318 ISCHIATIC AND INTERNAL PUDIC ARTERIES. 



be traced forwards by the side of the fundus of the bladder to near its 

 apex, whence it ascends by the side of the linea alba and urachus to the- 

 umbilicus. 



The Middle vesical artery is generally a branch of the umbilical, and 

 sometimes of the internal iliac. It is somewhat larger than the superior 

 vesical, and is distributed to the posterior part of the body of the bladder, 

 the vesiculse seminales, and prostate gland. 



The Middle hamorrhoidal artery is as frequently derived from the 

 ischiatic or internal pudic as from the internal iliac. It is of variable size, 

 and is distributed to the rectum, base of the bladder, vesiculse seminales, 

 and prostate gland, and inosculates with the superior and external haBmor- 

 rhoidal arteries. 



The ISCHIATIC ARTERY is the larger of the two terminal branches of the 

 anterior division of the internal iliac. It passes downwar.ds between the 

 posterior border of the levator ani and the pyriformis, resting on the sacral 

 plexus of nerves, and lying behind the internal pudic artery, to the lower 

 border of the great ischiatic notch, where it escapes from the pelvis below 

 the pyriformis muscle. It then descends in the space between the tro- 

 chanter major and the tuberosity of the ischium in company with the 

 ischiatic nerves, and divides into branches. 



Its branches within the pelvis are hcemorrlioidal, which supply the rec- 

 tum conjointly with the middle haBinorrhoidal, and sometimes take the 

 place of that artery, and the inferior vesical^ which is distributed to the 

 base and neck of the bladder, the vesiculaB seminales, and prostate gland. 

 The branches externally to the pelvis, are four in number, namely, coccy- 

 geal, inferior gluteal, comes nervi ischiatici, and muscular branches. 



The Coccygeal branch pierces the great sacro-ischiatic ligament, and is 

 distributed to the coccygeus and levator ani muscles, and to the integu- 

 ment around the anus and coccyx. 



The Inferior gluteal branches supply the gluteus maximus muscle. , 



The Comes nervi ischiatici is a small but regular branch, which accom- 

 panies the great ischiatic nerve to the lower part of the thigh. 



The Muscular branches supply the muscles of the posterior part of the 

 hip and thigh, and inosculate with the internal and external circumflex 

 arteries, with the obturator, and with the superior perforating artery. 



The INTERNAL PUDIC ARTERY, the other terminal branch of the anterior 

 runk of the internal iliac, descends in front of the ischiatic artery to the 

 lower border of the great ischiatic foramen. It emerges from the pelvis 

 through the great sacro-ischiatic foramen below the pyriformis muscle, 

 crosses the spine of the ischium, and re-enters the pelvis through the lesser 

 sacro-ischiatic foramen ; it then crosses the internal obturator muscle to 

 the ramus of the ischium, being situated at about an inch from the margin 

 of the tuberosity, and bound down by the obturator fascia ; it next ascends 

 the ramus of the ischium, enters between the two layers of the deep pen- 

 neal fascia lying along the border of the ramus of the os pubis, and at the 

 symphysis pierces the anterior layer of the deep perineal fascia, and, very 

 much diminished in size, reaches the dorsum of the penis along which it 

 runs, supplying that organ under the name of dorsalis penis. 



Branches. The branches of the internal pudic artery within the pelvis 

 are several small ramuscules to the base of the bladder, the vesicula? semi- 



