THE ABDOMEN, INTERIOR. 519 



lower border of the fourth lumbar vertebra, to the junction 

 of the sacrum and ilium, where they divide into the external 

 and internal iliacs. 



The right common iliac is slightly longer than the left 

 (right, two inches, left one and three-quarters). They are 

 crossed by the ureters near their bifurcation, and in the 

 female, by the ovarian arteries. 



For the relation to the corresponding veins, see below. 



The External Iliac Arteries. Figs. 103 to 107. 



Continue the direction of the common iliac arteries from 

 their termination, outward beneath Poupart's ligament, 

 where they become the femoral. 



Under Poupart's ligament the external iliac artery is at a 

 point midway between the anterior superior iliac spine and 

 the symphysis pubis. A line drawn from this point to one- 

 half of an inch below and at the left of the umbilicus, will 

 indicate the course of the common and external iliac arteries. 



The external iliac is crossed by the vas deferens in the 

 male, the round ligament in the female, and by the deep 

 circumflex iliac vein in both. 



For relations to vein, see below. 



Branches. 



(1) The deep epigastric. See page 456. Figs. 94, 

 103 to 107. 



(2) The deep circumflex iliac. Figs. 106, 107. Arises 

 from the outside of the external iliac and takes a course 

 outward, following the direction of Poupart's ligament and 

 the crest of the ilium, to anastomose by its terminal 

 branches with the iliolumbar artery. 



Its muscular branches perforate the transversalis muscle 

 and ascend between this and the internal oblique muscles, 

 supplying the abdominal wall and anastomosing with the 



