THE ILIAC ARTERIES 275 



branches to the cervix of the uterus, cervicouterine, and a 

 branch which descends on the vagina, cervicovaginal, and, join- 

 ing with branches from the vaginal arteries, form a median 

 longitudinal vessel both in front and behind; these continue on 

 the anterior and posterior surfaces of the vagina, and are called 

 the azygos arteries of the vagina. 



(/) The obturator runs forward below the pelvic brim, between 

 the peritoneum and pelvic fascia below the nerve, then through 

 the upper part of the obturator foramen, dividing beneath the 

 obturator externus into an external and an internal branch. 

 Skirting the edges of the foramen, they join below with each 

 other and the internal circumflex. The external also joins the 

 sciatic, and sends a branch along the ligamentum teres, through 

 the cotyloid notch, to the joint. 



The termination of the anterior trunk of the internal iliac then 

 divides into two branches, the sciatic and the internal pudic 

 arteries. 



(g) The internal pudic escapes from the pelvis through the 

 great sciatic foramen, crosses the ischial spine, and re-enters the 

 pelvis by the lesser foramen, then runs along the outer wall of 

 the ischiorectal fossa an inch and a half above the tuberosity, 

 and upon the rami of the ischium and pubes, to the subpubic 

 arch, where it divides into the artery of the corpus cavernosum 

 and the dorsal artery of the penis. 



This vessel is at -first in front of the pyriformis, the sacral 

 plexus intervening, and external to the rectum. On the ischial 

 spine it lies beneath the gluteus maximus, the pudic nerve 

 internally. In the ischiorectal fossa it lies on the obturator 

 internus, ensheathed by the obturator fascia, then between the 

 layers of tlie perineal fascia. 



Branches,. (a) Two or three inferior hemorrhoidal, to skin and 

 muscles around the anus. 



(b) The superficial perineal runs over or under the trans versus 

 perinei to the back of the scrotum, sending branches to the 

 skin and muscles of the perineum. 



(c) The transverse perineal, to the parts between the anus and 

 bulb, joins its fellow. 



(d) The artery of the bulb runs in the constrictor urethrse, 

 pierces the bulb, and sends a branch to Cowper's gland. 



(e) The artery of the corpus cavernosum runs forward in the 

 centre of that body after piercing the crus penis. 



