540 THE ARTERIES. 



vesical branches also, though very rarely, come from the internal artery of 

 the bulb ; in which case the obliteration of the umbilical artery is complete. 



2. Internal Pudic Artery, or Artery of the Bulb. 



(Figs. 274,7; 275,16; 277,4.) 



This vessel differs in its distribution in the male and female. 



INTERNAL PUDIC ARTERY IN THE MALE. It proceeds from the internal 

 iliac, near the origin of that vessel, by a trunk common to it and the 

 umbilical artery ; it is then directed backwards, following the superior border 

 of the internal obturator (pyriformis) muscle, and placed either without or 

 within the texture of the great ischiatic ligament. Arrived at the neck of the 

 bladder, it enters the pelvic cavity, lying beside the prostate and Cowper's 

 glands, and is finally inflected downwards, passing round the ischial arch to 

 reach the bulb of the urethra. 



In its progress it furnishes : 



1. Insignificant ramuscules to the muscle adjoining the sacro-ischiatic 

 ligament. 



2. The vesico-prostatic artery (Figs. 274, 8; 275, 17). This is a 

 branch constant in its distribution, but variable in its origin. Destined to 

 supply the prostate gland, vesiculse seminales, the pelvic dilatation of the 

 deferent canal and the canal itself, as well as the bladder, it usually 

 commences near the prostate gland, and passes from behind to before, in a 

 flexuous manner, on the vesiculae seminales and the deferent canal. 



3. Slender ramifications for the pelvic portion of the urethral canal, 

 Cowper's glands, the anus, and the ischio-cavernous muscle (erector penis). 



The terminal extremity of the vessel is insinuated beneath the accel- 

 erator muscle, and immediately divides into a multitude of ramuscules 

 which enter the erectile tissue of the urethral bulb, where they comport 

 themselves as in all tissues of this kind. 



Varieties. -It is not rare to see the artery of the bulb detach, before 

 attaining Cowper's gland, the cavernous artery, which then passes round the 

 ischial arch along with the nerve of the penis. Sometimes it only gives off 

 the posterior dorsal artery of the penis, a branch of the cavernous. 



DISTRIBUTION OF THE INTERNAL PUDIC ARTERY IN THE FEMALE. (Fig. 

 277, 4.) This artery terminates, towards the vagina, by rectal, vulvular, 

 vaginal, and bulbous branches ; the latter are for the bulb of the vagina. 

 As in the male, it does not give off more than one important branch on its 

 course ; this, the vaginal artery (Fig. 277, 5) is analogous in every respect to 

 the vesico-prostatic artery ; its terminal divisions go, not only to the middle 

 portion of the vagina, but also to the body of the uterus, where they 

 anastomose largely with the branches of the uterine artery, and even pass 

 to the bladder and rectum. 



The internal pudic artery of the female, as in the male, is liable to nu- 

 merous variations. It may furnish the cavernous artery, or only the dorsal 

 artery of the clitoris. We have seen the vaginal artery come from the 

 umbilical. 



3. Subsacral or Lateral Sacral Artery. (Figs. 275, 2 ; 277, 6.) 



Rising within the internal iliac artery, at, or a little behind the lumbo- 

 eacral articulation, lying above the peritoneum, and beneath the sacral 

 foramina and the large nerves passing through them, this vessel is directed 

 backwards and arrives near the posterior extremity of the sacrum, where 



