/^ J^H TITTBBUMm A6ADEMY OF MEDICINJKf 222 North Craig St., THE ANATOMICAL REMEMBRANCER; OR COMPLETE POCKET ANATOMIST. THE ANATOMICAL REMEMBRANCER; OR COMPLETE POCKET ANATOMIST : CONTAINING A CONCISE DESCRIPTION" OF THE BONES, LIGA- MENTS, MUSCLES, AND VISCERA ; THE DISTRIBUTION OF THE NERVES, BLOOD-VESSELS, AND ABSORBENTS; fTHE ARRANGEMENT OF THE SEVERAL FASCIiE ; THE ORGANS OF Generation in the Male and Female; AND THE ORGANS OF THE SENSES. O From the second London edition, revised, i j NEW YORK: SAMUEL S. AND WILLIAM WOOD, 261 Pearl Street. % 1845. Entered according to Act of Congress, in the year 1845, BY SAMUEL S, & WILLIAM WOOD, In the Clerk's Office of the District Court for the Southern District of New York. PREFACE TO THE FIRST EDITION. The sole object of this little Manual, is to recall to the mind of the Student in An- atomy, the information he may have ac- quired either by actual dissection, or by the perusal of works which profess to treat more fully on the subject. The Author, therefore, presumes it will be found highly useful to those who are preparing for ex- amination at the Royal Colleges of Sur- geons and Societies of Apothecaries. te4IO djf>of PREFACE TO THE SECOND EDITION. The rapid sale of a book is the best prac- tical test the public can give of its value. The Author of the Anatomical Remem- brancer has little further to add to this, the Second Edition of his Manual, than his thanks to the Students of Anatomy, and the Medical Press, for the favorable manner in which they have received it. Recommendations of the Medical Press. " The Anatomy is correctly given, and the descriptions, though condensed to the very highest degree, still remain clear and intelligible.5' — Lancet. " It contains but two hundred and fifty pages, and is really an Anatomical mul- tum in parvo." — London Med. and Surg. Journal. INDEX. OSTEOLOGY. Page, The Spinal Column 17 Common characters of a true vertebra . 18 Characters of the lumbar vertebrae . . 18 Deviations ; 19 Characters of the dorsal vertebra? . . 19 Deviations . • . . .20 Characters of the cervical vertebrae . . 21 Deviations . ... . . .21 False vertebrae ...... 24 Os sacrum 24 Os coccyx ...... 25 The Thorax 25 Common characters of a rib ... 25 Deviations 26 The sternum 27 The Pelvis ...... 28 Os Innominatum % .... 28 Os ilium 2S Os pubis . 29 Os ischium ...... 30 X INDEX. Page. The Bones of the Superior Extremity . 31 The Bones of the Lower Extremity . 42 The Sesamoid Bones 54 The Skull and Face 54 Frontal bone 55 Parietal bones 57 Occipital bone 58 Temporal bone .;-... 59 JEthmoid bone 62 Sphenoid bone . . . . . .63 Malar bone . . . • .66 Superior maxillary bone . . . . 67 Palate bone 68 Inferior spongy bone 70 Lachrymal bone 70 Nasal bones . . ... . . .71 Vomer 71 Inferior maxillary bone .... 71 Os hyoides 73 The Cranial and Facial Sutures . . 73 The Orbits 75 The Temporal Fossa . ... . .75 The Zygomatic Fossa 75 The Pterygo-Maxillary Fissure . . 76 The Articulations 76 Temporo-maxillary articulation ... 76 Occipito-atlantoid articulation ... 77 Occipito-axoid articulation ... 77 Atlanto-axoid articulation .... 77 INDEX. XI Common vertebral articulation . Page. . 78 Costo-spinal articulations . 79 Costo-sternal articulation . 80 Lumbo-sacral articulation . . 80 Ilio-sacral articulation . 80 Sacro-coccygeal articulation . 80 Pubic articulation .... . 81 Sterno-clavicular articulation . 81 Scapulo-clavicular articulation . 81 Coraco-clavicular articulation . 82 Ligaments of the scapula 82 Humero-scapular articulation 82 Humero-cubital articulation 83 Superior radio-ulnar articulation . 84 Inferior radio-uhiar articulation . . 84 Radio-carpal articulation 84 Carpal articulations 85 Carpo-metacarpal articulation 85 Metacarpophalangeal articulations 85 Inter-phalangeal articulations 86 Ilio-femoral articulation . 86 Femoro-tibial articulation . 87 Tibio-fibular articulation . 88 Articulation of the ankle 88 Articulations of the tarsus . 89 Tarso-metatarsal articulations 90 The Muscles . 90 Muscles of the head 90 Muscles of the external ear , 90 xu INDEX. Page, Muscles of face . 91 Muscles of lower jaw .... 92 Muscles on anterior and lateralrparts of the neck . 93 Muscles of the pharynx .... 95 Muscles of the palate .... 95 Muscles of the larynx ; 96 Deep muscles on anterior and lateral parts of the neck .... 97 Muscles of the thorax .... 98 Muscles of the back .... 99 Muscles of shoulder and arm 102 Muscles of forearm and hand 104 Muscles of abdomen .... 109 Deep Muscles of abdomen .... 110 Muscles of male perinaeum . . . . 111 Muscles of female perinceum 112 Muscles of inferior extremity 113 Muscles of hip .... 115 Muscles on back of thigh .... 116 Muscles on anterior and external part of leg 116 Muscles on outer part of leg ... 117 Muscles of back of leg .... 118 Muscles of foot .... 119 Muscles of orbit .... 121 Muscles of internal ear .... 122 The Brain and its Membranes 122 Dura mater 122 Sinuses .... 123 INDEX. Xlll Page. Tunica arachnoidea . Pi a mater . 126 Cerebrum . 126 Cerebellum 133 Medulla oblongata . 134 Base of the brain . 135 Origins of the cerebral nerves . 135 Distribution of the cerebral nerves . . 137 Ganglions in connection w ith the fifth pair 139 Spinal nerves , . .144 Distribution of the eight cervical nerves and first dorsal nerves . 145 Cervical plexus . . 145 Brachial plexus . . 146 Dorsal nerves . . 148 Nerves of "Wrisberg . . 149 Lumbar nerves . . 149 Lumbar plexus . . 149 Sacral nerves . . 151 Sacral plexus . . . .151 Sympathetic nerves . . 153 Cervical ganglions . . 153 Cardiac nerves < . . . 154 Cardiac plexus . , . 155 Thoracieganglions . . 155 Semi-lunar ganglions . . 156 Solar plexus . . 156 Renal Plexus . • 156 Inferior mesenteric plexus , . 157 Lumbar ganglions . . 157 XIV INDEX. Page. Sacral ganglions . 157 Ganglion impar . 157 The Thorax and its Contents . 157 Pleurae . 158 Anterior mediastinum . 159 Middle mediastinum . 159 Posterior mediastinum . 160 The Lungs . 160 The Trachea and its Ramifications . . 162 The Heart and Pericardium . 163 The Arteries . 170 The Veins . 180 The Digestive Apparatus . 185 Mouth . 185 Teeth . . . 186 Pharynx . 186 (Esophagus and Stomach . 187 Duodenum . 189 Jjejunum and ilium . . 190 Ccecum . 191 Colon and rectum . 192 Parotid gland . 192 Submaxillary and sublingual glands . . 193 Liver . 194 Pancreas . 196 Spleen . 197 The Urinary Apparatus . 197 Kidneys . 197 Ureters . 199 Urinary Bladder . 199 INDEX. XV Page. The Peritoneum . 201 The Male Organs of Generation . 205 Testicles . 205 Spermatic chord . 209 Vesiculae seminales and prostate gla nd . 209 Cowper's glands . 210 Penis . 210 Urethra . 211 The Female Organs of Generation . 214 Mamma? . 216 The Organs of the Senses . . 217 Organ of touch . 217 Organ of smell . 218 Organ of taste . 220 Organ of vision , 220 Appendages of the eye . 224 Organ of hearing . 227 The Absorbent System . 231 Peculiarities of the Fcetus . 234 The Fascle . 235 Cervical fascia . 235 Superficial fascia of the abdomen . 235 Fascia transversalis and fascia iliaca .236 Superficial perinaeal fascia . . 238 Deep perinaeal fascia or triangular li gament of the urethra . * . 238 Fascia of upper extremity . 239 Fascia lata . 239 The Larynx . 242 The Thyroid Body . 244 THE COMPLETE POCKET ANATOMIST OSTEOLOGY. The assemblage of bones composing the human body, constitutes the skeleton, which is divided into head, trunk, and extremities. The Trunk consists of three parts, the spine or vertebral column, the chest or thorax, and the pelvis. The Spinal or Vertebral Column, situate in the posterior part of the trunk, supports the head, and is itself supported by the pelvis. The bones which enter into its formation are called vertebras, of which there are two classes, the true and the false. The true vertebra are twenty-four in num- ber, and are subdivided into three classes, viz : seven cervical, twelve dorsal, and five lumbar. The false vertebra are nine, five in the os sa- crum, and four in the os coccyx, both of which bones enter into the formation of the pelvis. 2 18 COMMON CHARACTERS OF A TRUE VERTEBRA. A ring of bone, the opening of which is called the spinal or vertebral foramen. The Body, a mass of bone placed anterior to the ring, thick, spongy, and presenting many small holes for blood-vessels. Laminae, two lateral processes which pass backwards from the posterior part of the body, forming the sides of the ring, and terminating posteriorly in the spinous process, from the exis- ence of which the vertebral column has been called spine. Two transverse processes, which pass outwards from the sides of the laminae. Four articular processes, two upon the upper and two upon the lower surface of each verte- bra, which arise from the roots of the trans- verse processes, and articulate with the verte- bra above and below. AJ1 these processes differ from the body in being formed of a more compact bony texture. Four notches, two above and two below, which are formed by the iaminee being grooved out where they join the body. Each of these, with the corresponding notch above and below, forms a lateral hole for the exit of the spinal nerves and the entrance of blood-vessels, and is called the intervertebral foramen. CHARACTERS OF THE LUMBAR VERTEBR.E. 1st. They are the largest of the three classes. 19 2d. The bodies are very broad transversely, of an oval form, deepened upon their upper and lower surfaces by a more compact lamina of bone, which, projecting beyond their bodies, render them concave from above downwards upon their fore part. 3d. The laminae and spinous processes are broad, thick, and short. 4th. The transverse processes are long, thin, and horizontal. 5th. The superior articulating surfaces are oval, concave, and look inwards and back- wards ; the inferior being oval, and convex, di- rected outwards and forwards. 6th. The spinal foramina are of a triangular shape, and larger than in the dorsal vertebrae. 7th. The notches, particularly the inferior, are very large, and form larger foramina than at any other part of the spine. DEVIATIONS. TJie last lumbar vertebra has its body cut off obliquely upon its sacral aspect, so that it is much thicker before than behind. Its trans- verse processes also are short and rounded. CHARACTERS OF THE DORSAL VERTEBRA. 1st. They are intermediate in size between the cervical and lumbar vertebrae. 2d. Tlieir bodies are thicker behind than be- fore, and more convex transversely, assuming ... ^ y^r% -.. . 20 upon their surfaces a triangular rather than an oval form. On either side at the upper and in- ferior margins each body presents two small depressions, the upper being the larger, which, with the intervertebral cartilage and the conti- guous vertebrae form depressions for lodging the heads of the ribs. 3c?. The lamina are broad and strong. 4th. The spinous processes are long, prismatic, tuberculated at their extremities, and directed obliquely downwards. 5th. The transverse processes are long, and directed backwards ; on the extremity and an- terior aspect of each is an oval articular surface for the tubercle of the rib. 6th. The articular processes are nearly verti- cal, the superior looking backwards, the infe- rior forwards. 7th. The spinal foramen is smaller than in the cervical or lumbar vertebrae, and is of an oval shape. 8th. The notches are situated anterior to the articular processes. DEVIATIONS. The first dorsal vertebra has a full depression for the head of the first rib, besides the half de- pression for the second ; its body is longer in the transverse direction, its spinous process is strong and horizontal, and its articular processes are oblique. The 10th, 11th, and 12th, have each a full 21 depression upon the body for the corresponding rib, but want the depression on the transverse processes: the 12th resembles a lumbar verte- bra in the shape of its body, and of its inferior articulating processes. CHARACTERS OF THE CERVICAL VERTEBRA. 1st. They are the smallest of the three classes. 2d. Their bodies, deeper before than behind, and long transversely, are concave from side to side upon their upper surface, and concave from before backwards upon their lower. 3d. The lamince. are broad and thin. 4th. The spinous processes are short, horizon- tal and bifid. 5th. The transverse processes also bifid and short, are grooved upon their upper surface for the spinal nerves, and perforated by a round hole at their bases for the vertebral artery, the direction of which is upwards. 6th. The articular processes are oval in shape, the superior being convex, and directed oblique- ly backwards and upwards; the inferior being concave, and directed obliquely forwards and downwards. 7th. The notches, nearly of equal size, are small, and anterior to the articular processes. 8th. T/ie spinal foramen is large and triangu- lar. DEVIATIONS. The first, or atlas, consists of a large bony 22 ring, enclosing an irregular hole ; instead of a body, the anterior arch of the ring of bone pre- sents a small tubercle before, and a smooth oval articular surface behind, for the odontoid pro- cess of the second vertebra. From the extremi- ties of this arch the ring acquires great density and thickness, and presents upon its upper and lower aspects the articular processes, the supe- rior of which, horizontal and oval from before backwards, look upwards and inwards, and arti- culate with the condyles of the occipital bone ; the inferior circular, slightly oval, and directed downwards and inwards, to articulate with the second vertebra. The transverse processes are not bifid, but are pierced at their bases by the foramen for the vertebral artery, the direction of which is upwards and backwards, and be- hind the superior articular surface is a groove, which marks the continued course of this ves- sel. The spinous process is represented by a small tubercle upon the posterior surface of the ring; corresponding to the articular surfaces, are two small tubercles, to afford attachment to the transverse ligament, which ligament sepa- rates the ring into two, the anterior being for the odontoid process, the posterior for the com- mencement of the spinal chord. The second, or axis, is distinguished by the great length of its body, from the upper edge of which arises its large tooth-like, or odontoid, process. This process presents anteriorly a 23 small articular surface for articulation with the ring of the atlas, and posteriorly a second, which moves against the transverse ligament, whilst its apex presents an acuminated top, to which the check ligaments are attached. The laminae are very thick and strong, and termi- nate behind in the spinous process, which is likewise strong and bifid ; the vertebral foramen is heart shaped, the apex being behind. The superior articular surfaces are convex, and di- rected a little outwards, whilst the inferior, looking downwards and forwards, are smaller and flat. The transverse processes, not bifid, are short and directed downwards, the aspect of the fo- ramen for the vertebral artery, being directed obliquely upwards and outwards ; the superior notches are behind the superior articular pro- cesses, whilst the inferior notches are before the inferior processes. The seventh cervical vertebra is larger than the others ; its spinous process is long, not bifid and prominent, and the foramina, when they exist in the transverse processes, give passage to the vertebral veins. In examining the peculiar characters of the different vertebrae, it is best to select one from near the centre of each class : thus, the third Lumbar, the sixth or seventh Dorsal, and the fourth or fifth Cervical, offer the best examples of the class to which each belongs ; for as the 24 cervical vertebrae approach the dorsal, they be- gin to assume more or less the characters of the latter, and the last dorsal vertebra, upon its un- der surface, presents the characters of a lumbar vertebra. FALSE VERTEBRiE. Os Sacrum. Figure, triangular, the base resembling a lum- bar vertebra ; the apex presenting a small oval surface to articulate with the os coccyx ; the sides presenting two surfaces; the superior, large and irregular for articulation with the ilium ; the inferior thin, for the attachment of the sacro-sciatic ligaments. Pelvic surface, anterior smooth, concave from above downwards, traversed by four transverse lines, and presenting on either side of the me- dian line four holes, called anterior sacral, for the transmission of the anterior sacral nerves. Dorsal surface, irregularly convex, rough, presenting in the median line irregular processes of bone (spinous processes,) and more exter- nally on either side tubercles of bone analagous to the articular processes of the true vertebrae. On either side of the median line are the poste- rior sacral foramina,, for the transmission of the posterior sacral nerves. Spinal canal, at the base is large, and of a triangular form, runs at the dorsal aspect of the bone, and terminates in a triangular fossa at the 25 apex of the bone, where it is bounded on either side by two tubercles, which are in general prolonged to join the base of the os coccyx. Os Coccyx. Figure, triangular, the base articulating with the sacrum. Anterior surface, smooth, and supports the extremity of the rectum. Posterior surface, rough, for attachment of ligaments and muscles. Cornua, are two, placed superiorly, which unite with the last tubercles of the sacrum. THE THORAX, is formed by the dorsal vertebrae posteriorly, the ribs laterally, and the sternum anteriorly. THE RIBS, twelve in number, are divided into seven true, and five false ; the lowest two of the false being called abdominal, or floating ribs. The true ribs are each attached to the sternum by separate cartilages. The three superior of the false ribs have their cartilages attached to each other and to the car- tilage of the seventh rib. The false or floating ribs have their cartilages free. Common Characters of a Rib. The head, round, and divided by a ridge into 26 two articular surfaces, which are received into the depressions on the sides of the bodies of the dorsal vertebrae, the ridge affording attachment to an inter-articular ligament. The neck, narrow and round; at its union with the shaft is The tubercle, a prominence of bone, with an articular surface looking backwards and down- wards to articulate with the transverse process of the vertebra beneath. The angle, is marked by a rough line, and is the point where the rib makes its great turn to circumscribe the thorax. The shaft, — that portion of the rib which ex- tends from the angle to its sternal end, presents an external smooth convex surface, and an in- ternal concave one ; its upper edge being round and smooth, its lower edge thin, and grooved for the intercostal vessels, and its sternal ex- tremity offering an oval pit for the reception of the costal cartilage. DEVIATIONS. 'First Rib, Has no angle, is very short and flat, a round head with no ridge, and but one articular sur- face, its extremity being thick and strong ; one surface is directed upwards, the other down- wards ; the superior presenting a ridge for the attachment of the anterior scalenus muscle, 27 which separates two grooves, one for the sub- clavian artery, the other for the subclavian vein. Eleventh and Twelfth Ribs, have neither angle, tubercle, nor groove, are very short, and the head resembles that of the first. THE STERNUM. Figure, flat, elongated, broad above, narrower in the centre, and pointed inferiorly. Anterior surface, is marked by four trans- verse lines, and is rather convex. Posterior surface, smooth and concave. Upper piece, quadrilateral and thick, is con- cave from side to side upon its upper edge, and presents at each superior angle two semilunar depressions for articulation with the clavicles ; its lower edge is united to the second piece ; its lateral edges receive on either side the cartilage of the first rib and half that of the second. Lower piece, long and narrow ; receives by five depressions upon its lateral edges, the car- tilages of the five inferior true ribs, and by a notch at its superior angle half the cartilage of the second rib, its inferior extremity being long and thin, and ending in a cartilaginous epiphy- sis, called the Ensiform cartilage, which is generally bifid, and pierced by a foramen, its direction being variable. 28 THE PELVIS, Is formed of the os sacrum, os coccyx, (both of which bones have been already described) and the two ossa innominata. OS INNOMINATUM, . Consists in early life of three bones, the ilium, ischium, and pubis. We shall describe each of these bones separately. os ILIUM. Situation, upwards and outwards in regard to the pelvis, forming the upper part of the acetabulum, and the lower lateral part of the abdomen. Body, constricted, forms the upper and outer part of the acetabulum, joining the pubis ante- riorly, and ischium posteriorly. Ala, expanded, offers four aspects, viz., the dorsum, which is rough posteriorly for the gluteus maximus, and presents two semicircu- lar lines for the gluteus medius and minimus muscles ; also a nutritious foramen — the venter which forms the iliac fossa, in which also is a nutritious foramen — the rough articular surface for connection with the side of the sacrum, and a small portion smooth and immediately above the sciatic notch, which enters into the forma- tion of the true pelvis. 29 Processes. The Crest which forms the upper border of the ala. The anterior superior spine, which terminates the crest anteriorly. The anterior inferior spine, immediately above the acetabulum. Both spines are separated by a notch. The posterior superior spine, winch terminates the crest behind. The posterior inferior spine, separated from the former by a small notch. The Bio-pubic eminence, marks the union of this bone with the following, OS PUBIS. Situation, fore part of pelvis, and internal part of acetabulum. Body, forms the internal and superior part of the acetabulum. Horizontal ramus, passes inwards to meet the opposite ramus. Symphysis pubis, is formed by the union of both horizontal rami. The angle is formed by the horizontal ramus turning down to form the symphysis. The tuberosity is about three-quarters of an inch external to the angle. The crest is the small upper transverse por- tion of bone between the angle and tuberosity. 30 The obturator groove is situated upon the under surface of the horizontal ramus. The descending ramus passes backwards and outwards to meet the ascending ramus of the ischium, it bounds the thyroid hole, and by the divarication of the two descending rami, the arch of the pubis is formed. THE ISCHIUM. Situation, lower, outer and back part of the pelvis. Body, forms the outer and back part of the acetabulum ; immediately beneath this cavity is a groove for the tendon of the obturator ex- ternus muscle. The anterior thin edge of the body assists to form the thyroid hole, the pos- terior to form the sciatic notch. Spine, projects backwards and inwards, and bounds the great sciatic notch inferiorly. Tuberosity, the thickest part of the bone, on which we rest when sitting. Between this process and the spinal is a pully-like surface, for the tendon of the obturator internus muscle. Ascending ramus, turns forwards, upwards, and inwards, and joins the descending ramus of the pubis ; it bounds the thyroid hole by its outer thin edge, and the lower aperture of the pelvis, by its thick one, ACETABULUM, [s formed by the union of the bodies of the 31 ilium, ischium, and pubis ; the ilium forming less than two-fifths; the ischium more than two-fifths; and the pubis the smallest part. It presents an articular surface for the head of the femur, and a rough surface inferiorly and inter- nally for the ligamentum teres, where also this cavity is shallowest, and its border deficient. SUPERIOR EXTREMITY, Consists of the shoulder, the arm, the fore- arm, the wrist, and the hand. THE SHOULDER, Is formed of the clavicle and the scapula. THE CLAVICLE. Situation, from the semilunar notch in the upper piece of the sternum, to the acromion process of the scapula. Figure, curved like the italic/. Sternal end, thick, presenting a triangular articular surface ; its edge is rough for liga- ments. Body, cylindrical towards sternum, flat and expanded towards its acromial end. Upon its under surface are a ridge for the rhomboid liga- ment, a rough tubercle for the coraco-clavicular ligaments, and between both a groove for the subclavian muscle, in which groove is found the nutritious foramen. 32 Acromial end, rough and flattened, passes over the coracoid process to meet the acromion scapulas, with which it articulates by a small oval surface. SCAPULA. Situation, upper and back part of thorax, ex- tending from the second to the seventh rib. Figure, triangular. Costtz or edges. The superior or cervical is the shortest and is interrupted by a notch for the supra-scapular nerve ; the inferior or axillary is next in size, and is the thickest ; the poste- rior or vertebral is the longest, and is also call- ed the base of the scapula. Angles. The superior posterior angle is acute and prominent, the inferior angle is thicker and rounded, and the anterior angle has connected to it the neck of the bone. Costal surface, or sub-scapular fossa, is slightly concave and divided by three or four lines, which run from above obliquely downwards and inwards. Dorsal surface is divided unequally by the spine, which thus gives rise to the fossae. Spine arises at the vertebral margin, and pro- ceeds forwards, becoming more elevated, and terminates in the acromion, which surmounts the shoulder joint and articulates with the acromial end of the clavicle by a small oval surface. 33 Supra- spinous fossa, situated above the spine, is deep, and presents a nutritious foramen ; it lodges the supra- spinatus muscle. Infra-spinous fossa, larger, irregularly con- cave and convex, affords attachment to the in- fra-spinatus muscle, the teres minor muscle, and by an inferior rough surface, to the teres major muscle. Coracoid process overhangs the inner and upper part of the glenoid cavity. This process has a crooked appearance, and gives attachment to the pectoralis minor, the short head of the biceps and the coraco-brachialis muscles, also to ligaments. Glenoid cavity, articulates with the head of the humerus, is shallow and oval form, being broader below, and giving attachment by its upper narrow part to the long head of the bi- ceps muscle. Neck is the contracted portion of the scapula immediately behind the glenoid cavity; it gives attachment to the capsular ligament of the joint. OS HUMERI. Connections to the scapula above and radius and ulna below. Head forms a small section of a large sphere, is smooth and covered with cartilage in the re- cent state. Neck, a slight contracted line, rough for the 3 34 attachment of the capsular ligament. It is united to the shaft hy an obtuse angle. Tuberosities exist at the junction of the shaft with the neck. The largest is posterior, and affords attachments to the supra- spin atus, infra- spinatus, and teres minor muscles ; the smallest being anterior, more prominent, and giving at- tachment to the sub-scapular muscle. Bicipital groove is between both tuberosities, lodges the long biceps tendon, and affords at- tachment by its anterior margin to the pectora- lis major muscle, and by its posterior margin to the latissimus dorsi and teres major muscles. Shaft is rather twisted, the upper extremity cylindrical, the lower flattened ; upon its ex- ternal and central aspect, is a rough portion for insertion of the deltoid muscle and upon the in- ner side of the bicipital groove is a slight rough line for the insertion of the coraco-brachialis muscle. The nutritious foramen is directed downwards towards the elbow joint. Internal condyle is prominent and sharp, af- fording attachment to the pronator and flexor muscles, and to the internal lateral ligament. External condyle is less prominent, but de- scends nearer the elbow joint, and gives attach- ment to the supinator and extensor muscles, and to the external lateral ligament. Articulating surfaces. First, a small round head, situated externally and nearer the anterior than the posterior part of the bone, for the ra- 35 dins. Second, the trochlea or pully-like surface placed internally for the ulna ; being much be- low the level of the head, so as to give the ar- ticular surfaces an oblique direction from above downwards and inwards. C or onoid fossa at the fore part of the trochlea to receive the coronoid process in the bent po- sition of the forearm. Olecranoid fossa at the back part of the tro- chlea, to receive the coronoid process in the ex- tended position of the forearm. ULNA. Situation at the inner side of the forearm. Upper extremity articulates with the humerus and radius. Olecranon process, posterior forming the pro- jection of the elbow, is the highest point of the bone, and by its superior border gives attach- ment to the triceps muscle ; beneath this it is smooth for a bursa mucosa. Coronoid process, anterior and inferior to the olecranon, is smaller than it, and gives attach- ment to the brachialis anticus muscle, the flex- ors and pronators of the forearm and to the in- ternal lateral ligament. Lesser sigmoid cavity, oval and receives the side of the head of the radius. Greater sigmoid cavity has its long axis from before backwards, is divided in the centre by a transverse line, and by a vertical ridge into two 36 lateral portions, is bounded above by the ole- cranon process, and below by the coronoid process. Shaft presents three surfaces and three edges ; the anterior surface affords attachment to the flexor profundus muscle, and is pierced by the nutritious foramen, which is directed upwards. The posterior gives attachment to the anconeus muscle and to the extensor mus- cles of the thumb ; the internal is subcutaneous for its greatest extent. Of the edges, the exter- nal is the best marked, and gives attachment to the inter-osseous ligament. Carpal extremity slender and rounded, pre- sents the head, which by its side articulates with the radius, and by its carpal aspect with the nbro-cartilage of the wrist-joint ; also the styloid process at its inner margin, which by its apex gives attachment to the internal lateral ligament of the carpus, by a depression at its root, to the nbro-cartilage ; and posteriorly it presents a groove for the tendon of the flexor carpi ulnaris muscle. RADIUS. Situation, external to the ulna; it is also shorter than that bone. Head, a superficial circular cavity articulat- ing above with the humerus and laterally with the ulna. Neck an inch in length, narrow and rounded, and terminating in the Tubercle, a prominent process into which the tendon of the biceps muscle is inserted. Shaft, triangular, by its anterior surface af- fording attachment to the flexor pollicis pro- prius, and pronator quadratus muscles, by its posterior convex surface to the supinator brevis muscle, and extensor muscles of the thumb ; its external surface being round and convex, and rough near its centre for the pronator teres muscle. The inner edge of the shaft is sharp for the attachment of the inter-osseous liga- ment, and the nutritious foramen upon the an- terior surface of the shaft is directed upwards. Carpal extremity expanded, gives attachment by its anterior edge to the anterior carpal liga- ment; upon its posterior edge is a shallow groove at its ulnar side for the extensor com- munis digitorum and indicator muscles, a second more externally, narrow and oblique for the tendon of the extensor secundi internodii pollicis muscle, and a third more external than the last for the tendons of the extensores carpi radialis longior and brevior. Upon the radial edge of this extremity is the mark of the passage of the extensor ossis metacarpi and the extensor primi internodii pollicis muscles. Styloid process, prolonged on the outer side of the bone downwards, giving attachment to the external lateral ligament of the carpus. 38 Sigmoid cavity on the inner border of the carpal extremity for articulation with the ulna. Carpal aspect presents two articular surfaces, divided by a slight elevation ; the external be- ing triangular for articulation with the os sca- phoides, the internal square for the os lunare. CARPUS. This part consists of two rows of small bones, four bones in each row, placed between the forearm and metacarpus. It is convex and rough upon its dorsal aspect, and concave upon its palmar aspect, where the vessels, nerves, and tendons of the flexor muscles are situated ; towards the radius and interarticular cartilage of the wrist, it is convex ; towards the meta- carpus it presents articular surfaces for the metacarpal bones. FIRST ROW. Os Scaphoides. Situation, on outer and upper part of the carpus, next the styloid process of the radius. Articulations, with the radius above, with the trapezium and trapezoides below, and with the lunare and magnum internally. Os Lunare. Situation, between the scaphoides and cunei- forme. Articulations, with the radius above, with 39 the magnum and unciforme below, with the scaphoid externally, and with the cuneiforme internally. Os Cuneiforme. Situation, at the internal and upper part of the carpus between the lunare and pisiforme. Articulations, with the lunare externally, with the carpal fibro- cartilage above, with the unciforme below, and upon its palmar aspect with the pisiforme. Os Pisiforme. Situation, upon the inner and palmar aspect of the cuneiforme. Articulation, by a circular small surface with the cuneiforme. SECOND ROW. Os Trapezium. Situation, between the scaphoides and meta- carpal bone of the thumb. Articulations, with the scaphoides above, with the metacarpal bone of thumb below, and internally with the trapezoides and side of the metacarpal bone of the index finger. Groove, upon its palmar aspect for lodging the tendon of the flexor carpi ulnaris muscle. Os Trapezoides. Situation, between the trapezium, magnum, 40 scaphoides, and metacarpal bone of the index finger. Articulations, with the scaphoides above, the trapezium externally, the magnum internally, and below with the metacarpal bone of the in- dex finger. Os Magnum. Processes, head, neck, and body. Situation, between the scaphoides and lu- nare, and the second, third, and fourth meta- carpal bones. Articulations, by its head with the sca- phoides and lunare above, by its base with the second, third, and fourth metacarpal bones be- low, externally with the trapezoides, and inter- nally with the unciforme. Os Unciforme. Situation, between the cuneiforme and meta- carpal bones of the ring and little fingers. Articulations, with the lunare above, the magnum externally, the cuneiforme internally, and below with the fourth and fifth metacarpal bones. Process, a hook-like process upon its palmar aspect. METACARPUS. This part consists of five long bones placed between the carpus and the fingers. 41 Bases, irregularly flattened for articulation with the second row of carpal bones, with rough surfaces for the attachment of ligaments. Heads, convex, and rounded for articulation with the first bones of the lingers, and afford- ing attachments for the capsular, transverse, and lateral ligaments. Bodies. — The first, for the thumb is the thickest and shortest ; the second, third, and fourth present on the dorsal aspect of each a prominent line, which bifurcates towards the head ; the fifth presents an oblique line on its dorsal aspect, which divides it into two sur- faces. The third is the longest. FINGERS. The fingers are composed of three phalanges, except the thumb, which has only two. The metacarpal, or first Phalanges, are five in number, their bases presenting oval con- cavities for the heads of the metacarpal bones ; their anterior extremities are convex from be- fore backwards, and concave from side to side, to articulate with the second phalanges. The Middle, or second Phalanges, are four in number, and smaller than the first ; their bases present pully-like surfaces, to form a ginglymoid joint with the first phalanges, and at their anterior extremities resemble the first. The Ungual, or third Phalanges, are five in number, and the smallest. J3y their bases they 42 form a ginglymoid joint with the middle pha- langes ; and their extremities are convex upon their dorsal aspects for the support of the nail, whilst their palmar aspects are irregularly tu- berculated for the extremities of the fingers. Tlie Sesamoid Bones are sometimes absent. In general two are to be found between the metacarpal bone of the thumb and its first pha- lanx, and one or two at the corresponding joint of the index finger. LOWER EXTREMITY. The bones proper to the lower extremity are the femur, the tibia, the fibula, the patella, seven tarsal bones, five metatarsal bones, and fourteen phalanges. THE FEMUR. Head, forms nearly two-thirds of a sphere, and is received into the acetabulum, being di- rected forwards, upwards, and inwards ; below its centre is a rough pit for the ligamentum teres, and its junction with the neck is marked by a rough line. With the exception of these parts it is covered by cartilage in the recent state. Neck, extends obliquely downwards and out- wards from the head to the shaft, which it joins at an obtuse angle ; it is flattened anteriorly and posteriorly, and its lower edge is much longer than its upper. 43 Great trochanter, is continued upwards from the shaft, but does not extend as high as the head, is situated externally, and gives attach- ment to the glutseus medius, glutaeus minimus, and quadratus femoris muscles. Digital fossa, is situated at the root of the great trochanter, and affords insertion to the external rotator muscles. Lesser trochanter, is situated posterior and internal to the shaft, and has inserted into it the psoas and iliac muscles. Inter-trochanteric lines, are two in number, one anterior, the other posterior ; as their name implies, they pass (obliquely) from one tro- chanter to the other. Shaft, is broad at either extremity, par- ticularly towards the knee, and is narrow and triangular in the centre; it is arched and smooth anteriorly ; at its posterior part it is concave, and presents a rough line called linea aspera, about the centre of which, and directed downwards, is the foramen for the nutritious vessels. Linea aspera, is best marked for the central third of the shaft ; towards the upper third *it bifurcates, one ridge running to each trochanter ; inferiorly it also divides into two ridges, which pass to either condyle, the inner one being in- terrupted where the popliteal vessels pass over it. By these inferior ridges a flat triangular 44 surface of the femur is bounded laterally, which receives the name of popliteal surface. External condyle, is larger and projects more upon the anterior surface of the femur than the internal, it is also broader and ascends higher upon the shaft. Internal condyle, narrower than the external; it also descends lower, in order that both con- dyles should rest upon the tibia in the natural oblique direction of the femur. External tuberosity, above the external con- dyle for the attachment of the external lateral ligament of the knee-joint. Internal tuberosity, above the internal con- dyle, and more prominent than the external, for the internal lateral ligament and the insertion of the great adductor tendon. Popliteal groove, between the external tuber- osity, and the external condyle ; it lodges the popliteal tendon in the flexed position of the joint. Trochlea, between the condyles on their an- terior aspect, supports the patella when the leg is extended. •Intel'- condyloid fossa, is situated posteriorly between the condyles. PATELLA. Shape, triangular, the base superiorly having the extensor muscles inserted into it, the apex 45 below to which is attached the ligamentum patellae. External surface, presents a fibrous appear- ance, and is convex. Internal surface, presents two articular sur- faces, divided by a prominent edge ; the in- ternal surface is the deepest, whilst the external is broad and shallow. TIBIA. Shaft, is triangular, presenting three sur- faces, separated by corresponding edges. The inner surface is subcutaneous, except at its up- per part, where the tendons of the sartorius, gracilis and semitendinosus muscles pass over it, it terminates in the inner malleolus ; the external surface is covered by the belly of the tibialis anticus muscle for its upper extent, and is here concave ; inferiorly it is convex, and anterior to support the tendons of the extensor muscles of the toes ; the posterior surface pre- sents an oblique line directed upwards and out- wards for the attachment of the solseus, popli- tseus, and deep flexor muscles, the nutritious foramen, which is the largest in the body, is a little below this line, and directed downwards. Of the edges, the anterior is most prominent and subcutaneous ; the inner is less denned, and the outer is well marked, affording attach- ment to the interosseous ligament. Upper or femoral extremity, expanded to ar- 46 ticulate with the femur, is convex upon its sides and anterior aspect, being grooved posteriorly. Tuberosities, are three in number, two later- ally, and one anteriorly ; the anterior is most prominent for the insertion of the ligament of the patella ; the inner is less so, and affords attachment to the internal lateral ligament of the knee-joint, and the semimembranosus muscle, and the outer is the least developed. Superior articular surfaces, are three in num- ber, two for the femur, and one for the head of the fibula ; those for the femur are separated by the spine, the internal being oval and deep ; the external, circular, shallow, and inclined downwards and outwards ; that for the fibula is behind the external tuberosity, and looks downwards. Spine, placed between the articular surfaces for the femur, projects upwards, and is bifid at its apex. Lovjer or tarsal extremity, is much smaller than the upper and quadrilateral, the anterior edge being convex for the passage of the ex- tensor tendons ; the posterior marked by a groove, for the passage of the tendon of the flexor pollicis proprius muscle ; the external presenting a rough triangular surface for the fibula, and the internal terminating in the in- ternal malleolus. Internal malleolus, is convex and sub-cu- taneous internally, its external or articular 47 aspect being smooth, to articulate with the astragalus, besides giving attachment to the internal lateral ligament of the ankle-joint, by its inferior edge it affords a groove posteriorly for the tendons of the flexor communis and tibialis posticus muscles. Inferior articular surface, rests upon the crown of the astragalus ; it is quadrilateral and concave from before backwards, and joins the small articular surface of the internal malleolus at a right angle. FIBULA. Situation, on the outer side of the tibia. Shaft, triangular and twisted, gives attach- ment to the peronasi muscles by its external surface, to the solaeus and flexor pollicis mus- cles by its posterior surface, and to the extensor muscles by its anterior surface. Its inner edge is well developed to afford attachment to the inter-osseous ligament, and the nutritious fora- men, directed upwards, is placed upon the pos- terior aspect of the bone. Head, articulates with the tibia by a small circular surface directed upwards and inwards, and affords attachment to the external lateral ligament of the knee-joint, and the biceps flexor muscle by a rough projection situated posteriorly, Neck, is the small constricted part by which the head is united to the shaft. 48 Tarsal extremity, presents a large oval pro- cess called the external malleolus, about two inches and a half above which the shaft is con- stricted. External malleolus, is larger than the inter- nal on a line posterior to which it is situated ; by its edge it affords attachments to the exter- nal lateral ligaments of the ankle-joint. Its outer surface is convex and subcutaneous, the inner or articular being smooth to articulate with the outer side of the astragalus; above this surface is a triangular rough aspect for the inferior connection of the bone with the tibia. TARSUS. Forms the posterior part of the foot, the bones which compose it are seven in number, which articulate with each other. It is con- nected above to the tibia and fibula, below it is hollow, and anteriorly it unites by articular surfaces with the five metatarsal bones. The seven tarsal bones are the calcaneum, astraga- lus, navicular, cuboid, and three cuneiform. CALCANEUM, OR OS CALCIS. Situation at the posterior and under part of the tarsus. Posterior aspect, elongated to form the heel, presents a smoothness above for a bursa mu- cosa, and a rough surface below for the inser- tion of the tendo achillis. 49 Anterior aspect articulates by a smooth sur- face with the cuboid bone. Superior aspect presents two articular sur- faces, which support the astragalus ; these are separated by a groove, into which ligaments are inserted. Inferior aspect is irregular, presenting two small tubercles, and two lines for the attach- ment of muscles and ligaments. External aspect presents a small tubercle for the insertion of the middle external lateral liga- ment of the ankle joint ; it is also slightly grooved for the passage of the peronaei tendons. Internal aspect presents a projection for the internal lateral ligament, and a fossa for the lodgment of posterior tibial vessels and nerve and tendons of muscles. ASTRAGALUS. Situation, at the upper and middle part of the tarsus, between the malleoli at either side : the tibia above, and the os calcis below. Crown, broader anteriorly than posteriorly, presents three articular surfaces ; one, large superiorly, to articulate with the tibia; the others, one on either side, to articulate with the malleoli. Head, convex and smooth, is directed for- wards and inwards, and is larger than the con- cavity of the navicular bone with which it ar- ticulates. 4 50 Neck, the contracted portion between the crown and the head, is rough for the attach- ment of ligaments. Inferior aspect presents two articular surfaces for connection with the os calcis; these are also separated by a groove, from which liga- ments pass to the groove in the os calcis. Posterior aspect is narrow, and presents a groove for the tendon of the flexor pollicis lon- gus muscle, and a pointed eminence for the posterior external lateral ligament of the ankle joint. NAVICULARE. Situation, middle of the tarsus. Posterior aspect is smooth and concave, to articulate with the head of the astragalus. Anterior aspect presents two vertical lines, which divides it into three smooth surfaces for articulation with the three cuneiform bones, and, in general, a small articular surface, externally, where it touches the cuboid bone. Tubercle, situated inferiorly for the insertion of the tendon of the tibialis posticus muscle. CUBOIDES. Situation, outer and anterior part of the tarsus. Upper surface, flat and rough for ligaments. Lower surface, tubercular behind, for the cal- caneocuboid ligament, and presenting a groove 51 anteriorly for the tendon of the peronaeus longus muscle. Posterior surface, smooth and concave trans- versely, to articulate with the os calcis. Anterior surface presents two articular sur- faces ; the external triangular to articulate with the metatarsal bone of the little toe, the inner square for the fourth metatarsal bone. External surface narrow and free. Internal surface presents posteriorly a small articular surface for the naviculare, and ante- riorly another, which is larger, to articulate with the outer side of the external cuneiform bone. INTERNAL CUNEIFORM BONE. The largest of the three, articulates behind with the scaphoid ; before, with the first meta- tarsal bone ; externally, with the middle cunei- form and side of the second metatarsal bone. Tubercle is situated inferiorly for the inser- tion of the tendon of the tibialis anticus mus- cle, and part of the tendon of the tibialis pos- ticus. MIDDLE CUNEIFORM BONE. The smallest articulates behind with the sca- phoid bone; before, with the second metatarsal bone ; externally, with the external cuneiform ; and internally, with the internal cuneiform, 52 EXTERNAL CUNEIFORM BONE. Articulates behind with the scaphoid bone ; before, with the third metatarsal bone; inter- nally, with the middle cuneiform and side of the second metatarsal bone ; and externally, with the cuboid and fourth metatarsal bone. METATARSUS is the middle part of the foot, and is composed of five long bones placed between the tarsus and the toes. FIRST METATARSAL BONE, the shortest and thickest, is convex above and concave below. Posterior extremity is smooth and oval, to ar- ticulate with the internal cuneiform bone. Anterior extremity, round, to articulate with the great toe. The under surface of this ex- tremity articulates with two sesamoid bones, and receives the insertion of the tendon of the peronaeus longus. SECOND METATARSAL BONE, the longest. Posterior extremity articulates with the three cuneiform bones, and also with the third meta- tarsal bone. Anterior extremity presents a round head, for articulation with the second toe ; it is separated from the shaft of the bone by a groove. 53 THIRD METATARSAL BONE. Posterior extremity articulates with the third cuneiform bone. Anterior extremity resembles the second, and articulates with the third toe. FOURTH METATARSAL BONE. Posterior extremity articulates with the cuboid bone, and by its inner side with the third cu- neiform. Anterior extremity resembles the second, and articulates with the fourth toe. FIFTH METATARSAL BONE. Posterior extremity articulates with the cuboid bone by a surface directed obliquely upwards and outwards. Anterior extremity resembles the second, and articulates with the fifth toe. PHALANGES, OR TOES, are composed of fourteen bones, three to each toe, except the first, which has only two. FIRST PHALANGES. Shape, convex above, concave below, and the longest. Anterior extremities, convex from above downwards, and concave laterally ; form ging- lymoid articulations with the second phalanges. Posterior extremities are large, and present 54 rounded concavities for the heads of the meta- tarsal bones. SECOND PHALANGES. Anterior extremities resemble those of the first phalanges. Posterior extremities, concave from above downwards, and convex transversely; articu- late with the first phalanges. THIRD PHALANGES. Anterior extremities, pyramidal in form, sup- port the nails on their upper surface, and are tubercular and porous on their under surface. Posterior extremities resemble the posterior extremities of the middle phalanges. SESAMOID BONES are uncertain in development ; two are gener- ally found at the base of the first phalanx of the great toe, and one al that of the fifth toe. They are also frequently developed in the ten- dons which cross the sole of the foot in those situations where they are subjected to much pressure. THE SKULL, consists of eight bones, four of which are sym- metrical, viz : the frontal, the ethmoid, the sphenoid, and the occipital; and four arranged in pairs, viz : two parietal, and two temporal. 55 FRONTAL BONE. Situation, upper and anterior part of the skull. External, or frontal aspect, is convex and arched, and presents a median vertical depres- sion, which marks the original division of the bone into two. Nasal spine, at the inferior part of the median depression or line. Frontal eminences, on either side of the me- dian line marking the points of ossification of the bone. Superciliary arches, two convexities which extend for about an inch on either side of the median line inferiorly. Eminence of frontal sinuses, between, but a little above the superciliary arches. Orbitar arches, form the upper edges of the orbits, and present towards their inner thirds the supra-orbital holes or notches, for the pas- sage of the frontal nerve and artery. External angular processes, at the outer ter- minations of the orbitar arches. Internal angular processes, at the inner ter- mination of the orbitar arches. Temporal ridges, extend backwards and up- wards from the external angular processes. \- Internal or cerebral aspect, is concave, and presents in the median line a groove which cor- responds to the longitudinal sinus. 56 Crest, at the commencement of the median groove, gives attachment to the falx. Foramen ccecum, at the root of crest, gives passage to a vein from the nose, which opens into the longitudinal sinus. Eminences and depressions, on either side of the median line, correspond to the convolutions of the brain. Orbito-ethmoidal aspect, is irregular, forming on either side part of the orbits, and in the me- dian line part of the nose. Ethmoidal notch, quadrilateral, articulates with the ethmoidal bone by a serrated margin ; its edges being cellular to unite with the eth- moidal cells. Anterior and posterior ethmoidal holes, along the margins of the ethmoidal notch, giving pas- sage to the nasal twig of the opthalmic nerve and the ethmoidal arteries. Orbital processes, triangular, and on either side of the ethmoidal notch, form the roofs of the orbits by their smooth concave surface, and on their convex surface are marked by the con- volutions of the brain. Towards the external angular process of each is the fossa for lodging the lachrymal gland, and at the nasal margin is a depression for the reflected tendon of the su- perior oblique muscle. Frontal sinuses, at the anteroinferior part of the bone, and between its two tables ; they open at either side of the nasal process. 57 PARIETAL BONES. Situation, upper and lateral parts of cranium, being quadrilateral. External surface, convex, and marked by a semicircular ridge, which is continued from the temporal ridge of the frontal bone. In the centre of the bone is the parietal eminence, and about one-third from the superior posterior angle is the parietal foramen. Four edges.— The upper is the longest, and joins its fellow, — the anterior joins the frontal bone, — the posterior is very irregular, and joins the occipital, — and the inferior is thin and semicircular, and joins the temporal bone. Four angles. — The anterior inferior is long and curved, and joins the sphenoid bone ; upon its cerebral aspect a canal or a groove exists for the trunk of the middle-meningeal artery. The posterior inferior angle is grooved upon its cerebral aspect to lodge part of the lateral sinus. The superior angles are rather rounded. Internal surface, concave, and marked by the convolutions of the brain and the ramifi- cations of the middle meningeal artery, presents along its upper edge a shallow groove, which, with its fellow, accommodates the superior longitudinal sinus ; external to this groove are depressions marking where the glandulse Pac- chioni externa were situated. 98 OCCIPITAL BONE. Situation, posterior and inferior part of cranium. Tuberosity, near the centre of external sur- face. Superior tranverse ridge, leads from either side of the spine transversely outwards. Inferior transverse ridge, midway between tuberosity and foramen magnum. Spine, leads from tuberosity down to the foramen magnum. Foramen magnum, larger internally than ex- ternally, it is of an oval form, and transmits the medulla spinalis, vertebral arteries, and sub-occipital nerves. Basilar process, passes forwards and upwards to join the sphenoid bone, is rough inferiorly for the attachment of the pharynx ; and upon its cerebral aspect is smooth and concave from side to side to support the pons variolii and basilar artery. Condyles, smooth and oblong, look down- wards, outwards, and backwards, each presents a roughness internally for the moderator liga- ments. Anterior condyloid foramina, situated before the condyle for the passage for the ninth pair of nerves. Posterior condyloid foramina, behind the 59 condyles for the passage of veins and twigs of arteries. These are sometimes absent. Jugular eminences, external to either condyle. Crucial spine, on the cerebral aspect, and formed by a transverse and vertical line, gives attachment to the falx major by the upper half of the vertical line, in which is a groove for the termination of the longitudinal sinus, and to the falx minor by its lower half ; the trans- verse ridge gives attachment to the tentorium, and also presents a groove on either side for the lateral sinuses. Four fossa, two superior for the posterior lobes of the cerebrum, and two inferior and deeper for the cerebellum. Grooves for inferior petrosal sinuses, one on either side of the cerebral aspect of the basilar process. Grooves for the termination of the lateral sinuses on each side of the foramen magnum above the jugular eminences. TEMPORAL BONE. Situation, at the lateral, middle, and inferior part of the skull. Squamous portion, semicircular, flat, and thin, forming part of the side of the skull and of the temporal fossa. Zygomatic process, arises by two roots, one anterior bounding the front of the glenoid cavity, the other posterior, which is bifurcated ; 60 the process then passes forwards, and presents a serrated edge to unite with the malar bone. Zygomatic tubercle is situated at the union of the zygomatic roots. Trochlea, between the posterior root of the zygomatic process and the squamous plate, for the passage of the posterior fibres of the tem- poral muscle. Glenoid cavity, transversely oval, deep an- teriorly for the reception of the maxillary con- dyle, and shallow behind, wThere it lodges a portion of the parotid gland. Glasserian fissure, crosses the glenoid cavity in a direction obliquely forwards and inwards. Auditory process, commences by the external meatus, and leads inwards and forwards to the membrana tympani, and presents externally a nigged edge for the attachment of the cartilage of the ear. Internal surface of squamous plate, is marked by the convolutions of the brain and blood vessels. Mastoid process, at the posterior and inferior aspect of the bone. Mastoid grooves internal to the mastoid pro- cess for the occipital artery and posterior belly of the digastric muscle. Mastoid foramen, posterior to mastoid pro- cess for the transmission of a vein. Mastoid fossa, in the cerebral aspect for the lateral sinus. 61 Mastoid cells, in the interior of mastoid process. Petrous portion, extends forwards and in- wards, and presents three aspects, being of a prismatic form. Aqueduct of the cochlea, a minute foramen on the under surface, posterior to the styloid process. Styloid process, long and tapering, descends obliquely forwards and inwards. Vaginal process, a plate of bone between the glenoid cavity and the carotid foramen. Stylo-mastoid foramen, between the styloid and mastoid processes for the exit of the portio dura nerve. Carotid canal, commences in front of the styloid process, turns forwards, upwards, and inwards, and terminates by the side of the body of the sphenoid bone. Processus cochleariformis, a thin plate of bone separating two canals, which are situated in the angle between the petrous and squamous portions ; the superior of which transmits the tensor tympani muscle; the inferior forming the bony part of the eustachian tube. Superior petrosal ridge, separates the anterior from the posterior surface, and gives attach- ment to the tentorium. Depression for Gasserian ganglion, on the anterior extremity of the superior surface. 62 Hiatus Fallopii, a foramen on the superior surface for the passage of the vidian nerve. Meatus auditorius intemus, on the posterior surface, for the transmission of the seventh pair of nerves. Aqueduct of the vestibule, a small slit-like opening posterior to the meatus intemus. The superior semicircular canal, forms an eminence on the superior petrosal surface. .ETHMOID BONE. Situation, in the sethmoidal notch. Crista galli, an angular process which di- vides the cerebral aspect into two equal por- tions, to which is attached the commencement of the falx. Cribriform plate, on either side of the crista galJi, concave, to lodge the olfactory bulbs, and perforated with holes, for the passage of the filaments of the olfactory nerves, the nasal di- vision of the ophthalmic nerve, and some small blood vessels. Nasal plate, descends from the under surface of the crista galli, joins the sphenoid bone pos- teriorly, the vomer and nasal cartilage interi- orly, and the os frontis and nasal bones ante- riorly. Orbital plate, a smooth square plate of bone situated externally, and forming part of the or- bit ; in its upper edge are two notches, which, 63 with those in the frontal bone, form the internal orbital foramina. JEthmoidal cells, between the orbital plate and the nasal plate, being ten or twelve in number. Superior spongy bone, descends in a curved manner outwards from the upper and posterior part of the bone, forming a short channel, call- ed the superior meatus of the nose. Middle spongy bone, larger and more curved, descends outwards, forming the middle meatus of the nose. Infundibulum, a smooth groove leading from the anterior ethmoidal cells to the middle meatus. SPHENOID BONE. Body, corresponds to the median line, and presents six aspects. Posterior aspect, is rough for connection with the basilar process of occipital bone. Anterior aspect, presents the openings of the sphenoidal sinus. Inferior aspect, presents the azygos process, which articulates with the vomer. Superior or cerebral aspect, presents a fossa, called sella turcica. Lateral aspects, join the great alae. Sella turcica, a deep fossa on the cerebral aspect of the body for lodging the pituitary- gland. 64 Posterior clinoid processes, two rounded emi- nences posterior to the sella turcica. Anterior clinoid processes, two rounded emi- nences situated external and anterior to the sella turcica. Olivary process, an eminence between the anterior clinoid processes, and anterior to the sella turcica, on which the optic commissure rests. Carotid grooves, one on either side of the sella turcica for the internal carotid arteries. Transverse spines or lesser wings, two thin plates of hone extending forwards and out- wards from the anterior clinoid processes, pre- senting anteriorly a spine in the median line, to unite with the ethmoid bone, and a serrated margin on either side to unite with the frontal bone. Their posterior free edges afford attach- ment to the sphenoidal folds of the dura mater. The external extremity of each terminates in an acute point, their cerebral aspect being smooth to support the anterior lobes of the brain. Great wings, extend laterally from the sides of the body ; each presents three aspects, one an- terior and smooth to assist in forming the outer part of the orbit, the second posterior, concave, and marked by cerebral convolutions, to assist in forming the middle cranial fossa, and the third external, being divided by a crest ; the portion above which forms part of the temporal 65 fossa, and the portion below, part of the zygo- matic fossa. Spinous processes, extend backwards and out- wards from the posterior termination of each great wing. Pterygoid processes, two on either side, de- scend from the angle of junction of each great ala and the body. The external is broad and irregular ; the internal is long and narrow, and terminates in a hook called the hamular process. Pterygoid fossa, is the hollow between the pterygoid processes posteriorly. Foramina lacera, on either side of the sella turcica, are placed between the greater and les.se? wings ; each gives transmission to the third9 fourth, first branch of the fifth, and the sixth pairs of nerves, and to the ophthalmic vein. Foramina optica, at the roots of the lesser wings, give passage to the optic nerves and ophthalmic arteries. Foramina rotunda, posterior, and a little external to the bases ol the foramina lacera, give passage to the second division of the fifth. Foramina ovalia, near the posterior termina- tions of the great wings, give passage to the third division of the fifth. Foramina spinosa, in the spinous processes, give passage to the middle meningeal artery of either side. Foramina pterygoidea, at the roots of the 5 66 pterygoid processes, for the passage of the vi- dian nerves. BONES OF THE FACE. MALAR BONE. Situation, at the outer and under part of the orbit, forming the cheek. External surface, convex, and of an irregular quadrilateral form. External angular process, at the upper and outer edge, joins the frontal bone. Maxillary process, serrated and at inner edge, rests on the superior maxillary bone. Zygomatic process, passes backwards, and supports the zygomatic process of the temporal bone by a serrated edge. Upper edge, forms the outer and inferior margin of the orbit. Orbital process, a thin plate of bone, which passes from the upper edge backwards and in- wards. Lower edge thick and uneven for the attach- ment of the masseter muscle. Temporal aspect, behind the zygomatic pro- cess, is smooth for the lodgment of the temporal muscle. Foramina, two or three in number on its cu- taneous aspect, for vessels and branches of lachrymal nerves. 67 SUPERIOR MAXILLARY BONE. Body, quadrilateral, presents anteriorly the canine fossa. Malar process, externally and superiorly, presents a rough surface which supports the malar bone. Nasal process, internally and superiorly, is serrated above to join the frontal bone, and also presents a groove to support the nasal bone. Its cutaneous aspect is perforated by two or three small holes for blood vessels, its posterior aspect is deeply grooved to assist in forming the fossa for the lodgment of the lachrymal sac and duct, and its internal or nasal aspect is- di- vided by a ridge, which supports the inferior spongy bone. Orbital plate, triangular, assists to form the floor of the orbit. Infra-orbital canal, passes from behind for- wards between the plates of the orbital process, and terminates in the infra-orbital foramen. Temporal aspect, presents behind the malar process a smooth depression for the temporal muscle and more posteriorly and inferiorly a tuberosity which corresponds to the dens sa- pientia. Posterior dental foramina are three or four small holes which give passage to the posterior dental nerves ; and are found near the tubero- sity. 68 Palatine process is thick internally and rough where it joins its fellow, its circumference cor- responds to the alveolar processes, and its pos- terior edge is thin and serrated where it joins the palate hone ; its upper surface is smooth and concave from side to side, forming part of the floor of the nose, and its under surface is rough, forming with the gum, part of the hard palate. Nasal crest, at the union of the palatine pro- cesses, projects upwards to receive the vomer. Nasal spine projects forwards, ahove and be? tween the central incisor teeth. Foramen incisivum,\s common to both bones, and exists inferiorly at the anterior union of their palatine plates ; superiorly it bifurcates and opens by two foramina, one to each nostril. Antrum maxillare a large cavity in the body of the bone, bouuded above by the orbital plate, below by the alveoli of the molar teeth, ante- riorly by the canine fossa, and posteriorly by the temporal aspect : externally it corresponds to the malar process, and internally it presents a large irregular opening. PALATE BONE. Horizontal or palate plate, quadrilateral, is concave and smooth above, and completes the floor of the nose, and rough below where it completes the hard palate. Its anterior edge is serrated to join the superior maxillary bone, its posterior edge is concave, and gives attachment 69 to the soft palate, its inner edge is serrated where it joins with its fellow and sends a crest upwards to support the vomer; its outer edge joins the nasal plate. Nasal spine projects backwards from the union of the palate plates. Nasal process, broad and thin, its inner sur- face is divided into two by a ridge which sup- ports the inferior spongy bone : above and be- low this ridge the process is slightly concave to assist in forming the inferior and middle meatuses : its external surface is rough and marked by the posterior palatine vessels and nerves ; its anterior thin edge assists to close the antrum and the posterior edge joins the pterygoid processes of ophenoid bone. Pterygoid process, the thickest part of the bone, of a wedge shape, inclines backwards and outwards ; it presents three grooves, a cen- tral one smooth which completes the pterygoid fossa, and a rough one on^either side to articu- late with the extremities of the pterygoid pro- cesses. Palatine foramina, at the junction of ptery- goid and palatine processes give passage to the palatine nerve and vessels. Orbital process, surmounting the nasal pro- cess, is divided into two by a notch, which forms with the sphenoid bone the sphenopala- tine hole. Anterior orbital process3 is large and hollow, 70 and of a triangular form ; it forms the posterior part of the floor of the orbit by its upper smooth surface ; joins the orbital plate of the superior maxillary bone and title os planum of the eth- moid bone by its two serrated edges ; and its smooth edge looks towards the spheno-maxil- lary fissure. Posterior orbital process, articulates with the body and spongy plate of the sphenoid bone and is also hollow. INFERIOR SPONGY BONE. Rough and convex towards the septum of the nose and concave externally, presents a free margin inferiorly and is attached above to the os unguis, and to the ridge on the superior maxillary and palate bones. It perfects the na- sal duct inferiorly. os UNGUIS. Situation, inner and anterior part of orbit. Edges serrated to join the os frontis above, the maxillary bone below, the nasal bone ante- riorly, and the ethmoid bone behind. External surface, divided by a perpendicular ridge, presents a groove anteriorly for the lach- rymal sac, and a smooth surface behind to assist in forming the orbit. Internal surface, covers the anterior eth- moidal cells. 71 NASAL BONES. Situation, beneath the nasal process of frontal bone, and between the nasal processes of supe- rior maxillary bones. External surface, convex and presents small foramina for blood vessels. Internal surface, concave and grooved by the nasal nerves. Superior edge, thick and serrated to join the frontal bone. Inferior edge, thin and expanded, joins the lateral nasal cartilages. External edge is the longest, and is serrated to join the superior maxillary bone. Internal edge is flat and joins its fellow. VOMER. Situation, in thS median line of nose. Superior edge grooved to receive the azygos process of the sphenoid bone. Anterior edge slightly grooved to receive the ethmoidal plate and nasal cartilage. Posterior edge free, looks towards the pha- rynx. Inferior edge the longest, is received into the nasal crest of the superior maxillary and palate bones. INFERIOR MAXILLARY BONE. Body, the anterior portion, projects inferiorly into mental process or chin — superiorly is sur- 72 mounted by alveoli of four incisor teeth — ante- riorly has on each side a depression for mus- cles, and posteriorly, eminences and depressions for muscles. Symphysis a vertical ridge in the centre of body. Horizontal rami. — On the outer surface of each is an oblique ridge for muscles; on the inner is the mylo-hyoidean ridge, above which is a depression for the sub-lingual gland and another below for the sub-maxillary gland. The lower edge is rounded and grooved for the facial artery, and upon the upper edge are al- veolar processes. Angle obtuse and rough for muscles. Ascending rami are thick and round poste- riorly— externally smooth — internally grooved. Coronoid process passes upwards from ante- rior part of ascending ramus. Condyle, transversely oblong to articulate with temporal bone. Neck constricted part below condyle. Semilunar notch between condyle and coro- noid process. Inferior dental foramen situated at internal surface of ascending ramus and surmounted by a spine. Mental foramen situated at anterior surface of bone external to body. Dental canal traverses bone between the two foramina, and communicates with each alveoli. 73 OS HYOIDES. Situation in the anterior part of the neck be- tween the chin and larynx. Body square, is rough anteriorly for muscles, and smooth behind where it corresponds to the epiglottidean gland. Greater cornua, pass obliquely upwards and outwards from the sides of the body. Lesser cornua are very small, and pass ob- liquely backwards and upwards from the point of junction of the great cornua and body. The bones of the ear are described in con- nection with the organ of hearing. SUTURES OF THE CRANIUM AND FACE. Frontal suture, commences a little behind the external angular process of the frontal bone, at the upper termination of the great wing of the sphenoid bone, and, inclining backwards, ex- tends across the cranium to the opposite cor- responding point, connecting in its course the frontal to the parietal bones. Lambdoidal suture, commences at the union of the petrous portion of the temporal bone with the parietal and occipital bones, and extending across the posterior part of the cranium to the opposite corresponding point, connects the occi- pital to the parietal bones. Sagittal suture, extends from the angle of the occipital bone forwards, connecting in its course 74 the parietal bones and corresponding to the median line ; it generally terminates in the co- ronal suture, but is occasionally prolonged to the nasal bones, dividing the frontal bone. Squamous suture, corresponds to the semicir- cular edge of the squamous portion of the tem- poral bone, and connects it to the great wing of the sphenoid bones, and to the parietal bone. Additamentum suturce lambdoidalis, extends from the termination of the lambdoidal suture to the foramen lacerum posterious, and unites the mastoid process of the temporal bone to the occipital. Additamentum suturce squamosce, extends nearly horizontally backwards from the poste- rior termination of the squamous suture to the lambdoidal suture, connecting the upper extre- mity of the mastoid portion of the temporal bone to the parietal bone. Sphenoidal suture, extends around the irregular margins of the sphenoid bone, connecting it to all the bones of the head, and to the malar, su- perior maxillary, and palate bones. Ethmoidal suture, surrounds the ethmoid bone, connecting it to the frontal, nasal, supe- rior maxillary, lachrymal, and palatine bones, and to the vomer. Transverse suture, connects the bones of the face to those of the head. Zygomatic suture, corresponds to the junction of the temporal with the malar bone. 75 ORBITS. The orbits are two pyramidal cavities, the bases of which look outwards and forwards and their apices in the contrary direction ; so that two lines passing through their axes if prolonged posteriorly would decussate at the sella turcica. Each orbit is formed of seven bones, three of which, viz. the frontal, sphe- noid, and ethmoid, are common to both orbits ; the other four, viz. the lachrymal, superior maxillary, malar, and palate bones belonging to the orbit of their corresponding side. The foramina in the base of the orbit are, the supra- orbital, the infra- orbital, and the upper orifice of the nasal duct : within the orbit are the op- tic-foramen, the superior lacerated foramen, the spheno-maxillary fissure and the two internal orbital foramina. TEMPORAL FOSSA, Placed on the side of the cranium, is bounded by the frontal, sphenoid, parietal, and temporal bones, and lodges the temporal muscle. ZYGOMATIC FOSSA, Extends from the temporal fossa downwards, and is bounded by the zygomatic arch, the su- perior maxillary bone and the portion of the great wing of the sphenoid bone below its crest. 76 PTERYGO MAXILLARY FISSURE, Lies deep in the zygomatic fossa, is bounded by the pterygoid processes, the tuberosity of the superior maxilla and the nasal process of the palate bone ; and communicates with the sphe- no-maxillary fissure. ARTICULATIONS. TEMPORO-MAXILLARY ARTICULATION. Bony formation. — Glenoid cavity of temporal bone and condyle of inferior maxillary bone. External lateral ligament. — Origin, zygo- matic process and tubercle of temporal bone. Insertion, outer side of the neck of condyle of lower jaw. Internal lateral ligament. — Origin, spinous process of sphenoid bone. Insertion, margin of orifice of inferior dental canal. Stylo-maxillary ligament. — Origin, styloid process of temporal bone. Insertion, angle of inferior maxillary. Synovial membranes, one is reflected from the cartilaginous surface of zygomatic eminence and glenoid cavity over the superior surface of the fibro-cartilage. The other covers the un- der surface of the fibro-cartilage and is reflected over the condyle. 77 Inter-articular, or fibro-cartilage, of an oval figure, thick in its circumference, thin in the centre. Divides the joint into two. Capsular ligament. — Origin, zygomatic emi- nence, and glenoid fissure. Insertion, neck of lower jaw. OCCIPITO-ATLANTOID ARTICULATION. Bony formation, condyles of occipital bone and superior oblique processes of atlas. Capsular ligament, imperfect. Synovial membranes, cover the opposed carti- laginous surfaces. Anterior ligament. — Origin, anterior edge of foramen magnum. Insertion, upper edge of atlas anterior to its articular processes. Posterior ligament. — Origin, posterior edge of foramen magnum. Insertion, upper edge of atlas behind its articular processes. OCCIPITO-AXOID ARTICULATION. Moderator, or oblique ligaments. — Origin, from each side of odontoid process. Insertion, inner side of each condyle. Apparatus ligamentosus. — Origin, lower part of cuneiform process, being posterior to odon- toid process. Insertion, superior part of trans- verse ligament of atlas and bodies of second and third vertebise. ATLANTO-AXOID ARTICULATION. Bony formation.- -The anterior portion of 78 the spinal hole of the atlas, and the odontoid process of axis. Anterior and posterior ligaments, as in all the other vertebras. Transverse ligament, attached on each side to inner edge of oblique process of axis, and by means of apparatus ligamentosus to cuneiform process above, and body of axis below. Synovial membranes. One between posterior surface of odontoid process, and anterior sur- face of transverse ligament. Another covers the opposed cartilaginous surfaces of the atlas and odontoid process. COMMON VERTEBRAL ARTICULATION. Bony formation. — Opposed surfaces of the bodies and oblique process of the vertebras. Anterior vertebral ligament extends from axis to sacrum adhering to the bones and the inter-vertebral substances. Posterior vertebral ligament, extends along the posterior part of bodies of vertebras in front of spinal canal. Inter-vertebral ligaments, or fibro-cartilages, are placed between the bodies of all the verte- bras, except the atlas and dentata, and united to their flat surface above and below. They are thicker in front than behind in the neck and loins, and the contrary in the back. Synovial membranes and ligamentous fibres connect the oblique processes. 79 Ligamenta sub-flava, are situated between the laminae of the vertebrae from the second to the sacrum, completing the posterior part of the spinal canal. Supraspinous and inter-spinous ligaments, connect the spinous processes of the vertebrae. Inter-transverse ligaments connect the trans- verse processes. COSTO- SPINAL ARTICULATIONS. Bony formation. — Heads, and tubercles of ribs, and bodies and transverse processes of vertebrae. Anterior ligament, — origin, front of head of rib. Insertion, side of the vertebrae above and below, and to the inter-vertebral substance. Inter -articular ligaments,— origin, projecting ridge in the articular surface of each rib. Inser- tion, cavity in the inter-vertebral substance in which the head is received. The upper and lower divisions of this joint have distinct syno- vial membranes. Inferior costo-transverse ligament, — origin, neck of each rib. Insertion, transverse process of the vertebrae above. Posterior and external costo transverse liga- ments connect the tubercle of each rib to the cor- responding transverse process. Synovial membranes are between the tubercles and transverse processes. 80 COSTO-STERNAL ARTICULATION. The ribs are connected to the sternum through the intervention of their cartilages, which are secured anteriorly and posteriorly by ligamen- tous fibres. LUMEO-SACRAL ARTICULATION. Bony formation. — Last lumbar vertebra and sacrum. These are joined together in the same manner as the other vertebrae. Ilio lumbar ligament — origin, transverse pro- cesses of fourth and fifth lumbar vertebras and back part of the sacrum, Insertion, posterior superior spinous processes and crest of ilium. ILIO-SACRAL ARTICULATION. The ilium and sacrum are connected anterior- ly and posteriorly by short ligamentous fibres. Great sacro-sciatic ligament, — origin, low- er and baCk part of posterior inferior spine of ilium and back part of sacrum and coccyx. In- sertion, lower edge of tuber ischii. Lesser sacro-sciatic ligament, — origin, side of sacrum and coccyx. Insertion, spine of ischium. SACRO- COCCYGEAL ARTICULATION. The sacrum and coccyx are united together by a similar substance to the inter-vertebral, and by ligamentous bands anteriorly and pos- teriorly. 81 PUBIC ARTICULATION. Fibro-cartilage, attaches closely the bones of the pubis* also ligamentous fibres. Sub-pubic ligament passes from the ramus of one bone to the other, and rounds off the angle formed by their union. Obturator ligament, attached to the circum- ference of obturator foramen, except superior- ly, where the thyroid nerye and vessels pass through. STERNQ-CLAVICULAR ARTICULATION.. Anterior ligament, — origin, anterior sur- face of sternal end of clavicle. Insertion, an- terior surface of sternum. Posterior ligament, — origin, posterior sur- face of sternal end of clavicle. Insertion, back part of sternum. Costo-clamcular ligament, -^origin, lower surface of sternal end of clavicle. Insertion* cartilage of first rib. Inter -clavicular ligament, extends from the posterior surface of one clavicle to the other. Inter-articular cartilage, thin below and at- tached to sternum ; thick above and attached to clavicle ; having a synovial membrane con- nected to each surface and its corresponding bone. SCAPULOCLAVICULAR ARTICULATION. Superior acromioclavicular ligaments, — ori~ 82 gin, upper surface of acromion. Insertion, upper part of clavicle. Inferior acromio- clavicular ligament. — At- tached to under surface of each bone. CORACO-CLAVICULAR ARTICULATION. Conoid ligament, triangular ; base connected to the tubercle on inferior surface of clavicle, apex at the broad part of coracoid process. Trapezoid ligament, attached above to an oblique line on the clavicle ; below to upper part of the coracoid process. LIGAMENTS OF THE SCAPULA. Coraco-acromial ligament, — origin, broad from coracoid process. Insertion, narrow into point of acromion. Posterior or coracoid ligament, — origin, superior costa of scapula behind the notch. Insertion, base of coracoid process. This liga- ment converts the notch into a foramen. HUMERO-SCAPULAR ARTICULATION. Bony formation. — Head of humerus and gle- noid cavity of scapula. Capsular ligament, — origin, circumference of neck of scapula. Insertion, around the neck of humerus. Coraco-humaral ligament, — origin, coracoid process. Insertion, anterior part of great tu- berosity. 83 Synovial membrane is reflected over the sur- face of the glenoid cavity around the glenoid ligament ; lines the capsular ligament, head of humerus, and becipital groove. HUMERO-CUBITAL ARTICULATION. Bony formation, articular processes of hu- merus, great sigmoid cavity of ulna head of radius. External lateral ligament-^origin, external condyle of humerus. Insertion, annular liga- ment of radius. Internal lateral ligament — origin, internal condyle. Insertion, inner edge of olecranon and coranoid processes. Anterior ligament consists of thin fibres — origin, principally from above internal condyle and depression on fore part of humerus, inser*- tion, annular ligament of radius and synovial membrane. Posterior ligament is composed of fibres which extend from one condyle to the other, and are attached to the synovial membrane. Synovial membrane is reflected from behind the anterior ligament to neck of radius and an- nular ligament ; it then lines the sigmoid cavi- ties of the ulna and is reflected to the lateral ligaments and tendon of the triceps muscle, which conducts it to the posterior depression of the humerus ; it is then expanded over its ar- ticular processes. 84 SUPERIOR RADIOULNAR ARTICULATION. Bony formation, lesser sigmoid cavity of ulna and inner side of head of radius. Annular ligament — origin, anterior border of lesser sigmoid cavity of ulna, insertion pos- terior border of the same cavity. It encircles the neck of radius. Oblique ligament—origin, coranoid process of ulna. Insertion, radius below its tubercle. Inter-osseous ligament connects the opposed edges of radius and ulna, its fibres descending obliquely inwards from the former bone to the latter. INFERIOR RADIO-ULNAR ARTICULATION, * Bony formation round head of ulna, and sig- moid cavity of radius. Sacciform ligament passes from radius to the ulna, forming -a sac above the following Fibro-cartilage — -origin, styloid process of ulna. Insertion, inner edge of radius below the ulna. RADIO -CARPAL ARTICULATION. Bony formation, lower end of radius; sca- phoid, lunar, and cuneiform bones. External lateral ligament— -origin, styloid process of radius. Insertion, scaphoid bone, and by some fibres into annular ligament and trapezium. 85 Internal lateral ligament — origin, styloid process of ulna. Insertion, cuneiform bone. Posterior ligament — origin, posterior part of radius and fibro- cartilage. Insertion, back part of superior row of carpus. Anterior ligament — origin, anterior part of radius and iibro-cartilage. Insertion, fore part of first row of carpus. CARPAL ARTICULATIONS. The bones of carpus are articulated by liga- mentous bands, both anteriorly, and posteriorly. An internal and external lateral ligament at- tach the two rows. Synovial membrane extends between the two rows and sends processes between the bones. Annular ligament — origin, trapezium, and scaphoid bones. Insertion, cuneiform and un- ciform bones. CARPO-METACARPAL ARTICULATION. The carpus and metacarpus are secured by fibrous bands which pass in different directions, and cover the synovial membrane. METACARPOPHALANGEAL ARTICULATIONS. The heads of the metacarpus and first pha- langes are secured by lateral ligaments, and are lined by synovial membranes. 86 INTER-PHALANGEAL ARTICULATIONS. The phalanges are connected to each other by means of lateral ligaments, and between each of their joints is a synovial membrane. ILIO-FEMORAL ARTICULATION. Bony formation, acetabulum and head and part of neck of femur. Cotyloid ligament, a fibro-cartilaginous cir- cular band adhering to the edge of the aceta- bulum. Transverse ligament, attached to the opposite points of the notch, and partly filling it up. Capsular ligament — origin, circumference of acetabulum. Insertion, below root of trochan- ter major, and the two inter-trochanteric lines. Accessory ligament — origin, anterior inferior spinous process of ilium. Insertion, fore part of lesser trochanter. Synovial membrane, reflected from inside of capsule upon periosteum of neck, and cartilagi- nous surface of head ; is continued over inter- articular ligament, and thence is reflected upon the cartilaginous surface of the acetabulum. Inter-articular ligament or ligamentum teres — origin, depression on head of femur. Inser- tion by two bands into the extremities of the notch, and by synovial membrane into the fatty substance at the bottom of the cavity. 87 FEMORO-TLBIAL ARTICULATION. Bony formation condyles of femur and head of tibia. Ligamentum patella — origin, lower angle of patella. Insertion, tubercle of tibia. Posterior ligament — origin, tendon of semi- membranosus muscle at internal and posterior part of tibia. Insertion, external condyle of femur. Internal lateral ligament — origin, internal condyle of femur, hisertion, internal condyle of tibia and semilunar cartilage. External lateral ligament— origin, external condyle. Insertion, head of fibula. This liga- ment is often divided into two by the tendon of the biceps muscle. Synovial membrane lines the back part of the patella, from which it is reflected two or three inches on the fore part of the femur, and on its condyles ; from thence it is conducted by the crucial ligaments to the semi-lunar cartilages, and head of tibia. Alar ligaments arise from each side of patella arid unite below that bone. They are mere folds of synovial membrane. Ligamentum mucosum — origin, fatty sub- stance behind ligamentum patellae. Insertion, hollow between the condyles. It also is a fold of synovia] membrane. 88 Transverse ligament, attached to the anterior portion of each semi-lunar cartilage. Anterior crucial ligament — origin, inner side of external condyle. Insertion, near the fore part of head of tibia. Posterior crucial ligament — origin, outer side of internal condyle. Insertion, depression on back part of head of tibia, and external semi-lunar cartilage. Semi-lunar cartilages, thick externally, thin internally ; concave above, flat below. Their outer convex edges are attached to the lateral ligaments : their inner edges are free : the an- terior and posterior extremities of each are at- tached to the head of the tibia. The outer car- tilage is circular, the inner is oval. TIBIO- FIBULAR ARTICULATION. The head of the fibula is attached to the tibia by anterior and posterior fibrous bands and synovial membrane. Inter-osseous membrane extends from one bone to the other, nearly the whole length. The lower extremities of the tibia and fibula are connected together by anterior and posterior ligaments. ARTICULATION OF THE ANKLE. Bony formation, lower ends of tibia, fibula, and astragulus 89 Internal lateral ligament — origin, internal malleolus. Insertion, astragulus, naviculare and calcis. External lateral ligaments are three ; all take their origin from the external malleolus. In- sertion of anterior, upper and outer part of as- tragulus. Insertion of middle, os calcis. In- sertion of posterior, ridge on the back of astra- gulus. Anterior ligament — origin, anterior edge of tibia. Insertion, upper and outer part of astra- gulus. ARTICULATION OF THE TARSUS. The astragulus and os calcis have two ar- ticular surfaces, covered by synovial mem- branes. Inter -osseous ligament passes nearly perpen- dicularly from the groove which separates the inferior articular surfaces of the astragulus, to the corresponding groove in the os calcis. Posterior ligament is attached to the posterior edges of the astragulus and os calcis. The bones of the tarsus are connected on their dorsal and plantar aspects by numerous ligamentous bands. Calcaneo-namcular ligament — origin, inferior surface of os calcis. Insertion, inferior- surface of os naviculare. Calcaneo- cuboid ligament — origin, posterior 90 inferior part of os calcis. Insertion, under part of cuboid bone, and third and fourth metatarsal bones. Synovial membranes line the several articula- tions of the tarsus. TARSO-METATARSAL ARTICULATIONS. These joints are secured by dorsal and plan- tar ligaments, and are lined by synovial mem- branes. The metatarsal bones are secured to the phalanges, and the phalanges to each other by lateral ligaments and synovial membranes. MUSCLES. HEAD. Occipito-frontalis. Origin, two external thirds of superior transverse ridge of occipital bone and posterior external part of mastoid pro- cess of temporal bone. Insertion, integuments of eyebrows, nasal bones and angular processes of the os frontis. MUSCLES OF EXTERNAL EAR. Superior Auris. O. cranial aponeurosis above external ear. I. upper and anterior part of cartilage of ear. Anterior Auris. O. posterior part of zygo- matic process and cranial aponeurosis. I. ante- rior part of helix. Posterior Auris. 0. mastoid process. 1. back part of concha. 91 FACE. Orbicularis palpebrarum. 0. internal angu- lar process of os frontis and upper edge of tendo oculi. I. nasal process of superior maxillary Lone and inferior edge of tendo oculi. Tensor tarsi. 0. posterior edge of os un- guis. I. lachrymal ducts as far as puncta. Corrugator supercilii. O. internal angular process of os frontis. I. middle of eyebrow, Pyramidalis nasi. 0. occipito-frontalis mus- cle, descends along nasal bones. I. compressor nasi muscle. Compressor nasi. O. canine fossa in supe- rior maxilla. J. dorsum of nose. Levator labii superioris alceque nasi. 0. up- per extremity of nasal process of superior max- illa, and from edge of orbit above infra-orbital hole. 1. ala nasi, upper lip and orbicularis oris muscle. Zygomaticus minor. 0. upper part of malar bone. I. upper lip, near commissure. Some- times wanting. Zygomaticus major. O. lower part of malar bone, near zygomatic suture. I. angle of mouth. Levator anguli oris. O. canine fossa above aveola of first molar tooth. I. commissure of lips and orbicularis oris. Depressor labii superioris al&que nasi. O. alveoli of canine and incisor teeth, of superior 92 maxilla. I. integuments of upper lip and flbro- cartilage of septum and ala nasi. Depressor anguli oris. 0. external oblique line on lower jaw, extending from anterior edge of masseter muscle to mental foramen. I. commissure of lips. Depressor labii inferioris. O. side and front of lower maxilla, above its base. I. half of lower lip and orbicularis oris. Levator labii inferioris. O. alveoli of in- cisor teeth of lower jaw. I. integuments of chin. Orbicularis oris surrounds mouth by two fleshy fasciculi. Buccinator. O. two last alveoli of superior maxilla and external surface of posterior alveoli of lower maxilla, also inter-maxillary ligament. I. commissure of lips. MUSCLES OF LOWER JAW. Masseter consists of two portions : Anterior portion. 0. superior maxilla where it joins malar bone, and inferior edge of latter. I. outer surface of angle of lower jaw. Posterior portion. 0. edge of malar bone and zygomatic arch, as far as glenoid cavity. I. external side of angle and ramus of lower jaw. Temporal. 0. side of cranium, beneath semicircular ridge on parietal bone, temporal fossa, and aponeurosis. /. coronoid process of inferior maxilla to last molar tooth. 93 Pterygoideus internus. O. inner side of ex- ternal pterygoid plate and pterygoid process of palate bone. I, inner side of angle of jaw and rough surface above. Pterygoideus externus. 0. outer side of external pterygoid plate, crest on great ala of sphenoid bone and tuberosity of superior max- illa. I. anterior and internal part of neck of lower jaw, inter-articular cartilage, and inferior synovial membrane. MUSCLES ON ANTERIOR ANEfe LATERAL PARTS OF NECK. Platysma-myodes. 0. cellular membrane covering upper and outer part of deltoid and great pectoral muscles. I. chin ; fascia along side of lower jaw ; and fascia covering parotid gland. Sterno-cleido mastoideus. O. upper and anterior part of first bone of sternum and ster- nal third, sometimes half, of clavicle. I. upper part of mastoid process and external third of superior transverse ridge of occipital bone. Slerno-hyoideus. 0. posterior surface of first bone of sternum, cartilage of first rib, ster- nal end of clavicle, and sterno-clavicular capsule. J. lower border of body of os hyoides. Sterno-ihyroideus. 0. posterior surface of first bone of sternum and cartilage of second rib. I. oblique line on ala of thyroid cartilage. 94 Omo-hyoideus. 0. behind semilunar notch in scapula, from the ligament which passes over the notch, and from base of coracoid pro- cess. I. lower border of os hyoides, at the junction of its body and great cornu. Digastric. 0. groove, internal to mastoid process. I. rough depression on inner side of base of jaw, near its symphysis. Mylo-kyoideus. 0. mylo-hyoid ridge of inferior maxilla. I. base of os hyoides, chin, and middle tendinous line common to it and its fellow. Genio-hyoideus. 0. inner side of chin, above the digastricus. I. base of os hyoides. Myo-glossus. 0. cornu and part of body of os hyoides. I. side of tongue. Genio-hyo-glossus. O. eminence inside chin, below froenum linguae. I. mesial line of tongue from apex to base, and body and lesser cornu of os hyoides. Lingualis consists of fasciculi of fibres, run- ning from base to apex of tongue, and lying be- tween the genio-hyo-glossus, and the hyo and stylo glossi. Stylo -hyo idem. 0. outer side of styloid process near its base. I. cornu and body of os hyoides. Stylo- glossus. O. styloid process, near its tip and the stylo-maxillary ligament. I. side of tongue, as far as the tip. Stylo-pharyngeus. O. back part of root of 95 styloid process. /. side of pharynx, cornu of os hyoides, and thyroid cartilage. MUSCLES OF THE PHARYNX. Constrictor pharyngis inferior. 0. side of cricoid cartilage, inferior cornu,~and posterior part of ala of thyroid cartilage. I. with its fellow, along mesial line on back of pharynx. Constrictor pharyngis medius. 0. cornu and appendix of os hyoides, also stylo-hyoid and thyro-hyoid ligaments. I. mesial tendinous line, and cuneiform process of occipital bone. Constrictor pharyngis superior. O. petrous portion of temporal bone, lower part of internal pterygoid plate and hamular process of sphe- noid bone, also intermaxillary ligament, pos- terior third of mylo-hyoid, and side of base of tongue. I. cuneiform process of occipital bone and mesial line of pharynx. MUSCLES OF THE PALATE. Levator palati. O. petrous portion of tem- poral bone in front of foramen caroticum. I. broad, into the velum. Tensor, vel circumflexus palati. O. depres- sion at root of internal pterygoid plate, spinous process of sphenoid bone and fore part of Eu- stachian tube: tendon turns round hamular process, I. into velum, meeting its fellow in the mesial line. Motores uvula, O. posterior extremity of spine of palate bones. 1. cellular tissue of uvula. Palato-glossus. O. inferior surface of ve- lum. I. side of tongue. Palato-pharyngeus. O. inferior surface of palate. I. side and back of pharynx, and su- perior cornu of thyroid cartilage. LARYNX. Thyro-hyoideus. O. oblique ridge on ala of thyroid cartilage. I. lower edge of cornu of os hyoides. Crico-tHiyroideus. O. fore part of cricoid cartilage. J. lower border of thyroid cartilage. Thyro-arytenoideus. 0. posterior surface of thyroid cartilage, near its angle. I. anterior edge of arytenoid cartilage. Crico-arytenoideus lateralis. O. upper edge of side of crocoid cartilage. I. base of ary- tenoid cartilage. Crico-arytenoideus posticus. O. depression on posterior surface of cricoid cartilage. I. outer side of base of arytenoid cartilage. Arytenoideus fills the interval between aryte- noid cartilages, and consists of twot arrange- ments of fibres : oblique, run from apex of one cartilage to base of opposite one; transverse, are attached to posterior surface of each cartilage. 97 DEEP MUSCLES ON ANTERIOR AND LATERAL PARTS OF THE NECK. Longus colli. O. bodies of three superior dorsal and four inferior cervical vertebrae, inter- vertebral ligaments, head of first rib, and an- terior tubercles of transverse processes of the four inferior cervical vertebrae. I. fore part of first, second, and third cervical vertebrae. Rectus capitis anticus major. O. anterior tubercles of transverse processes of four inferior cervical vertebrae. I. cuneiform process of occipital bone. Rectus capitis anticus minor. O. transverse process of atlas. I. cuneiform process of occipital bone. Rectus capitis lateralis. O. transverse pro- cess of atlas. I. jugular process of occipital bone. Scalenus anticus. O. anterior tubercles of transverse processes of third, fourth, fifth, and sixth cervical vertebrae. I. upper surface of first rib, near its cartilage. Scalenus medius. O. posterior tubercles of transverse processes of four or five inferior cervical vertebrae. I. upper edge of second rib. Scalenus posticus. O. posterior tubercles of two or three inferior cervical vertebrae. I. upper edge of second rib between its tubercle and angle. 7 98 THORAX. Pectoralis major. O. sternal half of clavicle, anterior surface of sternum, cartilages of third, fourth, fifth, and sixth ribs, and aponeurosis common to it and external oblique muscle. I. by a flat tendon into anterior edge of bicipital groove, and by an aponeurosis into fascia of forearm. Pectoralis minor. O. external surfaces and upper edges of third, fourth, and fifth ribs, sometimes from second. I. inner and upper surface of coracoid process of scapula. Subclavius. O. cartilage of first rib. J. ex- ternal half of inferior surface of clavicle. Serratus magnus. O. by eight or nine fleshy slips, from eight or nine superior ribs. 1. base of scapula. Inter costales. are twenty-two in number on each side : eleven internal and eleven external. External. O. inferior edge of each rib com- mencing at transverse processes of vertebrae. I. external lip of superior edge of rib beneath, extending to behind costal extremities of car- tilages. Internal. O. at sternum from the inner lip of lower edge of each cartilage and rib as far as angle. I inner lip of superior edge of car- tilage and rib beneath. Levatores costarum. O. extremity of each 99 dorsal transverse process. I. upper edge of rib below, between tubercle and angle. Triangularis sterni. 0. posterior surface and edge of lower part of sternum and ensiform cartilage. I. cartilages of fourth, fifth, and sixth ribs. MUSCLES OF THE BACK. First Layer. Trapezius. O. internal third of superior transverse ridge of occipital bone, ligamentum nuchse, and spinous process of last cervical and dorsal vertebrae. I. posterior border of external third of clavicle and acromion process, also su- perior edge of spine of scapula* Latissimus dorsi. O. six inferior dorsal spines, and by lumbar fascia from all lumbar spines, from back of sacrum, posterior third of crest of ilium, and from three to four inferior ribs. I. posterior edge of bicipital groove of humerus. Second Layer. Rhomboideus minor. O. lower part of liga- mentum nuchse and two last cervical spinous processes. /. base of scapula, opposite to and above its spine. Rhomboideus major. O. four or five su- perior dorsal spines. I. base of scapula from spine to inferior angle. Levator anguli scapula, O. posterior tuber- 100 cles of transverse processes of four or five su- perior cervica 1 vertebrae. I. vertebral margin of scapula, between spincand superior angle. Serratus posticus superior. O. ligamentum nuchae, and two or three dorsal spines. I. second, third, and fourth ribs, external to angles. Serratus posticus inferior. O. two last dorsal and two superior lumbar spines. I. lower edges of four inferior ribs anterior to angles. Splenitis colli. 0. spines of third, fourth, fifth, and sixth dorsal vertebrae. I. transverse processes of three or four superior cervical vertebrae. Splenius capitis. 0. spines of two superior dorsal, and three inferior cervical vertebrae and ligamentum nuchae. /. posterior part of mas- toid process, and occipital bone, below its su- perior transverse ridge. Third Layer. Sacro-lumbalis. 0. posterior third of crest of ilium, oblique and transverse processes of sacrum, sacro-iliac ligaments, and transverse and oblique processes of lumbar vertebrae. 2. all the ribs, near their angles. Longissimus clorsi. 0. posterior surface of sacrum, and transverse and oblique processes of lumbar vertebrae. 7. all dorsal vertebrae, and ribs between tubercles and angles. Spinalis clorsi. 0. two superior lumbal' and 101 three inferior dorsal spines. I. nine superior dorsal spines. Musculi accessor ii. 0. superior edge of each rib. I. tendons of sacro-lumbalis. Cervical is descendens. 0. from four or five superior ribs between tubercles and angles. /. transverse processes of fourth, fifth, and sixth cervical vertebrae. Transversalis colli. 0. transverse processes of five or six superior dorsal vertebras. I. trans- verse processes of three or four inferior cervi- cal vertebras. Trachelo-mastoideus. O. transverse proces- ses of three or four superior dorsal vertebras, and as many inferior cervical. I. inner and back part of mastoid process. Complexus. O. transverse and oblique pro- cesses of three or four inferior cervical and five or six superior dorsal vertebras. I. into occi- pital bone, between its two transverse ridges. Fourth Layer. Spinalis colli. 0. extremities of transverse processes of five or six superior dorsal vertebras. I. by four heads into spines of second, third, fourth, and fifth cervical vertebras. Semi-spinalis dorsi. O. by five or six ten- dons, from transverse processes of dorsal verte- bras, from fifth to eleventh, I. extremity of spines of two inferior cervical and three or four superior dorsal vertebrae. 102 Multifidus spina. O. first fasciculus arises from spine of vertebra dentata, and is inserted into transverse process of third, each success- ively in a similar manner down to the last, which arises from the spine of last lumbar vertebra, and is inserted into false transverse process of sacrum. Inter -spinales — are situated between spinous processes of vertebrae. Inter-transversales — attached and situated as their name implies. Rectus capitis posticus major. O. spinous process of second vertebras. I. inferior trans- verse ridge of os occipitis. Rectus capitis posticus minor. 0. posterior part of atlas. I. occipital bone, behind fora- men magnum. Obliquus capitis inferior. 0. spinous pro- cess of second vertebra. I. extremity of transverse process of atlas. Obliquus capitis superior. O. upper part of transverse process of atlas. I. occipital bone, between its transverse ridges, posterior to mas- toid process. UPPER EXTREMITY. Shoulder Arm. Deltoideus. 0. lower edge of spine of scap- ula, anterior edge of acromion, and external third of clavicle. I. rough surface on outer side of humerus, near its centre. 103 Supra-spinatus. O. all scapula above the spine, which forms supra- spinous fossa, and from fascia covering muscle. I. upper and fore part of great tuberosity of humerus. Infraspinatus. 0. inferior surface of spine and dorsum of scapula beneath, as low down as posterior ridge on inferior costa. I. middle of great tuberosity of humerus. Teres minor. 0. depression between the two ridges on inferior costa of scapula, from fascia covering it, and ligamentous septa. I. inferior depression on great tuberosity of humerus. Sub-scapidaris. O. all the surface and cir- cumference of sub- scapular fossa. I. lesser tu- bercle of humerus. Teres major. O. rough surface on inferior angle of scapula, below infra-spinatus. I. pos- terior edge of bicipital groove. Coraco-brachialis. 0. coracoid process and tendon of short head of biceps. I. internal side of humerus, about its middle, and by an aponeurosis, into ridge leading to internal con- dyle. Biceps. 0. short head, from coracoid pro- cess, long head from upper edge of glenoid cavity. I. back part of tubercle of radius. Brachialis-anticus. O. centre of humerus by two slips on either side of insertion of deltoid, and fore part of humerus to its condyles. I. coronoid process of ulna and rough surface beneath. 104 Triceps extensor cubiti. O. long head, from lower part of neck of scapula and inferior costa. Second head, from ridge on humerus, below insertion of teres minor. Third head, from ridge below insertion of teres major, leading to the internal condyle, and from internal inter- muscular ligament. I. olecranon process of ulna, and fascia of forearm. Forearm and Hand. Pahnaris brevis. O. annular ligament and palmar fascia. I. integuments on inner side of palm. /Pronator radii teres. O. anterior part of internal condyle, fascia of forearm, inter-mus- cular septa, and coronoid process of ulna. I. outer and back part of radius, about its centre. Flexor carpi radialis. O. inner condyle and / inter- muscular septa. I. base of metacarpal bone of index finger. j, Palmaris longus. O. inner condyle and / fascia of forearm. I. Annular ligament and palmar aponeurosis, near root of thumb. f Flexor carpi ulnar is. O. inner condyle, inner side of olecranon, inner edge of nearly whole length of ulna and forearm. I. os pisiforme and base of fifth metacarpal bone. /Flexor digitorum sublimis perforatus. O. inner condyle, internal lateral ligament, coro- noid process, and radius below tubercle. J. 105 anterior part of second phalanges of each fin- ger. Flexor digitorum profundus perforans. O. three upper fourths of anterior surface of ulna, internal half of inter-osseous ligament, some- times from radius below its tubercle. I. last phalanx of each finger. Flexor pollicis longus. O. fore part of radius below the tubercle, and from inter-osseous membrane to within two inches of carpus, sometimes from coronoid process. I. last pha- lanx of thumb. Pronator quadratus. O. inferior fifth of anterior surface of ulna. I. anterior part of inferior fourth of radius. Supinator radii longus. O. external ridge of humerus to within two inches of outer con- dyle, and from inter-muscular ligament. I. rough surface on the outer side of radius, near its sty- loid process. , Extensor carpi radialis longior. O. ridge of / humerus, between supinator longus and exter- nal condyle. I. back part of carpal extremity of metacarpal bone of index finger. Extensor carpi radialis brevior. O. inferior / and posterior part of external condyle, and ex- ternal lateral ligament. I. carpal extremity of third metacarpal bone. y Extensor digitorum communis. O. External condyle, fascia of forearm and its inter-muscu- / 106 lar septa, and from ulna. I. posterior aspect of all the phalanges of four fingers. Extensor carpi ulnaris. O. external con- dyle, fascia, and septa, from ulna. I. carpal end of fifth metacarpal bone. Anonaus. O. posterior and inferior part of external condyle, and lateral ligament. I. ex- ternal surface of olecranon, and superior fifth of posterior surface of ulna. Extensor minimi digiti. 0. in common with and between extensor digitorum communis and extensor carpi ulnaris. I. posterior part of phalanges of little finger. Supinator radii brevis. O. External condyle, external lateral, and coronary ligaments, and from a ridge on outer side of ulna, which com- mences below its lesser sigmoid cavity. I. upper third of external and anterior surface of radius, from above its tubercle to the insertion of pronator radii teres. Extensor ossis metacarpi pollicis. O. middle of posterior part of ulna, below the anconeus, inter-osseous ligament, and posterior surface of radius. I. os trapezium and upper and back part of metacarpal bone of thumb. Extensor primi internodii pollicis. O. back part of ulna, below its middle, inter-osseous lig- ament, and radius. I. posterior part of first phalanx, and often the second. Extensor secundi internodii pollicis. O. pos- terior surface of ulna, above its centre, and 107 from inter-osseous ligament. I. posterior part of last phalanx. Extensor indicis. O. middle of posterior surface of ulna, and inter-osseous ligament. I. second and third phalanges. Abductor pollicis. O. anterior aspect of an- nular ligament, os naviculare, and trapezium. I. outside of base of first phalanx, and by an expansion into both phalanges. Opponens pollicis. O. annular ligament and os naviculare. I. anterior extremity of meta- carpal bone of thumb. Flexor pollicis brevis. O. external head, from inside of annular ligament and trapezium and scaphoid bones. I. external sesamoid bone and base of first phalanx of thumb. Internal head. O. from os magnum and base of meta- carpal bone of middle finger. I. internal sesa- moid bone and base of first phalanx. Abductor pollicis. O. three-fourths of ante- rior surface of the third, metacarpal bone. /. inner side of root of first phalanx of thumb. Abductor indicis. O. metacarpal bone of forefinger and one-lialf of that of thumb. I. outer side of base of first phalanx. Lumbricales. O. outer side of the tendons of flexor profundis, near the carpus, a little be- yond annular ligament. 1. middle of first pha- lanx into tendinous expansion covering the back of each finger. 108 Abductor minimi digiti. O. annular liga- ment and os pisiforme. I. ulnar side of first phalanx. Flexor brevis minimi digiti. 0. annular lig- ament and unciform bone. I. base of first phalanx of little finger. Adductor minimi digiti. O. internal to last, and overlapped by it. I. all the metacarpal bone of little finger. Inter -ossei antici,.vel interni, vel palmares. O. sides of metacarpal bones, I. first phalan- ges and tendinous expansion, covering the dor- sum of each finger. 1 st, vel prior, vel externus indicis. O. radial side of second metacarpal bone. I. external side of first phalanx of forefinger. 2d, vel posterior, vel interims , vel adductor indicis. O. ulnar side of second metacarpal bone. I. inner side of first phalanx of ring finger. 3d, vel prior, vel externus, vel adductor annu- laris. O. radial side of fourth metacarpal bone. J. external side of phalanx of forefinger. 4th, vel abductor minimi digiti. O. radial side of fifth metacarpal bone. I. outside of first phalanx of little finger. Inier-ossei posteriores. O. opposed sides of two metacarpal bones, I. base of first pha- lanx of each finger and posterior tendinous ex- pansion. 109 1st, prior vel externus medii. O. second and third metacarpal bones. I. outer side of base of first phalanx of middle finger. 2d, vel interims medii. O. between the metacarpal bones of middle and ring fingers. I. inner side of first phalanx of middle finger. 3d, vel externus annularis. O. between fourth and fifth metacarpal bones. /. inner side of ring finger. ABDOMEN. Obliquus externus vel descendens. O. exter- nal surfaces of eight or nine inferior ribs at a little distance from their cartilages. I. ensi- form cartilage, linea alba, os pubis, Poupart's ligament, anterior superior spinous process of ilium, and outer edge of two anterior thirds of crista ilii. Obliquus internus vel ascendens. O. fascia lumborum, all the crista ilii, and external third or fourth of Poupart's ligament. I. cartilages of seven inferior ribs, ensiform cartilage, linea alba, also by conjoined tendons into symphysis and upper edge of pubis, and into linea ileo pectinea. Cremaster. This muscle, deriving part of its origin from internal oblique, is here described, though being a muscle of the testicle. 0. inner surface of external third of Poupart's ligament, and from lower edge of obliquus internus, and sometimes from trans versalis ; it often has an 110 «ju«a.climp.at io the pubis. I. tunica vaginalis and scrotum. Transversalis. 0. fascia lumborum, poste- rior part of crista ilii, iliac third of Poupart's ligament, and inner side of seven inferior ribs. I. along with posterior lamina of obliquus in- ternus, into the whole length of linea alba, upper edge of pubis and the linea innominata. Rectus. O. upper and anterior part of pubis. I. ensiform cartilage, costo-xiphoid ligament, and cartilages of sixth and seventh ribs. Pyramidalis. 0. broad from pubis. I. linea alba, mid-wTay to umbilicus ; sometimes want- ing. DEEP MUSCLES OF THE ABDOMEN. Diaphragm is divided into two portions ; a superior broad or true diaphragm ; and an in- ferior lesser portion, or crura of the diaphragm. True Diaphragm. 0. posterior surface of xiphoid cartilage, internal surfaces of cartilages of the last true and all the false ribs, external or false ligament arcuatum, and convex edge of true ligamentum arcuatum. I. cordiform tendon. False or lesser diaphragm, or crura. 0. right cms, from fore part of bodies of four superior lumbar vertebrae. Left eras from the sides of the two or three superior lumbar vertebrae. I. posterior border of cordiform tendon. Quadratus lumborum. 0. posterior fourth of spine of ilium, and from ilio-lumbar ligament. Ill I. extremity of transverse processes of four su- perior lumbar and last dorsal vertebrae, also inner surface of posterior half of last rib. Psoas parvus. 0. side of last dorsal and first lumbar vertebrae. 1. linea ileo-pectinea, fascia iliaca, and fascia lata, behind the femoral ves- sels ; sometimes wanting. Psoas magnus. 0. sides of bodies of two last dorsal, and from bodies and transverse processes of all the lumbar vertebrae, also from inter-ver- tebral ligaments. I. inferior part of lesser tro- chanter and ridge below that process. Hiacus internus. 0. transverse processes of last lumbar vertebra, inner margin of three an- terior fourths of crista ilii, and its two anterior spinous processes and intervening notch, brim of acetabulum, capsular ligament, iliac fossa, and iliac fascia. I. into psoas magnus; the inferior fibres are inserted into anterior and inner surface of femur, below trochanter minor. MUSCLES OF MALE PERLNJEUM. Sphincter ani. 0. ano-coccygeal ligament. I. into raphe, superficial fascia, and common central point of perinaeum. Sphincter internus encircles the lower part of rectum. Erector penis. O. inner surface of tuber ischii, and from insertion of great or inferior sciatic ligament. I. fibrous membrane of cms penis. Accelerator urinm. 0. 1st, triangular liga- 112 ment of the urethra ; 2d, by a broad tendon common to opposite muscles, which lies above urethra, between it and pubis ; 3d, by a tendi- nous expansion from the side of cms penis. I. middle tendinous line or raphe of perinseum. Transversalis perincei. O. inside of tuber ischii. I. central point of perinseum. Levator ani. 0. posterior part of symphysis pubis, obturator fascia, ilium above thyroid foramen, inner surface of ischium, and its spi- nous process. I. anterior fibres into central point of perinasum and fore part of rectum ; middle fibres into side of rectum, posterior fibres into back part of rectum, os coccygis, and last bones of sacrum. Compressor urethra. O. by a tendon from the inside of symphysis pubis. I. below mem- branous portion of urethra, into the narrow tendinous line, which becomes lost in central point of perineeum. Coccygeus. 0. inner surface of spine of ischium. I. extremity of sacrum and side of coccyx. MUSCLES OF FEMALE PERINEUM. Sphincter ani. 0. ano-coccygeal ligament. I. raphe, superficial fascia, and common central point of perinseum. Levator ant. O. posterior part bf symphysis pubis, below true ligaments of bladder, obtura- tor fascia, ilium above thyroid foramen, inner 113 surface, and spine of ischium. J. the same as in the male. Coccygeus, as in the male. Transversalis perincei, as in the male. Erector ditoridis. 0. inner surface of tuber ischii, and insertion of great sciatic ligament. I. fibrous membrane of crus clitoridis. Sphincter vagince, extends from clitoris supe- riorly, around each side of vagina to central point of perinseum, in front of anus. MUSCLES OF THE INFERIOR EXTREMITY. Fore Part and Sides of the Thigh. Tensor vagince femoris. 0. external part of anterior superior spine of ilium. I. fascia lata about three inches below the great trochanter. Sartorius. 0. anterior superior spine of ilium and notch beneath it I. inner side of upper end of tibia, below its tubercle. Rectus femoris. 0. anterior inferior spinous process of ilium, acetabulum, capsular ligament I. upper edge of patella. Vastus externus. O. root and anterior part of great trochanter, outer edge of linea aspera, oblique ridge leading to external condyle, ex- ternal surface of femur, and fascia lata. J. ex- ternal edge of tendon of rectus, side of patella, and head of tibia. Vastus internus. 0. anterior part of femur, linea inter-trochanterica, inner edge of linea as- 8 114 pera, and inside of femur. I. inner edge of ten- don of rectus, patella, and head of tibia. Crurceus. O. anterior and external part of femur, commencing at linea inter-trochanterica, and extending along three-fourths of the bone, as far outwards as linea aspera. J. upper and outer edge of patella, and synovial membrane of knee joint. Subcrurceus or capsularis. O, inferior fourth of anterior surface of femur. I. synovial mem- brane of knee joint. Gracilis 0. lower half of symphysis, and in- ner edge of descending ramus of os pubis. I. superior part of internal surface of tibia. Pectinceus. 0. linea innominata on horizon- tal ramus of pubis. I. rough ridge leading from lesser trochanter to linea aspera. Triceps adductor femoris. 1st. adductor longus. O. anterior surface of pubis, between spine and symphysis. I. mid- dle third of linea aspera. 2d. adductor brevis. 0. anterior inferior surface of pubis, between symphysis and thy- roid foramen. I. superior third of internal root of linea aspera to three inches below lesser tro- chanter. 3d. adductor magnus. O. anterior surface of descending ramus of pubis, ramus of ischium, and external border of its tuberosity. I. rough ridge leading from great trochanter to linea as- 115 pera, linea aspera, and internal condyle of fe- mur. MUSCLES OF HIP. Gluteus maximus. 0. posterior fifth of cris- ta illii, the rough surface between it, and supe- rior semi- circular ridge, posterior ilio-sacral lig- aments, lumbar fascia, spines of sacrum, side of coccyx, and great sciatic Hgament. I. rough ridge leading from great trochanter to linea as- pera, upper third of linea aspera, and fascia lata. Gluteus medius. 0. deep surface of fascia covering it, three anterior fourths of crista ilii, superior semicircular ridge, and surface of ilium above and below it. I. upper and outer part of great trochanter. Gluteus minimus. 0. inferior semicircular ridge on dorsum of ilium, rough surface between it, and edge of acetabulum. /. upper and an- terior part of great trochanter. Piriformis. 0. concave aspect of 2d, 3d, and 4th divisions of sacrum, upper and back part of ilium, and anterior surface of great scia- tic ligament. I. upper part of digital fossa. Gemellus superior. 0. spine of ischium. I. upper part of digital fossa. Gemellus inferior. 0. upper part of tuber ischii, and great sciatic ligament. I. digital fossa. Obturator internus. 0, pelvic surface of ob- 116 turator ligament, circumference of obturator foramen, and obturator fascia. I. digital fossa. Quadratus femoris. O. external surface of tuber ischii. I. Inferior and posterior part of great trochanter and posterior inter-trochanteric line. Obturator externus. O. inferior surface of obturator ligament and surrounding surfaces of pubis and ischium. I. digital fossa. MUSCLES ON BACK PART OF THIGH. Biceps flexor cruris. Long head. O. outer and back part of tuber ischii. Short head. O. linea aspera, from below insertion of glutseus maximus to within two inches of external con- dyle. I. head of fibula. Semitendinosus. O. tuberosity of ischium, and from three inches of the tendon of the long head of biceps. I. anterior angle of tibia, below tubercle. Semimembranosus. O. upper and outer part of tuber ischii. I. internal condyle of tibia and posterior part of external condyle of femur, crossing the knee joint, and thus forming the ligament of Winslow. MUSCLES ON ANTERIOR. AND EXTERNAL PART OF LEG. P Tibialis anticus. 0. outer part of two su- perior thirds of tibia head of fibula, inner half of interosseous ligament, fascia of leg, and in- 117 termuscular septa. I. inner side of internal cuneiform bone and base of first metatarsal bone. Extensor digitorum longus. O. external part of head of tibia, head and three-fourths of fibula, part of interosseous ligament, fascia of leg, and intermuscular septa. I. last phalanges of four external toes. Extensor pollicis proprius. 0. inner edge of middle third of fibula, interosseous ligament, and lower part of tibia. I. bases of first and second phalanges of great toe. Peronaus tertius. O. anterior surface of lower half of fibula. I. base of fifth metatar- sal bone. Extensor digitorum brevis. O. upper and anterior part of os calcis, cuboid bone, astrag- alus and annular ligament. I. internal tendon into base of first phalanx of great toe, the three others join the outer edges of correspond- ing tendons of extensor digitorum longus. MUSCLES ON OUTER PART OF LEG. Peronceus longus. 0. around head of fibula, adjacent surface of tibia, upper half of external angle of fibula, fascia and intermuscular septa. I. outer side of metatarsal bone of great toe, adjacent sesamoid bone, internal cuneiform bone and base of second metatarsal bone. Peronceus brevis. O. outer and back part of 118 lower half of fibula, and intermuscular septa. I. os cuboides and base of metatarsal bone of little toe. MUSCLES OF BACK OF LEG. Superficial Layer. Gastrocnemius. O. internal head, upper and back part of internal condyle of femur, and oblique ridge above it; exterrud head, from above external condyle. I. lower and back part of os calcis. Plantaris. O. back part of femur above ex- ternal condyle, and posterior ligament of knee. I. posterior part of os calcis. Solceus. O. external head, from] back part of head and superior third of fibula ; internal head, from middle third of tibia, unites with gastrocnemius to form tendo Achillis. I. lower and back part of os calcis. Poplitceus. 0. depression on outer condyle of femur. I. flat triangular surface, occupy- ing the superior posterior fifth of tibia. Flexor digitorum perforans. O. posterior flat surface of tibia, from below poplitseus to within three inches of ankle, fascia, and inter- muscular septa. I. last phalanges of four lesser toes. Tibialis posticus. O. posterior internal part of fibula, upper part of tibia, and nearly whole length of interosseous ligament. /. inferior and internal tuberosity on os naviculare, inter- 119 nal cuneiform and cuboid bones, and second and third metatarsal bones. Flexor pollicis longus. O. two inferior thirds of fibula. I. last phalanx of great toe. MUSCLES OF FOOT. First Layer. Abductor pollicis. O. lower and inner part of os calcis, internal annular ligament, plantar aponeurosis, and internal intermuscular sep- tum, i". internal sesamoid, and internal side of base of first phalanx of great toe. Flexor digitorum brevis perforatus. 0. in- ferior and internal part of os calcis, internal annular ligament, plantar aponeurosis, and in- termuscular septa. 1. second phalanges of four lesser toes. Abductor minimi digiti. O. outer side of os calcis, ligament extending from os calcis to outer side of fifth metatarsal bone, plantar fascia, external intermuscular septum, and base of fifth metatarsal bone. 1. outer side of base of first phalanx of little toe. Second Layer. Musculus accessorius. O. inferior and in- ternal part of os calcis. I. outer part of ten- don of flexor digitorum longus. Lumbricales. 0. tendons of flexor digitorum longus. I. internal side of first phalanges of four lesser toes. 120 Third Layer. Flexor pollicis brevis. 0. lower and anterior part of os calcis and external cuneiform bone. I. sesamoid bones, beneath first phalanx of great toe. Adductor pollicis. O. calceo- cuboid liga- ment and base of second and third metatarsal bones. I. external sesamoid bone. Transversal-is pedis. 0. anterior extremities of four external metatarsal bones. I. external sesamoid bone of great toe. Flexor brevis minimi digiti. O. cuboid and fifth metatarsal bones, and sheath of tendon of peronseus longus. I. inner side of base of first phalanx of little toe. Fourth Layer. Seven interossei muscles. Three on sole of foot, and four upon its dorsum. lnferiores, vel interossei interni. 1st. adductor medii digiti. O. inner side of third metatarsal bone. I. base of first phalanx of fourth toe. 2d. adductor quarti digiti. O. inner side of fourth metatarsal bone. I. inner side of first phalanx of third toe. 3d. adductor minimi digiti. O. fifth meta- tarsal bone. I. inner side of base of first phalanx of little toe. Superiores, vel interossei externi. 121 1st. O. intersal side of second metatarsal bone and outer side of first. I. inner side of base of first phalanx of second toe. 2d. O. opposite sides of second fand third metatarsal bones. I. outer side of first phalanx of second toe. 3d. 0. opposite sides of third and fourth metatarsal bones. I. outer side of first pha- lanx of middle toe. p 4th. 0. opposite sides of fourth and fifth metatarsal bones. I. outer side of first phalanx of fourth toe. THE MUSCLES OF THE ORBIT. 1. Levator palpebra superioris. O. upper edge of foramen opticum. I. superior border of tarsal cartilage. 2. Obliquus superior. 0. foramen opticum. I. sclerotic coat between superior and external rectus. 3. Obliquus inferior. O. orbital edge of superior maxillary bone. I. sclerotic coat be- tween it and external rectus muscle. 4. Rectus superior. 5. Rectus inferior. 6. Rectus internus. 7. Rectus externus. [All arise round optic foramen, the external rectus being also attached to margin of sphe- noidal fissure, and they are inserted about a quarter of an inch behind cornea.] 122 MUSCLES OF INTERNAL EAR. Stapedius. O. within pyramid. J. neck of stapes. Tensor tympani. O. canal in petrous por- tion of temporal bone, above Eustachian tube. I. short process below neck of malleus. Laxator tympani. O. spinous process of sphenoid bone and Eustachian tube. J. pro- cesses gracilis of malleus. BRAIN AND ITS MEMBRANES. DURA MATER. A firm dense fibrous membrane, adhering by its outer surface to the bones of the cranium, its inner surface being intimately connected with the arachnoid membrane. It defends the brain, acts as an internal periosteum to the bones of the skull, forms the sinuses, and sends envelopes upon the several nerves as they pass through the cranial holes. It sends off the following processes. Falx cerebri commences narrow at crista galli, and arches backwards between the lobes of the cerebrum, becoming deeper until it meets the tentorium, with which process it is contin- uous on either side. Its convex edge corre- sponds to the median groove of the os frontis, the sagittal edges of the parietal bones and the upper half of the perpendicular ridge of the occipital bone. The great longitudinal sinus 123 is in its upper edge, and the lesser longitudinal sinus in its inferior free concave edge. Tentorium extends in a horizontal manner above the cerebellum and below the posterior lobes of the cerebrum. Its convex edges con- tain the lateral sinuses, and correspond to the transverse ridges of the occipital bone, the in- ferior posterior angles of the parietal bones, the superior angles of the petrous portion of the temporal bones, and to the clinoid processes of the sphenoid bone. Falx cerebelli is attached to the lower half of the perpendicular ridge of the occipital bone, and extends between the lobes of the cerebel- lum towards the foramen magnum. Sphenoidal folds are attached to the lesser wings of the sphenoid bone. SINUSES. Great longitudinal sinus, of a triangular form, extends along the convex margin of the falx cerebri. It commences by a small vein in the foramen coecum, and increasing in size as it proceeds backwards and pours its blood into the torcular Herophili. Its interior is crossed by small bands called chorda Willisii, and pre- sents the openings of the veins which course upon the upper surface of the cerebral hemi- spheres, and a number of small whitish gran- ules called glandules Pacchioni medics. Upon the outer surface of the upper wall of the si- 124 nus, between it and the cranium, are situated the glandulce Pacchioni externa. Inferior longitudinal sinus is very small, runs along the concave edge of the falx cerebri, and terminates in the straight sinus. Straight sinus passes from the termination of the inferior longitudinal sinus downwards and backwards, receiving the blood of the ve- nas Galeni, and empties itself into the torcular Herophili. Lateral sinuses, each corresponds to the transverse groove in the occipital bone, the groove in the posterior inferior angle of the parietal bone, the mastoid fossa of the temporal bone, and the groove in the occipital bone in either side of the foramen magnum ; when it passes through the foramen lacerum posterious and terminates in the jugular vein. Torcular Herophili corresponds to the centre of the crucial spine of the occipital bone ; six sinuses communicate with it, viz : the two lateral, the great longitudinal, the straight, and the two occipital. Cavernous sinuses, each extends from the anterior clinoid process, to the petrous portion of the occipital bone ; and upon being cut into presents a cellular appearance. The internal carotid artery, the sixth nerve, and branches of the sympathetic nerve, are found within each, but separated from the blood by the reflected venous lining membrane. In the outer wall of 125 each run the third and fourth nerves, and the first branch of the fifth ; the sinus of either side presents the openings of the ophthalmic vein, of the two petrosal sinuses, and of the circular sinus. Circular sinus surrounds the pituitary body, and is formed of an anterior and posterior transverse vein which extends from one ca- vernous sinus to the other. Superior petrosal sinuses, each passes from the cavernous sinus along the upper angle of the petrous portion of the temporal bone, to the lateral sinus. Inferior petrosal sinuses, each passes from the cavernous sinus downwards and backwards, along the line of contact of the petrosal por- tion of the temporal bone, and the occipital to the lateral sinus. Transverse sinus crosses the cuneiform pro- cess of the occipital bone, and connects the inferior petrosal sinuses. Occipital sinuses, two in number, are con- tained in the falx cerebelli, and open into the torcular Herophili. TUNICA ARACHNOIDEA Belongs to the class of serous membranes, is spread o^er the surface of the brain without penetrating between its convolutions, and is reflected upon the dura mater, in those situa- tions where the nerves and veins pierce this 126 fibrous membrane, thus, after the manner of all serous membranes, forming a shut sac, and consisting of a parietal and a visceral layer. It also gains access to the interior of the brain by the arachnoid canal, and lines the free sur- faces of the ventricles. PIA MATER. The vascular covering of the brain lines its entire surface, dipping between its convolu- tions and sending numerous blood-vessels into its substance, it is intimately connected to the arachnoid membrane by its outer surface, ex- cept at the base and sulci of brain ; and enter- ing the ventricles by the great transverse fissure at the base of the brain, presents the choroid plexuses and the choroid membrane. . THE BRAIN. The brain is subdivided into three portions, viz : the cerebrum, the cerebellum, and the medulla oblongata. THE CEREBRUM. This is the largest of the three divisions, is of an oval form, and is divided into two equal portions called hemispheres^ by a fissure which extends along the median line upon its upper surface, and contains the falx cerebri and the arteries of the corpus callosum. At the base 127 of the brain the cerebrum is also divided at each extremity, by the median fissure, but in the centre both hemispheres are united. Hemispheres, right and left, are convex su- periorly and externally, and flat towards each other, where they correspond to the falx. Lobes. Each hemisphere is divided into three lobes upon its under surface ; the anterior, which is the smallest, rests upon the roof of the orbit and presents a groove for the lodge- ment of the olfactory nerve ; the middle, promi- nent and convex, lies in the middle fossa, in the base of the cranium ; and the posterior rests upon the tentorium. Fissura Sylvii separates the anterior from the middle lobe, and corresponds to the lesser wing of the sphenoid bone and its fold of dura ma- ter. The cerebral roof of this fissure is pierced by small arteries, branches of the middle cere- bral artery. Convolutions, or gyri, are eminences longi- tudinal and rounded, but directed in various ways upon the surface of each hemisphere. Sulci are the fissures which separate the con- volutions from each other, over which the arachnoid membrane passes, but into which the pi a mater dips. Cineritious substance of brain is of a yellow- ish grey color, from three to four lines in thick- ness, soft and vascular, and for the most part situated upon the outer surface of the brain. 128 It is however found in striae and masses in the interior of the brain, and surrounded by the me- dullary substance. In some situations its color assumes a dark hue, as is seen when a section of the crus cerebri is made. Medullary substance, white, elastic and fibrous, forms the greater part of the brain. Centrum ovale minus, an oval mass of me- dullary substance surrounded by cineritious substance, and rendered apparent by making a section of each hemisphere within a few lines of the corpus callosum. Centrum ovale magnum, the large oval mass of medullary structure, which is rendered ap- parent by slicing both hemispheres on a level with the corpus callosum. Corpus Callosum, unites the hemispheres to each other, is about three inches in length, and presents upon its upper surface the raphe, which corresponds to the anterior cerebral arteries, and from which, on either side, pass the con- necting transverse fibres of the hemispheres, called linse transversa. It unites by its poste- rior extremity with the fornix and the hippo- campus, major and minor ; its anterior ex- tremity being curved upon itself and continuous with the optic commissure and tuber cinereum at the base of the brain. Septum Lucidum descends from the raphe of the corpus callosum to the fornix, separating the lateral ventricles from each other. It con- 129 sists of four layers, two of which are cineritious and two medullary ; the medullary layers having in general a cavity between them called the fifth ventricle : its form is triangular, the apex corresponding to the union of the corpus callo- sum and the fornix, the base anterior, cor- responding to the curved portion of the corpus callosum. Lateral ventricles, each consists of a body and three cornua, the body corresponding to the centre of each cerebral hemisphere, the cor- nua proceeding, one to each lobe. The bodies of the ventricles are separated from each other by the septum lucid urn. Corpora striata, two pear-shaped bodies, their large bulbous extremities being contained in the anterior cornua of the lateral ventricles, their narrow stalk-like extremities being direct- ed backwards into the bodies of the ventricles ; they are cineritious on their surface, but when cut into present alternating striae of cineritious and medullary matter, and hence their name. Optic thalami, two large bodies placed behind and between the corpora striata, each presents upon its inferior surface two tubercles, called copwa gleniculata. Towards the median line the optic thalami are flat and united to each other by a soft cineritious structure, called commissura mollis; upon their external sur- face they are white, but their interior is grey. Tania Semicircularis, a narrow medullary 9 130 band situated in the groove between the optic thalamus and corpus striatum of either side. Fornix, placed horizontally beneath the sep- tum lucidum and corpus callosum, and com- posed of medullary structure, arches above the third ventricle, and lies upon the velum inter- positum and choroid plexus. It commences by its two 'posterior crura, one of which lies in the inferior cornu of either lateral ventricle ; these unite in the median line and form what is called the body of the fornix, which passes forwards and terminates in the anterior crura; finally, the anterior crura descend to the base of the brain, where they terminate in the corpora mammillaria. The Lyra, is the appearance presented upon the under surface of the fornix by some slight lines and depressions which correspond to the vessels of the velum interpositum. Choroid plexus. The fold of pia mater which lies upon the optic thalamus, and which entered the body of the lateral ventricle by the inferior cornu ; the choroid plexus of either side passes forwards and inwards, and both unite in the foramen commune anterius. Velum interpositum, lying underneath the fornix, unites the choroid plexuses of either side ; it is composed of arachnoid membrane and pia mater, and contains in its centre the venae Galeni. Vena Galeni, contained in the velum interpo- 131 silum, pass from before backwards and termi- nate in the staight sinus. These veins return the blood from the choroid plexuses and from the parts within the ventricles. Pineal gland, a small conical cineritious body containing in general sandy matter. It is placed upon the corpora quadrigemina and is connect- ed with the brain by a small transverse medul- lary band and two peduncles. Hippocampus minor, an oval eminence in the posterior cornu of the lateral ventricle ; medul- lary externally, and cineritious in its interior. Hippocampus major, a similar eminence to the minor, but larger, and placed in the inferior cornu of the lateral ventricle. Pes hippocampi, the tuberculated appearance which the extremity of the hippocampus major presents. Tcznea hippocampi, another name for the pos- terior crura of the fornix, which are attached to the hippocampus major of either side by their convex margins, their concave edges being free. Corpus denticulatum, a cineritious serrated line in the inferior cornu of the lateral ventri- cle, and which is exposed upon removing the tenia hippocampi, beneath which it lies. Third ventricle, a deep fissure between the optic thalami, exposed by separating these bodies. It is bounded anteriorly by the descend- ing crura of the fornix and the anterior com- 132 missure, posteriorly by the posterior commis- sure and the tubercula quadrigemina, laterally by the optic thalami : its floor corresponds to the locus perforatus and tuber- cinereum, and it is covered in by the velum interpositum and fornix. Foramen commune anterius, a hole by which the choroid plexuses unite anteriorly. It forms a medium of communication for the two lateral and the third ventricle. Infundibulum, an opening leading from the anterior and inferior part of the third ventricle to the pituitary gland. Iter a tertio ad quartum ventriculwn, an open- ing in the posterior part of the third ventricle, under the posterior commissure and tubercula quadrigemina, and leading obliquely backwards and downwards to the fourth ventricle. Anterior commissure, a medullary, round cord, anterior to the crura of the fornix, and passing transversely from one corpus striatum to the other. Posterior commissure, extends transversely from one optic thalamus to the other. It is shorter and smaller than the anterior commis- sure. Tubercula quadrigemina, four eminences, called also nates and testes; situated under the posterior part of the velum interpositum, and the pineal gland ; the two anterior (the nates) 133 are connected to the optic thalami ; the poste- rior (the testes) being connected to the cerebel- lum by the following processes. Processus a cerebello ad testes, two thin med- ullaty plates, which pass obliquely from the cerebellum upwards and inwards to the testes. Valve of Vieussens, a layer of cineritious substance, of a triangular form, attached by its sides to the processus a cerebello ad testes, by its base to the cerebellum, and by its apex to the testes. Fourth ventricle, is exposed by cutting through the valve of Vieussens. It is bounded anterior- ly by the pons Varolii, laterally by the processus a cerebello ad testes, superiorly by the valve of Vieussens, inferiorly by pia mater and arach- noid membrane, and posteriorly by the cerebel- lum. Calamus scriptorius, the fissure seen upon the posterior surface of the pons Varolii, in the fourth ventricle ; from either side of which four or five lines proceed. Choroid plexus of fourth ventricle, a small fold of pia mater, which enters the ventricle as this membrane is passing from the cerebellum to the spinal chord. CEREBELLUM, Consists, like the cerebrum, of two hemi- spheres, united anteriorly by the pons Varolii, 134 and posteriorly by the superior and inferior vermiform processes. Hemispheres, are flat superiorly, where they correspond to the tentorium, and convex inte- riorly where they rest in the inferior occipital fossa : the surface of each presents semicircu- lar narrow lines, arising from the laminated arrangement of the cineritious portion of the organ ; between these lamina the pia mater en- ters, but the arachnoid passes over them. Crura cerebelli, two medullary chords which pass from either hemisphere and unite in the pons Varolii. Superior vermiform process, a small conical eminence corresponding to the superior and central part of the cerebellum. Inferior vermiform process, larger than the superior and corresponding to the inferior and central part of the cerebellum and the com- mencement of the spinal chord. Arbor vitce, the branching of the medullary substance of the cerebellum, exposed by mak- ing a vertical section of it. Corpus dentatum, a small oval mass of cine- ritious substance, surrounded by medullary, and exposed upon making a section of the cerebel- lum parallel to, but an inch distant from, the median line. MEDULLA OBLONGATA, A large conical process of medullary structure, 135 extending from the lower margin of the pons Varolii to the commencement of the spinal chord. It is rather more than an inch in length, and presents the following six bodies, which are separated from each other by distinct grooves. Corpora pyramidalia, the two anterior emi- nences of the medulla oblongata. Corpora olivariay smaller than the pyramidal bodies, are situated laterally. Corpora restiformia are large, and situated posteriorly. BASE Or THE BRAIN Presents on either side of the median line, the anterior and middle lobe of the cerebrum, sepa- rated from each other by the fissure of Sylvius, and a lobe of the cerebellum resting upon the posterior lobe of the cerebrum. In the median line, proceeding from before backwards, is the anterior extremity of the median fissure, the lower extremity of the corpus callosum, the optic commissure, the tuber cinereum, the pitu- itary gland and infundibulum,the corpora albi- cantia, the locus perforatus, (on either side of this is the crus cerebri,) the pons Varolii, and lastly the posterior extremity of the median fis- sure. ORIGIN OF THE CEREBRAL NERVES. First pair (olfactory), each arises by three 136 roots, the external, long and white from the fis- sure of Sylvius ; the internal, also white from the posterior internal surface of the under part of the anterior lobe and the middle, short and cineritious, from the posterior edge of the ante- rior lobe. Second pair (optic), each arises by two roots from the corresponding natis and testis ; that from the natis joins the corpus geniculatum externum ; the other the corpus geniculatum internum ; the roots then unite and form the tractus opticus, which passes around the cms cerebri, and to which it is united by fine cellular tissue; the tracts, one from either side, then unite in the optic commissure, having previ- ously sent a few fibres into the tuber-cinereum and from the anterior part of this commissure, proceed the optic nerves. Third pair (oculo-muscular), each arises from the inner side of the crus cerebri, near the pons Varolii, and from the corpus pyrami- dale, as this body passes through the pons. Fourth pair (inner oculo-muscular), each arises from the processus e cerebello or its cor- responding side by two or three fine filaments. Fifth pair (trigeminal), consists of two por- tions, one for sensation, the other for motion. The motor division arises from the corpus pyra- midale, in the substance of the pons Varolii, and the sensory division from the angle be- tween the crus cerebelli and the pons Varolii. 137 Sixth pair (abducentes), each arises from the corpus pyramidale near its junction with the pons Varolii. Seventh pair consists of the portio dura, or facial, and the portio mollis, or auditory. The portio dura arises from the groove between the corpus pyramidale and olivare, a little below the pons Varolii. The portio mollis arises by three or four white lines from the calamus scriptorius in the fourth ventricle. Eighth pair consists of the glosso-pharyngeal, pneumo- gastric and spinal accessory The glosso- pharyngeal arises from the groove between cor- pus olivare and corpus resitiforme, by four or five filaments. The pneumo- gastric arises in the same groove, but below the glossopharyn- geal, by eight or ten filaments, and the spinal accessory arises from the side of the cervical spinal chord, about its middle, by several fila- ments. The ninth (linguales) each arises by seven or eight filaments from the groove between the pyramidal and olivary bodies, about half an inch below the origin of the sixth. CEREBRAL NERVES. First pair (or olfactory), sends off three sets of branches. Internal branches to septum nasi ; middle branches to mucous membrane of roof of each nostril ; and external branches to spongy bone. 138 Second pair (or optic), pierce the sclerotic coat of the eye, and form the retina. Third pair (or motores oculorum). Superior, or smaller branch, supplies the superior rectus, and the levator palpebrae. Inferior, or larger branch, supplies the internal rectus, the inferior rectus, and the inferior oblique ; and also sends a branch to the lenticular ganglion. Fourth pair (or pathetici), are distributed to superior oblique muscles of eye. Fifth pair (or trigemini), first form the Gas- serian ganglion and divide into three main branches. Ophthalmic division. — 1. Descending branches to unite with the sympathetic. 2. Lachrymal nerve, which sends a branch through the sphe- no-maxillary fissure, to unite with the superior maxillary nerve and a branch through the malar bone to the cheek, the terminal branches being distributed to the lachrymal gland, and the con- junctiva. 3. Frontal nerve, sends a branch to unite with the infra- trochlear branch of the nasal ; a supra-trochlear branch, which becomes the internal frontal, and the proper frontal, which passes over the frontal bone to the forehead. 4. Naso-ocular nerve, sends a branch to com- municate with the sympathetic — a branch to the third pair — two long ciliary nerves — a branch to the lenticular ganglion — the inira-trochlear branch, and the nasal branch. Superior maxillary division. — 1 . Orbital 139 branch which sends off a malar twig and a tem- poral twig. 2. Two branches to Meckel's gan- glion. 3. Posterior dental, which sends off an anterior branch to the buccinator muscle and gums, and a posterior branch to the molar teeth. 4. Anterior dental, to the antrum and teeth. 5. Infra- orbital, distributed to the face. Inferior maxillary division. — 1. The supe- rior or external branch sends off deep temporal twigs — a masseteric branch to massetur muscle and temporo-maxillary articulation — a buccal branch to the buccinator and temporal muscles, and a pterygoid branch to the pterygoid and pa- latine muscles. 2. Inferior or internal branch, sends off the temporo-auricular, which goes to the cartilages of the ear and temple and the in- ferior dental, which gives off the mylo-hyoid nerve, and the mental nerve. 3. The gusta- tory, which goes to the muscles, glands, and papillse of the tongue, and is joined by the chorda tympani nerve. GANGLIONS IN CONNECTION WITH THE FIFTH PAIR. Gasserian Ganglion. — A large grey semi- lunar body, placed in the middle fossa of the base of the cranium, concave posteriorly, where it receives the fifth nerve, and convex anteriorly and externally, from which part proceed the three main divisions of the fifth, just described. Meckel's Ganglion. — A litte red body of a tri- angular shape, situated deep in the fat and eel- 140 lular tissue of the pterygo-maxillary fossa ; it communicates superiorly by two small nervous twigs with the second divison of the fifth, and sends off — 1. Spheno-palatine nerve to the mucous membrane of the superior and middle spongy hones, from which proceeds the naso- palatine branch, which runs along the septum nasi, and terminates in the foramen incisivum. 2. Palatine nerve, descends in the palatine ca- nal, and divides into anterior branches which supply the teeth, and posterior and middle branches, which supply the amygdalae soft pa- late and uvula. 3. Vidian nerve, passes back- wards through the vidian canal, enters the cranium by the foramen lacerum anterius, and divides into an inferior and a superior branch, having first sent filaments to the sphenoidal sinus; the inferior branch enters the cavernous sinus, and unites with the branches of the sympathetic, whilst the superior branch runs beneath the gasserian ganglion on the petrous portion of the temporal bone, enters the hiatus Fallopii, attaches itself to the portio dura nerve, again leaves it, and enters the tympanum a little below the pyramid, and is here called chorda tympani. It then passes between the long crus of the incus and the handle of the malleus, emerges from the tympanum by the glenoid fis- sure, unites with the gustatory nerve, and at the submaxillary gland it terminates in a small gan- glion named after Boch. Tlie lenticular ganglion is situated between 143 sympathetic. 5. Inferior laryngeal or recurrent nerve which sends off cardiac filaments — branches to the forepart of the trachea and thyroid gland, and branches to the pharynx, laryngeal muscles, and mucous membrane, on which they communicate with branches of the superior laryngeal. 6. Pulmonary branches which send oft branches in front of the bron- chial tubes to form the anterior or lesser pul- monic plexus ; this plexus sends filaments to the pulmonary vessels, also to the lungs and peri- cardium, and to the posterior pulmonic plexus. 7. Posterior, or greater pulmonic plexus, is formed by the pneumo-gastric nerves which in- crease in size at the root of each lung, and sub- divide and unite in an areolar manner. This plexus is joined by several branches of the sympathetic nerve, and its branches accompany the bronchial tubes through the substance of the lung. 8. (Esophageal plexus or plexus gulee, is formed by the communications of both nerves, encircling the oesophagus in their course along this tube. 9. Cardiac, or gastric plexus, is formed by both nerves dividing, subdividing, and uniting upon the stomach. The left pneu- mo-gastric nerve is anterior upon the stomach, and sends branches to the lesser omentum and liver ; the right is posterior. Nervus accessorius, or third branch of the eighth. 1 . Branches to communicate with the eighth, ninth, and sympathetic nerves. 2. 144 Branches to the sterno-cleido-mastoid muscle, which muscle it then perforates. 3. Terminal branches to the trapezius muscle and skin. Ninth pair, or lingual. — 1. Descendeus noni receives a filament from the pneumo-gas- tric, and unites with the internal descending branches of the cervical plexus, forming a small triangular plexus, the branches of which pass to the omo and sterno-hyoid and thyroid mus- cles. 2. Branches to the constrictors of the pharynx and thyro-hyoid muscle. 3. Branches to the hyo-glossus and surrounding muscles, and to the gustatory branch of the fifth pair. 4. Terminal branches to the geniohyo-glossus muscle. SPINAL NERVES. Symmetrical, 30 pairs,* viz :— 8 cervical, 12 dorsal, 5 lumbar, and 5 sacral. Each spinal nerve has two roots, an anterior and a posterior. The anterior is small, and is the motor division. The posterior large, with a ganglion upon it, and is for sensation. These roots are separated by the chord itself, and by the ligamenta denticu- lata. The anterior root is connected to the sur- face of the ganglion of the posterior root. On the outer side of the ganglion both nerves unite in a single chord, which after a short course, divides into an anterior and posterior branch. * Some describe 31 pairs, making 6 sacral. 145 The posterior branches of this division are the smaller, (except that of the second cervical,) and are distributed to the dorsal muscles and integu- ments. The anterior branches form the several plexuses, and supply the muscles and integu- ments anterior to the spine, and also the ex- tremities. DISTRIBUTION OF THE EIGHT CERVICAL NERVES AND FIRST DORSAL NERVES. Posterior branches are small, except the second cervical, which accompanies the occipital arte- ry ; the rest are lost in the neighboring muscles and integuments. Anterior branches. — The first, or sub-occipi- tal, twists round the atlas, to unite with the second, forming the nervous loop of the atlas; and the second, having received the first, de- scends to unite with the third. The third unites in like manner with the fourth, and thus is formed, by the anterior branches of the four first cervical nerves, the CERVICAL PLEXUS. From this plexus proceed I — 1. Ascending superficial branches to the pla- tysma, integuments, parotid gland, ear, and back of the head. One of these is called ascendens colli, which arising chiefly from the third cer- vical, is distributed to the ear ; it accompanies the external jugular vein. 10 146 2. Ascending deep branches, which supply sterno-cleido-mastoid, digastric, splenhis, and adjacent muscles. 3. Descending internal branches, which send a superficial branch to join the descendens noni and the deep or phrenic, or internal respiratory, which comes chiefly from the fourth cervical, and often receives a filament from the brachial plexus, having sent small filaments to the liver, oesophagus, inferior cava, and stomach ; it ulti- mately distributes itself to the diaphragm. 4. Descending external branches. — The super- ficial branches of this set are distributed to the clavicle, acromion, pectoral, and deltoid muscles and integuments; and the deep branches to muscles of the neck and scapula, one of which (the largest) is given to the serratus magnus muscle, and is the external respiratory nerve. THE BRACHIAL PLEXUS, Is formed by the union of the anterior branches of the four inferior cervical and first dorsal nerves. From this plexus proceed — TJioracic nerves; they are four or five in num- ber, and come off' from the upper part of the plexus ; they divide into anterior thoracic branches, which descend behind the clavicle, in front of the axillary artery, and supply the pec- toral muscles, and posterior thoracic branches, which pass behind the axillary vessels to the serratus magnus and rhomboid muscles. 147 2. Supra-scapular nerve passes through the notch in the scapula, and supplies the supra- spinatus, infra-spinatus, and teres muscles. 3. Subscapular nerves, are three or four in number, and descend behind the vessels to the subscapular, Jatissimus dorsi, and teres major muscles. 4. Internal cutaneous nerve, sends an external branch, which descends over the bend of the el- bow, as low as the wrist, and an internal branch which descends towards inner condyle, and sends branches to inner and posterior part of the forearm. 5. External cutaneous, musculocutaneous or perforans casserii, which sends branches to the coraco-brachialis biceps and brachiaeus anticus ; an anterior branch to the ball of the thumb and palm of the hand ; and a posterior branch to the dorsum of the hand. 6. Median nerve, or brachial nerve, sends branches to the superficial and deep pronators and flexors — the anterior interosseal nerve, which supplies the deep flexors, and sends a branch to the pronator quadratus, and another to the dorsum of the hand — a superficial branch which is given off above the wrist, and which runs to the palm of the hand, and five digital branches, which supply the thumb, index, and fore fingers, and the radial edge of the ring fin- ger. 7. Ulnar nerve, sends muscular branches to 148 triceps, flexor sublimis, and flexor lunaris mus- cles— the nervus dorsalis carpi ulnaris to the integuments on the dorsum of the hand and the three inner fingers — the superficial palmar branch which divides into three digital branches which supply the little finger and the ulnar edge of the ring finger, and the deep palmar branch to form the deep palmar arch, which supplies the interossei muscles. 8. Musculo-spiral, or radial nerve, branches to the triceps — a long cutaneous branch to the thumb— branches to the supinators and exten- sors— the anterior or radial branch which runs along the inner side of the supinator radii longus, which it supplies, and sends a branch to the integuments of the thumb, and another to the dorsum of the hand, which supplies the index and middle fingers, and communicates with the dorsalis ulnaris ; and a deep branch, or poste- rior interosseal, which supplies by superficial and deep branches the extensor muscles. 9. Circumflex, or articular nerve, sends branches to the subscapular and adjacent mus- cles, and is principally distributed to the deltoid muscle. TWELVE PAIR OF DORSAL NERVES. Posterior branches are small, and pass back- wards to the muscles and integuments of the back and loins. Anterior brandies, or Intercostals. — First M9 is the largest; it contributes to the formation of the brachial plexus. Second and third run backwards and outwards, and at the angle of the ribs pass between the intercostal muscles, and running along the lower edge of each rib, supply the surrounding muscles : opposite the axilla they send off the nerves of JVeisberg, or cutaneous nerves of the arm, and the terminal branches supply the muscles and skin upon the lateral and forepart of the thorax. Fourth to twelfth, inclusive, are similar to the second and third in distribution, supplying the intercostal and adjacent muscles ; the two last go chiefly to the diaphragm, and the 12th sends a branch to join the first lumbar, [xlll the intercostals are connected by two short branches to the ganglions of the sympathetic] FIVE PAIR OF LUMBAR NERVES. They are larger than the dorsal, and like them divide into posterior and anterior branches. Posterior branches are distributed to the lumbar muscles. Anterior branches unite in the substance of the psoas muscle, to form the lumbar plexus. LUMBAR PLEXUS. 1. External inguino- cutaneous, sends branch- es to the abdominal muscles, a cutaneous branch to the integuments on the outer part of the thigh, and the external spermatic nerve. 150 2. Middle inguino- cutaneous to the skin, on the outer part of the thigh. 3. Internal iuguino- cutaneous, sends ahranch to the spermatic chord, which accompanies the spermatic vessels, and a hranch to the integu- ments and glands of the groin. 4. Anterior crural nerve formed by the four superior nerves, passes beneath Pouparfs liga- ment, and divides into two fasciculi. The su- perior fasciculus sends four or five long branch- es, which pierce the fascia lata, and descend to the knee, some of them accompany the saphena vein ; and the deep fasciculus sends external muscular branches to the vastus internus, rec- tus, iliacus internus, and tensor vaginae femoris muscles, and internal branches to the sartorius, vastus internus, and cruraBus: branches also accompany the femoral artery, near to the knee, and the internal saphenus nerve, which joins the saphena vein at the knee, lying between the tendons of the gracilis and sartorius, goes on to the inner side of the foot,sending off nume- rous branches to the integuments. 5. Obturator nerve sends branches to the ob- turator internus, an anterior branch to the ad- ductor brevis, pectineeus, and vastus internus muscles ; and a posterior branch to the gracilis and the adductor magnus and longus muscles. 6. Lumbosacral nerve proceeds from the fourth and and fifth lumbar into the pelvis, and divides into the superior glutaeal and the com- 151 municating nerve ; the superior gluteal is dis- tributed to the gluteus medius and minimus muscles ; and the communicating branch joins the first sacral nerve. FIVE PAIR OF SACRAL NERVES. Posterior branches very small, to muscles and integuments. Anterior branches very large, particularly the three superior : these five, with the com- municating branch of the lumbo-sacral, form the sacral plexus. SACRAL PLEXUS, Sends off internal or pelvic branches, which are named haemorrhoidal, vesical, uterine and vagi- nal. External branches. 1. Lesser Sciatic nerve, sends off superfi- cial branches, these pass over the hamstring muscles, with the posterior cutaneous nerve, and are lost in these muscles ; the deep branch- es go to the quadratus femoris, the abductor muscles, and to the hip joint. 2. Inferior gluteal nerve, to the gluteus maximus, perinseum, and the inner side of the thigh. 3. Posterior cutaneous nerve, to the back part of the thigh and leg. 4. Pudic nerve, sends an inferior branch to the muscles of the perinseum and to the scro- 152 turn ; and a superior branch which passes along the dorsum of the penis to its glans. 5. Grand Sciatic nerve, or Posterior Crural, sends off several cutaneous branches to supply the hamstring, the gracilis, and the adductor muscles ; it divides at the upper and outer part of the popliteal space into two branches, viz., the peroneal nerve and the posterior tibial nerve. The peroneal nerve first sends off the external cutaneous nerves of the ]eg, which communicate with the external saphenus nerve ; it next gives off the musculo-cutaneous nerve, which divides into an internal and an external branch, the former being distributed to the in- teguments of the first and second toes, and the latter to the integuments of the third, fourth, and fifth toes; and its last branch, the anterior tibial, supplies the integuments on the anterior part of the leg and the tibialis anticus, the ex- tensor digitorum longus, the extensor pollicis, and the extensor digitorum brevis muscles, and terminates at the first interosseal space by com- municating with the plantar nerves, having first supplied the inner interosseal muscle. The posterior tibial division of the great sciatic first sends off the external saphenus nerve, which is distributed to the gastrocnemius soloeus, plan- taris and deep muscles, and small branches to the anterior and posterior tibial arteries; it finally divides into the internal and external plantar nerves ; the former sending branches to 153 the plantar muscles and skin, and four digital branches to supply the 1st, 2d, 3d toes, and in- ner side of the 4th toe, and the latter a superfi- cial branch to the little toe and outer side of the 4th toe, and a deep branch to the plantar and interossei muscles. SYMPATHETIC OR GANGLIONIC SYSTEM OF NERVES. The sympathetic nerves communicate by their superior extremities with several of the cerebral nerves by fine filaments, also with all the spinal nerves ; by one filament with each cervical, and by two filaments with each dorsal, lumbar, and sacral. THE CERVICAL GANGLIONS, Are three in number. Superior cervical ganglion extends from the first to the third cervical vertebra, and sends off, 1. Two superior branches, which ascend along with the carotid artery in the carotid canal to the cavernous sinus, where they communicate with the sixth or abducens nerve, and with the vidian nerve. 2. Descending or inferior fila- ments which join the laryngeal and pneumo- gastric nerves, the superior cardiac nerve, and the middle cervical ganglion, if it exists ; if not, they join the inferior ganglion. 3. Inter- nal branches which unite with the pharyngeal plexus. 4. External branches to join the su- perior cervical nerves. 5. Anterior branches which unite with the pneumo-gastric and facial 154 nerves, and form a plexus around the carotid artery, from which branches proceed along the external carotid and its divisions. Middle cervical ganglion is sometimes absent ; when present it sends branches to unite with the vagus and cervical nerves, and branches to join the cardiac nerves. Inferior cervical ganglion is situated be- tween the transverse process of the last cervi- cal vertebra and the neck of the first rib ; it _sends branches to the phrenic nerve, brachial plexus, subclavian artery, and its ramifications, and branches to the inferior cardiac nerve. Cardiac Nerves are three in number, and are named superior, middle, and inferior. 1. Su- perior Cardiac Nerves, arise fey two or three filaments from the superior cervical ganglion, communicate with the vagus and laryngeal nerves, and with the middle and inferior cervi- cal ganglia, pass along the coats of the arteria innominata on the right side, and between the left carotid and left subclavian on the left side to the aorta, and here communicate with the recurrent nerves, and with the middle and infe- rior cardiac nerves, and the cardiac ganglion or plexus. 2. Middle Cardiac Nerves. That of the right side is generally the largest ; on the left side it is something wanting. They enter the thorax anterior to the subclavian artery, are joined by branches from the pneumo-gas- tric and recurrent nerves, and, passing along 155 the arteria innominata, terminate in the car- diac ganglion and plexus. 3. Inferior Cardiac Branches. The right descend along the arteria innominata to the fore part of the arch of the aorta, and terminate in the anterior cardiac plexus : some branches pass between the aorta and pulmonary artery to the cardiac ganglion ; on the left these nerves accompany the subcla- vian artery, and partly join the middle cardiac nerve, and partly the cardiac plexus. Cardiac Plexus, or Cardiac Ganglion, is sit- uated behind the ascending aorta, near its ori- gin, in front of the trachea and right pulmo- nary artery ; it consists of a plexus of nerves formed by the cardiac nerves of the opposite sides and branches of the eighth pair and recur- rent. In the meshes of this plexus several small ganglions are enclosed, and to these con- jointly the term cardiac ganglion is applied. Branches proceed from this plexus to the coro- nary and pulmonary vessels, to the aorta and vena cava, and to the substance of the heart itself. Tlioracic Ganglions are twelve on each side, sometimes only eleven, the last cervical and first dorsal being united. 1. Branches to the mediastinum, which ramify on the aorta and adjacent vessels, and communicate with the pulmonary plexus. 2. Great Splanchnic Nerve is formed by distinct roots, from the 6th, 7th, 8th, 9th, and 10th ganglions,which unite on the 10th 156 dorsal vertebra into one chord, which chord en- tering the abdomen along with the aorta, or sep- arated from it by a fasciculus of the diaphragm, expands into the semilunar ganglion. 3. Les- ser Splanchnic Nerve arises by two roots from the 10th and 11th ganglions, and uniting on the side of the last dorsal vertebra, enters the abdomen through the crus of the diaphragm, and ends in the renal plexus. Semilunar Ganglia are situated on the dia- phragm, partly on the aorta, and on either side of the cceliac axis, and above and behind the supra-renal capsule. They are the largest ganglia of the sympathetic ; several nervous filaments, on which small ganglia are placed, pass from one to the other surrounding the cce- liac axis, forming a plexus, called the Solar Plexus, which is situated behind the stomach, above the pancreas, and in front of the aorta. 1. Branches in various directions, accompanying the blood-vessels, forming plex- uses around each, and named accordingly, as hepatic, splenic, and gastric, and these commu- nicate with the eighth pair. 2. Branches de- scending in front of the aorta, which subdivide at the renal and mesenteric arteries, accompa- nying them, and forming plexuses, named ac- cordingly, viz : renal, superior, and inferior mesenteric, and into each of these branches the lumbar ganglions enter. Renal Plexus receives the lesser splanchnic 157 nerves ; from it descends 1. Spermatic Plexus, which goes to the testicle in the male, and to the ovarium and uterus in the female. Inferior Mesenteric Plexus sends branches which descend to the brim of the pelvis, unite with others from the lumbar ganglions, and form a plexus around the internal iliac artery and its branches, named hypogastric plexus. It is joined by numerous filaments from the lumbar and sacral ganglions of the sympathetic, and communicates with the pelvic branches of the sacral plexus. Lumbar Ganglions are five on each side, sometimes only three or four. 1. Branches to anterior branches of lumbar spinal nerves. 2. Branches to assist in forming the several ab- dominal plexuses. Sacral Ganglions are three or four in num- ber. 1. Branches to sacral nerves. 2. Fila- ments to hypogastric and pelvic plexuses. 3. A small branch from the last ganglion, which passes in front of the coccyx, there forming with its fellow the Ganglion Impar, which sends branches to the coccygseus, levator, and sphincter ani mus- cles. THE THOHAX AND ITS CONTENTS. The thorax is bounded anteriorly by the ster- num and cartilages of the ribs, posteriorly by the vertebras and lesser circle of the ribs, and on either 158 side by the shafts of the ribs and the intercos- tal muscles. Its upper orifice is transversely oval, and allows the exit and entrance of ves- sels, nerves, and muscles to and from its cavity ; its inferior orifice, or circumference, being much larger, and closed by the diaphragm. The thorax contains the heart and lungs, and also several vessels, nerves, glands, &c, to be noticed as we proceed. THE PLEURiE Are two serous membranes, one on either side, which cover the inner surface of the tho- rax, and are reflected upon the outer surfaces of the parts contained in its cavity. That portion of the pleura which lines the thorax, is called the parietal layer, and that which lines the contained parts the visceral layer. Each pleura can be traced in the following manner : — From the posterior surface of the sternum it passses backwards until it meets with the anterior sur- face of the pericardium, along the side of which it passes to the anterior surface of the root of the lung ; from this it passes upon the lung, and is reflected over the entire surface of the organ, until it arrives at the posterior surface of its root and of the pericardium, from whence it passes upon the sides of the bodies of the ver- tebrae, reaching as high as the transverse pro- cess of the sixth cervical vertebra on the right side, the seventh on the left, and descending to 159 the diaphragm ; the thoracic aspect of which it covers ; it finally lines the ribs and intercostal muscles, until it arrives at the portion which was opened, and which corresponds to the pos- terior aspect of the sternum. Ligamentum latum -pulmonis (one on either side) is merely a triangular fold of pleura, formed by the reflection of the membrane from the lower edge of the root of the lung upon the diaphragm. ANTERIOR MEDIASTINUM. A triangular cavity formed by tearing through the cellular tissue, which connects the right and left pleura behind the sternum ; the base is formed by the sternum, the sides by the separated pleura, and the apex corresponds to the anterior surface of the pericardium, where the pleurse separate to enclose this bag. Thus formed, it contains the origins of the sterno- hyoid and sterno-thyroid muscles, branches of the descendens noni nerve, the remains of the thymus gland, lymphatic glands and absorb- ents, the mammary vessels, the triangulares sterni muscles, and loose cellular tissue. MIDDLE MEDIASTINUM. Is of an oval shape, and is . formed by the re- flection of the pleurae upon the sides of the pericardium ; it consequently contains this bag and its contents. 160 POSTERIOR MEDIASTINUM. Is formed by the reflection of the pleurae upon the sides of the bodies of the vertebras ; it is of a triangular form, the apex anterior corre- sponding to the posterior surface of the peri- cardium, the sides formed by the pleura, and the base represented by the anterior surfaces of the bodies of the vertebras ; it extends from the third to the tenth dorsal vertebra, and con- tains the following parts : — the bifurcation of the trachea, the oesophagus and pneumo-gastric nerves, the thoracic duct, the vena azygos, the thoracic aorta, the splanchnic nerves, lympha- tic glands, absorbents and loose cellular tissue. THE LUNGS Are two soft, spongy, vascular bodies, one contained on each side of the cavity of the chest. Each lung resembles a cone, with that side corresponding to the median line trun- cated ; the base concave corresponds to the diaphragm, the obtuse rounded apex rises in the neck, a little above the level of the first rib ; the external convex surface corresponds to the internal concave surface of the thoracic parietes, and the flat or truncated surface cor- responds to the mediastina. The posterior edge of the lung is thick and rounded, whilst the anterior is thin and irregular. Each lung is distinguished into lobes, which are separated 161 from each other by fissures ; a little above the centre of each is the root formed by. the pul- monary vessels and bronchial tube, connected to each other by cellular tissue, and invested by the pleura. The bronchial tube is situated posterior and superior to the pulmonary vessels ; the two pulmonary veins are placed anterior and inferior to the artery and bronchus, and the pulmonary artery is placed between the bronchus and the pulmonary veins, but behind the pulmonary veins and before the bronchus. The root of each lung has anterior to it the phrenic nerve and filaments of the pneumo- gastric nerve, posterior to it the pulmonic plexus, and inferior the ligamentum latum. The root of the right lung has the vena azygos arching over it. The right and left lungs differ from each other in some important particulars : the right lung is broader and shorter than the left, and consists of three lobes, separated by two fis- sures ; the right also ascends higher in the neck, and the anterior edge of the left presents a notch where it corresponds to the apex of the heart. The intimate structure of the lungs consists of the ultimate ramifications of the bronchial tubes, which are the continuations of the trachea, and the branches of the pulmonary artery and veins ; they also receive bronchial arteries for their nutrition. 11 162 TRACHEA AND ITS RAMIFICATIONS. The wind-pipe, or trachea, is a cylindrical tube, extending from the crycoid cartilage of the larynx to the level of the third dorsal ver- tebra. It consists of from seventeen to twenty fibro-cartilaginous rings, truncated behind, and connected to each other by an elastic membrane ; about the posterior fourth of each ring is de- ficient, and its place is supplied by fibrous membrane. Opposite the third dorsal vertebra the trachea divides into the right and left bronchial tubes ; the right bronchus is larger than the left, and runs transversely into the root of the lung and divides into three branches; the left bronchus passes through the arch of the aorta to the root of the left lung, and divides into two branches. The bronchi consist of cartilaginous rings, but as these tubes advance into the substance of the lung they diminish in size and firmness, until their place is supplied by fibrous tissue, or transverse circular fibres, which tissue also disappears, and at length nothing remains but the mucous membrane, which terminates in the air-cells, upon which ramify the ultimate rami- fications of the pulmonary artery and the com- mencing radicles of the pulmonary veins. The ramifications of the pulmonary artery communicate with those of the pulmonary veins, beneath the mucous membrane of the 163 air-cells, and are enveloped in fine cellular tissue ; and except this cellular tissue the lung has no proper parenchyma, its structure being entirely filaments-vascular. The lungs are supplied with blood by the bronchial arteries, derived from the thoracic aorta ; these vessels run along the bronchial tubes, subdivide as they proceed, and form a minute net- work on the attached surface of the bronchial mucous membrane ; the blood they convey to the lungs is returned to the vena azygos, or superior cava. The nerves distributed to the lungs are derived from the eighth pair, and a few filaments from the sympathetic. HEART AND PERICARDIUM. Tlie pericardium consists of two layers, an outer or proper fibrous layer and an internal or serous layer. It is of a conical form, the base below connected to the central di- vision of the cordiform tendon of the dia- phragm ; the apex above corresponding to the great vessels at the base of the heart, along the outer coats of which the fibrous layer is gradually lost ; it is connected laterally to the pleura and to the pulmonary vessels, and the phrenic nerves, one on each side, run in close contact with it to the diaphragm. Upon laying open the pericardium, the cavity of the serous layer is exposed, and, like all serous mem- branes, consists of two portions — a parietal 164 layer, which lines the inner surface of the fibrous pericardium, and a visceral layer which lines the outer surfaces of the heart and great vessels. Covered by the serous membrane, when the pericardium is fully opened, we bring into view the right auricle, the venae cavse, the left auricular appendix, the right ventricle, the tip of the left ventricle, which forms the apex of the heart, the aorta, the pulmonary artery and the anterior branches of the coronary vessels, with the ramifications of the cardiac nerves. Upon turning up the heart its posterior surface will be brought into view, presenting the left auricle, proceeding to which, on either side, are the pulmonary veins, and the left ventricle. The serous membrane may be traced in the following manner : — after having lined the fibrous pericardium it is reflected on the supe- rior cava, and the aorta, and the pulmonary ar- tery, as these vessels are passing through the fibrous membrane, ascending highest, however, upon the aorta ; inferiorly it is partly reflected around the inferior cava, as this vessel pierces the fibrous pericardium to enter the right auricle, and laterally it is reflected upon the pulmonary veins as these vessels pierce the fibrous pericardium to enter the left auricle ; from these different points it reaches the sur- face of the heart, which it completely covers. The heart, of a conical shape, is situate obliquely between the lungs, its base being 165 superior, posterior, and to the right side, its apex pointing towards the cartilage of the sixth rib of the left side. The axis ot the heart is obliquely from right to left, and from behind forwards. It is retained in its situation by the great vessels and the reflections of the serous membrane. The heart consists of four cavities, two au- ricles and two ventricles ; the auricles are separated from each other by a partition, called septum auricularum, the ventricles by the sep- tum ventriculorum. We shall examine these cavities in the order of the circulation. The right auricle is placed between the two venae cavae, the blood conveyed by which it re- ceives and transmits to the right ventricle ; the small loose portion is called the auricular ap- pendix, and the portion between the cavae the sinus of the auricle. Upon laying open this auricle, by a perpendicular cut from the supe- rior cava to within a few lines of the entrance of the inferior cava, and by a second cut from the centre of this, at right angles towards the auricular appendix, the following parts present themselves. Tuberculum Loweri, an eminence upon the under surface of the sinus of the auricle and placed between the orifices of entrance or the venae cavae. Septum auricularum, a membrano -muscular partition separating this auricle from the left. 166 Fossa Ovalis, an oval depression in the sep- tum which marks the situation of the foramen ovale, or the oval communication which existed between both auricles in the foetus. The edges of this fossa present a thickened margin, the anterior part of which is named the left or an- terior limbus of the fossa ovalis, and the poste- rior, the right or posterior limbus. This fossa and its limbi exist in the right aspect of the sep- tum on account of the valve in the fcetus, which is destined to close the opening between the two auricles when the pulmonic circulation is estab- lished, being situated in the left auricle and be- ing applied to the foramen on its left aspect. We accordingly find the left aspect of the sep- tum auricularum perfectly smooth. Valvula Nobilis or Eustachian valve, a semilu- nar fold of the lining membrane attached by one cornu to the anterior limbus of the fossa ovalis, and continued around the anterior aspect of the inferior vena cava, to reach the posterior limbus of the fossa ovalis, to which it is attached by its inferior cornu. Musculi Pectinanti, the muscular bands situ- ated in the auricular appendix. Openings of the Yen& Cava. The superior cava opens at the upper and back part of the auricle, its direction being downwards, forwards, and inwards ; the inferior cava opens beneath, in a direction upwards, backwards, and inwards. Opening of the Coronary Vein is situated t 1(37 between the Eustachian valve and the right ventricle, and is guarded by a semilunar valve (the valve of the coronary vein.) Opening of the Auricular Appendix, is small and circular, and exists where this portion of the auricle joins the sinus. Foramina Thesebii, small orifices on different parts of the auricle, supposed to be the openings of veins. Right Auriculo-ventricular opening, the large opening by which the auricle communicates with the ventricle, the boundaries of each cav- ity being marked by a white line. Right ventricle, of a conical form, is joined by its basis to the right auricle, its apex being above the apex of the heart, in consequence of the apex of this organ being formed by the left ventricle. Septum ventriculorum, a thick muscular parti- tion which separates one ventricle^ from the other. Carnoe. Columna, the muscular projections in the interior of the ventricle, which give it its irregular appearance. Chorda tendinecB, the delicate but strong tendinous cords which are connected by one extremity to the carneae columns, and by the other to the tricuspid valve. Tricuspid valve, three triangular dupli- eatures of the lining membrane of the heart, strengthened by the chordae tendineae which 168 pass from their apices to their bases. These triangular valves are attached by their bases to the right auriculo- ventricular opening, and by their apices to the chordae tendinese, and pre- vent the regurgitation of the blood from the ventricle into the auricle by closing the open- ing of communication between both cavities when the ventricle contracts. Orifice of the Pulmonary Artery is situa- ted at the left extremity of the base of the ven- tricle, close to the right auriculo-ventricular opening, which is situated inferior, posterior and to its right, and separated from the mouth of the artery by the largest triangular division of the tricuspid valve. Pars Planum is a name given to that smooth portion of the ventricle, which leads to the mouth of the pulmonary artery. Pulmonic Semilunar Valves extend from the line of junction of the pulmonary artery and right ventricle into the cavity of the former. I hese three valves are duplicatures of the lin- ing membrane, and are attached by their con- vex edges to the roots of the pulmonary artery ; their free concave margins presenting in their centre a small tubercle, called corpus sesamoi- deum. These valves, when the blood passes from this ventricle into the pulmonary artery, are thrown down, and thus, by closing the opening, prevent a reflux of the blood back again into the ventricle. 169 Left Auricle is placed at the upper and back part of the heart, and is of a quadrilateral form. It is smaller than the right auricle, and receives, at its four angles, the opening of the pulmo- nary veins ; its parietes are much thicker than the right ; its auricular appendix smaller, hut the musculi pectinati are the stronger; with the exception of the auricular appendix its inner surface is smooth, and it communicates with its corresponding ventricle by the left auriculo- ventricular opening, which is situated inferior to the opening of the auricular appendix, and marked by a whitish line. The septum auri- cularum presents towards this auricle asmooth aspect, from circumstances already explained. Left Ventricle is longer, stronger, and small- er than the right; from its greater length it forms the apex of the heart ; from its greater strength it is of power sufficient to propel the arterial blood through the aorta and its ramifi- cations. We consequently find the carness columnar, the chordae tendinese, the bicuspid, or mitral valve, the parietes of the cavity, the aorta, which arises from it, and the semilunar valves, with their corpora sesamoidea, which guard the opening of this vessel, much stronger than in the right division of the heart. The left auriculo -ventricular opening, and the mouth of the aorta, are situated at the base of this cavity, and are close to each other, the aortic opening being anterior, and both being J 170 separated, as in the right ventricle, by the larger division of the bicuspid valve. With the exception of the peculiarities just mentioned, the left auricle and ventricle are, in their ana- tomical configuration, similar to the right, and the several valves, muscular eminences, ten- dons, cords, &c. serve similar purposes. ARTERIES. THE AORTA » Is divided into three portions, viz., the arch of the aorta, the thoracic aorta, and the abdominal aorta. THE ARCH OF THE AORTA Sends off five branches. A. Arteria coronaria dextra, which sends a branch to the right auricle, a branch to the an- terior part of the right ventricle, and a branch to the posterior part of the right ventricle. B. Arteria coronaria sinistra, which sends a branch to the left auricle and a branch to the left ventricle. C. Arteria innominata, which divides into the right carotid and right subclavian arteries. D. Left carotid artery. E. Left subclavian artery. THE COMMON CAROTIDS Divide into two branches. A, External carotid artery. B. Internal carotid artery. 171 THE EXTERNAL CAROTID sends off ten branches, viz. — A. Superior thyroid, which sends off 1st, a hyoidean branch ; 2d, a superficial branch ; 3d, a laryngeal branch ; and 4th, a thyroidean branch. B. Lingual, which sends off, 1st, a hyoidean branch; 2d, the dorsalis linguae artery; 3d, the sublingual artery ; and 4th, the ranine ar- tery. C. Facial, which . sends off, 1st, the inferior palatine; 2d, the tonsillar; 3d, the glandular; 4th, the submental ; 5th, the inferior labial ; 6th, the inferior coronary ; 7th, masseteric ; 8th, su- perior coronary; 9th, the lateral nasal; and 10th, the angular. D. Muscular. E. Occipital, which gives off the cervicalis descendens, the inferior meningeal, and the su- perficial. F. Posterior auris, which gives off' the mus- cular, the glandular, and the stylo -mastoid. G. Ascending pharyngeal, which gives off the pharyngeal branches, and the meningeal branches. H. Transverse facial. I. Superficial temporal, which gives off, 1st, the anterior auris ; 2d, the capsular branches ; 3d, the middle temporal; 4th, the posterior temporal; and 5th, the anterior temporal. 172 K. Internal maxillary, which gives off 1st. the meningea media ; 2d, the inferior maxilla- ry ; 3d, the pterygoid ; 4th, the deep temporal ; 5th, the masseteric; 6th, the huccal ; 7th, the dental ; 8th, the infra-orbital ; 9th, the descend- ing palatine ; and 10th, the nasal. THE INTERNAL CAROTID sends off five branches. A. Arteries tympani. B. Arteries receptaculi. C. Ophthalmic artery, which sends off, 1st, the lachrymal; 2d, the centralis retinae; 3d, the supra-orbital ; 4th, the ciliary branches ; 5th, the muscular ; 6th, the posterior ethmoi- dal ; 7th, the anterior ethmoidal ; 8th, the pal- pebral ; 9th, the nasal; and 10th, the frontal. D. Posterior communicating artery. E. Anterior cerebral, which sends off, 1st, the anterior communicans; 2d, the arteria corporis callosi ; and 3d, the middle cerebral, which furnishes the arteria choroidea. THE SUBCLAVIAN ARTERY sends of five branches. A. Vertebral, which gives off, 1st, the arte- rial medullas spinalis transversa^; 2d, the menin- geal ; 3d, the inferior cerebellar ; 4th, the ar- teria medullas spinalis ; and 5th, the arteria basilaris : from this artery arises the superior 173 cerebellar artery, and the posterior cerebral, two in number. B. Internal mammary, which gives off, 1st, the anterior intercostal ; 2d, the mediastinal ; 3d, the comes neivi phrenici; 4th, the musculo- phrenic ; and 5th, the superior epigastric. C. Thyroid axis, which gives off, 1st, the in- ferior thyroid ; 2d, the cervicalis ascendens ; 3d, the supra-scapular; from which arises the superior acromial, the supra-spinal, and the in- fra-spinal ; 4th, the posterior scapularis, which gives off the glandular, the superficial cervical, and the posterior scapular. D. Cervicalis profunda. E. Superior intercostal. THE AXILLARY ARTERY. sends off seven branches. A. Acromial thoracic. B. Thoracica suprema. C. Thoracica alaris. D. External mammary. E. Subscapular, which sends off an anterior and a posterior branch. F. Posterior circumflex. G. Anterior circumflex. THE BRACHIAL ARTEEY sends off four branches. A. Profunda superior, which sends off, 1st, 174 an ascending branch; and 2d, the musculo- spiral branch. B. Nutritia humeri. C. Profunda inferior. J). Anastomatica magna. THE RADIAL ARTERY sends off ten branches. A. Recurrent radial. B. Mascular. C. Superficialis voice. D. Anterior carpi radialis. E. Dorsalis carpi radialis. F. Dorsalis pollicis. G. Dorsalis indicis. H. Princeps pollicis. I. Radialis indicis. K. Palmaris profunda. THE ULNAR ARTERY sends off eight branches. A. Anterior recurrent. B. Posterior recurrent. C. Interosseous, which sends off, 1st, the an- terior recurrent; 2d, the anterior interosseous; 3rd, the posterior interosseous ; 4th, the poste- rior recurrent ; and 5th, the posterior descend- ing branch. D. Muscular. E. Carpi idnaris anterior. F. TJlnaris posterior. 175 G. Arteria communicans. H. Palmaris super jicialis. PALMAR ARCHES. The deep palmar arch is formed by the pal- maris profunda of the radial, uniting with the arteria communicans from the ulnar; it sends off five small branches to supply the interossei muscles. THE SUPERFICIAL PALMAR ARCH is formed by the arteria palmaris of the ulnar 3 uniting with the superficialis volae from the ra- dial. It sends off four branches. A. Branches to ulnar edge of little finger. JS. Branch to cleft between little and ring fin- gers. C. Branch to cleft between ring and middle fingers. D. Branch to cleft between middle and index fingers. THE THORACIC AORTA sends off five sets of branches. A. Pericardiac. B. Mediastinal. C. Bronchial. D. (Esophageal. E. Intercostals, each divides into, 1st, the pos- terior branches ; and 2d, the anterior branches, 176 THE AORTA ABDOMINALIS sends off the following branches: — A. The two phrenic arteries. B. The caliac axis. From this axis arise — 1st, the superior gastric artery, which divides into a superior and an inferior branch ; 2d, the hepatic artery, which gives off the superior pyloric artery, the gastro-duodenal artery, which divides into the arteria pancreatica duo- denalis, and the arteria gastro-epiploica dextra. The hepatic artery then divides into the left he- patic and right hepatic arteries, from the last of which proceeds a small branch to the gall-blad- der, called arteria cystica ; 3d, the splenic ar- tery, which sends off the pancreaticae parvse, the pancreatica magna, the vasa brevia, splenic branches, and the gastro-epiploica sinistra. C. The superior mesenteric artery, which gives off, 1st, the colica dextra, which divides into a superior and an inferior branch ; 2d, the colica media, which divides into a right and left branch ; 3d, the ileo- colica, which divides into a superior branch, a middle branch, and an inferior branch, and, lastly, the mesenteric branches, from fifteen to twenty in number. D. Two capsular. E. Two renal. F. Two spermatic. G. Inferior mesenteric, which sends off, 1 st, the colica sinistra, which divides into an ascend- 177 ing branch and a descending branch ; 2d, the sigmoid artery, and 3d, the superior hemorrhoi- dal artery. H. Ureteric arteries. I. Lumbar arteries. K . Sacra media. THE COMMON ILIAC ARTERIES divide into two branches, viz : The internal and External iliac arteries. THE INTERNAL ILIAC ARTERY sends off eleven branches in the female. A. Arteria ilio-lumbalis, which sends off, 1st, ascending branches; 2d, external branches; and 3d, descending branches. B. Lateral sacral. C. Middle hemorrhoidal. D. Vesical. E. Urobilical, F. Uterine. G. Vaginal. H. Obturator, which sends off, 1st, the branches within the pelvis ; and 2d, branches without the pelvis. I. Gluteal, which sends off, 1st, a superficial branch ; and 2d, a deep branch. K. Ischiatic, which sends off, 1st, the coccy- geal branch ; 2d, the arteria comes nervi ischiatici ; and 3d, the muscular branches. L. Pudic, which sends off, 1st, the external 12 178 hemorrhoidal arteries; 2d, the perinseal ; 3d, the transversalis perinei ; 4th, the arteria cor- poris tmlbosi, which gives a branch to Cowper's gland, and a branch to the corpus spongiosum ; 5th, the arteria corporis cavernosi penis ; and 6th, arteria dorsalis penis. THE EXTERNAL ILIAC sends off two branches. A. Epigastric, which sends off, 1st, the spermatic artery ; and 2d, the muscular artery. B. Circumflexa ilii. THE FEMORAL ARTERY sends off the following branches. A. Superficial epigastric. B. Pudendce super jicialis. C. Circumflexa ilii superficialis.. D. Profunda femoris, which sends off, 1st, the circumflexa externa, from which arise the ascending branches, the circumflex branches, and descending branches ; 2d, the circumflexa interna, from which arise arterial branches to the muscles of the hip joint, and a branch to the interior of the hip joint ; 3d, the arteria perf orans prima ; 4th, the peri'orans secunda ; 5th, the perforans tertia. E. Anastomotica magna,. THE POPLITEAL ARTERY sends off seven branches. 179 A. Superior muscular. A. Articularis superior externa, which sends off a superficial branch, and a deep branch. C. Articularis superior interna, which sends off a superficial branch, and a deep branch. D. Azygos branch. E. Articularis inferior externa. F. Articularis inferior interna. G. Inferior muscular. THE TIBIALIS POSTICA sends off A. Muscular. B. Peroneal, which sends off, 1st, the nutri* tia fibulae ; 2d, the muscular ; 3d, the anterior peroneal ; and 4th, the posterior peronseal. C. Nutritia tibice. D. Internal plantar. E. External plantar. THE TIBIALIS ANTICA sends off the following branches, A. Muscular. B. Recurrent. C. Internal malleolar. D. External malleolar. E. Tarsal branch. F. Metatarsal branches. G. Arteria pollicis. H. Arteria communicans, 180 THE PLANTAR ARCH is formed by the external plantar artery uniting with the arteria communicans of the anterior tibial : it sends off two sets of branches. A. Arteria perforantes. B. Arteria digitales, THE PULMONARY ARTERY divides into two branches. A. Right pulmonary. JB. Left pulmonary. VEINS. The veins are not so uniform in their distri- bution as the arteries. Besides the numerous superficial veins which ramify on the skin, one or two are found to accompany each artery. In the extremities there are generally two to each artery, and in these situations they receive the name of vena comites. When, however, an artery is of great size, as the femoral or the axillary, it is accompanied but by one vein, which receives the same name as the artery. VEINS OF THE HEAD AND NECK. The Parietal and Temporal veins unite behind the angle of the jaw, and here receive the internal maxillary vein ; by their union is formed the 181 External jugular vein. This vessel descends obliquely backwards, and joins the subclavian vein. A little after its formation it receives the trunk of the facial vein, and in its course down the neck it receives several superficial veins. Internal jugular vein commences at the ter- mination of the lateral sinus, descends along the outer side of the common carotid artery, and joins the subclavian vein at the sternal ex- tremity of the clavicle. It receives the laryn- geal and some muscular veins. VEINS OF THE SUPERIOR EXTREMITY. The Cephalic vein is formed by the union of several veins from the back of the hand. It ascends along the radial side of the extremity, and terminates in the axillary vein. The Basilic vein commences by a small vein from the little finger (vena salvatella) as- cends along the inner side of the extremity, and terminates in the axilliary vein, or joins one of the venae comites, which accompany the brachial artery. TJie Median vein commences at the fore-part of the wrist and hand, ascends along the ante- rior aspect of the forearm, and at the elbow ter- minates, by dividing into two branches. One of these joins the basilic vein, and is named the median basilic; the other joins the cephalic vein, and is named median cephalic. The Axillary vein, formed by the union of 182 the veins just described, and by the brachial vena comites, ascends in front of the axillary artery, receiving the thoracic veins, and passes beneath the clavicle, where it terminates in the subclavian vein. The Subclavian vein passes inwards over the anterior scalenus muscle, receives numerous veins from the neck and shoulder; also the external jugular and vertebral veins, and joins the internal jugular vein behind the sternal extremi- ty of the clavicle. Vena innominata, formed by the union of the internal jugular and subclavian veins, on the right side is very short and descends into the thorax ; the left vena innominata, which is much longer, enters the thorax in a transverse direction in front of the trachea, to join the right vein, and in its course it receives the thyroid veins and veins from the anterior mediastinum. By the union of the venae innominatee is formed the Vena cava superior, which descends in front of the right pulmonary vessels, enters the peri- cardium, and opens into the right auricle. VENA AZYGOS commences on the first lumbar vertebra by one or two small veins, gains the posterior medias- tinum, by passing through the aortic opening of the diaphragm, ascends along the right side of the bodies of the dorsal vertebras, curves for- 183 wards over the root of the right lung, and ter- minates at the posterior aspect of the superior vena cava, as this vessel is entering the peri- cardium. In its course it receives the intercostal veins of each side, and the oesophageal veins. VEINS OF THE INFERIOR EXTREMITY. Internal saphena vein commences at the inner part of the foot, ascends along the inner side of the leg and knee, behind the inner condyle, becomes more anterior upon the thigh, and reaching to within about two inches of Pou- part's ligament, passes through the saphenic opening of the fascia lata, and joins the femoral vein. External saphena, vein commences at the outer part of the foot, ascends along the back part o£ the leg and ham, and joins the popliteal vein. Both these veins are superficial, and in their course receive several veins from the integu- ments. Deep veins of the leg? two veins (venas coml- tes) accompany each artery in the leg, and ter- minate in the following — Popliteal vein, this vessel accompanies the artery of the same name, and having received the external saphena vein, and the veins of the knee, terminates in the femoral vein. Femoral vein accompanies the femoral ar- tery, and having received the profunda vein, the internal saphena vein, and a few muscular 184 veins, passes beneath the crural arch and ends in the external iliac vein. External Iliac vein accompanies the external iliac artery. Internal Iliac vein is formed by the union of the veins which accompany the internal iliac artery and join the external iliac vein at the sacro-iliac symphysis. Common Iliac vein, formed by the union of the internal and external iliac veins, joins its fellow at the right side of the body of the fourth lumbar vertebra to form the inferior vena cava. Inferior vena cava ascends along the right side of the bodies of the lumbar vertebrse, be- hind the liver, and passes through the quadri- lateral opening in the diaphragm, and opens into the right auricle at its lower and back part. It receives the middle sacral, one and sometimes both spermatic veins, the emulgent and capsu- lar veins, the venae cavse hepaticse, and the phrenic veins. VENA PORTiE commences on the back of the rectum by one of the hcemorrhoidal veins, ascends towards the meso-colon and unites with the inferior mesen- teric vein ; this trunk next unites with the supe- rior mesenteric vein, and behind the pancreas it unites with the great splenic vein and receives veins from the stomach, duodenum and pan- creas. The vena portse thus formed ascends 185 to the right side, enclosed in the capsule of Glisson, and reaches the transverse fissure of the liver, where it divides into two branches ; these enter the liver, ramify through its sub- stance like an artery, and its blood is returned to the inferior vena cava by the venae cavas hepaticEe, which are three or four in number, and open into the cava as this vessel is entering its opening in the diaphragm. THE DIGESTIVE APPARATUS. THE MOUTH. This cavity is bounded superiorly by the hard and soft palate, inferiorly by the tongue and the reflections of mucous membrane from it to the gums, and laterally by the cheeks. Its anterior opening, which forms the com- mencement of the digestive canal, corresponds to the lips ; and posteriorly it communicates with the pharynx through the opening called isthmus faucium, the boundaries of which are the soft palate and uvula superiorly, the tongue inferiorly, and the pillars of the palate and ton- sils laterally. Within the mouth we observe the opening of the three salivary glands and follicles, and the teeth of either side. The pa- rotid gland opens by a single orifice opposite the second superior molar tooth ; the sub-max- illary gland of either side, by a single orifice at the anterior part of the tongue, by the side of 186 the reflection of mucous membrane called fre- num linguae, and the third salivary gland or sublingual by several small orifices (eight or ten) on either side of the tongue. THE TEETH. The number of teeth in the adult is thirty- two, sixteen in each jaw; and to distinguish them from the teeth of the child they are called permanent. They are divided into eight in- cisors, four canine, eight bicuspids, and twelve multicuspids or molars. The last four molars do not appear until late in life, and hence have been called the wisdom teeth. They are, how- ever, sometimes wanting. In the child the number of teeth is only twenty, and are called milk, deciduous, or temporary teeth. They are divided into eight incisors, four canine, and eight molars. THE PHARYNX Is a musculo-membranous bag of a conical shape extending by its base from the posterior part of the mylo-hyoid ridge and base of the skull, to the posterior aspect of the cricoid cartilage, where it terminates in the oesophagus. It is connected by its posterior wall to the vertebra by loose cellular tissue, and interiorly it coresponds to the mouth and larynx. On laying open the cavity of the pharynx by 187 a perpendicular incision along its posterior median line, the internal mucous lining of the bag will be exposed, and the following open- ings, viz : superiorly, one on either side of the medial line, the openings of the posterior nares ; more externally, one on either side the open- ings of the Eustachian tubes; inferior to these is the opening of the mouth into the pharynx, or the isthmus faucium ; posterior and inferior to the tongue is the glottis, and lastly the opening of the pharynx into the oesophagus. THE OESOPHAGUS Extends from the termination of the pharynx to the stomach : it is placed, above, between the vertebrae and the trachea, inclines at the inferior part of that tube to the left side, and passes behind its left bifurcation to reach the posterior mediastinum. In the mediastinum it descends forwards, passes through the oval aperture of the diaphragm, and terminates in the stomach. The mucous membrane of the mouth, pharynx and oesophagus is covered by epidermis. THE STOMACH. A large pyriform musculo-membranous bag, situate in the epigastric and left hypochondriac regions, communicating at one extremity with the oesophagus, and at the other with the duodenum. 188 Connections. — Its large extremity, or fundus, to the spleen by the gastro-splenic omentum ; its upper concave, small edge to the liver by the gastro-hepatic omentum ; and its lower, convex large edge to the colon by the gastro- colic omentum. Its cesophagus, or cardiac orifice, situated between the fundus and lesser curve, connects it to the diaphragm, and its pyloric orifice to the duodenum. The su- perior anterior surface of the stomach looks to- wards the diaphragm, ribs, and left lobe of the liver ; the posterior inferior surface towards the meso-colon. The stomach is composed of three tunics, connected by cellular tissue, an external peri- toneal coat, and internal mucous coat, and be- tween both the muscular coat. The muscular fibres of the stomach observe three directions ; the longitudinal are seen along the edges or curves, the oblique on the fundus, and the circular are well developed at the centre of the organ, and at its pyloric orifice. The mucous coat presents minute piles (villi), it is thrown into wrinkles (ruga), or folds (plica), which in- tersect each other, enclosing irregular quadri- lateral spaces. Numerous mucous glands are found along the curves, and at the pylorus; in the fundus small glands exist, which have been supposed to secrete the gastric juice. At the pyloric orifice the mucous membrane is thrown into a circular fold, which forms an imperfect 189 valve between the stomach and duodenum ; and at the (esophageal opening the epidermic lining is observed to terminate in a fringed edge. SMALL INTESTINES, Are divided into duodenum, jejunum and ileum. Duodenum, the shortest portion of the small intestines, forms a curve in the concavity of which is situated the head of the pancreas ; it is divided into a superior transverse portion, a middle perpendicular portion, and an inferior transverse portion. The superior part is covered by peritoneum on both its surfaces, and on this account is more moveable than the perpendicular or inferior portions, which are only covered on their anterior surface by this membrane. Besides the numerous mucous glands called Brunnefs glands, which open on its interior sur- face, the apertures of the pancreatic duct, and of the common biliary duct enter at its perpendicular division. This intestine differs not only in these particulars from the rest of the small intestines, but also in being much larger, more dilatable, more fixed to its position, in having a greater number of valvulae conniventes (or circular folds of the mucous membrane), and in its muscular fibres being much stronger. The duodenum has also been called venlri- culus succenturiatus. 190 Jejunum and Ileum form the longest part of the intestinal tube, being in general from 28 to 30 feet in length ; the upper two-fifths are given to the jejunum, and the remainder to the ileum, but there is no anatomical foundation for this arbitrary boundary, as the intestines run into each other insensibly, and from the duo* denum the remainder of the small intestinal tube gradually diminishes in thickness, has fewer valvulae conniventes and exhibits less vascularity ; so much so that the termination of the ileum is much thinner and paler than the upper part of the jejunum, and it is in these situations only that the differences between both are marked and striking. The mucous membrane of the small intestine is studded with glands of two orders, viz : the glandulce solitaries and the glandules agminatce or Peijefs glands. The solitariae are disseminated like granules over the mucous membrane, and the agminatas are placed in oval clusters. The fibres of the muscular coat of the small intes- tines take a circular and longitudinal direction the latter being placed externally. LARGE INTESTINE, divided into the ccecum, colon, and rectum, forms about one-fifth of the intestinal canal. It differs from the small intestine in its great size, in being sacculated, in having small processes along its entire course called appendices epu 191 ploicce, in presenting three well defined longi- tudinal bands, and in being thinner. It is com- posed of an external serous coat, an internal mucous coat, and between both, a muscular coat. The fibres of the musclar coat take a circular direction, and some have contended, that the longitudinal bands are also muscular ; but, in addition to their anatomical structure, the use these bands serve in throwing the in- testine into a permanent sacculated condition renders it very probable they are of an aponeu* rotic nature. Ccecum or caput coli, placed in the right iliac fossa and connected to the iliac and psoas muscles, is fixed in its situation by the peri- toneum, which only covers it anteriorly and somewhat laterally; it receives at its inner side the ileum, which terminates in its cavity by a slit-like opening, and which is guarded by two valves; these, in health, allow the transit of alimentary and excremental matter from the ileum to the colon, but not in the con- verse direction. The inferior valve or ileo* ccacal is the larger and placed obliquely ; the superior or ileo-colic is smaller and rather hori- zontal ; both are united at their extremities, forming the commissures, from each of which proceeds a permanent fold of mucous mem- brane called retinaculum. The appendix ver- miformis is a small diverticulum which pro- ceeds from the posterior part of the ccecum, it 192 is the size of a goose-quill in diameter, and from three to five inches in length, its orifice of entrance into the ccBCum is guarded by a small valve, and is thrown into irregular sacculi by the three longitudinal bands. Tlie colon extends from the ccecum to the rectum, and is divided into four portions, viz : the right or ascending colon, the middle or transverse, the left or descending, and the sig- moid flexure. Tlie rectum extends from the sigmoid flexure of the colon to the anus ; its upper third is covered by peritoneum, its middle third is only covered by this membrane upon its anterior aspect and sides, and its inferior third has no peritoneal covering. In the male subject the anteroinferior aspect of the rectum is con- nected to the inferior fundus of the bladder, the vesiculse seminales, and the prostate gland, and in the female to the uterus and vagina. The rectum has no longitudinal bands and is not sacculated like the other parts of the large intestine. SALIVARY GLANDS are three in number, viz : the Parotid, the Sub- maxillary, and the Sublingual. Parotid gland, the largest of the three, is bounded superiorly by the zygoma, posteriorly by the mastoid process and sterno-mastoid 193 muscle, and advances on the side of the face partly resting upon the masseter muscle. It sends off deep processes, which fill the posterior part of the glenoid cavity, the fossa between the ear and perpendicular process of the lower jaw, and the intervals between the pterygoid, digastric, and styloid muscles ; it often unites with the sub -maxillary gland. Its duct (duct of Steno) passes across the masseter muscle, pierces the buccinator muscle, and opens into the mouth opposite the second superior molar tooth. A small gland (socia parotidis) occasionally is found between Steno's duct and the zygoma, the duct of which unites with that of the parotid gland. Sub-maxillary gland, placed in the digastric space, and covered by the skin, platysma- myoides muscle, and deep cervical superficial fascia, is of an oval figure and much smaller than the parotid. Its duct (Whartonian) turns round the posterior edge of the mylo-hyoid muscle, and runs forwards and inwards to- wards the frainum lingua at the side of which it opens into the mouth. Sublingual gland, is placed between the mucous membrane of the mouth and the mylo- hyoid muscle, is the smallest of the salivary glands, and opens by several small ducts (Rivinian), which perforate the mucous mem- brane, reflected from the side of the tongue. 13 194 LIVER. Situated in the right hypochondriac, the epigastric, and partly in the left hypochondriac regions, is the largest gland in the hody. It presents an upper convex surface, a lower irregularly concave surface, a posterior thick margin attached to the diaphragm, and an an- terior inferior margin which is free. The upper surface is unequally divided by the falci- form ligament into a right and left lobe. The inferior surface presents the following fissures and depressions. 1. Horizontal fissure extends from a notch in the anterior thin edge of the liver back- wards and upwards, defining the boundary between the right and left lobes of the organ ; it is crossed at right angles by the transverse fissure, which thus divides it into an anterior and posterior portion, the former containing the obliterated remains of the umbilical vein, the latter the obliterated ductus venosus. 2. Transverse fissure extends from the hori- zontal fissure into the right lobe of the liver, it contains the trunks of the right and left hepa- tic arteries, the trunk of the portal vein, the he- patic extremities of the biliary ducts, the hepa- tic plexus of nerves and absorbents. 3. Fissure of the vena cava, situated to the right of the horizontal fissure and behind the transverse fissure, forms the right boundary of the lobulus Spigelii. 199 external cortical substance, the apices towards the inner concave edge of the gland. Papillae, is the name given to the nipple-like apices of the conical fasciculi. Each papilla pre- sents numerous minute tubes,the apertures of the tubes of which the cones are composed ; these apertures are not so numerous as the tubes, seve- ral of which are united in one common orifice. The Calyces are small membranous sacs which surround one or more papillae. The Infundibula are three funnel-shaped tubes formed by the union of the calyces. The Pelvis is the membranous reservoir formed by the union of the three infundibula. Tlie Ureters extend from the termination of the pelvis of either kidney to the bladder. Each ureter, about eighteen inches long and of the diameter of a moderate sized quill, passes behind the peritoneum, lying anterior to the psoas magnus muscles and to the iliac vessels, and gaining the interior and posterior part of the bladder, passes obliquely between its coats, and perforates its interior at the outer angle of its trigone.* THE URINARY BLADDER. This musculo-membranous viscus when mod- erately distended is of an ovoid figure and oc- * To gain a view of the parts just described, a perpendicular section of the gland should be made from its cony ex to its concave margin. 200 cupies the lower region of the pelvis, behind the pubal symphysis, and anterior and superior to the rectum in the male, and the uterus and vagina in the female. Ligaments of the bladder are divided into true and false. The true ligaments are four in number, viz : two anterior and two lateral. These, being nothing more than reflections of the vesical layer of the pelvic fascia, will be noticed when this structure is described, The false ligaments are five in number, viz : two posterior, two lateral, and one superior, and are formed by the reflections of the peritoneum. The regions of the bladder are divided into six. 1st. The superior region, to which are attached the urachus and obliterated umbilical arteries. 2d. and 3d. TJie lateral regions, on which the vesical fascia of either side passes. 4th. The anterior region, the aspect of which looks towards the recti muscles, the pubes, and the triangular ligament of the urethra or the deep perineal fascia. 5th. The posterior region , the aspect of which looks towards the rectum in the male and the uterus in the female. 6th.. TJieinferior region or fundus which rests on the vesiculse seminales, the prostate gland, and the rectum in the male, and on the uterus and va- gina in the female. Coats of the bladder. Besides the partial peritoneal covering which invests all the poste- rior region and the posterior parts of the upper. 201 lower, and lateral regions, there are also three proper coats. 1st. TJie muscular, placed exter- nally, the fleshy fibres of which take two direc- tions ; the external run longitudinally, the ante- rior and superior fibres being stronger have been distinguished by the name of detrusor uri- nes, and the deep circular fibres immediately in connection with the mucous coat, which are best developed around the neck of the bladder. 2d. The cellular coat, and 3d. The mucous, which is exposed on opening the bladder. This coat is in general thrown into rugae by the pro- jection of the muscular fibres. The trigone or vesical triangle is the name given to a smooth space enclosed between the openings of the ureters into the bladder and the vesical orifice of the urethra. The uvula is a small duplicature of the mu- cous membrane on the under surface of the vesical orifice of the urethra, and corresponds to the third lobe of the prostate gland. The urethra which terminates the urinary apparatus being in the male more connected with the reproductive organs, we shall defer its consideration until those organs are being de- scribed. THE PERITONEUM, The largest serous membrane in the body, lines the parietes of the abdomen, and invests almost all the abdominal viscera : like all se- 202 rous membranes, it is distinguished into two layers, a parietal and a visceral. The abdomi- nal parietes being divided by a transverse inci- sion, corresponding to the umbilicus, the unin- terrupted continuity of the peritoneum, and the different productions it forms in its course may be thus demonstrated : — lining the inner surface of the upper section of the abdominal parietes, it ascends to the margin of the thorax, and lines the inferior surface of the diaphragm; from this muscle it is reflected on the spleen on the left side, on the stomach in the centre, and on the liver on the right side, forming its liga- ments (vide ligaments of liver). From the trans- verse fissure of the liver the two layers which cover the convex and concave aspects of this gland meet, and are conducted by the hepatic vessels to the lesser curvature of the stomach, thus forming the gastro-hepatic omentum, which is also called the capsule of Glisson, and between the two layers of which are con- tained the hepatic artery to the left, the ductus communis choledochus lying to the right, and the vena porta, lying behind and between both. At the lesser curve of the stomach the two laminae of the gastro-hepatic omentum sep- arate and enclose this organ, passing from its left extremity to the spleen, thus forming the gastro- splenic omentum, and at the great curve of the stomach, and lower extremity of the spleen, the two laminae again meet and descend 203 in front of the colon, and the small intestines, to the lower part of the abdomen ; these two layers then turn upon themselves backwards, and ascend to the transverse arch of the colon, where they separate to enclose this intestine, thus forming the great omentum. Having en- closed the colon, the ascending layers again unite and form the transverse meso-colon, which passes backwards to the spine ; having arrived at the spine, the two laminse again sep- arate into a descending and an ascending layer ; the descending layer passes into the lumbar regions where it is reflected upon the ascending and descending colon, forming the right and left lumbar meso-colon, and attaching itself to the left sides of the bodies of the lumbar verte- brae forms the anterior lamina of the root of the mesentery ; from this fixed point it is continued around the jejunum and ileum, forming the peritoneal coat of these intestines, and returns again to the spine, forming the posterior lamina of the root of the mesentery. This descending layer of the transverse meso-colon, having thus formed the mesentery, still pursues its descend- ing course, aud passes into either iliac region, and into the pelvis ; on the right it attaches the ccecum to the right iliac fossa, thus forming the meso-ccecum, on the left side it attaches the sigmoid flexure of the colon to the left iliac fossa, forming the sigmoid meso-colon, and in the midddle it connects the upper portion of the 204 rectum to the upper and anterior part of the sacrum, forming the meso-rectum ; still pursu- ing its course downwards, and covering the upper and anterior aspect of the middle third of the rectum, it is at length reflected on the posterior surface and sides of the bladder, to the superior region of this viscus, from which, and from the iliac fossa, it is reflected on the inner surface of the loAver section of the abdo- minal parietes to the transverse incision, from the upper edge of which the description was commenced. Having thus traced the descend- ing layer of the transverse meso-colon, the continuity of the ascending layer remains to be noticed : — ascending in front of the inferior and middle portions of the duodenum and of the pancreas, it is conducted to the liver by the vena cava on the right of the Spigelian lobe, of which gland it becomes continuous with the perito- neum, which has been reflected from the dia- phragm on the posterior aspect of the liver. Foramen of Window. — By this opening the cavity which is between the layers of the great omentum, communicates with the general peritoneal cavity of the abdomen. It is of an oval form, being bounded anteriorly by the gastro-hepatic omentum, posteriorly by the ascending layer of the meso-colon, superiorly by the liver, and inferiorly by the duodenum. Inguinal Pouches. — As the peritoneum is ascending on the lower part of the abdominal 205 parietes, it is thrown into four pouches, two on either side, by the obliterated hypo-gastric artery. The external pouch, between the ilium and hypo-gastric artery, is the largest, and cor- responds to the internal abdominal and the femoral rings ; the internal corresponding to the external ring. In the female the peritoneum passes from the rectum on the upper and back part of the va- gina, from which it ascends on the uterus, forming on each side its broad ligaments, and is reflected from the anterior part of the uterus to the back of the bladder. MALE ORGANS OF GENERATION. THE TESTICLES Are two in number, of an oval form, are con- tained in the scrotum, and are likewise envel- oped by proper tunics. Tubuli seminiferi are numerous capillary tubes, which form the body of each testicle. They are very long and tortuous, and are ar- ranged in conical fasciculi, which are separated from each other by fibrous bands, derived from the tunica albuginea. Tubuli recti are from sixteen to twenty in number, are formed by the union of the tubuli seminiferi, and are contained between the layers of the corpus Highmorianum. Vasa efferentia are five, or six in number, 206 and are formed by the union of the tubuli recti. These tortuous vessels pierce the tunica albu- ginea, arrive at the head of the epididymis, and by their union form the vas deferens. Vas deferens, or seminal excretory duct, is of great length, and is folded on itself by innu- merable turns for the first part of its course. By its convolutions it, and the vasa efferentia, form the globus major, or head of the epididy- mis, which is situated at the upper part of the body of the testicle ; still convoluted, it passes downwards, forming the body of the epididy- mis, which is narrow and placed at the poste- rior part of the body of the testicle, and arriving at the inferior part of the gland, it forms the globus minor, or tail of the epididymis. The vas deferens, having thus formed the epididy- mis, escapes from the globus minor, and having increased in size and density ascends along the inner aspect of this body, until it becomes con- nected to the spermatic vessels and cremaster muscle ; it then passes through the external abdominal ring and the inguinal canal, and having passed through the internal abdominal ring, it separates from the spermatic vessels, and is conducted by the false lateral ligaments of the bladder to this viscus, along the side and inferior fundus of which it runs, lying internal to its corresponding vesicula seminalis. It here approaches its fellow of the opposite side, and both ducts becoming flattened arrive at the base 207 of the prostate gland, where they are joined by the ducts of the vesicula seminalis, their union forming the common ejaculatory ducts; these run through the prostate gland, and open into the prostatic portion of the urethra, at the side of the verumontanum. PROPER COATS OF EACH TESTICLE. Tunica albuginea. — A strong fibrous invest- ment, of an opaque white color, which forms the proper capsule of the gland. From its inner surface it sends two lamina, which project into the back part of the testicle for about two lines, thus forming the body called corpus Highmori- anum ; from the free edge of which proceed the fibrous bands, already mentioned as separating the conical bundles of tubuli seminiferi, to be attached to the opposite surface of the tunica albuginea. Tunica vaginalis. — A serous membrane, consisting of two layers, one covering the tes- ticle called tunica vaginalis testis, the other lining the scrotum called tunica vaginalis scroti. When the tunica vaginalis scroti is divided, its continuity with the glandular layer may be de- monstrated by tracing the membrane, when it will be found to be reflected on the side and fore part of the epididymis and testicle, forming a pouch between these bodies, and also for a short distance on the fore part of the chord. Tunica communis, formed by the fibres of the 208 cremaster muscle and cellular membrane, sur- rounds the chord and the fore part and sides of the testicle. COMMON COVERINGS OF BOTH TESTICLES. The scrotum, a production of the common integument, is of a brownish color, slightly- studded with hairs and sebaceous follicles, pre- senting in the median line a hard ridge, called the raphe, from either side of which it is thrown into rugse. The dartos, supposed by some to be mus- cular, is formed by the subcutaneous cellular tissue and the ramifications of numerous blood- vessels, which give this coat a reddish appear- ance. The superficial fascia lies immediately under the dartos, is derived from the superficial fascia of the abdomen, and is continuous with the su- perficial fascia of the perineum. Septum scroti. — This partition, which di- vides the scrotum into two, is formed by the dartos and superficial fascia, these membranes being attached to the raphe, and from thence ascending between the testicles, to the urethra. BLOOD-VESSELS AND NERVES OF THE TESTICLES. Each testicle is supplied with blood by the spermatic artery, the blood of which is returned by the spermatic veins; it receives nerves from the spermatic plexus, which is formed by 209 branches from the lumbar ganglions of the sym- pathetic, from the splanchnic nerves, and from the renal plexus. Rete testis. — Upon separating the laminae of the tunica albuginea, which form the corpus Highmorianum, the arteries, veins and nerves of the testicle, together with its vasa recti, will be seen to pass to and from the gland. The reticular appearance these present is called rete testis. The spermatic chord is composed of the vas deferens, the spermatic arteries, veins and nerves, and absorbents; all of which are con- nected to each other by fine cellular tissue, and are enveloped by fascia and the cremaster muscle. The chord, thus formed, extends from the epididymis to the internal abdominal ring, where its constituents separate from each other. Corpus pampiniforme is the name given to the venous plexus, formed by the spermatic veins after these vessels have escaped from the testicles. The vesiculce seminales are two oblong flat- tened bodies situated at the inferior fundus of the bladder, behind the prostate gland, and on the outer side of the vasa defer entia. Each seminal vesicle is about two inches long, and consists of a long tortuous membranous tube convoluted on itself, the small excretory duct of which joins its corresponding vas deferens. The prostate gland is a flat conoidal body, the 14 210 base being posterior corresponding to the vesi- culae seminaies,the apex anterior corresponding to the vesical extremity of the urethra. It is distinguished into three lobes : two lateral, large, and united in the medial line, their union being marked by a slight groove ; and a third or small lobe situated in the angle between the two lateral lobes, towards the base of the gland. The prostate gland is firm and resisting to the touch, and composed of numerous follicles, with minute ducts, which unite to form larger tubes, the openings of which, ten or twelve in number, are on the under surface of the ure- thra, on either side of the verumontanum. Cowpefs glands are two small oblong- round bodies placed before the prostate gland (hence also called anti- prostatic glands), and contained between the layers of the triangular ligament of the urethra. The duct of each gland having run a course of about an inch, opens into the urethra a little anterior to its bulb. THE PENIS. This organ, the shape of which is familiar, consists of two cylindrical bodies, named cor- pora cavernosa ; and a body named corpus spongiosum which contains the urethra, all these parts being connected together and sur- rounded by the superficial fascia and the com- mon integuments. 211 The corpora cavernosa, are two cylindrical bodies, united to each other in the mesial line; they are composed of a cellular structure contain- ing several veins and the arteries of the corpora cavernosa, derived from the pudic artery, all of which are enclosed in a strong fibrous in- vestment. Each corpus cavernosum commences by the cms penis, which is the narrowest part, and which is attached to the rami of the ischium and pubis. At the symphysis pubis both crura unite, forming the chief part of the body of the penis, and terminate anteriorly in an obtuse point, to which is intimately attached the glans penis. Septum pectiniforme, a partition, imperfect as its name implies, which corresponds to the mesial line, and marks the division of the cor- pora cavernosa. The urethra is a membranous canal, extend- ing from the neck of the bladder to the extremity of the glans penis, its length and width vary- ing according to the erect or collapsed state of the organ. In the latter condition its length is from seven to eight inches, and its calibre about three or four lines. It is lined by mucous mem- brane, and is distinguished into, 1st, the pros- tatic portion, which is from an inch and a quar- ter to an inch and a half in length : 2d, the mem- branous portion, which is about half an inch long ; 3d, the bulbous portion, which is scarcely 212 an inch, and 4th, the spongy portion, which oc- cupies the remainder of its length. The corpus spongiosum urethra is a celiulo- vascular tube surrounding the urethra and oc- cupying the under mesial line of union of the corpora cavernosa ; it commences in the hulb of the urethra and extends along the canal to its extremity, where it terminates in the glans penis, the bulb and glans penis being merely expan- sions of this structure. Upon exposing the mucous surface of the urethra by an incision, we observe, 1st, a slit- like contraction at the orifice ; 2d, behind this a dilatation, called fossa navicularis ; 3d, the constant diameter of the canal until we arrive at the bulb where it is again dilated, forming, 4th, the sinus of the bulb ; 5th, the narrowest part of the canal which corresponds to the membranous portion ; 6th, the dilatation cor- responding to prostate gland, and 7th, a con- tracted orifice at its termination in the bladder. In the prostatic portion of the urethra a promi- nent fold of mucous membrane, called verumon- tanum, projects from its under surface, and pre- sents in its centre a large lacuna, the sinus pocularis, the orifice of which is directed for- wards. On either side of the verumontanum the prostatic sinuses are situated. Upon the upper surface of the urethra, from the orifice to the bulb, are the openings of numerous mucous follicles, directed forwards, the largest of which 213 is about an inch from the orifice, and is called, from its size, lacuna magna. The ducts of the seminal glands already described in connection with the genito-urinary organs open on the un- der surface of the urethra. The orifices of Cowper's glands open a little anterior to the sinus of the bulb, the common ejaculatory ducts on either side of the verumontanum, and the ducts of the prostate in the prostatic sinuses. Tlie superficial fascia, which envelopes the penis, is derived from that of the abdomen, and terminates at the corona glandis. It is strong where it passes from the linea alba upon the dorsum of the penis, forming the suspensory ligament, but is exceedingly delicate and loose upon the body of the organ. Tlie skin of the penis is remarkably thin and loose, and extending for an indefinite length be- yond the organ, is reflected inwards, and is in- timately attached to the corona glandis ; the loose fold thus formed is called the prepuce. From the corona glandis it is continued along the glans until it becomes identified with the mucous mem- brane at the orifice of the urethra, having first formed a fold which lies posterior and inferior to this opening, and is called fmnum preputii. Glandidce odor if era, are a number of small sebaceous glands which surround the corona glandis, and which lie beneath the skin. 214 THE FEMALE ORGANS OF GENERA- TION. Tlie ovaries are two ovoidal bodies placed, one on either side of the womb, in the duplica- tures of the peritoneum called the broad liga- ments of the uterus. Each ovary, enveloped by a white fibrous membrane, consists of a pulpy brownish-grey substance, highly vascu- lar, and containing from fifteen to twenty min- ute vesicles, each of which is composed of a thin membrane containing a viscid yellowish fluid ; these are called the Graafian vesicles. The Fallopian tubes are the excretory ducts of the ovaries ; each is about four inches in length, and is contained in the broad ligament, one extremity being attached to the superior angle of the uterus into which it opens by a small orifice (orificium uterinum), the other be- ing free and surrounded by a fringed slip of pe- ritoneum (corpus fimbriatum), in the centre of which is the peritoneal aperture {orificium su- perius.) The uterus is a hollow organ of a pyriform shape, and is distinguished into the fundus, the body, and the cervix. The fundus is superior and posterior and receives at either angle the Fallo- pian tube : the body is intermediate between the fundus and the neck, the latter being inferior and anterior and surrounded by the vagina : at the 215 extremity of the neck is a small elliptical open- ing surrounded by a thick margin, which from its resemblance to the mouth of a tench, has been called os tinea as well as os uteri. The cavity of the uterus is small compared to the thickness of its walls, and is of a triangular shape ; its superior and outer angles presenting the orifices of the Fallopian tubes, the inferior presenting the os tincse. The uterus is placed between the bladder and rectum. The vagina is a membrano-vascular tube, extending from the neck of the uterus to the ex- ternal outlet, where it is continuous with the surface. It is composed of mucous membrane surrounded by cellular tissue, a vascular net- work, and the sphincter vaginae muscle ; its length is about four inches, its breadth one, but being very distensible these measurements vary. Its mucous membrane is thrown into transverse rugae on its anterior and posterior surface, and is studded with the orifices of numerous mucous follicles. The color of the mucous membrane varies, at the external orifice being red, and of a grey and sometimes marbled color as it approaches the uterus. The mons veneris is a soft adipose eminence, situate on the upper and anterior part of the pubes, covered by common integument, which, in the adult, is thickly set with hairs. The vulva is the fissure extending from the mons veneris to the perineum. 216 The labia magna are ]arge folds of the integu- ments which bound the vulva on either side, and unite below in a crescentic edge (the four- chette.) The clitoris, a small oblong conical body, placed between the upper extremities of the la- bia. It consists of a structure similar to the corpus spongiosum urethrse in the males, and arises by two crura from the pubes ; these unite to form its body, at the extremity of which is placed a red protuberance, called the glans cli- toridis, over which is thrown a loose fold of in- teguments (theprepuce). Meatus urinanus is about half an inch below the clitoris. Labia parva, or nymphce, are two red crescen- tic folds of mucous membrane, enclosing nu- merous erectile vessels ; they descend, one on each side, from the prepuce of the clitoris, and are lost about the centre of the vulva. The hymen, when it exists, is a crescentic fold of mucous membrane, surrounding the sides and inferior orifice of the vagina. The carunculcs myrtiformes are small reddish bodies surrounding the orifice of the vagina, and which are the remains of the hymen. THE MAMMiE are two in number, situated at the anterior and superior part of the thorax, and connected to the great pectoral muscles by a capsule of 217 condensed cellular tissue. Each of these con- glomerate glands, of a hemispherical shape, con- sists of numerous acini, very small and united together so as to form lohules. From the acini proceed minute tubes, named lactiferous ; these unite, forming larger ducts, all of which con- verge towards the root of the nipple, and expand into conical sacs from which smaller ducts proceed and open on the surface. The nipple is a conical process, surrounded by a brownish areola, and composed externally of the integu- ments, which are very thin, and internally of the lactiferous tubes, together with numerous blood-vessels, from which the nipple derives its property of occasional erection. ORGANS OF THE SENSES. THE ORGAN OF TOUCH. Tlie skin is composed of the cuticle, or epi- dermis, the rete mucosum, and the corion, or cutis vera. The cuticle is a transparent inorganic layer of membrane, extending over the corion. Its thickness varies, being thinnest in those parts least exposed to pressure and friction, and thick- est in the soles and palms. Tlie rete mucosum is a tbin membrane attach- ed to the outer surface of the corion, highly vascular, and gives the color to the skin, being 218 black in the negro, and white, brown, or yellow in the European. The corion is a dense strong membrane, con- sisting of fibres, interwoven with each other, which are more firmly compacted the nearer they are to its outer surface. Its internal sur- face is cellular, its external very vascular, and presenting numerous small conical papillae ; at the extremities of the fingers these papillae are best developed, are furnished with minute nervous filaments, and covered with very thin cuticle ; thus affording a delicacy of organiza- tion necessary for the greater perfection of the sense of touch. THE ORGAN OF SMELL. The nose is bounded superiorly by the nasal, frontal, ethmoid, and sphenoid bones ; inferiorly by the palatine plates of the superior maxillary and palate bones ; externally on either side by the superior maxillary, lachrymal, inferior spongy, ethmoid and palate bones, and by the internal pterygoid plates of the sphenoid bone. It is divided into the two nares by the septum nasi, which is formed by the azygos process of the sphenoid bone, the nasal plate of the eth- moid bone, the vomer and the mesial spines of the superior maxillary and palate bones. Be- sides the bony boundaries, the nose presents, an- teriorly, five cartilages, which form the anterior nares, or the nostrils. The middle vertical car- 219 tilage is of a triangular form, and rests in the fissure of the vomer inferiorly, is attached to the vertical plate of the ethmoid bone above, and presents anteriorly a subcutaneous, free, thick edge, and thus completes the septum nasi. The lateral cartilages which form the wings of the nose, are also triangular, are attached to the superior maxillary and nasal bones, and in the median line to the vertical cartilage. The in- ferior lateral fibro-cartiiages, are attached to the three cartilages just described, are thick and semi-circular, forming, with the vertical carti- lage, the anterior inferior oval openings of the nostrils. The posterior nares are of an oval shape, and open into the upper part of the pharynx ; they are separated from each other by the posterior free edge of the vomer, are bounded superiorly by the body of the sphenoid bone, inferiorly by the palate bones, and externally by the internal pterygoid plates of the sphenoid bone. The ex- ternal lateral wall of each naris, from the ar- rangement of the spongy bones, form three fos- sae, called meatuses, with which several orifices communicate. In the inferior meatus, at the junction of its anterior with its middle third, is the opening of the nasal duct, and posteriorly, on a level with the inferior spongy bone, is the opening of the Eustachian tube. In the middle meatus is the slit-like opening of the antrum maxillare, ante- 220 rior to which is the groove called infundibu- lum, which leads from the frontal sinus, and into which open the anterior ethmoidal cells. Into the superior meatus, the posterior eth- moidal cells and the sphenoidal sinus open. The interior of the nose is lined with the Schneiderian membrane, which is highly vas- cular and sensible, and consists of two layers, a fibrous layer, which is the periosteum, or the perichondrium of the nasal cavities, and a mu- cous membrane. The nerves which supply the nasal cavities are the olfactory, the internal nasal of the ophthalmic, and branches derived from Meckel's ganglion. THE ORGAN OF TASTE. The tongue presents several papillae covered by mucous membrane. It is of a triangular form, is connected by its base to the os hyoides, by folds of mucous membrane to the epiglottis and palate, and by muscles to the lower jaw. It is highly vascular, and receives six nerves, three on either side, viz : the gustatory branch of the fifth for taste, the ninth, or lingual, for motion, and the glossopharyngeal to connect it in sympathy with the pharynx. THE ORGANS OF VISION. The eyes are distinguished into the globes of the eyes and their appendages. The eye-ball 221 is composed of membranes and fluids, called humours. The sclerotic coat, occupying about four-fifths of the globe, is of a strong fibrous structure, is thicker behind and anteriorly than in its centre. Its outer surface is in contact with the adipose tissue of the orbit, the tendinous expansions of the orbital muscles, and anteriorly with the conjunctiva, its inner surface being lined by the choroid coat. It presents posteriorly a small aperture for the transmission of the optic nerves, and an anterior large one, about six or seven lines in diameter, for the cornea. The cornea, which forms the anterior fifth of the globe, is smooth and transparent. It con- sists of three layers, viz : the conjunctival layer externally, the elastic cornea internally, and, between both, the proper cornea, which is com- posed of laminse, connected together by fine cellular tissue. The choroid coat is a thin vascular membrane, situated between the sclerotic coat and the retina; it extends from the entrance of the optic nerve to the ciliary ligament, to which it is firmly connected ; it then is directed inwards, and forms the folds called ciliary processes. Its internal surface is covered by a dark brownish secretion, called nigrum pigmentwn, its outer surface being connected to the sclerotic coat by fine cellular tissue, and by the ciliary vessels and nerves ; on this surface the veins observe 222 an arched arrangement, and are called vasa vor- ticosa. The ciliary ligament is about a line and a half in breadth, of a greyish white cellular structure, and corresponds to the circle of junc- tion of the cornea and sclerotic coat externally, and of the choroid and iris internally. The ciliary processes vary in number from sixty to seventy, and are productions or con- tinuations of the choroid coat ; each ciliary pro- cess is of a triangular figure, the anterior edge being attached to the ciliary ligament, the pos- terior to the hyaloid membrane, and the inter- nal free projecting into the posterior chamber of the aqueous humour, towards the lens but not attached to this body. The Iris is a circular membrane placed in a transverse vertical position, attached by its lar- ger circumference to the ciliary ligament, float- ing in the aqueous humour, and presenting a circular opening in the centre called the pupil. It divides the space between the anterior sur- face of the capsule of the lens, and the poste- rior surface of the cornea, unequally into wThat are termed the chambers of the aqueous humour , the anterior chamber being much the largest ; both chambers, however, communicate through the pupil. The anterior surface of the iris pre- sents a radiated appearance, and varies in color in different individuals ; the posterior surface is covered by nigrum pigmentum, and has re- 223 ceived the name of uvea. The iris is supplied by the ciliary nerves and vessels. The retina, placed between the choroid coat and vitreous humour, consists of three layers, an external or serous layer, called from its dis- coverer membrana Jacobi, an internal or vascu- lar layer, and between both the nervous layer. About two lines on the temporal side of the en- trance of the optic nerve the retina presents a small hole surrounded by a yellow margin, called the foramen of Soemmering, round which the retina is thrown into a fold. The aqueous humour is contained in the an- terior and posterior chambers of the eye, is per- fectly transparent, and is from four to five grains in quantity. The vitreous humour occupies about the three posterior fourths of the eye ; it is contained in the hyaloid membrane, which not only envelopes it, but sends numerous partitions from its inner surface to form cells in which this transparent fluid is deposited. The vitreous humor thus contained in its capsule is convex posteriorly and on its lateral circumference, but presents anteriorly a concavity for the reception of the crystalline lens ; around the circumference of this cavity the vitreous humour presents a stria- ted appearance, caused by the marks of the cil- iary processes, to which the term corona ciliaris is applied. The crystalline lens, enclosed in its capsule 224 and placed in the anterior depression of the vit- reous humour, is a transparent body, present- ing an anterior and a posterior convex surface, the latter being more prominent, and correspond- ing to the vitreous humour. Its external sur- face is soft and pulpy, gradually increasing in density towards its centre. The capsule of this body, like the lens itself, is transparent, and from its thickness, strength, and elasticity, is considered by Dr. Jacob as be- ing cartilaginous. The lens and its capsule derive their nutri- ment from the vessels of the hyaloid membrane. Liquor Morgani is a fluid which is found some hours after death, between the lens and its capsule. It is the effect of transudation. Canal of Petit. — The lens is retained in its situation by the hyaloid membrane, which, splitting into two laminae at its circumference, pass one anterior the other posterior to its cap- sule ; a triangular canal is thus formed, and is intersected by minute septa ; this is the canal of Petit, and may be demonstrated by distending it with air, when it will present a vesicular appearance. THE APPENDAGES OF THE EYE. The lachrymal gland, placed in the upper and outer part of the orbit, behind the external angular process of the os frontis, and about the size of a small almond, is of a greyish color, 225 consists of numerous granules, united by an. imperfect capsule, and pours forth its secretion of tears by means of ten or twelve minute ducts, which open behind the upper eyelid, in the angle formed by the reflection of the con- junctiva. Tunica Conjunctiva, a mucous membrane which lines the interior of each eyelid, and is reflected on the anterior part of the globe of the eye. At the inner angle of the eye it forms a small fold called plica semilunaris, covers the caruncula lachrymalis, and having lined the lachrymal sac and duct becomes continuous with the mucous membrane of the nose. This membrame, where it passes over the cornea, is perfectly transparent. Caruncula lachrymalis, a small vascular body composed of mucous glands and cellular tissue situated in the nasal angle of the eye, and covered by the membrana conjunctiva. The palpebrce or eyelids, semicircular inform, are composed of skin externally, which is very fine, the tunica conjunctiva internally, and be- tween both the orbicularis palpebrarum muscle, the tarsal cartilages and their ligaments, and the Miebomian glands, together with blood- vessels, nerves, and absorbents. The superior eyelid, besides being the largest, has peculiar to it the levator palpebrae superio- ris muscle. The tarsal cartilages are thin cartilaginous 15 226 plates of a semicircular form, the superior being the largest; to their convex margins are at- tached the palpebral ligaments, which are con- tinuations of the orbital periosteum. The Miebomian glands, of a yellow color, are very numerous, particularly in the upper eyelid, and are arranged in vertical rows. The opposed edges of the eyelids are thick, and are bevelled off obliquely towards the eye, so that when closed they only touch at their anterior edges, thus leaving a triangular canal, the base of which is formed by the tunica con- junctiva, along which the tears are conducted to the pun eta lachrymalia. The cilice or eyelashes, attached by their roots to the opposed margins of the eyelids, observe a curved arrangement, their convexi- ties looking towards each other. The puncta lachrymalia are the two minute orifices of the lachrymal canals, placed within two or three lines of the nasal terminations of the eyelids, and upon their opposed edges. The lachrymal canals, the superior of which is longer and curved, the inferior being nearly straight, lead from the puncta lachrymaka to the lachrymal sac. The lachrymal sac, placed in the fossa formed by the lachrymal and superior maxillary bones, is of an oval form, receives the lachrymal se- cretion by the puncta lachrymalia and trans- 227 fnits it to the nasal duct with which it is con- nected inferiorly. The nasal dud, enclosed in a bony canal formed by the lachrymal, superior maxillary, and inferior spongy bones, passes obliquely downwards, backwards, and outwards, and ter- minates in the inferior meatus of the nose. THE ORGAN OF HEARING. This organ consists of the external ear, in- cluding the auricle and meatus auditorius exter- nus; the middle ear, including the cavity of the tympanum and its appendages, and the internal ear or labyrinth, including the vestibule, semi- circular canals, and cochlea. The external ear consists of a fibro- cartilagi- nous plate covered by skin, and so moulded as to form different elevations and depressions, which have been described with more minute- ness than they deserve. The- helix is the semicircular eminence which forms the outline of the external ear. The anti-helix commences superiorly by two roots, which enclose a fossa {fossa navicularis), and is situated inferior to the helix. The tragus is an eminence placed anterior and inferior to the meatus externus. The anti-tragus\& a smaller eminence poste- rior to the meatus externus. The lobule is a pendulous body placed under- neath the anti-tragus. 228 The concha, a deep conoidal cavity which leads to the meatus externus and in which the several depressions, formed by the eminences just described, terminate. The meatus externus is a curved canal which leads from the concha to the membrana tym- pani; it is lined by skin, beneath which are placed small glands .(glandules ceruminosce), which secrete the ear-wax (cerumen). The inner half of this canal is surrounded by bone. The membrana tympani, separating the exter- nal from the middle ear, is of an oval form and consists of three layers, viz : the external or cuticular, the internal or mucous, and between both a fibrous layer, which some have supposed to be muscular. To its inner aspect is attached the eras of the malleus, which, by drawing it towards the inner ear, gives it a concave aspect externally. The middle ear consists of the cavity of the tympanum and the small bones of the ear and their muscles. The cavity of the tympanum is an irregular cylindrical space, closed externally by the mem- brana tympani, and bounded posteriorly by a bony partition which separates it from the la- byririth, ft presents the following eminences and foramina, viz : the promontory, a convex eminence situated on its internal side and which marks the situation of the vestibule ; the fora- men ovale, placed above the promontory and to 229 which the base of the stapes is affixed ; the foramen rotundum, below the promontory, closed by a membrane {lesser tympanum), which separates the scala tympani of the cochlea from the cavity of the tympanum ; the opening of the mastoid cells, situated posteriorly and superiorly ; the pyramid, a bony projection placed below the opening of the mastoid cells, hollow within and containing the stapedius muscle ; a small foramen below the pyramid for the transmission of the chorda tympani nerve ; anteriorly the openings of the two bony canals, the superior of which lodges the tensor tympani muscle, the inferior forming the bony part oi the Eustachian tube; inferiorly is the opening of the Glasserian fissure, and superi- orly are several small foramina for blood-ves- sels. The bones of the ear are three in number, very small and contained within the cavity of the tympanum. The malleus is divided into the head, which is smooth and articulates with the incus ; the neck, which is small and connects the head to the shaft ; the handle or shaft, which descends from the neck, and is attached to the membrana tympani, and the processus gracillis, which passes from the neck to the Glasserian fissure. The Incus is divided into its body, which presents a cup-like cavity for the head of the malleus ; a superior crus, which is short and 230 lies in the mastoid cells, and a long eras, to the extremity of which is attached a small process of bone, considered by some as a distinct bone and called os orbiculare. The Stapes presents a small head, which is attached to the orbicular process, a short neck, two curved crura, which terminate in the base, and the base itself, which is of an oval shape and connected to the foramen ovale. The internal ear or labyrinth. The vestibule, placed behind the cochlea and before the semicircular canals, is a small oval cavity lined by a membrane common to the labyrinth, contains a watery fluid, and presents the following openings, viz : The foramen ovale, the five orifices of the semicircular canals, the orifice of the scala vestibuli of the cochlea, and the orifice of the aqueduct of the vestibule. The semicircular canals, placed behind the vestibule, arethree in number, two vertical and one horizontal; of the former, one is superior and the other posterior. The openings of these canals are only five in number, in consequence of one opening of the vertical canals being common to both. The Cochlea, of a conical form, the base to- wards the internal meatus, the apex towards the carotid canal, is composed of a bony tube which makes two turns and a half round a central pillar called the mediolus. This tube is 231 divided longitudinally by a thin plate, half bony, half membranous, called lamina spiralis, into two independent cavities : the two tubes thus formed are called the scalae of the cochlea, they both unite at the apex in a cavity called infun- dibulum, and at the base of the cochlea they separate, one called scala vestibuli, which opens into the vestibule, the other called scala tym- pani, which opens into the tympanum by the foramen rotundum. From the scala tympani proceeds a narrow bony canal called the aque- duct of the cochlea, which terminates in a slit- like opening in the petrous bone, a little inferior to the meatus auditorius internus. The auditory nerve gains the internal ear by the minute foramina at the base of the meatus auditorius internus, and is expanded in the form of soft pulpy filaments in the cochlea and vestibule. THE ABSORBENT SYSTEM comprehends, 1st, the vessels which convey the lymph and chyle into the veins ; and 2dly, the enlargements which occur in their course called glands or ganglia. The Lacteal or Chyliferous vessels commence on the mucous surface of the intestines, pass through the mesenteric glands backwards to- wards the spine, where they terminate in the thoracic duct. 232 The lymphatic vessels are found in most situ- ations of the body, and generally observe a deep and superficial arrangement. Lymphatics of the lower extremities. The superficial set accompany the external and in- ternal saphena veins ; they communicate freely in their course with the deep lymphatic trunks which accompany the deep vessels. Those which accompany the external saphena vein enter the glands in the popliteal space, whilst those accompanying the internal saphena vein ascend to the groin and pass through the in- guinal glands, having formed numerous con- nections with the superficial lymphatics of the abdomen, the perineum, and the genitals. The deep lymphatics of the hip and perineum are conducted by the branches of the internal iliac vessels into the pelvis, and pass through the pelvic glands. From the inguinal and pelvic glands the lymphatics pass along the primitive iliac vessels to the receptaculum cliyli. The Thoracic Duct. This canal commences by a dilatation called receptaculum cliyli, placed on the body of the 2d or 3d lumbar verte- bra : passing between the crura of the dia- phragm it gains the posterior mediastinum, where it lies between the aorta and the vena azygos ; at the fifth dorsal vertebra it crosses the spine obliquely to the left side, passing behind the oesophagus and arch of the aorta, and placed behind the left pleura and between 233 the left carotid and left subclavian arteries ; it is then conducted by the oesophagus to the left side of the neck as high as the sixth cervical vertebra, where, making a slight curve down- wards and outwards, it opens close to the ex- ternal angle formed by the left subclavian and jugular veins. Lymphatics of the upper extremities. — The superficial set accompany the superficial veins, and pass through two or three glands situated at the inner condyle ; having joined the deep lymphatics which accompany the vense comites, they proceed onwards to the axilla, and pass through the axillary glands; following the course of the axillary vein, they pass beneath the clavicle, join the lymphatics of the neck, and terminate in the thoracic duct. The lym- phatics of the right upper extremity and right side of the neck unite to form the right or lesser thoracic duct, which opens into the right vena innominata. The lymphatics of the trunk consist of a deep and superficial set ; in the chest the former are seated between the muscles and pleura, in the abdomen between the muscles and peri- toneum, the superficial being subcutaneous. The viscera contained in the chest and abdomen also have a superficial and deep layer of lym- phatics, the deep being distributed through the peculiar tissue of each organ, the superficial running beneath the membranous envelope. 234 Lymphatics have been denied to the brain and spinal chord, and to the ear, eye, and placenta. PECULIARITIES OF THE FCETUS. The principal anatomical peculiarities of the foetus, by which it is distinguished from the adult, are the following : '?. The Thymus gland occupies the anterior me- diastinum,— the kidneys are tabulated, and each is covered by a cellulo-vascular body called renal capsule, which is larger than the kidney itself, — the liver is very large, particularly its left lobe, — the lungs are compact, and of a deep red color, and sink in water, the bronchial tubes and their ramifications being void of air, — the auricles of the heart communicate by the fora- men ovale, — at the bifurcation of the pulmonary artery an arterial trunk about nine lines in length, called ductus arteriosus, proceeds to the aorta, into which vessel it opens, — the um- bilical vein proceeds to the liver, where, having distributed some branches to its left lobe, it divides into the communicating branch, which unites with the portal vein, and the ductus venosus, which opens into the vena cava in- ferior— the internal iliac arteries, under the name of umbilical or hypogastric, turn upwards and forwards along the sides of the bladder, pass through the umbilicus, and run a tortuous 235 course along the umbilical vein to the placenta, and the urinary bladder is in the abdominal part of the pelvis, from the summit of which a ligamentous chord, called urackus, passes to the umbilicus. Until the seventh month the pupil is closed by a membrane, called membrana pupillaris, and in the male the testes are con- tained in the abdomen. THE FASCIAE. CERVICAL FASCIA consists of a superficial and a deep layer. The superficial layer, which is in intimate union with the fibres of the platysma-myoides muscle, is in connection superiorly with the lower jaw and parotid gland, and the cartilage of the ear of either side ; and, extending over the anterior and lateral parts of the neck, is continued down- wards over the forepart of the thorax, where it becomes thin and continuous with the common subcutaneous cellular tissue. The deep layer passes behind the sterno-mastoid and omo-hyoid muscles ; adheres to the upper part of the sternum, the inter-clavicular ligament and the sheath of the carotid vessels, and behind the angle of the jaw, it adheres to the styloid pro- cess and stylo-maxillary ligament. SUPERFICIAL FASCIA OF THE ABDOMEN passes downwards from the thorax over the 236 abdominal muscles, and Poupart's ligament to the thigh. In the median line it passes off the pubis upon the penis, forming its suspensory ligament, and in the female it descends into the labia. In the male it passes on either side round the spermatic chord into the scrotum.' and becomes continuous with the fascia of the peri- naeum. After having passed over Poupart's ligament it forms envelopes for the inguinal glands and adheres to the fascia lata, presenting a cribriform appearance (vide fascia lata) ; and continuing its course downwards becomes iden- tified with the subcutaneous cellular tissue of the lower extremity. FASCIA TRANSVERSALIS AND FASCIA ILIACA. The fascia transversalis is a layer of con- densed cellular tissue, placed between the transversalis muscle and the peritoneum ; it is very strong inferiorly, and is connected to the internal lip of the ilium, and to the whole length of Poupart's ligament, and is continuous, be- hind the rectus muscle, with the fascia of the opposite side. As the external iliac vessels are passing beneath Poupart's ligament, a produc- tion of this fascia extends along the anterior aspect of their sheath, and becomes identified with the cribriform fascia in the groin. The spermatic chord in the male, and the round liga- ment in the female, receive a covering from this fascia about half an inch above Poupart's liga- 237 ment, and midway between the spine of the ilium and the symphysis pubis ; this opening is the internal abdominal ring. The fascia iliaca is much stronger than the fascia transversalis, it is connected to the inner lip of the ilium, passes over the iliacus inter- nus muscle, adheres to Poupart's ligament, from which it passes behind the sheath of the femoral vessels into the thigh, and is connected with the capsular ligament of the hip-joint, and the pectineal portion of the fascia lata. When the fascia iliaca arrives at the outer aspect of the external iliac artery, it sends off a layer of fascia which passes anterior to the external iliac vessels to Poupart's ligament, and from this crosses the femoral ring to become continu- ous with the fascia transversalis. This layer of fascia forms the fascia propria of a femoral hernia. Having sent off this layer the fascia iliaca continues its course behind the external iliac vessels as far as the brim of the pelvis ; it here takes the name of pelvic fascia. The pel- vic fascia, from the brim of the pelvis, lines the parietes of this cavity as far as the upper origin of the levator ani muscle, where it divides into two layers ; one layer (the outer) is called the obturator fascia, which descends between the obturator interims muscle and the levator ani, and is inserted into the great sciatic ligament, the tuberosity of the ischium and pubis. The ligaments of opposite sides become continuous 238 with each other, by extending across the arch of the pelvis, formed by the rami of opposite sides, and thus form the triangular ligament of the urethra, or the deep perineal fascia. The internal layer of the pelvic fascia, called also vesical fascia, passes downwards along the inner surface of the levator ani muscle to the inferior margin of the symphysis pubis from which it is reflected on the prostate gland and neck of the bladder, forming the anterior true ligament of the bladder, and laterally it is reflected on the side of this viscus, forming its true lateral liga- ments. SUPERFICIAL PERINEAL FASCIA adheres to the rami of the ischium and pubis of either side, and extends across the perinaeum, being continuous anteriorly with the superficial fascia of the scrotum derived from the superfi- cial fascia of the abdomen. DEEP PERINEAL FASCIA OR TRIANGULAR LIGA- MENT OF THE URETHRA, is connected, on either side, to the rami of the ischium and pubis, its base looking towards the rectum, its apex towards the sub-pubic ligament, and is pierced by the membranous portion of the urethra, which passes through the ligament about three-quarters of an inch below the pubes. It consists of two layers, between which are situated the artery of the 239 bulb and Cowper's glands ; one layer (the ante- rior) is expanded ontthebulb keeping that body in its situation ; the other (the posterior) is con- tinued along the membranous portion of the urethra to the prostate gland, forms its cap- sule, and becomes continuous on the bladder with the vesical layer of the fascia iliaca. FASCIA OF UPPER EXTREMITY consists of tendinous fibres, which are strongeT in some situations than others ; it invests the entire arm, and sends partitions between the several muscles. It takes its origin superiorly from the spine of the ecapula, adheres to the condyles of the humerus, and to the ridges which lead to them ; passes from thence on the forearm, where it is very strong, particularly at its posterior part, and, binding down the seve- ral muscles, reaches the wrist-joint, to the annu- lar ligaments of which^it is connected. The Palmar fascia, of a triangular form, is very strong, and takes its origin from the ante- rior annular ligament ; from this it expands over the palm, and near the fingers divides into four fasciculi, each of which is forked and inserted into either side of the sheaths of the flexor tendons, and into the ligaments of the first phalanges. FASCIA LATA. This fascia takes its origin from the crest of 240 the ilium, the spines of the sacrum, the os coccygis, Poupart's ligament, the tuberosity of the ischium, and the rami of the ischium and pubis. From this extensive connection it ex- tends down the thigh, confining the different muscles in their situation, and also sending partitions between them. At the posterior part of the thigh it adheres intimately to the linea aspera, and at the knee-joint to the condyles of the femur and the capsular ligament ; it is then continued over the heads of the tibia and fibula, to which it adheres and forms the fascia of the leg. Upon the anterior and upper part ol the thigh, the fascia lata, from its special arrange- ment, has been divided into the iliac and pubic portions, and about an inch and a half below Poupart's ligament, and between the iliac and pubic portions, it presents the opening for the saphena vein. This opening is semi-lunar, the concavity being directed towards Poupart's ligament ; it presents an internal and external cornu, and its edge, turning inwards on itself, becomes continuous with the sheath of the femoral vessels. The pubic portion of the fascia lata covers the pectinseus muscie, adheres to the spine of the pubis and the linea ileo-pectinea, passes behind the sheath of the femoral vessels, and becomes continuous with the fascia iliaca. The iliac portion of the fascia lata covers the 241 sartorius, tensor vaginas femoris, rectus and iliac muscles, and presents, towards the pubic portion, acrescentic] ox falciform edge, the aspect of which is directed upwards and inwards; the inferior cornu of this edge is continuous with the outer corner of the saphenic opening, and its superior cornu extends along Poupart's ligament, crosses the femoral vessels, and is inserted into the linea ileo-pectinea. The cribriform fascia. The superficial fascia, in passing over Poupart's ligament to the groin, adheres to the crescentic edge of the fascia lata, and to the edge of the saphenic opening, and is attached to that layer of the fascia transver- salis, which passes anterior to the sheath of the femoral vessels ; this portion of the superficial fascia is perforated by numerous small blood- vessels, and by the anterior superficial absorb- ents of the limb, which gives it, when dissected, a cribriform appearance, from which it derives its name. The fascia of the leg adheres to the heads of the tibia and fibula, and to the spine of the tibia, to the annular ligaments of the ankle- joint, and to the malleoli ; it binds down the muscles, sends partitions between them, which pass from its posterior surface to the bones of the leg and inter-osseous membrane, and from the anterior annular ligament it is continued thin upon the dorsum of the foot. The Plantar fascia is very strong, and arises 16 242 from the under aspect of the os calcis, is attached to the sides of tarsus and metatarsus, and sends two processes between the muscles of the sole of the foot, dividing them into an internal, a middle, and an external set. At the base of the toes it divides into five portions, each of which bifurcates, and is inserted between two fasci- culi into the lateral ligaments of the joints, and into the sheaths of the flexor tendons. This fascia is strengthened by transverse fibres. THE LARYNX. Besides the muscles, vessels, nerves, and mucous membrane which enter into the forma- tion of the larynx, there are four cartilages and one fibro-cartilage. The thyroid cartilage, the largest, presents anteriorly a prominent angle called pomum Adami, which is formed by the meeting of its alse. Each alas, is of a quadrilateral form, and presents posteriorly two cornua ; the superior cornu is the longest, and is connected to the great cornu of the os hyoides by the thyro-hyoid ligament; the lesser or inferior cornu being connected to the side of the cricoid cartilage by synovial membrane and ligaments. The upper margin of each alas is connected to the os hyoides by the thyro-hyoid membrane, the inferior margin being connected to the cri- coid cartilage by the crico -thyroid membrane, which is of a yellow color and elastic ; the 243 outer surface of each is rough and divided un- equally by an oblique ridge, the inner surface being smooth and covered by raucous membrane. The cricoid cartilage is next in size, and forms a ring ; it is narrow before and deep be- hind, its inferior edge is connected to the first ring of the trachea, its superior edge, anteriorly, is connected by the crico-thyroid ligament to the thyroid cartilage, and posteriorly it supports the arytenoid cartilages; its inner surface is covered by mucous membrane, and its outer surface is rough and presents posteriorly a vertical ridge for the attachment of muscles. The arytenoid cartilages, two in number, are the smallest and of a triangular shape ; the apex of each is surmounted by a small moveable cartilaginous appendix, the base concave, moves upon the cricoid cartilage ; the posterior sur- face concave lodges on the arytenoid muscles, the external edge is convex for the attachment of muscles, and the inner edge is flat. The apex of each is connected to the epiglottis by a fold of mucous membrane called the aryteno-epi- glottideanfold, and the base is connected to the cricoid cartilage by synovial membrane and ligaments. The epiglottis, resembling in form an arti- choke leaf, is connected by a stalk-like process to the angle of the thyroid cartilage ; anteriorly to the body of the os hyoides by cellular tissue and mucous membrane, and to the base of the 244 tongue by three folds of mucous membrane, the central one of which is called frcenum epiglot- titis, and posteriorly by the aryteno-epiglotti- dean folds of mucous membrane. The glottis is the superior opening of the larynx, and is of a triangular form, its base being anterior, formed by the epiglottis, its apex posterior and inferior, formed by the ap- pendices of the arytenoid cartilages, and its sides formed by the aryteno-epiglottidean folds. The rima glottidis is also of a triangular form, and placed beneath the glottis ; the base is posterior, formed by the bases of the aryte- noid cartilages, the apex anterior corresponding to the angle formed by thealse of the thyroid car- tilage, and the sides are formed by the chordae vocales. The chordce vocales, two on either side, arise from the anterior aspect of the arytenoid carti- lages, and approaching each other, are inserted into the angle formed by alse of the thyroid cartilage ; the superior is semilunar, the inferior horizontal, and between the vocal chords of either side is a small oval fossa, called the ven- tricle of the larynx. THE THYROID BODY, Of a reddish-brown color, consists of two late- ral lobes* and a connecting middle lobe. The lateral lobes are placed by the sides of the tra- chea and larynx, and the middle lobe rests 245 upon the anterior aspect of the second, third and fourth rings of the trachea. Each lateral lobe is of a pyriform shape, the base in- ferior, and the apex ascending to the thyroid cartilage ; both lateral lobes overlap the carotid vessels, the thyroid artery, and the recurrent nerve; and are covered by the sterno-hyoid, sterno-thyroid, omo-hyoid, and platysma-my- oides muscles, the cervical fascia, and the integu- ments. This body or gland is supplied with blood by the superior thyroid arteries from the external carotid, the inferior thyroid arteries from the thyroid axis, which is a branch of the subclavian artery, and sometimes by an artery from the arteria innominata, or from the aorta itself called the middle thyroid artery ; its blood is returned by the thyroid veins, which de- scending on the anterior aspect of the trachea empty themselves into the left vena innominata. No excretory duct has been discovered emerging from this body. finis