THE VASCULAR SYSTEM. 145 



coronary to the stomach, and is continued as the splenic, 

 supplying the stomach and the spleen. The phrenic artery, 

 supplying the diaphragm, sometimes arises from the coeliac 

 axis, but usually from the adrenolumbalis. 



The superior mesenteric is about the same size as the 

 coeliac axis, and arises within one centimeter caudad. It 

 sends branches to the pancreas and both intestines. The 

 tidrenolumbalis is a small branch on the left side dividing 

 into the adrenal, phrenic, and muscular. The renal 

 arteries supply the kidneys and usually the suprarenal 

 bodies. The genital arteries are small, and arise from 

 one to two centimeters caudad of the renal arteries. 

 They pass obliquely caudad to the ovaries in the female, 

 and the testes in the male. The inferior mesenteric is 

 .almost as large as the superior mesenteric. It is dis- 

 tributed to the large intestine. The pair of iliolumbai 

 arteries are small branches supplying the muscles of tin- 

 iliac region. 



Four or five pairs of lumbar arteries are given off from 

 the dorsal side of the aorta at regular intervals between 

 the diaphragm and the origin of the external iliac arteries. 

 They supply the muscles of the back and spinal cord. 

 The external iliac arteries are the largest branches of the 

 abdominal aorta and carry blood to the hind-limbs. The 

 internal iliac arteries arise more than a centimeter caudad 

 to the external iliacs and furnish blood to the pelvic 

 viscera and the muscles of the innominate region. The 

 caudal artery is the continuation of the aorta beyond the 

 origin of the internal iliacs. It extends into the tail 

 (Fig. 70). 



ARTERIES OF THE HEAD AND NECK. 



From the arch of the aorta arise the brachio cephalic 

 and left subclaman, which supply the sternum, neck, 



