135 



HUMAN ANATOMY. 



(Fig. 1126), at whose anterior portion the nerve approaches the base of the tri- 

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

 nerve of the penis or chtoris. 



Branches of the pudic nerve are : (a) the inferior hemorrhoidal nerve , () the 

 perineal nerve and (c) the dorsal nerve of the penis or clitoris. 



a. The inferior hemorrhoidal nerve (nif. hemorrhoidales 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 mesially across the base of the ischio-rectal fossa toward 



FIG. 1126. 



Coccygeal nerves, posterior divisions 



Coccyx 



Perineal 

 branch of 

 IV. ante- 

 rior sacral 



Anus 



Vulva 



Coccygeal nerve, anterior division 



P Cutaneous branches from loops of V. lumbar 

 and I. II. and 111. sacral nerves, posterior 



divisions 



Branch of IV. sacral nerve 

 (perforating cutaneous) 



Levator ani and anal 

 fascia 



Pudic nerve 



Cut edge of obturatoi 



fascia 



Inferior hemor- 

 rhoidal nerve 

 Internal pudic 

 artery 



Perineal division of 

 pudic nerve 

 Dorsal nerve ot 

 clitoris 



Inferior 

 pudendal 



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-vesseis in canal on outer wall of 

 ischio-rectal lossa. 



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 : (a a ! a superficial and (bb] a 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 or posterior branch courses along the lateral margin of the perineum, 

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

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



The mesial, internal or anterior h>-'uuh is larger than the lateral and is more deeplv 

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

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

 (nn. scrotales vel laM.iles posterities ) 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. 



