286 THE RABBIT 



(g) The pair of internal iliac veins from the sciatic region of the legs and the 

 pelvic cavity. The postcaval vein arises or is formed from the union 

 of these two vessels at the posterior end of the body. 



B. The Arterial System. 



The aorta on leaving the heart bends over to the left, and from the aortic 

 arch thus formed the following arteries arise : — 



(a) The innominate artery, arising at the beginning of the aortic arch, and 



dividing into a right subclavian artery to the shoulder and a right 

 common carotid artery to the head. Just posterior to the larynx 

 the carotid divides into an internal carotid artery to the brain and an 

 external carotid artery to the right side of the head and face. The 

 subclavian is continued as the brachial artery into the fore-limb. 



(b) The left conmion carotid, arising from the arch at or near the base of the 



innominate. Its course and branches are the same as those of the 

 right common carotid artery. 



(c) The left subclavian artery, to the left shoulder and fore-limb. 



The aortic trunk then passes backwards as the dorsal aorta along the 

 ventral surface of the vertebral column. The dorsal aorta gives rise to 

 the following arteries :— 



(a) The cceliac artery, arising about half an inch beyond the diaphragm, 



and branching into an hepatic to the liver, and a lieno-gastric to 

 the stomach and spleen. 



(b) The anterior mesenteric artery, about an inch behind the cceliac, and 



supplying the duodenum and paincreas, the ileum, cfecum, and colon. 



(c) The pair of renal arteries to the kidneys. 



{d) The pair of spermatic arteries to the testes, or the pair of ovarian arteries 

 to the ovaries. 



(e) The posterior mesenteric artery to the rectum. 



(/) The pair of common iliac arteries, formed (in front of the pubic sym- 

 physis) by the division of the aorta, and running to the hind-limbs 

 and there continued as the femoral arteries. Each common iliac gives 

 rise (in the abdomen) to an ilio-himbar artery to the body-wall, and 

 an internal iliac artery to the anal region. 



(g) The small caudal or median sacral artery, arising from the dorsal aorta 

 just in front of the origin of the common iliacs. 



Make a sketch, showing the complete vascular system. {See Fig. 95 

 page 288.) 



The Urino-genital System. 



A. The Renal or Urinary System. 



Examine the kidneys (metanephros), noting their ovoid shape and the notch 

 on the inner side (the hilus) where the blood-vessels and ureters enter and leave. 

 Trace the ureters from the kidneys to the bladder. Note the form and the thin 

 wall of the bladder. Note also the supra-renal gland or adrenal body in front 

 of each kidnev. 



