The Abdominal Aorta. 203 



aorticus and passing to the diaphragm (usually seen better 

 on the right side). 



(b) The suprarenolumbar artery (a. suprarenolumbalis), 

 arising on either side from the renal artery, and passing an terc- 

 laterad to the body-wall, supplying also the suprarenal body. 



(c) The lumbar arteries (aa. lumbales), seven pairs of vessels 

 distributed metamerically to the lumbar portion of the 

 body-wall. Six pairs arise from the dorsal wall of the aorta, 

 the seventh from the median sacral artery. They arise as 

 single trunks, branching into right and left. 



(d) The median sacral artery (a. sacralis media) arises from the 

 dorsal wall of the aorta near its posterior end, and passes 

 backward on the ventral surface of the sacrum in the middle 

 line. Its first portion is concealed from the ventral surface 

 by the common hypogastric vein. 



2. The common iliac artery (a. iliaca communis) is a short 

 trunk, the branches of which pass to the posterior limb, the wall ot 

 the pelvis, and the pelvic viscera. After giving off the iliolumbar 

 artery (a. iliolumbalis), which passes laterad to the body-wall, the 

 common iliac divides into two branches the connections of which 

 may be traced as follows: 



(a) The external iliac artery (a. iliaca externa) is the larger 

 lateral branch, directed toward the inguinal ligament, over 

 which it passes to the medial surface of the limb, becoming the 

 femoral artery. Near its crossing with the ligament it gives 

 off the inferior epigastric artery (a. epigastrica inferior), 

 the main portion of which passes forward in the medial 

 portion of the abdominal wall. 



(b) The hypogastric artery (a. hypogastrica) is the smaller 

 medial branch, directed backward on the dorsal wall of che 

 pelvis. Its course may be traced without injury to the 

 nerves of the lumbosacral plexus. At its junction with the 

 external iliac the vessel gives off the umbilical artery 

 (a. umbilicalis) to the bladder, or in the female first to the 

 vagina and uterus (a^juterina). The obturator artery 

 (a. obturatoria) passes laterad. to the pelvic wall and the 

 middle haemorrhoidal to the side of the rectum and 



