194 HUMAN ANATOMY. 



Suprarenal, supply the suprarenal bodies ; 



Renal, supply the kidneys, a large trunk on each side spring- 

 ing directly from the aorta; 



Spermatic, descend to supply the testicles, and in their pas- 

 sage form one of the constituents of the spermatic cord ; 



Inferior mesenteric, gives off: 



(a) Colica sinistra, supplies the descending colon; 



Cb) Sigmoid, supplies the sigmoid flexure of the colon; 



(c) Superior hsemorrhoidal, the continuation of the inferior mes- 

 enteric, supplies the mucous and muscular coats of the rectum on its 

 posterior aspect. 



Lumbar brandies, four or five on each side, pass backward 

 and outward and divide into the 



Dorsal branches, supply the spinal cord, muscles, and skin 

 of back; 



Spinal branches, divide within the spinal canal, ascend and 

 descend, and form an arterial net-work throughout the whole 

 length of the spinal canal ; 



Abdominal branches, supply the abdominal walls; 



Middle sacral, is the continuation of the abdominal aorta, 

 descending in the middle of the sacrum to the upper part of the 

 coccyx. 



THE COMMON ILIAC ARTERIES 



descend from the bifurcation of the abdominal aorta, opposite 

 the body of the fourth lumbar vertebra, to a point midway be- 

 tween the last lumbar vertebra and the sacrum, where they divide 

 into the external and internal iliac arteries. The right common 

 iliac is a little larger than the left, and passes more obliquely 

 outward. 



Relations. The right common iliac is in relation in front with the 

 small intestine, the ureter, the peritoneum, and the sympathetic nerves ; 

 behind, with the left and right common iliac veins, and to its outer side 

 it rests upon the psoas muscle, and is in relation with the vena cava 

 and the right common iliac vein. The left common iliac is in relation 

 in front with the ureter, the peritoneum, the superior hsemorrhoidal 

 artery, and the sympathetic nerves; behind with the left common iliac 

 vein, to its outer side the psoas muscle, and to its inner side the left 

 common iliac vein. 



The common iliac arteries give off a few unimportant 

 branches to the ureters, peritoneum, etc. 



THE INTERNAL ILIAC ARTERY 



is about an inch and a half in length, extending from the bifurca- 

 tion of the common iliac, about the sacro-lumbar junction, to 



