Part 73

The =vena humeri profunda= (Fig. 68, No. 1) emerges at the height of the elbow, and collects blood from the skin of the dorsal surface of the wing. It also receives veins from the muscles of the posterior side of the upper arm. It passes subcutaneously and dorsally over the dorsal portion of the humerus in company with the external radial muscle and passes with it around the external part of the humerus between the long and short heads of the triceps. It takes a diagonal course to the shoulder cavity and at that point empties into the brachial trunk.

The =profundus ulnaris= originates at the volar surface of the hand, proceeds in company with the ulnar artery, and sends on the base of the hand small anastomotic veins to the vena cutanea ulnaris or basilica. It passes along the anterior arm and between the flexor carpi ulnaris and the pronator profundus muscle to the elbow-joint. On the median surface of the biceps it passes upward and anastomoses with the radial vein. The ulnar vein, in the region of the elbow-joint, receives a large lateral branch which extends around the end tendon of the biceps and anastomoses above with the vena basilica.

The =vena basilica= or cutanea ulnaris is a long vein which originates from the subcutaneous dorsal surface of the index-finger. Near the base of the hand it receives an anastomosing branch from the vena radialis and the vena ulnaris, and then passes upward along the posterior rim of the ulna. It receives numerous branches from the roots of the flight feathers. It crosses below the elbow-joint and reaches the volar surface of the arm. It receives a large branch from the ulnar vein, and then, passing in a diagonal and median direction to the triceps, extends to the shoulder cavity where it empties into the axillary vein.

The outer breast veins unite forming a trunk which crosses ventrally to the subclavian artery, and empties into the subclavian vein.

The vena cutanea abdomino-pectoralis collects the blood from a large skin area of the abdomen, the upper thigh, the breast, and the intercostal region. In the skin of the abdomen it forms a network.

BRANCHES OF THE ILIACS

( Vena metatarsalis ( Vena metatarsalis ( Vena ( interna or magna ( plantaris profunda ( tibialis ( Vena tibialis antica ( postica ( Vena metatarsalis ( Venæ metatarsales ( ( externa ( ( Vena ( Vena metatarsalis dorsalis profunda ( Vena ( tibialis ( Vena metatarsalis dorsalis interna ( poplitealis ( antica ( Vena peronealis ( ( Vena cutanea cruralis ( ( Venæ surales Vena ( iliaca ( ( Vena cutanea abdominalis femoralis externa ( Vena ( Vena femoralis interna profunda ( cruralis ( Vena femoralis anterior ( ( Vena epigastrica

The main trunk passes in the median abdominal line forward and then upward, along the outer edge of the pectoralis major, over the first sternal rib; receives blood from the infrascapular vein, and empties into the pectoralis externa.

The =vena brachialis= is located in the middle of the humerus and the triceps muscle. It is formed by the vena ulnaris, and the vena radialis. It passes with the median nerve and the brachial artery over the inner surface of the humeral joint. Posterior to the humeral head it receives the vena profunda humeri. At the shoulder cavity it receives the vena cutanea ulnaris or vena basilica.

The trunk of the axillary vein is very short and is formed by the veins of the shoulder and the wing. The deeper wing veins accompany the large arterial and the nerve trunks.

BRANCHES OF THE VENA ILIACA INTERNA

( Vena intervertebralis lumbalis ( Pars truncalis ( Vena renalis magna ( ( ( ( ( Vena hypogastrica caudalis sinistra ( ( Vena renalis ( Vena hypogastrica caudalis dextra ( ( ( Vena portalis ( ( Vena coccygea ( Vena cutanea et pudenda Vena iliaca ( ( Vena coccygea mesenterica interna or ( ( Vena cutanea pubica vena hypogastrica ( Pars caudalis ( Vena cutanea caudalis ( ( Vena pudenda ( Vena spermatica ( ( Vena caudalis muscularis ( ( Venæ sacrales ( ( Venæ intervertebrales sacralis ( Venæ renales ( ( Venæ renales ( Pars renalis ( Vena ischiadica ( Vena obturatoria ( Vena suprarenalis externa ( Azygos sacralis

THE POSTERIOR VENA CAVA

The posterior vena cava (Fig. 63, No. 18; Fig. 70, No. 8) has its origin in the posterior half of the body of the bird, somewhat to the right of the posterior aorta, near the anterior lobe of the kidney, by the union of the right and the left vena iliaca communis. It receives the blood from all of the posterior half of the body including the posterior limbs, of the visceral organs, of the abdominal and the pelvic cavity. The posterior vena cava passes dorsally through the right lobe of the liver and through the diaphragm and ends in a short, broad trunk on the posterior dorsal side of the right auricle of the heart. Its opening into the heart is guarded by two half-moon shaped valves. The basal part of the trunk reaches from the right auricle of the heart to the upper anterior rim of the liver where it receives three large trunks, first, the right and second, the left vena portalis hepatica magna, and third, smaller vessels from the liver substance.

THE VEINS OF THE POSTERIOR EXTREMITY

In the skin region on the inner sides of the toes near their bases the small veins collect into five metatarsal veins. The largest vein collects the blood from the first, the second, and the third toe, passes up the tarsus and is called the vena metatarsalis interna, or vena magna (Fig. 65, No. 7). It is located just beneath the skin on the inner surface of the metatarsal bone. It passes in a circle, around the condyle of the tibia and becomes the =vena tibialis postica= (Fig. 65, No. 3 and 8). The vena tibialis postica passes under the tendon Achillis and the tendon of the flexor digitorum brevis, lies subcutaneously upon the latter, and reaching the knee-joint crosses over the upper surface of the ischiadic nerve and becomes the =vena poplitealis=, at which point it receives the vena tibialis antica.

BRANCHES OF THE VENA CAVA POSTERIOR

( Vena ovariana ( Venæ testiculæ ( Vena proventricularis communis ( Vena suprarenalis revehentis ( Vena portalis magna sinistra ( Vena portalis magna dextra ( Venæ innominatæ ( Venæ hepaticæ Vena cava ( Vena cardis coronaria magna posterior ( Vena proventricularis inferior ( ( Vena iliaca interna ( Vena hypogastrica ( ( Vena iliaca externa ( Vena renalis ( ( Vena suprarenalis externa ( Vena iliaca ( Vena ischiadica ( communis ( Vena renalis ( ( Vena intervertebralis lumbalis ( ( Vena renalis magna

( Vena mesenterica communis ( Vena coccygo-mesenterica Vena ( ( Vena mesenterica anterior portalis ( Vena pancreatico-duodenalis dextra ( ( Vena proventricularis ( Vena proventricularis lienalis ( Vena splenica

Vena coccygo-mesenterica ( Vena hemorrhoidalis

On the dorsal side of the metatarsus are two veins. The =vena metatarsalis dorsalis profunda= (Fig. 65, No. 11), which extends under the tendon of the extensors of the toes, along with the artery and the nerve. It collects the blood from the third and the fourth toe and in the middle of the metatarsus receives the =vena metatarsalis dorsalis interna= (Fig. 65, No. 4), which connects the vena metatarsalis dorsalis profunda and the vena magna. The two dorsal veins anastomose with the vena magna, at the intertarsal joint. They pass transversely under the ligament and form the main trunk of the vena tibialis antica which lies close to the anterior surface of the tibia. Near this point there is formed a plexus of veins which again form a trunk and communicates with the vena peronealis and enters between the tibia and fibula with the tibialis antica. It extends along the flexure of the knee and the posterior part of the lower thigh.

The =vena metatarsalis externa= passes subcutaneously on the outside of the fourth toe and the metatarsus, and above the intertarsal point joins the tibialis postica.

The =vena metatarsalis plantaris profunda= (Fig. 65, No. 5) lies on the ventral side of the foot and forms several anastomosing arches with the other veins of the toes. Below the intertarsal joint it enters the vena metatarsalis magna (Fig. 65, No. 9).

The =vena cutanea cruralis= (Fig. 69, No. 7) originates at the height of the tarsal region and passes subcutaneously on the outer posterior surface of the lower thigh region to the vena poplitealis.

The =venæ surales= or inferior muscular branches of the vena poplitealis consist of many veins. One branch comes from the region of the shank and from the gastrocnemius muscle; another as a main branch from the posterior surface of the lower thigh; and a third from the outer surface of the muscles and skin of the upper thigh. The three branches together with the anterior and posterior tibial (Fig. 69, No. 2) unite at the flexure of the knee forming the vena poplitealis (Fig. 69, No. 1).

In the region of the upper thigh, between the knee and the abdominal cavity, the following four veins form the vena cruralis: (Fig. 66, No. 6; Fig. 69, No. 5). First, the =vena cutanea abdominalis femoralis= (Fig. 69, No. 6) which comes out of the side of the abdominal wall, draining the skin of the inner surface of the upper portion of the thigh, the adductor muscles, and the region of the abdominal and the breast border. It crosses the ischiadic artery in a diagonal direction, and enters the vena cruralis in the middle of the crural region.

Second, the =vena femoralis interna profunda= (Fig. 69, No. 3) forms a communication between the end of the suralis near the knee. It lies on the median portion of the flexor cruris internus muscle.

Third, the =vena femoralis anterior= (Fig. 69, No. 4) is formed from branches from the sartorius and adjacent structures, and anteriorly empties into the crural vein near where the latter enters the abdominal cavity.