Surgical Anatomy | by John A. C. MacEwen

Presents a concise yet connected account of the anatomical facts of importance to the surgeon, indicating the relative importance of these facts by brief references to their surgical bearing. The physiology of the parts under discussion has also been touched upon when of surgical import.

Title	Surgical Anatomy
Author	John A. C. MacEwen
Publisher	New York William Wood & Company
Year	1910
Copyright	1910, New York William Wood & Company
Amazon	Surgical Anatomy

By John A. C. Macewen, B.Sc. In Anatomy And Physiology With Honours Mb., Cm. With Honours Fellow Of The Faculty Of Phvsicians And Surgeons, Glasgow. Senior Assistant To The Regius Professor Of Surgery, Glasgow University J Surgeon To The Elder Hospital, Govan Assistant Surgeon To The Royal Infirmary, Glasgow, And To H.R.H. Princess Louise Hospital, Roseneath ; Late Civil Surgeon, South African Field Force.

Preface: The author's aim has been to present a concise yet connected account of the anatomical facts of importance to the surgeon, indicating the relative importance of these facts by brief references to thei...

Section I. Head And Neck, Vertebral Column, Brain And Spinal Cord. The Head. Surface Anatomy: The head is generally not symmetrical, the left half being the larger. In some cases this asymmetry is due to pressure at birth, rickets, or syphilis, and is very marked, the head presenting a lop-sid...

The Cranium: The scalp consists of the skin of the head, subcutaneous tissues, and occipito-frontalis muscle, these structures being intimately attached to one another by large numbers of small fibrous bands. The ...

Temporal Region: Over the temporal region the aponeurosis of the occipito-frontalis becomes very attenuated, losing itself gradually as it approaches the zygoma by numerous small insertions into the temporal fascia. I...

Temporal Region. Continued: The Wormian bones, or ossa triquitra, occur chiefly about the lambdoidal suture. Generally few in number and symmetrical, they may form a regular chain, and in cases of hydrocephalus are present in la...

The Cerebral Membranes: The brain is generally described as having three coverings-the dura, arachnoid, and pia mater. Surgically speaking, the pia and arachnoid are one over the greater part of their extent, and may be trea...

The Brain: Of importance to the surgeon is a knowledge of the location of the principal brain centres and their relation to the surface of the head. If two parallel lines be drawn from the nasion in front to a p...

The Brain. Continued: The island of Reil lies at the bottom of the posterior horizontal limb of the Sylvian fissure, and is thus closely related to the frontal, parietal, and temporal lobes by which it is enveloped. A shor...

Cerebral Circulation: The meningeal vessels are classified, according to the fossa they supply, into anterior, middle, and posterior meningeal sets. The anterior are derived from the ophthalmic artery, the posterior from t...

Cerebral Circulation. Part 2: The brain derives its blood-supply from the vertebral and internal carotid arteries, after these have anastomosed at the circle of Willis. This circle is formed posteriorly by the basilar (from juncti...

Cerebral Circulation. Part 3: The medulla is about 1 inch long, conical in shape, being broader above, and connects the pons with the cord. In direction it is vertical, and it ends about the foramen magnum, the ventral surface lyi...

The Cranial Nerves: The olfactory springs externally from the fissure of Sylvius, near the anterior perforated space. As it is close to the third frontal convolution, it follows that aphasia from affection of Broca's lob...

The Cranial Nerves. Continued: The supra-orbital foramen is situated at the junction of the inner and middle thirds of the supra-orbital margin, and a line drawn from that point to the interval between the bicusp teeth of both jaws...

The Ear: The pinna may be congenitally absent, malformed, or abnormally small (microtia) or large (macrotia). Small fistulae may be found, due to failure in fusion of the various tubercles from which the embry...

The Ear. Part 2: It is composed of fibrous tissue, and is lined externally with a very thin layer of skin, continuous with that of the meatus, while internally it is lined with mucous membrane, which is continuous wit...

The Ear. Part 3: The iter, or aditus, about ¼ inch long, leads from the posterior extremity of the attic of the middle ear to the mastoid antrum. Its roof, like that of the middle ear, is composed of a thin plate of b...

The Ear. Part 4: causing complete paralysis of the face on the same side (contrast with effect of pressure on face centre given above). It is thus a matter of great importance to be able to go down upon the mastoid...

The Ocular Apparatus: The eyeball, lying in the orbital cavity, is largely protected from injury by the prominent eyebrow and the bones forming the cavity. The eyebrow possesses a considerable range of movement, and when s...

The Ocular Apparatus. Continued: and to the superior maxilla in the case of the internal ligament, while th6 limbs are attached to the upper and lower tarsal plates. The internal tarsal ligament, or tendo oculi, is the stronger, and ...

Nerve-Supply to the Eye: All these muscles are supplied by the third nerve, except the superior oblique, which is supplied by the fourth, and the external rectus, which is supplied by the sixth. The third nerve also supplies ...

Outer Coat Of the Eye: The sclerotic is a dense, unyielding, nonvascular structure, which does not readily become inflamed nor yield to pressure. This latter characteristic accounts for the pain from pressure on the nerves ...

Outer Coat Of the Eye. Part 2: The chorioid, which is the most extensive part of the middle coat, reaching from the entrance of the optic nerve to about 3/16 inch from the corneal margin, consists of three layers. The outermost lay...

Outer Coat Of the Eye. Part 3: Glaucoma is a disease in which there is greatly increased intra-ocular tension. This increased tension is caused by obliteration of the filtering angle, preventing the escape of effete aqueous humour,...

The Nose: The shin of the nose is thin and movable over the nasal bones, but below is thick and adherent to the cartilage, and abundantly supplied with sweat and sebaceous glands. The lower portion is frequentl...

The Outer Wall of the Nose: Extending upwards and inwards from the anterior nares to the bony apertures of the fossa are the vestibules, which are lined with skin containing numerous stout hairs and sebaceous glands. Skin and mu...

The Accessory Sinuses: The Accessory Sinuses of the nose are important on account of their frequent involvement in nasal affections. The sinuses to be considered consist of two groups-a posterior, opening above the middle t...

The Posterior Group: The sphenoidal sinuses occupy the anterior portion of the body of the sphenoid, and are separated from one another by an osseous septum. Occasionally one or both may be absent, and they vary considera...

The Antrum Of Highmore: The Antrum Of Highmore presents three walls, a roof, and a floor. The anterior, or facial wall, is limited externally by the malar ridge, and below by the alveolar border. It is thin, and presents a p...

The Face: The skin of the face varies in character at different parts. In the orbital region it is very thin, and possesses but little subcutaneous tissue ; in the cheeks it is thicker, and possesses a single t...

Nerve-Supply to the Face: The facial is the motor nerve of the face. Having traversed the temporal bone, it emerges at the stylomastoid foramen, runs forwards, and forms the pes anserinus in the parotid gland, from which radia...

The Upper Jaw: While composed largely of thin bone, and containing the antrum of Highmore, the upper jaw, owing to the arrangement of buttresses by which the force of blows is distributed, is not frequently fracture...

The Parotid Region: The main part of the parotid gland lies in a recess bounded in front by the ramus of the jaw, with the masseter externally and the internal pterygoid internally ; the mastoid process and the sterno-ma...

The Lower Jaw: Congenital complete absence of the lower jaw has occurred ; also partial defects and incomplete development, the jaw remaining of small size. Fracture occurs most commonly at or near the mental forame...

Teeth: The time of eruption of the milk teeth is variable. The lower central incisors appear about the sixth to ninth month, upper incisors tenth month, lower lateral incisors and first four molars about twe...

The Pterygo-Maxillary Or Zygomatic Fossa: The Pterygo-Maxillary OR Zygomatic Fossa is a comparatively small space, bounded anteriorly by the zygomatic surface of the superior maxilla ; internally by the external pterygoid plate and pterygo-sp...

The Spheno-Maxillary Fossa: The Spheno-Maxillary Fossa is a small triangular space situated beneath the apex of the orbital cavity at the angle of junction of the spheno-maxillary and pterygo-maxillary fissures, which communicat...

The Cavity Of The Mouth: The Cavity Of The Mouth is described as consisting of two parts, an anterior, or vestibule, and a posterior, the mouth proper, or buccal cavity, which are separated from one another by the gums and te...

The Cavity Of The Mouth. Part 2: The tongue is almost entirely a muscular organ, which has the hyoid bone as a point of attachment, both for several of its muscles and for the hyo-glossal ligament. It plays an important part in masti...

The Cavity Of The Mouth. Part 3: Unilateral paralysis of the tongue results in deflection to the affected side when the organ is protruded. Complete paralysis of the tongue, which is generally due to a central lesion, produces rapid ...

Tonsils: The tonsil is composed of lymphoid tissue, and is situated between the pillars of the fauces, being kept in position by fibrous bands, which connect its deep surface with the muscles of the palatine a...

The Pharynx: The Pharynx extends from the basis cranii to the lower border of the sixth cervical vertebra. It is about 5 inches long, and is very distensible. It is common to both respiratory and digestive tracts,...

The Neck. Surface Anatomy: The neck is bounded above by a line drawn along the lower border of the lower jaw to the angle, thence to the mastoid process, and so to the superior curved line and external occipital protuberance ; ...

The Sterno-Mastoid: The Sterno-Mastoid region is that which is covered by the muscle of that name. The muscle presents a small fossa- the fossa supraclaviculars minor-between its two heads and just above the sterno-clavi...

The Sterno-Mastoid. Continued: (3) A prevertebral layer runs across the neck in front of the prevertebral muscles, forming a partition between the posterior muscular and anterior visceral segment of the neck. Above, it is attached ...

Submaxillary Region: The submaxillary region may be divided into a median submental triangle, common to both sides, a digastric triangle, and a space between the stylohyoid and digastric which widens posteriorly. The side...

The Infra-Hyoid Region: The thyro-hyoid membrane extends between the posterior aspect of the upper border of the hyoid bone and great cornu, and the upper border of the thyroid cartilage, and is rather over an inch in vertic...

The Infra-Hyoid Region. Part 2: The thyroid cartilage is composed of hyaline cartilage, but begins to ossify about the twentieth year near the cricothyroid joint. As ossification progresses with age, the cartilage becomes brittle, a...

The Infra-Hyoid Region. Part 3: The thyroid gland lies in front of the trachea (under the sterno-hyoid and thyroid muscles and part of the sterno-mas-toids), and is enclosed in a sheath of cervical fascia, which connects it to the l...

The Carotid Region: The common carotid arteries extend in the neck from the sterno-clavicular articulation to the upper border of the thyroid cartilage, a distance of about 3½ inches. In the lower part of their course th...

The Carotid Region. Continued: The posterior triangle of the neck is bounded in front by. the posterior border of the sterno-mastoid, behind by the anterior border of the trapezius, and below by the clavicle, beneath which and betw...

The Vertebral Column: The vertebral column supports the head, connects the upper and lower segments of the trunk, gives attachment to the ribs, is extremely flexible, and contains and protects the spinal cord. The spino...

The Cord: In the adult the cord is generally about 18 inches long, extending from the foramen magnum to the lower border of the body of the first lumbar vertebra. It sometimes ends about the depth of a vertebra...

Section II. Thorax: The skin of the chest is freely movable on the underlying structures, owing to the lax nature of the subcutaneous tissues, which are particularly abundant over the posterior and lateral regions. While...

The Sternum: Behind the manubrium there is little or no lung, the space being occupied chiefly by the vessels, etc. The left innominate vein is most superficial, and lies just below the upper border of the manubri...

The Ribs: The anterior extremities of the ribs are generally on a much lower level than their posterior. Thus, the anterior end of the first rib is on a level with the head of the fourth, the second with the si...

The Mammary Gland: The Mammary Gland is of epiblastic origin, and retains its rudimentary condition of a number of branching ducts with little glandular tissue until puberty, when the gland tissue rapidly increases. A f...

The Thoracic Cavity: The Thoracic Cavity contains the lungs, which are separated by the mediastinum, containing the heart, vessels, trachea, etc. The mediastinum extends from the sternum to the spine, forming a complete s...

The Heart: The Heart is somewhat pyramidal in shape, its long axis being nearly horizontal, and directed downwards, forwards, and to the left. The anterior surface presents itself when the pericardium is opened ...

The Thoracic Aorta: The Thoracic Aorta consists of three parts-ascending, arch, and descending. The ascending portion, about 2 inches long, runs upwards, forwards, and to the right to the level of the upper border of the...

The Thoracic Trachea: The Thoracic Trachea lies in the posterior portion of the superior mediastinum, separated from the vertebrae by the oesophagus. In front it is related to the aortic arch at the level of the fourth dor...

The Lungs: The Lungs, roughly conical in shape, occupy the thoracic cavity, being separated from one another by the mediastinum. The right lung is broader, shorter, and slightly larger than the left. The apex pr...

The Esophagus: The Esophagus is normally about 1o inches long and 1/2 inch wide, and presents two constrictions, one at the beginning, and the other at the point where it is crossed by the left bronchus, each capabl...

Section III. Abdomen And Pelvis. The Abdomen: The abdomen is bounded above by the ensiform cartilage and costal arches ; below by the crest of the ilium, Poupart's ligament, and the crest and symphysis pubis ; and behind by the lumbar spine. For ...

The Abdominal Parietes: The skin of the abdomen is thin, smooth, and movable. In certain abdominal affections, such as ascites, or in pregnancy, the skin becomes stretched and glazed, and presents dark horizontal marks from ...

The Abdominal Parietes. Continued: A separation of the recti, rarely extreme, occasionally occurs below the umbilicus, particularly after numerous pregnancies. The muscle is sometimes torn by muscular or other violence, the opisthotono...

Deep Vessels of the Abdomen: The two lower intercostal, the subcostal, and the four lumbar arteries, run forward between the transversalis and internal oblique, and anastomose with the internal mammary, deep epigastric, and circu...

The Inguinal Region: The Inguinal Region is of much importance surgically on account of the frequency with which hernia occurs in it. The arrangement of the abdominal muscles has already been given, and attention will now...

The Inguinal Region. Part 2: As the anatomical relationships of femoral hernia are closely allied to those of inguinal, it will be well to study these now, although, anatomically, they belong to the thigh. Looking once more at th...

The Inguinal Region. Part 3: A less common form of hernia is the obturator, in which the bowel, pushing the parietal peritoneum, extraperitoneal fat, and pelvic fascia before it, passes downwards, forwards, and inwards through th...

The Inguinal Region. Part 4: In the female the canal is occupied by the round ligament, along which a process of peritoneum, called the canal of Nuck, descends in the foetus for a short distance. A congenital form of inguinal her...

The Abdominal Cavity: The peritoneum is a single closed serous sac, composed of a thin fibrous layer, lined on its inner surface with endothelium. This closed sac is divided into two portions-a greater sac and a lesser sac...

The Stomach: The Stomach lies in the supramesocolic compartment of the abdomen, almost entirely to the left of the middle line, occupying a space immediately under the left dome of the diaphragm and left lobe of t...

The Stomach. Continued: The stomach is frequently affected by ulcers, which occur most often on the posterior wall toward the lesser curvature, but may occur at any part, and which also very frequently affect the pylorus and...

The Duodenum: The Duodenum is described in three sections, the whole being nearly a foot in length, and describing a rough circle, or sometimes being of a U or V shape, with the apex downwards. It has been suggeste...

The Small Intestine: The Small Intestine between the duodenum and caput caecum is on an average about 22 feet long, and is divided into two portions-jejunum and ileum-the first being about 8 feet, and the latter 14 feet, ...

Vessels of Small Intestine: Both jejunum and ileum are supplied by the superior mesenteric, from which some fifteen to twenty branches run forward between the mesenteric layers, form numerous anastomosing arches, and then give o...

The Large Intestine. The Caecum: The Caecum is that portion of large intestine which lies below the entrance of the ileum. It is normally situated in the right iliac fossa, its most dependent part midway between the anterior iliac sp...

The Vermiform Appendix: The Vermiform Appendix in the adult is situated on the inner and posterior aspect of the caecum, and is normally about 3½ inches long, and about ½ inch in diameter. Its position is very variable, even...

The Colon: The Colon, commencing at the ileo-caecal valve, and terminating at the junction with the rectum, opposite the front of the body of the third sacral vertebra, is fully 3 feet long, and has a diameter r...

Blood-Supply to The Colon: The caecum and vermiform appendix are supplied by the ileo-colic; the ascending colon by the right colic; and the transverse colon by the middle colic of the superior mesenteric ; while the descending...

The Liver: The Liver lies under the diaphragm, occupying the right and central portions of the cavity formed by that dome-shaped muscle to which its convex parietal surface is moulded, while its visceral surface...

Vessels of The Liver: The portal vein, formed by the junction of the superior mesenteric and splenic veins, commences behind the head of the pancreas, ascends behind the first part of the duodenum, and then, accompanied by...

The Pancreas: The Pancreas, about 6 inches long, runs almost horizontally across the abdomen at the level of the first lumbar vertebra, about 3 inches above the umbilicus. The tail is in contact with the spleen ; t...

The Spleen: The Spleen is about 5 inches long and 3 inches broad. It may be compared in shape to a thick pancake, which, instead of being circular, is roughly triangular in outline, while its visceral surface pre...

Lumbar Region: The lumbar region extends from the level of the twelfth dorsal vertebra and twelfth rib to the base of the sacrum, ilio-lumbar ligament, and iliac crest. Externally it is limited on the posterior aspe...

The Kidneys: The Kidneys are about 4 inches long, 2½ inches broad, and 1½ inches thick, the right being shorter and thicker than the left, which, however, is the larger. On the anterior surface of each kidney ther...

Nephrorrhaphy: These operations may be performed through a lumbar incision, commencing below the angle between the last rib and the outer border of the erector spinar, and extending down and out to about 1 inch abov...

The Suprarenal Capsules: The Suprarenal Capsules are situated at the upper extremities of the kidneys, and also extend along the inner border, the right being pyramidal and the left crescentic in shape. The right is moulded a...

The Solar Plexus: The Solar Plexus supplies the stomach, small intestine, liver, pancreas, spleen, and kidneys with sensation; controls the blood-supply, and also the calibre of the bowel. The plexus receives branches ...

The Aorta: The Aorta gives off numerous large branches to the intestines, the coeliac axis and superior mesenteric being as large as the carotid. These vessels form arches before finally supplying the bowel, but...

The Inferior Vena Cava: The Inferior Vena Cava commences on the right side of the fifth lumbar vertebra at the junction of the iliacs. Lying on the right side of the spine as it ascends, it is in front of the right lumbar, a...

The Thoracic Duct: The Thoracic Duct has been wounded, and also cut and ligatured without bad results. Its communications with the azygos veins in the posterior mediastinum and lymphatic vessels of the right side may se...

The Pelvis: The Pelvis is important surgically, not merely on account of its contained organs, but from its mechanical position. The centre of gravity of the adult body is just above the sacro-lumbar angle, and o...

The Pelvis. Part 2: The prostate, neck of the bladder, vesiculi seminales and base of the bladder between them, and last 2½ inches of the rectum are excluded by the attachment of the visceral layer of pelvic fascia from ...

The Pelvis. Part 3: The external iliac artery is invested by both peritoneum and extraperitoneal tissue, the latter (fascia of Abernethy) sending in a septum between the artery and vein. The artery is crossed near Poupar...

The Bladder: While for some time after birth the Bladder is an abdominal organ, and spindle-shaped, in the adult it occupies the pelvis, although it rises into the abdomen when distended. The bladder lies between ...

The Bladder. Continued: The arteries supplying the bladder are the superior and inferior vesical of the interior iliac, the latter of which is the larger, and supplies the more vascular floor. The veins have a plexiform arra...

The Urethra: The female urethra, 1½ inches long, runs downwards and forwards in a slight curve, pierces the triangular ligament, between the layers of which it is surrounded by the compressor urethral, and ends at...

Male Organs Of Generation. The Penis: The Penis is described as consisting of a root and body. The root consists of the bulb of the corpus spongiosum, which lies in the middle line in front of the anterior layer of the triangular ligament...

The Prostate: The Prostate has been compared in size and shape to a Spanish chestnut. It is 1¼ inches long, 1½ inches broad, and ¾ inch in antero-posterior depth. Normally it weighs 6 drams, but may be considered t...

The Testicle: The epididymis, composed of a much-convoluted tube some 20 feet long, is applied to the posterior border of the testicle, from which it is separated by an involution of the serous covering, forming a ...

Female Organs Of Generation. The Uterus: The Uterus is 3 inches long, 2 inches wide at its broadest part, and its canal, including the cervical portion, is 2½ inches long. It weighs about 1 ounce. It is composed of an upper expanded portion,...

The Vagina: The Vagina leading from the cervix to the vulva is about 3 inches long, and is partially occluded at its lower extremity in nulliparae by a fold of mucous membrane called the hymen It is directed down...

The Ovary: The Ovary, ovoid in shape and about 1¼ inches long by ½ inch broad at its widest part, is situated nearly vertically, its upper pole being attached to the pelvic brim by the suspensory ligament, while...

The Perineum: The Perineum Is a lozenge-shaped area, nearly 4 inches long and 3½ inches broad at the widest part, which corresponds to the outlet of the pelvis, being bounded in front by the symphysis ; laterally b...

The Perineum. Continued: Perineal lithotomy-to remove a stone from the bladder, which here lies at a depth of 3 inches-is an operation seldom performed. It may be either lateral or median. In the lateral operation an incision...

The Rectum: The Rectum commences opposite the body of the third sacral vertebra, and, descending in front of the sacrum and coccyx, runs forwards for 1½ inches upon the pelvic floor, formed by the two levatores a...

The Rectum. Part 2: The last inch or so of the rectum directed downwards and backwards is sometimes spoken of as the anal canal. It is surrounded by the internal and external sphincters, which, assisted by the levatores ...

The Rectum. Part 3: In the child the rectum is relatively larger in its upper part, is nearly straight, almost vertical, and is partly abdominal rather than pelvic. At birth, also, the peritoneal covering descends to the...

Section IV. Lower Extremity. Gluteal Region. Surface Anatomy: The Hip This region may be subdivided into gluteal and adductor portions, and region of Scarpa's triangle. The gluteal region is bounded above by the iliac crest, and below by the gluteal fold ;...

The Pyriformis: The glutei medius and minimus are also provided with bursae over the great trochanter, into which, along with the Pyriformis, obturator internus and gemelli, they are inserted. The bursa over the isch...

Scarpa's Triangle. Surface Anatomy: Scarpa's triangle is limited above by Poupart's ligament, extending from the anterior superior spine to the spine of the pubis in a slight curve, with the convexity downwards. Owing to the attachment ...

Scarpa's Triangle. Surface Anatomy. Part 2: Lying between Poupart's ligament and the innominate bone are a number of structures of surgical importance. The space is rougftly triangular in shape, bounded above by Poupart's ligament, externally b...

Scarpa's Triangle. Surface Anatomy. Part 3: Of the muscles, the ilio-psoas is of particular importance surgically, on account of its sheath directing the course of the pus in psoas abscess, where the spine is the seat of disease (q.v.). Being e...

The Hip-Joint: The Hip-Joint is an excellent example of a ball-and-socket joint. Ilium, ischium, and pubis all enter into the composition of the acetabulum, and are connected by a Y-shaped cartilage, which begins to...

The Hip-Joint. Part 2: The synovial membrane lines the inner surface of the capsule, from which it is reflected inwards on to the neck along the capsular insertion, being separated from the neck by the cervical ligaments. I...

The Hip-Joint. Part 3: Dislocation into the obturator foramen (thyroid) is produced where the head maintains its primary position, or moves slightly forwards. If, on the other hand, extension and external rotation are prese...

Hip-Joint Disease: The hip is often affected by tubercle, especially in children, and is less frequently attacked by rheumatoid arthritis. As the joint is deeply placed, evidence of swelling in the joint is not an early...

The Thigh. Surface Anatomy: Running from the apex of Scarpa's triangle to the internal condyle of the femur is a shallow groove, which lodges the sartorius muscle and corresponds to the position of the femoral artery in Hunter's...

The Femur: With reference to operations on and fractures of the femur, it should be remembered that the periosteum is much thicker in children than in adults, so that displacement is frequently prevented by it i...

The Knee. Surface Anatomy: When the leg is extended it does not lie in the same line as the thigh, but, owing to the obliquity of the latter, forms an angle of about 170 with it. The patella is generally easily recognized, part...

Bursae Of Front Of Knee: 1. Situated in the subcutaneous tissue over the lower part of the patella and upper part of the ligamentum patellae is the prepatellar bursa, which is the largest subcutaneous bursa in the body. It is...

The Knee-Joint: The Knee-Joint, the largest in the body, despite its exposed position is rarely dislocated owing to its great strength. This strength is due chiefly to the muscles, fasciae, and ligaments, including t...

The Ligamentum Patella. Fractures Of The Patella: The ligamentum patella, some 2 inches in length, is a continuation of the quadriceps tendon over the front of the patella, and also is attached to the apex of the bone, from which it inclines downward...

The Lateral Dislocations Of The Patella: Of the Lateral Dislocations of the patella, that outwards is the more common, owing to the tendency of the quadriceps when contracted to pull the patella and ligamentum patellae into,a straight line, ...

The Semilunar Fibro-Cartilages: The semilunar Fibro-Cartilages, roughly triangular in section, deepen the articular surfaces on the head of the tibia, the base being turned toward the capsule to which it is attached, while the free ...

The Semilunar Fibro-Cartilages. Continued: The periosteum is a tough fibrous coat, which lines the diaphyses of long bones, which acts as a limiting membrane to the bone cells, or osteoblasts, keeping them in bounds, and which supplies the bon...

The Leg. Surface Anatomy: The tibial crest running in a curved course downwards from the tibial spine forms a prominent landmark, while its internal surface being subcutaneous is easily palpated throughout its entire length. T...

The Leg. Surface Anatomy. Continued: The peroneus tertius, arising from the lower third of the fibula on its inner aspect, sends its tendon down on the outer-side of that of the extensor digitorum. The branch of the peroneal artery enter...

Bones Of The Leg: It should be remembered that the tibia alone articulates with the femur, and therefore bears the whole Weight of the body, while the fibula supplements it, particularly in resisting lateral and torsio...

The Ankle And Foot. Surface Anatomy: The malleoli form prominent landmarks, the tip of the external malleolus being about ½ inch below and behind that of the internal, while, owing to the greater breadth of the latter, their posterior bo...

The Ankle And Foot. Surface Anatomy. Continued: The superficial veins are most numerous on the dorsum, where they form a plexus, particularly about the internal malleolus, while the parts of the sole which touch the ground are comparatively free fr...

The Dorsalis Pedis: The interior tibial artery is crossed at the ankle by the tendon of the extensor hallucis, and then lies between it and that of the extensor digitorum, being continued into the foot as the Dorsalis pe...

The Ankle-Joint: The lower ends of the tibia and fibula are firmly bound together by a series of ligaments, while the malleoli project beyond and form a socket into which the upper and external surfaces of the astraga...

The Ligaments: The LIGAMENTS which hold the bones together are anterior and posterior inferior tibio-fibular ligaments ; an interosseous ligament, which is continuous above with the interosseous membrane, and below ...

The Tarsus: Three sets of joints exist in the tarsus : (i) Between astragalus and os calcis (posterior). (2) (a) Between astragalus and scaphoid, (b) between os calcis and cuboid. These two together constitute th...

The Tarso-Metatarsal Articulations: The first metatarsal articulates with the internal cuneiform by a complete joint, which undergoes an outward subluxation in the condition called hallux valgus, the suppurating bunion, which frequently...

The Tarso-Metatarsal Articulations. Continued: Pure talipes varus is very uncommon. Talipes valgus is the opposite of talipes varus, the foot being everted and raised, so that the patient walks on the inner margin. A pure valgus is not often met w...

The Nerves of the Lower Extremity: The spinal origins of the nerves supplying the muscles of the lower limb are :-adductors, ilio-psoas, pectineus, sartorius (third lumbar) ; quadriceps extensor cruris (fourth lumbar) ; hamstrings, glu...

Section V. Upper Extremity. Region Of The Shoulder. Surface Anatomy: This region may be divided into clavi pectoral, deltoid, and scapular portions. The clavi pectoral region is bounded by the clavicle above, the sternum internally, lower border of the pectoralis major...

The Clavi-Pectoral Region: The shoulder girdle is formed by the clavicle and scapula, the clavicle alone being articulated to the trunk at the sterno-clavicular articulation. A few cases of avulsion of the entire upper limb hav...

The Acromio-Clavicular: The Acromio-Clavicular joint is directed from before backwards, and slopes from above, down, and inwards, the outer end of the clavicle projecting to a varying extent above the upper surface of the ac...

The Scapular Region: The posterior scapular muscles are contained within fairly definite compartments, composed of deep fascia, which are attached round their origins to the bone, and accompany them to near their insertio...

The Deltoid Region: The skin in this region is thick, and possesses a considerable subcutaneous tissue, in which lipomata not infrequently develop, and which occasionally shift their position under gravity to perhaps the...

The Shoulder-Joint: While of the ball-and-socket variety, the shoulder-joint relies chiefly upon muscular support, and thus, while great latitude of movement is permitted, it also is prone to dislocation. The coraco-acro...

Subspinous Dislocation: In the true subspinous dislocation the head rests on the dorsum scapulae under the spine, the infraspinatus and teres minor muscles being pushed before it, while the subscapularis is drawn across the ...

The Axilla: The Axilla (Fig. 50) is a roughly funnel-shaped passage between the neck and the arm, whose apex is directed upwards and inwards, which is bounded in front by the clavicle and sub-clavius muscle, and ...

The Axilla. Continued: Ligature of the third part is performed through an incision along the line of the vessel (at the junction of the middle and anterior thirds of the axilla), which should not extend beyond the lower bor...

The Arm. Surface Anatomy: The region of the arm extends from the axilla to the elbow. The contour varies according to the muscular development, being cylindrical where the development is poor, but flattened from side to side w...

The Humerus: The Humerus is cylindrical above its centre, then prismatic, and finally flattened antero-posteriorly, presenting marked lateral supracondyloid ridges, which give attachment to the intermuscular septa...

Fractures Of The Humerus: Those which occur at the upper end may be classified as (a) anatomical neck ; (b) through the tubercles ; (c) separation of the upper epiphysis ; (d) surgical neck. (a) Anatomical Neck-This is a ra...

Fractures Of The Lower End Of The Humerus: (a) Transverse supracondyloid ; (b) T-shaped fracture ; (c) fractures of condyles ; (d) separation of lower epiphysis. All of these fractures occur more frequently in young subjects. (a) The transv...

The Elbow. Surface Anatomy: The lower end of the biceps muscle and its tendon form a tapering mass in the centre of the elbow, and is separated by an angular-shaped hollow from a mass on the outer side, consisting of supinator l...

The Skin Over The Back Of The Elbow: The Skin Over The Back Of The Elbow is thicker than in front, and slightly corrugated, or even scaly. It possesses great freedom of movement, and presents a bursa over the posterior aspect of the olec...

The Lower End Of The Humerus: The Lower End OF The Humerus, flattened from side to side and curved with the convexity forwards, presents at the junction of the shaft and articular extremity, and above the trochlea, two fossae-one,...

Dislocations Of The Elbow: The most common form of dislocation at the elbow is one of both bones backwards. The bones generally go together, owing to the firm connection between them. They tend to be displaced back or forwards ...

The Forearm. Surface Anatomy: The forearm, when well developed, is oval in section in the upper third, but slightly flattened anteriorly, and more convex posteriorly. In the middle third it is more nearly circular, while near the ...

The Inferior Radio-Ulnar Joint: The Inferior Radio-Ulnar Joint Consists of (a) an articulation between the head of the ulna and the sigmoid facet on the lower end of the radius, and (b) the articulation between the head of the ulna ...

Fractures Of The Radius And Ulna: Both bones are most frequently fractured, generally as a result of direct violence, both bones breaking about the same level, in the middle or lower third. Displacement depends chiefly on the fracturi...

The Wrist And Hand. Surface Anatomy: Like the lower portion of the forearm, the wrist is compressed antero-posteriorly, and presents for examination anterior and posterior surfaces. The styloid processes of radius and ulna form prominent...

The Wrist And Hand. Surface Anatomy. Part 2: On the dorsal aspect of the hand the tendons can generally be easily made out, particularly when the fingers are hyperextended. The first dorsal interosseous muscle is chiefly responsible for the emin...

The Wrist And Hand. Surface Anatomy. Part 3: Dupuytren's contraction of the palmar fascia most frequently affects the slips to the ring and little fingers, producing flexion of these fingers and wrinkling of the overlying skin when an attempt is...

The Wrist-Joint: The Wrist-Joint consists of the articulation between radius and triangular fibro-cartilage above, and scaphoid, semilunar, and cuneiform bones below, the upper or radial surface being concave from sid...

The Thumb And Fingers: The carpo-metacarpal joints of the index, middle, and ring fingers permit of little movement, whereas that of the thumb possesses free movement, and that of the little finger a much less degree. The d...

A Backward Dislocation Of The Thumb: A Backward Dislocation Of The Thumb (Hey's) at the metacarpo-phalangeal joint is not uncommon, being caused generally by forcible hyperextension, and presents considerable difficulty in reduction. Thi...

The Nerves Of The Upper Extremity: The spinal origins of the nerves supplying the muscles of the upper limb are : adductors and abductors of shoulder (circumflex, supra- and subscapulars), fifth and sixth cervical ; flexors of elbow (m...

Surgical Anatomy | by John A. C. MacEwen

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