480 THE ARTERIES OF THE ABDOMEN. 



and the prepuce. It supplies the integument of the penis, and several branches 

 pass through the fibrous sheath of the corpus cavernosum to the spongy tissue in its 

 interior, and anastomose with the offsets of the deep artery. The right and left 

 dorsal arteries communicate freely together in the glans penis. 



Varieties. The pudic artery is sometimes small, and fails to supply one or two, or even 

 three of its usual branches, which, in those circumstances, are furnished by a supplemental 

 vessel, the accessory inidlc. The defect most frequently met with is that in which the pudic ends 

 as the artery of the bulb, while the arteries of the corpus cavernosum and dorsum of the penis 

 are derived from the accessory pudic. But all the three arteries of the penis may be supplied by 

 the accessory pudic, the pudic itself ending- as the superficial perineal. A single accessory 

 pudic has been found to supply both cavernous arteries, while the pudic of the right side gave 

 both dorsal arteries (R. Quain). On the other hand, cases occur in which only a single branch is 

 furnished by the accessory artery, either to take the place of an ordinary branch altogether 

 wanting, or to supplement one of the branches which is diminutive in size. 



The accessory pudic artery generally arises from the pudic itself, before the passage of 

 that vessel through the sacro-sciatic foramen, and descends within the pelvis, along the lower 

 part of the urinary bladder and across the side of the prostate gland, to reach the root of the 

 penis by perforating the triangular ligament in front of the membranous part of the urethra. 

 Less frequently the accessory pudic is derived from the inferior vesical (p. 474), or from some 

 other branch of the internal iliac artery. It may also arise from the obturator artery within 

 the pelvis, that vessel taking origin from either the internal iliac or the epigastric artery ; 

 and in a few cases it has been given off by the epigastric artery directly. 



Branches. The artery of tlie bulb is sometimes small, sometimes wanting on one side, and 

 occasionally it is double. But a more important deviation from the common condition is 

 one sometimes met with, in which the vessel, arising earlier, and crossing the perineum 

 farther back than usual, reaches the bulb from behind. In such a case there is considerable 

 risk of dividing the artery in performing the lateral operation for stone. On the other hand, 

 when this vessel arises from an accessory pudic artery, it lies farther forwards than usual, 

 and is out of danger in case of operation. 



The dorsal artery of the penis has been observed to arise from the obturator artery in the 

 thyroid foramen, from the lower end of the external iliac, from one of the external pudic 

 branches of the femoral, or from the deep femoral artery. This branch is sometimes small 

 on one side, the deficiency being supplied by the opposite artery. The two dorsal arteries 

 are occasionally united by a cross branch, and they have been seen uniting into a common 

 trunk on the dorsum of the penis. 



The pudic artery in the female. In the female this vessel is much smaller 

 than in the male. It takes a similar course, but the following branches differ in 

 their size and distribution from the corresponding arteries in the male. 



The superficial perineal artery is larger than in the male, and is distributed to 

 the labia pudendi. 



The artery of the ~bulb is small, and supplies the bulb of the vestibule. 



The two terminal branches are much smaller than in the male. The artery of 

 the corpus cavernosum (art. profunda clitoridis) enters that body ; and the dorsal 

 artery of the clitoris passes forwards between the crura clitoridis and terminates in 

 the glans and in the membranous fold corresponding to the prepuce of the male. 



7. The sciatic artery (iv), the larger of the two terminal branches of the 

 anterior division of the internal iliac, is distributed chiefly to the muscles on the 

 back of the pelvis. It descends on the anterior surface of the pyriformis muscle 

 and the sacral plexus of nerves, and issues by the lower part of the great sacro- 

 sciatic foramen, in company with the pudic artery and the sciatic nerves. Con- 

 tinuing its course downwards, under cover of the gluteus maximus and resting upon 

 the obturator internus and gemelli muscles, it ends as a slender vessel which 

 accompanies the small sciatic nerve along the back of the thigh, supplying the 

 integument and anastomosing with superficial branches of the perforating arteries. 



Branches. (a) Muscular branches pass to the lower part of the gluteus maximus, 

 anastomosing in the muscle with the gluteal artery ; to the external rotator muscles, 

 anastomosing with twigs of the pudic artery ; and to the muscles arising from the 

 ischial tuberosity, anastomosing with the obturator and internal circumflex arteries. 



