478 



THE ARTERIES OF THE ABDOMEN. 



and other twigs which supply the external rotator muscles and anastomose with 

 offsets of the sciatic artery. In the perineum the following larger branches 

 arise : 



(a) The inferior or external hcemorrhoidal artery, often represented by two or 

 three separate branches, arises from the pudic artery as it enters the perineal space. 

 Directed inwards through the fat of the ischio-rectal fossa towards the anus, it 

 divides into branches which supply the superficial structures of the posterior part of 

 the perineum, the sphincter and levator ani muscles, and anastomose with the other 

 hsemorrhoidal arteries as well as with the corresponding vessels of the opposite side. 

 Small offsets also turn round the border of the gluteus maximus and supply the 

 overlying integument, while others pass forwards and communicate with the superfi- 

 cial perineal artery. 



() The superficial perineal artery (v) arises from the pudic at the fore part of the 

 ischio-rectal fossa. Crossing over or under the transversus perinei muscle, it runs 



Fig. 382. THE ARTERIES OP THE MALE PELVIS, AS SEEN ON THE REMOVAL OF THE LEFT 

 HIP-BONE, &o. (R. Quain.) 



a, external oblique muscle divided ; b, internal oblique ; c, transversalis ; d t d, the parts of the 

 divided rectus ; e, psoas magnus divided ; /, on the auricular surface of the sacrum, points to the sacral 

 plexus of nerves ; g, on the os pubis, sawn through a little to the left of the symphysis, points to the 

 divided spermatic cord ; A, crus penis divided ; i, bulb of corpus spongiosum ; k, external sphincter 

 muscle ; f, spine of ischium with the small sacro-sciatic ligament ; m, peritoneum ; n, upper part of 

 urinary bladder ; n f , n', vas deferens : n", ureter ; o, o, intestines ; 1, common iliac artery ; 2, external 

 iliac ; 3, internal iliac ; 4, obliterated hypogastric and superior vesical arteries ; 5, middle vesical ; 

 6, inferior vesical artery ; 7, placed on the sacral plexus, points to the common trunk of the pudic and 

 sciatic arteries ; close above 7, the gluteal artery is seen cut short ; 8, sciatic artery, cut short ; 9, on 

 the rectum, the pudic artery as it is about to pass behind the spine of the ischium ; 9', on the lower 

 part of the rectum, the inferior haemorrhoidal branches ; 9", superficial perineal artery ; 9'", on the 

 prostate gland, the pudic artery in the fore part of the perineum, giving off the artery of the bulb, and 

 finally dividing into the artery of the corpus cavernosum and the dorsal artery of the penis ; 10, on the 

 middle part of the rectum, the superior ha3morrhoidal artery. 



forwards beneath the superficial perineal fascia, in company with the nerves of the 

 same name, gives offsets to the subjacent muscles, and divides into long slender 

 branches which supply the back of the scrotum and anastomose with the external 

 pudic branches of the femoral artery. 



