I350 



HUMAN ANATOMY. 



(Fig. 1 1 26), at whose anterior portion the nerve approaches the base of the tri- 

 angular Hgament and divides into its terminal branches, the perineal and the dorsal 

 nerve of the penis or clitoris. 



Branches of the pudic nerve are : (a) the inferior hemorrhoidal 7ierve , (<5) the 

 peri7ieal nerve and (<:) the dorsal 7ierve of the penis or clitoris. 



a. The inferior hemorrhoidal nerve (nn. heraorrhoidales inferiores) (Fig. 1127) is usually 

 given off by the pudic upon entering the ischio-rectal fossa, but it may be derived directly from 

 the plexus, its fibres being offshoots of the third and fourth sacral nerves. In company with the 

 inferior hemorrhoidal vessels it passes mesial ly across the base of the ischio-rectal fossa toward 



Coccygeal nerves, posterior divisions 



Fig. 1126. 



Coccygeal nerve, anterior division 



Coccyx 



Perinea; 

 branch of 

 IV. ante- 

 rior sacral 



Anus 



Vulva 



[Cutaneous branches from loops of V. lumbar 

 and I. n. and HI. sacral nerves posteriof 

 division  



Branch of IV. sacral nerve 

 (perforating cutaneous) 



Levator ani and anal 

 fascia 



Pudic ner\-e 



Cut edge of obturatoi 

 fascia 



Inferior hemor- 

 rhoidal nerve 

 ernal pudic 



tery 

 Perineal division of 

 pudic ner\'e 

 Dorsal nerve of 

 clitoris 



Inferior 



pudendal 



nerve 



Superficial dissection of right side of female perineum and adjacent region, showing cutaneous nerves ; obturator 

 fascia has been partly removed to expose pudic nerve and accompanying blood-vessels in canal on outer wall of 

 ischio-rectal fossa. 



the anus, on approximating which it splits into a number of filaments, which supply the external 

 sphincter and the integument of the anal region, and inosculate with the small sciatic, 

 pudic and fourth sacral nerves. 



b. The perineal nerve (n. perinei) (Fig. 1126) is one of the terminal branches of the pudic 

 and arises at the bifurcation of that nerve near the posterior margin of the triangular ligament. 

 Soon after its origin it splits into : (aa) a superficial and {bb) ?i deep branch. 



aa. The superficial branch is entirely sensory and consists of two parts, a lateral or 

 posterior and a mesial or anterior. These pass forward toward the base of the scrotum 

 in company with the superficial perineal vessels. 



The lateral, external ox posterior branch courses along the lateral margin of the perineum, 

 distributing twigs in this region and sometimes sending branches to the inner aspect of the thigh 

 and a filament to the origin of the ischio-cavernosus muscle (Schwalbe). 



The mesial ittternal or anterior branch is larger than the lateral and is more deeply 

 placed. It pierces the posterior margin of the triangular ligament and runs forward either 

 beneath or through the transversus perinei muscle. It splits into two or more branches 

 (nn. scrotales vel labiales posteriores) which inosculate freely with each other. and supply the 

 integument of the scrotum or labium majus. They communicate with the pudendal branch of 

 the small sciatic nerve and with the inferior hemorrhoidal. 



