Hypogastric Arteries 373 



As already shown (p. 311), the hypogastric artery, in its ascent 

 between the peritoneum and the abdominal wall, causes a ridge- 

 like elevation of the peritoneum ; at the sides of the ridge are slight 

 depressions through either of which a direct inguinal hernia may pass. 



After birth the hypogastric arteries dwindle into fibrous cords 

 which, pervious nearly up to the top of the bladder, constitute the 

 superior vesical arteries ; the middle vesical branches are derived 

 from the superior, whilst the inferior vesical comes as a special 

 branch from the anterior division of the internal iliac, and supplies 

 the base of the bladder, the prostate, and the seminal vesicle, 

 and gives off the artery of the vets deferens. This last-named and 

 thread-like vessel leaves the abdomen with the spermatic cord, and 

 may eventually anastomose with the spermatic artery. The vesical 

 arteries anastomose with each other and with their fellows of the 

 opposite side, and with the lower rectal, vaginal, and perineal arteries. 



The uterine artery ascends between the layers of the broad liga- 

 ment, and anastomoses with the ovarian artery above, and with the 

 uterine vessels across the middle line, and below with the vaginal 

 arteries. The vaginal branch anastomoses with its fellow ; with the 

 uterine above ; and in front and behind with vesical and rectal 

 branches. The middle haemorrhoidal anastomoses with the ending 

 of the inferior mesenteric (p. 354) ; with its fellow of the opposite 

 side ; with the haemorrhoidal branches of the internal pudic and per- 

 haps lateral sacral, and with the vesical arteries. 



The obturator artery runs forwards from the anterior trunk of 

 the internal iliac to the upper part of the obturator foramen, through 

 which it passes with, but below, the obturator nerve (p. 358). Before 

 emerging it gives off a pubic branch which anastomoses with its fellow, 

 and with the pubic branch of the epigastric (v. p. 306) behind the 

 pubes. The obturator may also give off a vesical branch, and a twig 

 to anastomose in the iliac fossa with the ilio-lumbar artery. 



Outside the pelvis the obturator artery divides into a couple of 

 branches which, diverging, form an arterial circle around the thyroid 

 foramen ; the branch which runs inwards supplies the origin of the ad- 

 ductor muscles, and anastomoses with ascending twigs of the internal 

 circumflex. The outer division sends a branch to the hip-joint through 

 the cotyloid notch, and, supplying the muscles about the ischial 

 tuberosity, anastomoses with the sciatic. 



The irregular obturator artery has been described on p. 371, and 

 the internal pudlc on p. 441. 



The sciatic is one of the terminal branches of the anterior trunk 

 of the internal iliac artery. It emerges below the pyriformis and 

 passes over the small rotator muscles between the ischial tuberosity 

 and the great trochanter to join in the upper part of the cruciform 

 anastomosis ; that is to say, it joins with the inner and the outer 

 circumflex and the superior perforating arteries. The sciatic also 



