172 THE POCKET ANATOMY 



spine internal to pudic artery, and re-enters pelvis through 

 the small notch lying on inner side of internal pudic artery ; 

 it then enters, with accompanying vessels, a sheath of the 

 obturator fascia in the outer wall of the ischio-rectal fossa 

 and divides into its three branches. 



Branches : 



Inferior h&morrhoidal : crosses ischio-rectal fossa to supply 

 external sphincter, skin of anus ; communicates with inferior 

 pudendal of small sciatic and superficial perineal nerves. 



Perineal : largest terminal branch, accompanies perineal 

 artery, and divides into : 



Cutaneous or superficial perineal, two in number : the internal 

 passes with superficial perineal artery either under or over 

 the transversus perinaei to supply the scrotum ; the external 

 gives a branch to the anus, and, piercing the deep layer of 

 the superficial fascia, supplies the scrotum, joining the inferior 

 pudendal. 



Muscular branches supply transversus perinaei, erector penis, 

 ejaculator urinas, compressor urethras, sphincter and levator 

 ani. 



Nerve to bulb : pierces ejaculator urinaa and supplies 

 bulb. 



Dorsal nerve of the penis : accompanies internal pudic artery 

 between the layers of the triangular ligament lying on the 

 outer side of the artery, pierces the anterior layer of the liga- 

 ment, and the suspensory ligament to reach dorsum of penis, 

 along which it runs as far as the glans, gives off many branches 

 to supply the organ, and joins branches of the sympathetic. 

 In the female this nerve is distributed to the clitoris. 



Inferior gluteal : from the lumbo-sacral cord, ist and 2nd 

 sacral nerves ; passes out of pelvis below the pyriformis, at 

 the lower border of which it turns backwards, and, dividing 

 into numerous branches, enters deep surface of gluteus 

 maximus. Communicates near origin with the small sciatic. 



Small sciatic : a cutaneous nerve to lower part of buttock 

 and back of thigh ; it comes off from 2nd and 3rd sacral nerves. 

 It passes below the pyriformis with the sciatic artery, and runs 

 down the back of the thigh beneath the gluteus maximus, and 

 below this beneath the fascia lata, which it pierces in the 

 popliteal space. 



Branches : 



Internal cutaneous ; to integument of upper and inner side of 

 thigh : one larger one, the inferior pitdendal, turnj inwards 

 over hamstrings, supplies scrotum, and joins the external 

 superficial perineal nerve. 



