244 LABORATORY MANUAL FOR VERTEBRATE ANATOMY 



oviduct. These may be seen by turning the oviduct to the right. In their course 

 over the kidneys the renal portal veins give off branches into the kidney as 

 in lower forms. There is probably some portal circulation in the kidneys, but 

 most of the blood from the renal portals passes directly into the iliac veins. 

 The iliac vein receives renal veins from the kidney of which there is one chief 

 renal vein, which runs along the medial side of the kidney but is so imbedded 

 in the kidney substance as to be difficult to identify. Between the two renal 

 portal and iliac veins runs the dorsal aorta. 



Turn the animal dorsal side up and remove the skin over the thigh. By 

 separating the muscles pick up the femoral and sciatic veins and trace them into 

 the leg. The sciatic vein accompanies the large sciatic nerve and soon turns 

 forward to run parallel to the femoral vein. Both /eins are accompanied by 

 arteries of the same name. 



Draw the branches of the postcaval vein and the renal portal system. 



4. The pulmonary veins. The pulmonary veins emerge on each side from 

 the lung and pass toward the heart immediately posterior to the precaval veins. 

 There is usually one pulmonary vein from each lung but there may be two. Note 

 the branches collected by each vein from the lung. The veins pass to the dorsal 

 side of the bases of the precavals and enter the left auricle. Their entrance into 

 the auricle is best seen later when the heart is dissected. 



5. The arterial system. It has already been noted that the great arteries 

 spring directly from the ventricle. They are situated between the two auricles. 

 Separate their bases from the auricles. It will be then be found that there are 

 two arterial trunks. The larger, medially located one is the aorta. The smaller 

 one, passing to the left and dorsal to the aorta, is the pulmonary artery. The 

 ventral aorta in birds is split into these two vessels. 



a) The anterior branches of the aorta: Follow the aorta away from the heart. 

 The aorta immediately gives rise in the median line to two large arteries, the 

 brachioceplialic (innominate} arteries. The aorta then turns to the right and 

 disappears dorsally. It will be followed at a later time. Identify the branches 

 of the brachiocephalic arteries; as both have identical branches follow only 

 one. Each proceeds laterally and slightly anteriorly and forks into two branches, 

 an anterior common carotid artery and a lateral subclaman artery. The sub- 

 clavian artery soon gives rise to a number of branches: the small internal 

 mammary artery passing posteriorly along the inner surface of the ribs, the two 

 pectoral arteries to the pectoral muscles along with the veins of the same name, 

 and the axillary artery to the wing. The axillary artery runs anteriorly and 

 after giving off a branch into the shoulder enters the wing as the brachial artery. 

 The two common carotid arteries pass forward and at the level of the cervical 

 lymph gland each gives rise to a "vertebral artery, which passes dorsally into 

 the vertebrarterial canal of the vertebral column. The common carotid arteries 

 then approach the median line and penetrate the muscles on the ventral sur- 



