a catheter along the urethra into the bladder
may be rendered difficult by the point of the instrument im-
pinging against this projecting mass from a lateral lobe. Hence
it is advantageous to use a coude or elbowed catheter, so that it
may mount up over the elevation and pass more readily into the
bladder beyond.

Kemoval of an enlarged prostate, either by the suprapubic or
perineal route, is in many cases probably the enucleation of
adenomata which have compressed the prostatic tissue itself into a
very thin layer. It is, however, theoretically possible by inserting
the finger between the prostatic sheath proper and the visceral
layer of the pelvic, recto-vesical, fascia, to enucleate the whole of
the gland, but in such cases there is a great tendency for con-
siderable haemorrhage, on account of the damage done to the
plexus of veins lying between the two layers of fascia. In either
case the contained urethra is usually torn away.

Female.

the ovary.

Ovarian Cysts. — The ovary is placed in the peritoneum
forming the postero-internal layer of the fold constituting the

446 CLINICAL APPLIED ANATOMY.

broad ligament. Hence it follows that cysts of the ovary proper
during their enlargement do not separate the layers of the broad
ligament, but increase in an upward direction, lifting the intestines
and omentum above them, and having the broad ligament as a
pedicle.

The ovarian artery, derived from the abdominal aorta, runs
between the layers of the broad ligament just below the site of
the ovary itself, and ends by anastomosing with the termina-
tion of the uterine artery near the junction of the Fallopian tube
with the body of the uterus.

In securing the pedicle of an ovarian cyst the interlocked
ligature is tied round the ovarian artery in two places, one
between the artery and the pelvic brim, and the other between
the ovary and the uterus. Hence it follows that a piece of the
vessel itself is excised with the tumour.

Cysts derived from the parovarium, or remains of the Wolffian
tubules, lie between the two layers of the broad ligament, and
during their increase in size separate them. There is, therefore,
no true pedicle to such cysts, and a layer of peritoneum has to
be divided in order to remove them.

THE FALLOPIAN TUBE.

Salpingitis. — The direct communication of the lumen of the
Fallopian tube with the exterior through the vagina, the cervix
and body of the uterus, explains the fact that micro-organisms
not infrequently find their way into it.

Inflammation caused by the invasion of these bacteria may lead
to occlusion of portions of the tube and to the formation of pus
within the unobliterated parts. If the bacteria extend along the
whole length of the tube and through its ostium abdominale,
pelvic peritonitis may ensue, and this may lead to a sealing of
the fimbriated extremity, thereby preventing the passage of ova
through the canal.

On the right side the close proximity which the appendix
vermiformis, lying over the brim of the pelvis, has to the ovary

PEOLAPSE OF THE UTEEUS. 447

and tube explains why in certain cases of appendicitis the pain
and other symptoms are mistaken for disease of the uterine
appendages. It is of course possible on the other hand for septic
inflammation of the right tube to extend to the appendix lying
near it, but the reverse — that is to say, inflammation passing
from the vermiform appendix to the broad ligament — is more
common.

Tubal Pregnancy. — The ovum arrested in the Fallopian
tube may become impregnated, and a tubal pregnancy result.
The increase in the size of the ovum and the growth of its
membrane may erode the blood vessels supplying the part. The
consequent haemorrhage ploughs up the tissue of the broad
ligament, producing a haematoma, or ruptures the tube or the
broad ligament, and allows of free haemorrhage into the peritoneal
cavity.

THE UTERUS.

Prolapse. — Prolapse of the uterus is practically a hernia of
the organ together with a portion of the pelvic floor.

Procidentia is normally prevented by the support which the
uterus receives both from above and below.

From above, the round ligament, passing from the upper part
of the lateral aspect of the body of the uterus, extends across the
anterior part of the broad ligament into the inguinal canal, and
serves as a very adequate support.

The broad ligaments, directed outwards and then backwards,
reach the pelvic wall, to w^hich they become attached. Their
lower borders are separated from the muscles constituting the
pelvic floor by a layer of connective tissue supporting the ureter
and a number of large veins passing away from the uterus and
the vagina.

Lastly, the utero-sacral ligaments extend backwards from the
level of the supravaginal portion of the cervix, along the side of
the pelvis, to the front of the rectum. These form the upper
limit of the pouch of Douglas.

From below the uterus is supported by the perineal body and

448 CLINICAL APPLIED ANATOMY.

the visceral layer of the pelvic fascia, together with the muscles
forming the floor of the pelvis, particularly the levator ani, on
each side.

Coincidently with the descent of the uterus in prolapse, the
bladder is drawn downwards, and the vaginal wall may protrude
at the vulva, constituting a cystocele. Similarly, but later, the
rectum may be displaced together with the posterior vaginal wall,
forming a rectocele.

When the prolapse is great, the ureters may be so stretched as
to interfere with the passage of urine through them, and double
hydronephrosis result.

Metritis. — The serious consequences which result from septic
inflammation of the body of the uterus are readily explained
anatomically.

The blood from the uterus is returned through a large plexus
of veins in the broad ligament, which eventually empties its
contents into the internal iliac vein. In septic metritis following
upon parturition, the venous spaces in the uterine wall become
filled with blood clot teeming with micro-organisms, and
gradually an infective thrombosis extends proximally to the
internal iliac, and even the common iliac veins on one or both
sides. Should the common iliac veins become blocked with a
septic clot, phlegmasia will occur.

Inflammation of the wall of the uterus may extend laterally
into the tissue between the layers of the broad ligament,
constituting pelvic cellulitis or parametritis. Or it may progress
so as to involve the peritoneal covering, thereby inducing pelvic
peritonitis or perimetritis.

Pus originating from inflammation of the uterus may, if left
to itself, find its way out through the vagina, or may track
upwsirds between the layers of the broad ligament, so as to
reach the iliac fossa and point above the middle of Poupart's
ligament, or may evacuate itself through the rectum.

Myomata. — Myomata of the uterus may be said to exist in
three varieties, according to the position in which they are
found — interstitial, subperitoneal, and submucous.

MYOMA OF THE UTEKUS. 449

With the enkirgement of an interstitial myoma, the mucous
layer of the wall of the uterus will be separated from the serous
layer. The entire uterus increases in size, and the cavity of the
body is lengthened. The uterine and ovarian arteries become
considerably enlarged to supply the new growth. The veins in
the broad ligament are correspondingly dilated, and large venous
sinuses are formed in the capsule of the tumour.

When the myoma develops in that part of the uterine w^all
close to the broad ligament, particularly the region of the
supravaginal cervix, it may extend outwards and become intra-
ligamentous.

The subperitoneal variety tends to become pedunculated, and
as a result of traction or violence the pedicle may be twisted or
actually torn through. When the subserous myoma is formed
from the anterior aspect of the uterus, it not infrequently
carries the vesico-uterine fold of peritoneum upwards, and
now and again the bladder will be stretched out on the surface
of the tumour, and the ureter on one or both sides considerably
displaced.

When the myoma commences beneath the uterine mucosa, it
tends to become extruded into the cavity of the organ, and may
present as a pedunculated growth. The uterus will endeavour
to extrude what is really a foreign body, and consequently the
pedicle will become more and more lengthened, and the vascular
supply considerably diminished ; hence it is that gangrene of the
myoma frequently occurs.

The enlargement of the whole uterus tends to produce pressure
upon and displacement of the surrounding structures. Inter-
ference with micturition and defsecation are by no means
uncommon. Hgemorrhoids may also be induced by the inter-
ference with the return of blood from the mucous membrane of
the rectum. Pressure upon nerve trunks, where the growth
occupies and is somewhat impacted in the pelvic cavity, will
often induce very severe pain. Pressure upon the ureters may
result in obstruction and dilatation of the tubes, and subsequent
hydronephrosis and even urasmia.

C.A.A. 29

450 CLINICAL APPLIED ANATOMY.

Carcinoma. — There are four varieties of epithelium from which
carcinoma may arise — the stratified epithelium of the vaginal
portion of the cervix, the columnar epithelium of the cervical
canal, the epithelium of the cervical glands, and the epithelium
of the glands imbedded in the body of the uterus.

Whilst it is true that an epithelioma commencing in the cervix
may involve the vagina below and the uterus above, the im-
portant fact concerning the spread of the disease is that the
carcinoma extends in a lateral direction into the parametrium,
or the tissue at the base of the broad ligament. It is this
extension which renders futile any operation unless it is under-
taken in quite the early stages of the disease. The close relation
of the ureter to the supravaginal portion of the cervix, as it
passes forwards and inwards, explains why the tube is liable to
be injured during operations in this region.

It is in this situation that the growth tends to rapidly involve
the ureters, and produce obstruction of these tubes.

As it progresses anteriorly it will invade the bladder, which
may eventually be ulcerated into, a vesico-uterine or vesico-
vaginal fistula being thereby caused.

By the growth of the neoplasm into the uterine veins, particles
may become detached and carried by the blood stream to the
heart and lungs, inducing rapid dissemination and growth of
secondary deposits. The lymphatics may also convey the cells,
carrying them so as to infect the iliac group of glands, and later
those placed along the aorta, distal to the origin of the renal
arteries.

THE VAGINA AND VULVA.

Yulvitis and Yulvo-Yaginitis. — Invasion of the vulva, and
subsequently of the vagina, by micro-organisms, particularly
the staphylococcus and gonococcus, is very frequent, and on
account of certain anatomical peculiarities it is difficult to
entirely eradicate them.

Bacteria may lie latent in the various folds and depressions of
the labia, remnants of the hymen, and rugae of the vagina, as

MAMMITIS. 451

well as within the ducts and cavities of the vulvo-vaginal glands
and even the cervical canal or uterus.

Absorption of septic products by the lymphatics of the vulva
induces lymphadenitis in the inguinal region ; absorption by the
lymphatics of the lowest part of the vagina also infects the
inguinal glands, but absorption by those of the upper part of the
vagina involves the iliac lymphatic glands.

THE MAMMARY GLANDS.

Mastitis (inflammation of the nipple). — Inflammation of the
nipple is common during lactation. The skin surmounting the
nipple, although covered by stratified epithelium, is delicate and
becomes easily cracked. Fissures infected by bacteria thus
readily arise and may be extremely painful, sensations being
conveyed by the third and fourth thoracic nerves. In the areola
around the nipple are numerous large sebaceous cysts, which are
sometimes the seat of inflammation which may terminate in
suppuration giving rise to one form of supra-mammary abscess.

Mammitis (inflammation of the mamma or breast proper). —
The usual variety of mammitis is the acute, caused by septic
absorption from the nipple. The summit of the nipple is
slightly fissured, and opening upon it are the orifices of the
radiating milk ducts which, in the adult, and particularly during
lactation, are sufficiently large to admit a bristle. Just beneath
the surface the ducts are somewhat dilated. Each duct repre-
sents the excretory tube of a lobe of the gland, there being some
twelve to fifteen lobes and ducts. Each lobe is separated from its
neighbour by an intervening septum of fibrous tissue, often called
a suspensory ligament. It will thus be seen that there is a direct
and open channel along which organisms may pass from the
surface to the depth of the gland, through the orifices of the milk
ducts, and along the ducts themselves to the acini of the lobes.
There is also another track along which infection may occur,
namely the lymphatic, setting up an acute lymphangitis of the
mammary tissue.

29-2

452 CLINICAL APPLIED ANATOMY.

In whichever way the infection proceeds, it is usual for
more than one lobe to be involved. Should suppuration occur,
two or more foci of pus will be formed, which are, at any
rate in the earlier stages, quite distinct from one another,
being separated by the interlobular trabeculse. This fact is of
the greatest importance in the effectual treatment of intra-
mammary abscesses, for it indicates the necessity there is of
breaking down the intervening wall between the two cavities,
each containing pus, in order to ensure proper drainage. It is
for this reason that most of these abscesses require a general
anaesthetic to allow of the necessary manipulation being satisfac-
torily carried out. All incisions should be made radiating from
the nipple to avoid severance of the ducts, and should be placed
so as to secure the most thorough drainage, the exact site being
dependent on the position which the patient will for the most
part assume subsequent to the operation. Owing to the
mobility of the gland, and of the pectoral muscle beneath the
gland, it is often necessary, in order to obtain more rapid
healing, that the breast be bandaged back against the thorax,
and the arm be kept bound to the side.

Carcinoma. — The terrible frequency with which carcinoma
affects the mammary gland in the female, and the extensive
operations undertaken for its removal, make a knowledge of
the anatomy of the organ most essential. There are three
varieties of epithelium in connection with the mamma from
any of which carcinoma may arise. First there is the stratified
epithelium covering the nipple itself. Epithelioma of the
nipple starts from this. Secondly, there is the cubical or
columnar ej)ithelium of the ducts, from which so-called " duct
carcinoma " appears to have its origin. Thirdly, the spheroidal
or glandular epithelium of the acini is the origin of the varieties
of spheroidal-celled carcinoma, scirrhus, medullary, and atrophic.

The limits of the mammary tissue proper are very ill-defined,
and by no means consist only of the projection of the breast
from the thoracic wall, extending often as high as the level of
the second rib, so low as to lie on the upper part of the rectus

CAECINOMA OF THE MAMMA. 453

and external oblique muscles of the abdomen, as far inwards as
the margin of the sternum, and outwards well over the serratus
magnus to practically the mid-axillary line. This extensive area
must be remembered when it is requisite, as in excision for
carcinoma, to remove the whole of the glandular tissue.

Malignant disease of the mamma infiltrates the peri-glandular
connective tissue, and disseminates by the lymphatic vessels so
abundant in it. Hence it is that three of the most characteristic
signs of mammary carcinoma are not infrequently in evidence,
although too much stress cannot be laid on the fact that cancer
of the breast ought to be diagnosed long before the signs are
present, should the patient come at this early stage. Nothing
is more reprehensible than to wait for their appearance before
warning the sufferer of her serious complaint and advising
adequate treatment. The three signs are, (1) The skin becomes
adherent, and creases or puckers when moved or pinched over
the site of the disease. Tbis is due to the contraction of the
fibrous bands, surrounding and invaded by the growth, and
passing from the gland to the over-lying skin. (2) The nipple
becomes retracted. Again this is due to contraction of the con-
nective tissue around the affected acini, which tissue is continuous
superficially with that about the ducts passing through the nipple.
(3) Lymphatic glands become palpably enlarged. The gland is
everywhere freely supplied with lymphatics which form peri-
acinous and peri-ductal networks. Afterwards these are gathered
up in the interlobar trunks, and there is a free anastomosis
between these latter and the vessels found in the subcutaneous
tissue covering the gland, and in the pectoral fascia upon which
it lies. The efferent lymphatic vessels from the gland pass to at
least three sets of lymphatic nodes. The majority go directly into
the anterior axillary nodes, placed beneath the outer margin of
the pectoralis major. Through these the lymph may carry the
carcinomatous material to the central or deep nodes arranged
along the axillary artery and vein, and so to the nodes below
and above the clavicle. Other lymphatics, chiefly from the upper
and inner quadrant of the mamma, pass directly through the

454 CLINICAL APPLIED ANATOMY.

third, fourth, and fifth intercostal spaces to the nodes lying in
the anterior mediastinum. Some from the uppermost part of
the gland may pass directly to the glands situated above the
clavicle.

From this diffusion of lymph from the mamma, it is easy
to understand how impossible it is to be sure that the whole
of the disease has been eradicated, when even every lymph
node in the axilla and subclavicular region has been extirpated.
Apparently also in certain cases the lymphatic vessels of one
gland communicate with those of the opposite side across the
middle line. " Cancer en cuirasse," or the hide bound infiltra-
tion of the skin, is due to the passage of carcinomatous cells
along the connective tissue lymphatics from the gland to the skin,
and the spread of the growth through the subcutaneous lymph
network. This infiltration may possibly be precipitated by the
nearest chain of lymphatic glands becoming saturated as it were
by malignant deposit or even by the blockage of lymphatic
pathways by the removal of the axillary glands.

The extreme swelling of the upper limb often seen in the later
stages of carcinoma of the mamma is likewise due to the blockage
of lymphatics by malignant deposit.

Death may sometimes be brought about by direct extension of
the growth through the thoracic wall to the pleura, a malignant
pleurisy supervening which speedily exhausts the sufferer.

Secondary malignant deposits in bones during the course of
mammary carcinoma are explained by blood transmission.

CHAPTER XIX.
DISEASES OF THE EYE.

EYELIDS AND LACHRYMAL APPARATUS.

Hsematoma. — The areolar tissue of the eyehd is so loose that
it readily becomes infiltrated with blood after a blow, leading to
a characteristic " black eye " ; or with inflammatory products in
septic conditions in the neighbourhood ; or with air in fracture
of the nasal bones or of the frontal bone over the sinus.

Ciliary Blepharitis. — The large hair follicles, and the associated
sebaceous or Meibomian glands, are frequently the site of invasion
by bacteria, with resulting acute or chronic inflammation. In
consequence of this there may follow a certain amount of ectro-
pion, together with scarring of the edge of the lid. The duct
of one of the glands may become blocked, and a chalazion or
Meibomian cyst result. This is placed between the conjunctiva
and the tarsal cartilage, but it may cause some thinning of the
latter, and so present as a swelling which can be seen through
the skin of the lid.

A stye, or hordeolum, is a localised septic inflammation
occurring in a hair follicle or Meibomian gland, and the sup-
purating contents can often be readily evacuated by pulling out
the lash from the affected follicle.

Ptosis may be due to paralysis of the third nerve, the levator
palpebrae superioris becoming inactive, or to paralysis of the
seventh nerve producing a relaxation of the palpebral portion of
the orbicular muscle.

Entropion. — Granular conjunctivitis and spasm of the orbicu-
laris palpebrarum are the two most common causes of inversion
of the eyelids. The usual result of entropion is trichiasis, or
turning in of the cilia. This will lead to the surface of the

456 CLINICAL APPLIED ANATOMY.

cornea being irritated by the lashes, with consequent ulceration,
or pannus.

Ectropion. — Ectropion may be due to atrophy of the palpebral
portion of the orbicularis or to cicatricial contraction. E version
of the lower eyelid leads to a faulty position of the lower punctum
lachrymale, and therefore to epiphora.

Epiphora. — The overflowing of the lachrymal secretion from
the conjunctival sac down the cheeks, which is termed epiphora,
may be physiological or pathological.

The lachrymal apparatus consists, firstly, of the secreting
organ, the lachrymal gland. This is situated in the upper,
outer and anterior part of the orbit, resting up against a hollow
in the orbital surface of the frontal bone. It is invested in a
capsule of fascia which separates it from the rest of the orbital
space. The ducts of the gland are from twelve to fifteen in
number, and open at the fornix, or reflection, of the conjunctiva
beneath the upper lid. The gland is supplied wdth blood by the
lachrymal artery, a branch of the ophthalmic, and with secretory
stimulation by the lachrymal nerve, a branch of the first division
of the fifth cranial nerve. It is over-stimulation of the gland
through this nerve, usually reflexly, which induces physiological
epiphora, the drainage apparatus being unable to cope with the
superabundance of tears. It is possible to remove the gland for
tumour, over-action, incurable epiphora, or other reason without
invading the general cavity of the orbit.

The secondary part of the lachrymal system consists of the
drainage apparatus for conveying the secretion of the gland out
of the conjunctival sac into the nose. Each eyelid near the
inner canthus is provided with a minute aperture, the punctum,
that in the upper lid, however, being almost functionless. Each
punctum rests normally against the ocular conjunctiva, and
receiving the lachrymal secretion which has flowed across the
front of the eyeball, passes it on into two small channels, the
canaliculi, one in each lid. At first these are almost vertical
in direction, then, making a sudden bend, they run almost
horizontally inwards, above and below the caruncle, to open

CONJUNCTIVITIS. 457

either separately or after joining, into the lachrymal sac, situated
at the side of the nose in a groove on the lachrymal bone,
behind the tendo-oculi and in front of the tensor tarsi muscle.
The lachrymal sac opens into the nasal duct, which passes
downwards, somewhat backwards and outwards, to terminate in
the nose under cover of the anterior part of the inferior turbinate
bone. This duct contains as a rule two small valves of mucous
membrane. Generally, however, air can be blown from the nose
through the lachrymal channels and out through the puncta.
Obstruction to any part of the lachrymal drainage system may
induce epiphora.

THE CONJUNCTIVA.

The exposed position of the conjunctiva readily explains the
frequency with which it becomes infected, conjunctiYitis result-
ing. Reflex irritation of the orbicularis palpebrarum muscle
in conjunctivitis, is a cause of the blepharospasm. The loose
cellular tissue of the conjunction may become greatly infil-
trated by inflammatory products leading to chemosis. Blood
efi'used beneath the conjunctiva is not infrequently seen in cases
of fracture of the anterior fossa of the base of the skull.

THE CORNEA.

Normally the cornea is partially covered by the upper eyelid
even when the eyes are open, and wholly covered by the approxi-
mation of the lids during their closure. For this reason, as well
as owing to the lachrymal secretion, it is well protected and
cleansed, and therefore guarded from injury and infection. Its
want of blood vessels, however, may be a predisposing cause of
keratitis, and it is interesting to see how the surrounding con-
junctival blood vessels frequently invade the corneal area for the
purpose of absorbing inflammatory products. Thus a leash of
vessels can often be seen extending from the conjunctiva to
vascularise an ulcer of the cornea.

In the case of interstitial keratitis the vessels are derived

458 CLINICAL APPLIED ANATOMY.

from the deeply situated arteries of the adjacent sclerotic, and
hence they appear to come out from beneath the limbus. They
are often quite indistinct, and of a dirty red or greyish-red
colour, because they are covered by the clouded superficial layers
of the cornea. They are easily distinguished from the superficial
vessels, not only by their position and appearance, but also by
the fact that their branches are given off in tufts, like a brush,
whilst in superficial keratitis they branch in arborescent fashion.
Traces of these vessels can often be detected as thin parallel
fibres after all sign of interstitial keratitis has passed off — a point
of some importance in determining the presence of congenital
syphilis.

The opacities following upon corneal inflammation may be
placed in its most superficial layers, when the keratitis has only
damaged the surface epithelium. Nebulae deeper in its substance
are most commonly the outcome of interstitial inflammation.

Perforating wounds of the cornea, when occurring near the
periphery, allow of the escape of aqueous humour from the
anterior chamber, and possible prolapse of the iris, particularly
when the pupil is dilated ; hence the value of eserin for the
prevention of the extrusion of the iris. In the same way it may
happen that the iris, though not extruded, becomes attached to
the posterior surface of the cornea at the site of the perforation,
and a permanent anterior synechia is formed. In some instances,
after perforation of the cornea, the lens itself is pushed forw^ard
during the escape of aqueous, so that its anterior capsule becomes
applied to the posterior surface of the cornea. This sets up an
irritation which produces a permanent opacity in the anterior
capsule, known as an anterior polar cataract.

During the progress of an ulcer of the cornea, its tissue may
become so thinned that the normal intra-ocular pressure may
induce a bulging forward of the posterior lamellae, known as
keratectasia.

Wounds of the sclero-corneal junction are most dangerous
when septic, owing to the great risk of so-called " sympathetic
ophthalmitis." It is probable that in the majority of such cases

IKITIS. 459

the inflammation of the sympathising eye is due to invasion by
bacteria, and that the tract along which they travel may be as
follows : — from the lymphatic spaces of the sclero-corneal
junction to the lymphatic tracts in the optic nerve, and so to
the optic chiasma : across this structure, and along the lymph
vessels of the opposite optic nerve to the opposite eye.

The cornea is supplied by the long ciliary nerves, derived from
the nasal branch of the ophthalmic division of the fifth, and
associated with inflammation of these nerves, herpes of the cornea
may occur, whilst, if the function of the nerves is in abeyance,
ulceration of the cornea frequently follows.

THE IRIS.

Iritis. — The pain in iritis is felt over the distribution of the
ophthalmic division of the fifth nerve, hence the supra-orbital
and temporal neuralgia so frequently accompanying this disease.
The inflammatory oedema of the iris causes it to lose its lustre
and acquire a different colour. For the same reason, and because
of the increased amount of blood present in the dilated vessels,
the pupil becomes somewhat contracted, and at the same time
sluggish in its movements. The pink circumcorneal zone, due
to the injection of the epi-scleral vessels, is another indication of
the congested state of the part.

In plastic iritis the exudation on the posterior surface of the
iris brings it in contact with the anterior capsule of the lens,
inducing adhesion of the two. Such adhesion produces an
irregular pupil, and if the connection becomes organised and
thereby permanent, a posterior synechia will be present.

THE CILIARY BODY.

Cyclitis. — Owning to the extraordinary vascularity of the ciliary
processes, inflammation occurring in this region is usually
accompanied by a considerable amount of oedema and exudation.
The exudate first passes into the posterior chamber, where it

460 CLINICAL APPLIED ANATOMY.

may form a considerable mass, which, in some cases, leads to
the adhesion of the whole posterior surface of the iris to the
anterior capsule of the lens. Part of the exudate also commonly
passes into the vitreous, there to form vitreous opacities;
while another part may be carried through the pupil into the
anterior chamber. This last portion of the exudate consists
of conglomerations of round cells, many of which contain
pigment granules, and as the movements of the eye take place
they are thrown against the posterior surface of the cornea and
become deposited there. The larger cells usually fall to the
bottom, and the deposit has a triangular shape with its apex
upwards. Owing to the turbidity of the aqueous or the exudation
in front of the lens or in the vitreous, vision is necessarily
interfered with during an attack of cyclitis. Great pain is also
experienced when the ciliary region is palpated. The elevation
of the tension during the early stages of cyclitis is due to oedema
of the ciliary body blocking up the iridic angle, whilst the lowering
of tension in the later stages is to be accounted for by the
shrinking of the exudate.

An iridectomy in cases of glancoma opens up the lymphatic
spaces in the ciliary region and allows the absorption of the
fluid which is causing the increased tension of the eye.

CHAPTER XX.
DISEASES OF THE EAR.

Foreign body in external auditory meatus. — The difficulty
of extraction of foreign bodies from the external auditory meatus
depends partly upon the character of the body introduced, but
chiefly upon the anatomical peculiarities of the passage.

The external auditory canal extends from the bottom of the
concha to the membrana tympani. It passes in a direction
inwards and somewhat forwards; its anterior wall is slightly
convex, whilst its floor presents a distinct elevation, which again
renders this portion of the passage convex. Owing to the
obliquity of the membrana tympani, the lower and anterior walls
of the canal are longer than the upper and posterior.

The passage consists of two parts, an external shorter portion
composed of cartilage and an internal slightly longer portion
bounded by bone. By drawing the pinna upwards and backwards
the meatal canal can be made nearly straight — a factor of some
importance in connection with the extraction of a foreign body
and with obtaining a clear view^ of the membrana tympani. The
length of the canal in the adult is about one and a quarter inches,
but it is proportionately shorter in the child. The diameter of
the canal naturally varies with age, but is also not quite uniform
in its whole length. Two constrictions can usually be demon-
strated, one in the cartilaginous portion near its junction with
the bony part, and the other a little external to the membrane.
Impaction of a foreign body beyond one of these constrictions con-
stitutes a real difficulty in extraction. This impaction may often
be aggravated by the swelling caused by the onset of inflamma-
tion. If a stream of water can be forced betw-een the foreign body
and the wall of the meatus, the object can usually be driven out.

462 CLINICAL APPLIED ANATOMY.

Probably the most frequent seat of arrest is at the junction of
the cartilaginous and bony parts of the canal. If syringing fail
to remove the intruding substance, instrumental extraction will
have to be attempted, and the presence of the membrana tympani
at the end of the canal must be borne in mind, otherwise severe
damage may be done to it.

Exostosis of the external auditory meatus usually occurs at
the junction of the cartilaginous and osseous portions of the canal.
Such a bony outgrowth will have a great tendency to block the
meatus, causing retention of secretion and inflammation with
deafness.

Otitis media. — The middle ear or tympanum communicates
with the outer air through the Eustachian tube. Its mucous
membrane is thus brought into direct continuity with that of the
naso-pharynx, and a ready path for the passage of micro-
organisms provided. Seeing the frequency with which infective
conditions are met with about the upper portion of the pharynx,
it is remarkable how comparatively seldom the tympanic cavity
becomes affected. The action of the cilia of the epithelium of
the tube in a direction towards the naso-pharynx, tends to thwart
the ascent of bacteria. When infection of the mucous membrane
of the Eustachian tube occurs, its lumen is quickly obliterated ;
therefore any muco-purulent fluid poured out into the middle
ear, when this becomes involved in the ascending inflammation,
has no exit. Consequently the membrana tympani is of
necessity pressed upon from within, and thereby loses its natural
outward concavity, and may even become convex. The fluid in
many cases will find its way out through the tympanic membrane
by rapid ulceration, seeing that the membrane itself is not more
than i o£ an inch in thickness. As a rule, the perforation
takes place in the upper and anterior quadrant, an area which is
generally thinner than even the rest of the membrane. It is,
therefore, in this region that it is best to perform paracentesis of
the cavity. Occasionally the membrana tympani has a natural
aperture through it in its upper part, which would then readily
give exit to purulent fluid.

Temporal Bone.

Si)e from

■which to 'iL t

approach — t-
the mastoid
antrum.

Position of

sigmoid , '~\

portion of
the lateral
sinus.

V

\

-- " 0 '-JP''*

Supranieatal spine.

>

!^

Fig. 56. — A right temporal bone to show the relations of the mastoid antrum

t7'o faw page 463.

OTITIS MEDIA. 463

It must also be remembered that purulent fluid may find its way
into the mastoid antrum, through its foramen of communication
with the tympanic cavity. Further, the mastoid cells when
developed may also become infected through the antrum, and
mastoiditis result.

The roof of the tympanic cavity is composed of very thin
bone, covered above by fairly firmly attached dura mater. The
interior of the cranium may be reached by pathogenic micro-
organisms from the middle ear in various ways. Carious erosion
of bone is probably the commonest method of extension, giving
rise to an extra-dural collection of pus, and later on to meningitis.
Another route is along lymphatic channels passing between the
membranes and the tympanum; or along fibrous trabeculse,
stretching between the mucous membrane of the tympanic
cavity and the dura mater covering the petrous portion of the
temporal bone. Possibly also the bacteria may pass through
the petro-squamosal suture in quite young subjects. Also
infection may track along the sheaths of the facial and auditory
nerves. It is, however, very difficult to explain the exact method
by which micro-organisms may cause inflammation within the
substance of the cerebellum or the temporo-sphenoidal lobe,
without any meningitis being present intervening between the
site of the abscess and the source of infection.

The proximity of the sigmoid portion of the lateral sinus to
the mastoid antrum and cells, explains the occurrence of septic
thrombosis and subsequent pyaemia.

Occasionally pus from the middle ear may track downwards
along the side of the Eustachian tube, and give rise to a lateral
retro-pharyngeal abscess.

The course of the facial nerve from the internal auditory
meatus through the aqueductus Fallopii to the stylo-mastoid
foramen, lying in close relationship with the inner angle of the
roof of the tympanum, and subsequently along the posterior wall
of this cavity, indicates the reason why otitis media may be
accompanied by facial paralysis.

Pus in the mastoid antrum is placed in o cavity which can

464 CLINICAL APPLIED ANATOMY.

only be reached with safety by an intimate knowledge of the
anatomy of the part. The supra-meatal triangle is perhaps the
best guide in evacuating it. This little triangle is formed by the
horizontal part of the posterior portion of the temporal ridge
and the posterior curving margin of the auditory process, upon
which there is frequently a little prominence of bone called the
supra-meatal spine. Important structures lie in relationship
with this small cavity : above is the dura mater, only separated
by the thin tegmen antri, anteriorly is the facial nerve, inter-
nally the external semi-circular canal, and posteriorly the lateral
sinus. The cranial cavity can be avoided by directing the chisel
or drill horizontally inwards, the level of the floor of the cranial
cavity being slightly above the temporal ridge. The facial nerve
will be free from danger except when the chisel is directed
forwards, particularly when the opening between the antrum
and the tympanum is being enlarged. The external semi-
circular canal will not be injured unless the inner wall of the
antrum, which consists of a fairly thick layer of white compact
bone, is perforated. The lateral sinus will be in danger, more
particularly when the mastoid cells are being attacked, after the
antrum itself has been exposed.

INDEX

Abdominal hernia, 390

suppuration, 383
Abscess, alveolar, 343

axillary, 5

bone, 127

cerebellar, 180

cerebral, 177

cervical, 5

floccular, 181

hepatic, 408

inguinal, 6

intraperitoneal, 383

ischio-rectal, 5

mammary, 452

pancreatic, 417

pelvic, 389

perinephritic, 422

psoas, 6

retroperitoneal, 389

retropharyngeal, 8

scalp, 102

splenic, 300

subdiaphragmatic, 384

submandibular, 10

subperiosteal, 5

temporo-spenoidal, 179
Accessory spleen, 299
Acromegaly, 302
Acromio-clavicular joint, 114
Actinomycosis, 14
Addison's disease, 300
Adenoid growths, 304
Adenomata, 74
Alveolar abscess, 343
Aneurysm, 269

carotid, 275
innominate, 275
ophthalmic, 188
popliteal, 277
subclavian, 276
thoracic, 269
treatment of, 277
Angiomata, 70
Ankle-joint, dislocations of, 99, 124

synovitis of, 132
Anklyostomiasis, 59
Anterior poliomyelitis, 217, 219
Anthrax, 13
Antrum, Highmori, 303, 344

C.A.A.

Antrum, mastoid, 463

Aorta, abdominal, 276

arch of, 271

ascending, 269

descending, 273

Aortic cartilage, 251

disease, 251
Apex of heart, 247
of lung, 314
Appendicitis, 377
Arch of aorta, 271
of foot, 149
palmar, 267
Argyll Robertson pupil, 191, 225.
Arterial haemorrhage, 265
Arteries, obstruction of, 33
Astragalus, dislocation of, 125
Auditory nerve, 204
centres, 206
tract, 206
Auricular septum, 261
Axillary abscess, 5

Bartholin's glands, 451
Base of skull, fractures of, 107
tumours of, 186
Bed-sores, 42
Bile ducts, 411
Bladder, gall, 41 1

urinary, 432

distension of, 433
hypertrophy of, 433
inflammation of, 432
rupture of, 434
Boils, 4

Bone, abscess of, 127
hydatid of, 64
inflammation of, 126
tuberculosis of, 21
Bones of forearm, 88, 89, 90

of leg. 99
Brachial plexus, 232
Brain, abscess of, 177

haemorrhage into, 165
hydatids of, 63
softening of, 170
tumours of, 182
Bronchi, surface relations of, 310

30

466

INDEX.

Bronchi, compression of, 309
Bronchial glands, 24, 49, 339
Bronchiectasis, 308
Bronchitis, 311
Broncho-pneumonia, 311
Bubo, 6
Bunion, 4
Burns, 37

Bursse, disease of, 145
Bursitis, 145

syphilitic, 31

Caecum, carcinoma of, 367
Calcaneo-valgus, 155
Canal, inguinal, 391
Capillaries, obstruction of, 35
Caput Medusae, 406
Carcinomata, 74
Cardiac dulness, 245

impulse, 247
Caries of the spine, 22, 127
Carotid aneurysm, 275

artery, 266, 275
Cellulitis, 11
Cerebellar abscess, 180
peduncle, 195
tumour, 182
Cerebral abscess, 177

embolism, 168
haemorrhage, 165
thrombosis, 171, 173
tumours, 182
Cervical abscess, 5

glands. 24, 43, 287

lymphadenitis, 287
Chondromata, 67
Chyluria, 65
Ciliary body, 459
Circumflex nerve, 86, 241
Cirrhosis of the liver, 405
Clavicle, fractures of, 83
Cleft palate, 343
Cochlea nerve, 204
CoUes's fracture, 89
Colon, carcinoma of, 366
Compression of the brain, 168

spinal cord, 227
Condylomata, 29
Congenital disease of the heart, 258

hernia, 392
Conjunctivitis, 3, 457
Cord, spermatic, 442
Cornea, 457

inflammation of, 3, 457

wounds of, 458
Cough, 210
Cranial nerves, 187
Cranium, fractures of, 103
Cretinism, 292
Cyclitis, 459

Cystitis, 432
Cysts, 78

Depressed fractures, 105
Dermoid patches, 77
Dermoids, 75

Diaphragmatic hernia, 370
Diphtheria, 46
Dislocations, 113
Ductless glands, 289
Ductus arteriosus, 264
Duodenal hernia, 371

ulcer, 37, 363
Duodenum, 363
Dupuytren's contraction, 143
fracture, 100

Ear, 461

Ectopic gestation, 447

Ectropion, 456

Elbow-joint, dislocations of, 118

synovitis of, 129
Elevated fracture, 106
Embolism, 33

arterial, 33
cerebral, 168
Emotional expression, 200
Emphysema, 318

compensatory, 320
hypertrophic, 319
interstitial, 318
mediastinal, 329
surgical, 110
Empyema, 326

antral, 303, 344
interlobar, 325
Encephalocele, 78
Endarteritis, 29
Enteric fever, 39
Entropion, 455
Epididymitis, 435, 440
Epiphora, 456
Epithelioma of tongue, 346
Epitheliomata, 72
Epulis, 343

Equino-varus, 151, 164
Erb's palsy, 232

motor point, 232
Erysipelas, 11
Exostoses, 67

External auditory meatus, 461
exostosis of, 462
foreign body in, 461
Extravasation of urine, 438
Eye, 455
Eyelid, 455

haematoma of, 455
ptosis of, 455

Face, cortical centre for, 200

INDEX.

467

Facial artery, 265

hemiatrophy, 195
nerve, 199
paralysis, 201
vein, 11
Fallopian tube, 446
Fatty tumours, 68
Femur, fracture of, 92
Fibromata, 69
Fibula, fracture of, 99
Fifth cranial nerve, 194
Filarise, 64
Flat foot, 149

Foreign bodies in bronchus, 309
ear, 461
larynx, 306
nose, 304
oesophagus, 352
Fracture-dislocation of the spine. 111
Fractures, 79

greenstick, 57

Gall bladder, 411

stones, 413
Gangrene, 33, 268
Gasserian ganglion, 195
Gastric carcinoma, 357
dilatation, 360
ulcer, 353
Gastroptosis, 362
Genital tuberculosis, 19
German measles, 50
Glanders, 13
Glaucoma, 460
Glossitis, 29, 345
Glosso-labio-laryngeal palsy, 207
Glossopharyngeal nerve, 207
Goitre, 291
Gonorrhoea, 435
Gout, 53

Great sciatic nerve, 241
Gummata, 30

Hsematoma of scalp, 102
Hairy moles, 77
Hare-lip, 342
Haemorrhage, 265

arterial, 265
capillary, 265
cerebral, 164
venous, 265, 281
Heart, topography of, 249
disease, 247

disease, congenital, 258
Hemianopia, 188, 189, 190, 194, 302
Hemiplegia, 36, 166, 172, 200
Hernia, 390

congenital, 392
diaphragmatic, 370
duodenal, 371

Hernia, femoral, 394

inguinal, 390

internal, 370, 371, 372

intersigmoid, 372

umbilical, 396
Herpes ophthalmicus, 197
Hip-joint, dislocation of, 122

synovitis of, 130
Hordeolum, 455
Humerus, fractures of, 85
Hydatids, 61, 62
Hydrocele, 441
Hydrocephalus, 160
Hydronephrosis, 430
Hypoglossal nerve, 211

Icterus neonatorum, 403
Infantile paralysis, 217
Infarction of the liver, 405

spleen, 299
Inferior dental nerve, 82
Inflammation, 3
Inguinal abscess, 6

canal, 391

hernia, 390
Internal capsule, 165, 170, 172, 195

plantar nerve, 243

popliteal nerve, 242
Intersigmoid hernia, 372
Intestinal obstruction, 369

stricture, 375
Intestine, small, 366

ulcers of, 368
Intracranial tumours, 181
Intraperitoneal suppuration, 383
Intussusception, 373
Iris, 459
Iritis. 459

Jaundice catarrhal, 29, 403
in new born, 403

Jaw, dislocation of, 125

Joints, 128

dislocation of, 113
synovitis of, 128
tuberculosis, of, 21, 132

Kernig's sign, 160

Kidney, 421

abnormalities of, 421
calculi of, 427
congenital cystic, 421
enlargement of, 430
inflammation of, 425
injuries to, 422
movable, 423
tuberculosis of, 20, 426
tumours of, 430

468

INDEX.

Kidney, vascular areas of, 428
Knee-joint, dislocations at, 123

synovitis of, 131
Knock knee, 55, 56
Kyphosis from caries, 127
Laryngitis, 305
Larynx, 305

carcinoma of, 306
foreign body in, 306
oedema of, 38, 47, 306
paralysis of, 218, 272, 317, 334
spasm of, 210
Lingual artery, 266
Lipomata, 68
Lips, 341

carbuncle of, 341
carcinoma of, 341
syphilis of, 341
wounds of, 342
Liver, 401

abscess of, 408
carcinoma of, 410
cirrhosis of, 405
congestion of, 404
deformities of, 401
displacements of, 401
hydatids of, 61, 62
infarction of, 405
rupture of, 402
sarcoma of, 411
syphilis of, 28, 410
tuberculosis of, 410
Locomotor ataxy, 222
Lumbar abscess, 387
plexus, 233
Lung, apex of, 314

fissures of, 312
lobes of, 313
lower limits of, 409
lymphatics of, 318, 321
root of, 309, 325
Lymphadenitis, 285

cervical, 287
Lymphangiomata, 70
Lymphangitis, 284
Lymphatic glands, 285

tuberculosis of, 23
Lymphatic trunks, 285

Mamma, 451

carcinoma of, 452
inflammation of, 451
tuberculosis of, 23

Mammitis, 451

Mandible, dislocation of, 125
fractures of, 81

Mastitis, 451

Maxilla, fractures of, 81

Measles, 48

German, 50

Median nerve, 237

paralysis of, 239

Mediastina, 320

Mediastinal emphysema, 329
glands, 25, 339
growths, 332
inflammation, 331
suppuration, 331

Melanotic sarcoma, 71

Meningeal haemorrhage, 105, 168

Meningitis, 156

basic, 157
suppurative, 156
syphilitic, 162
tuberculous, 20, 161

Meningocele, 78

Mesenteric glands, 19, 24, 40, 379

Metacarpals, fractures of, 91

Metatarsalgia, 243

Metritis, 448

Mitral incompetence, 253
stenosis, 254

Moles, hairy, 77

Motor cortex, 170, 179, 183

Motor tract, 182, 183

Mumps, 50, 415

Muscles, actions of, 134
diseases of, 134
inflammation of, 139
injuries of, 140

Muscular dystrophy, 135

Musculo-cutaneous nerve, 240

Musculo-spiral nerve, 86, 239

paralysis of, 240

Myelitis, 212

Myelomata, 71

Myomata, 70, 448

Myositis, 139

Myxoedema, 292

Nasal bones, fractures of, 80

fossae, 303

polypi, 304
Naso-pharynx, 303

adenoids of, 304
Necrosis, 126

syphilitic, 31
tuberculous, 22
Nephritis, 425
Nerve, circumflex, 86, 264

gluteal, 234

laryngeal, 208, 218, 272, 317, 334

median, 237

musculo-cutaneous, 240

musculo-spiral, 86, 239

peroneal, 234, 242

popliteal, external, 242

internal, 234, 242

posterior interosseous, 240

plantar, 242

INDEX.

469

Nerve, radial, 239
sciatic, 241
ulnar, 234

cranial, second (optic), 187
third, 180, 183, 191
fourth, 184, 192
fifth, 183, 194
sixth, 184, 192, 194
seventh, 180, 183, 193,
199
eighth, 185, 204
ninth, 207
tenth, 207
eleventh, 185, 207
twelfth, 211
Nerves, cervical, 197, 232, 223
cranial, 187
peripheral, 232, 234
segmental distribution of, 226
Nose, 303
Nostril, foreign bodies in, 304

Occipital artery, 266
CEsophagus, 349

carcinoma of, 350
dilatation of, 353
diverticula of, 349
foreign bodies in. 352
rupture of, 353
stricture of, 352
Olecranon bursa, 148

fracture of, 88
Ophthalmoplegia, 190
Optic ohiasma, 188
nerve, 187
radiation, 189
thalamus, 165, 188, 190, 200
tract, 189
Orchitis, 440
Os calcis, fracture of, 101
Osteomata, 66

cancellous, 66
ivory, 67
Otitis media, 45, 48, 462
Ovarian cysts, 445

dermoids, 77
Ovary, 445

Palatine paralysis, 209
Pahnar arches, 267, 268

fascia, 143
Pancreas, 415

abscess of, 417
calculi in, 417
carcinoma of, 419
cysts of, 418
Pancreatitis, 415

hsemorrhagic, 417
sclerosing, 417

Papillomata, 72
Paralysis, anaesthetic, 282
climber's, 232
Duchenne's of infant, 232
Erb's, 232
facial, 201, 205
infantile, 217
Klumpke's, 233
median, 239
musculo-spiral, 240
obstetric, of mother, 234
of brachial plexus, 232
of lumbar plexus, 233
of sacral plexus. 234
Paraplegia, 128

compression, 128, 229
from myelitis, 216
thrombotic, 213
Parasites, internal, 58
Parathyroid bodies, 292
Parotid calculi, 400

gland, 50, 397
tumour, 399
Parotitis, 50, 398, 415
Parovarium, 446
Patella, dislocations of, 123

fractures of, 97
Pelvic abscess, 889
Pelvis, fracture of bones of, 91

of kidney, 427
Pericarditis, 18, 244
Peritonitis, acute, 382

suppurative, 383
tuberculous, 18
Peroneal nerve, 234, 242
Peyer's patch, 39
Phthisis, 17, 314
Pineal body, 207
Pituitary body, 802
Pleura, 320

lower limit of, 409
Pleurisy, 18, 321
Plexus, brachial, 232
limibar, 238
sacral, 238
Pneumonia, 812
Pneumonokoniosis, 318
Pneumothorax, 327
Polypi, nasal, 304
Post-ligamental bursa, 146
Pott's fracture, 99
Prepatellar bursa, 145
Progressive muscular atrophy, 219
Prostate, 444

enlargement of, 444
Prostatitis, 444
Pseudo-bulbar paralysis, 207
Psoas abscess, 6
bursa, 148
Pulmonary cartilage, 254
collapse, 312

470

INDEX.

Pulmonary tuberculosis, 17, 314
Pyaemia, 10
Pylephlebitis, 10, 414
Pyonephrosis, 430

Radial artery, 267
Radius, fracture of, 89, 90
Raynaud's disease, 36
Rectum, carcinoma of, 368

malformations of, 376
Reflexes, table of, 215
Retroperitoneal suppuration, 389
Retro-pharyngeal abscess, 8
Rheumatic nodules, 52
Rheumatism, acute, 51
Rhinitis, 303

Ribs, fractures of, 108, 327
Rickets, 54
Rickety pelvis, 56

Sacral plexus, 233
Salpingitis, 446
Salivary fistula, 398
glands, 397
Sarcomata, 71
Sartorius bursa, 147
Scalds, 37
Scalp, haematoma of, 102

wounds of, 101
Scapula, fractures of, 84
Scarlet fever, 43
Semilunar cartilages, 124
Septal deviations, 304
Septicaemia, 10
Sequestration dermoids, 75
Shoulder-joint, dislocations of, 114

synovitis of, 129
Sinuses, cerebral, thrombosis of, 173
Skull, fractures of, 101
Specific fevers, 39
Spermatic cord, 442
Spina bifida, 78
Spinal cord, 212, 227

central canal of, 325
compression of, 227
inflammation of, 212

nerves, 232

segments, 214
Spine, caries of, 22, 127

fractures of, 111
Spleen, 296

abscess of, 300

accessory, 299

congestion of, 299

enlargement of, 297

infarction of, 299

injuries to, 296

wandering, 299
Sterno-clavicLilar joint, 113

Sternum, fracture of, 110
Stomach, carcinoma of, 357

dilatation of, 360

prolapse of, 362

ulcer of, 353
Stricture of the urethra, 436
Stye, 455

Sub-crureal bursa, 147
Sub-deltoid bursa, 148
Subdiaphragmatic abscess, 384
Submandibular abscess, 10
gland, 400
Suprarenal body, 300
Surgical emphysema. 110
Synovitis, 128
Syphilis, 27

cerebral, 31

inoculation of, 27, 28

periosteal, 31

secondary, 28

tertiary, 30

visceral, 30
Syphilitic bursitis, 31

endarteritis, 29
meningitis, 162
necrosis, 31
strictures, 30
Syringomyelia, 225

Tabes dorsalis, 222
Tcenia. echinococcns, 61

solium^ 61
Talipes, 149
Tape-worms, 61
Taste, fibres, 198

Tendon sheaths, tuberculosis of, 23
Tendons, diseases of, 141
Tenosynovitis, 23, 142
Teratomata, 75
Testicle, 440

imperfect descent of, 441
inflammation of, 50, 440
new growth of, 440
Testicular dermoids, 77
Tetanus, 12

Thrombosis, 10, 33, 41, 213
Thumb, dislocations of the, 121
Thymus gland, 294
Thyroid gland, 289
Thyro-glossal duct, 289
Tibia, fractures of, 99
Toe, great, 4, 53
Tongue, 345

carcinoma of, 346

paralysis of, 183, 211, 212
Tonsil, 347

haemorrhage from. 266

inflammation of, 347
Tonsillitis, 347
Torticollis, 52

INDEX.

471

Trichina spir-alis, 60

Tropical abscess of the liver, 408

Tubal pregnancy, 447

Tuberculosis, 15

apical, 314
aural, 21
bone, 7, 21
genital, 19
hepatic, 410
inoculation of, 15
intestinal, 16
joint, 21, 132
laryngeal, 16
lingual, 16
lymphatic, 24, 27

Tuberculosis, mediastinal glands,
339
meningeal, 20
miliary, 24
nasal, 16
ocular, 21, 26
palatine, 15
pericardial, 18, 26
peritoneal, 18, 26
pharyngeal, 18
pleural, 18
pulmonary, 17, 314
renal, 426
serous membranes,

26, 27
tonsillar, 15
tracheal, 16
urinary, 20

Tubulo-dermoids, 76

Typhoid fever, 39

Ulcer,

duodenal, 363
gastric, 353
of large intestine, 369
of small intestine, 368
perforating, of foot, 225
varicose, 281

Ulna, fractures of, 88, 90

Ulnar artery, 267

nerve, 88, 234

paralysis of, 235

18,

18,

Urethra, stricture of, 436
Urethritis, specific, 435

tuberculous, 19
Ureter, 429
Ureteric calculi, 428
Urinary bladder, 432
Urine, extravasation of, 438

retention of, 434
Uterus, 447

carcinoma of, 450

inflammation of, 448

myoma of, 448

prolapse of, 447

veins of, 11

Vagina, 450

Vaginitis, 46, 450

Vagus nerve, 207

Valvular disease of the heart, 247

orifices, 251
Varicocele, 282
Varicose veins. 280
ulcer, 281
Vault of skull, fractures of, 103
Vein, external saphenous, 281

internal saphenous, 280

spermatic, 282
Veins, obstruction of, 33
Venous haemorrhage, 265, 281
Ventricular septum, 262
Vestibular nerve, 204
Visual cortex, 190

tract, 188
Volvulus, 372
Vomiting, 210
Vulvitis, 450

Word-deafness, 206
Worms, 59

round, 59

tape, 61

thread, 59

whip, 59
Wound infections, 11
Wounds of scalp, 101
Wrist-joint, dislocations of, 120
synovitis of, 130

THE END.

BRADBURY, AGNEW, & CO. LD., PRINTERS, LONDON AND TONBRIDOE.

DATE DU£ SLIP

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