THE HEART AND VASCULAR SYSTEM. 195 



the upper border of the great sacro-sciatic foramen, where it 

 divides into the anterior and posterior trunks. 



The branches from the anterior trunk are: 



Superior vesical, is the pervious remains of the foetal hypo- 

 gastric artery. It supplies the apex and body of bladder, ureter, 

 and vas deferens; 



Middle vesical, supplies the base of the bladder and part of 

 vesiculae seminales; it may be given off from the superior 

 vesical ; 



Inferior vesical, supplies the prostate gland, base of bladder, 

 and vesiculae seminales; 



Middle licemorrlioidal, supplies part of the rectum; 



Obturator, passes along the side of the pelvis to the obturator 

 foramen, through which it passes. It gives off within the pelvis 

 the iliac, vesical, and pubic branch; 



Internal pudic, supplies the external organs of generation. 

 It passes out of the pelvis through the great sacro-sciatic foramen, 

 winds around the ischial spine, and re-enters the pelvis through 

 the lesser sacro-sciatic foramen. 



It gives off the following branches in the perineum : 



(a) Inferior Ticemorrhoidal, supplies the muscles and skin of the 

 anus; 



(b) Superficial perincal, supplies the erector penis and accelerator 

 urinae muscles and the scrotum; 



(c) Transverse perincal, crosses the perineum on the transversus 

 muscle, which, together with the structures between the bulb and anus, 

 it supplies; 



(d) Bulbo-urcthral, supplies the bulb of the spongy body and Cow- 

 per's gland; 



(e) Cavernous, supplies the corpus cavernosum, and is one of the 

 terminal branches; 



(f) Dorsal artery of penis, or clitoris, runs forward on the dorsum 

 and supplies the glans and prepuce. 



The distribution of the internal pudic artery is much the 

 same in the female as in the male, supplying analogous struc- 

 tures the superficial artery to the labia, the artery of the bulb 

 to the bulb of the vagina, the artery of the corpus cavernosum 

 and dorsal artery to the clitoris. 



Sciatic artery supplies the muscles at the back of the pelvis, 

 coccygeus, pyriformis, and levator ani, and passes out of the 

 great sacro-sciatic foramen to follow the course of the sciatic 

 nerve. Its branches external to the pelvis are : 



Coccygeal, supplies back part of coccyx; 

 Inferior gluteal, to the glutens maximus muscle; 

 Comes nervi ischiadici, runs in the substance of the great sciatic 

 nerve; 



