THE PUDENDAL PLEXUS. 



1351 



bb. The deep branch of the perineal nerve is mainly muscular and consists of a single 

 trunk which breaks up into several branches, whose main destination is the muscles of 

 the perineum. Passing forward from the ischio-rectal fossa it enters the deep perineal 

 interspace and sends filaments to the external sphincter ani, the levator ani, the transversus 

 perinei, the ischio-cavernosus, the bulbo-cavemosus or sphincter vaginae and the compressor 

 urethrae. One branch, the nerve to the bulb, accompanied by the artery of the same name, 

 enters the bulb, supplying its tissue and that of the corpus spongiosum, and innervating the 

 urethra as far forward as the glans penis. 



c. The dorsal nerve of the penis (n. dorsalis penis) (Fig. 1 127) a terminal branch and the 

 most deeply situated of all the branches of the pudic, accompanies the dorsal artery of the penis 

 through the deep perineal interspace. It lies beneath the crus penis, the ischio-cavernosus 

 muscle and the inferior layer of the triangular ligament and over the compressor urethrae 



Fig. 1 127. 



Dorsal nerve 

 of penis 



Crus penis, 

 detached 



Ischio-cavernosus. 

 detached 



i>Ierve co ischio- 

 cavernosus 



Nerve to bulbo- 



cavernosus 

 Nerve to bulb 



Nerve to trans- 

 versus perinei 



Muscular br. oi perineal 

 di%ision of pudic ner\ e 



Dorsal nerve 

 of penis 



Cutaneous br. of perineal 

 division of pudic nerve 



Pudic nerve 



Liferior hemor- 

 rhoidal nerve 



Sphincter an'^ 

 externus 



Colles' J^ascla, 

 reflected 



Crus penis and 

 ischio-cavernosus 



Anterior (internal) 

 superficial 

 perineal nerv'e 



Inferior pudendal 

 nerve 



'I'ransversus 

 perinei 



Posterior superfi- 

 cial perineal nerve 



Dorsal nerve of penis 

 Perineal division 

 of pudic nerve, 

 muscular portion 

 Pudic nerve 



Inferior hemor- 

 rhoidal nerve 



Gluteus maximus 



From IV. sacral 



nerve 

 Perforating cutaneous nerve and a branch of IV. 



sacral nerve 



Dissection of male perineum, showing distribution of pudic nerve ; on left side of body Colles' fascia has been 

 reflected to expose superficial perineal interspace ; dorsal nerve of penis is seen in deep interspace on right side. 



muscle. Piercing the inferior layer of the triangular ligament and the suspensory ligament of 

 the penis it reaches the dorsum of the penis, along which it courses as far as the glans. It 

 gives off the nerve to the corpus cavernosum, which pierces the triangular ligament and supplies 

 the erectile tissue of the crus penis and corpus cavernosum. The main nerve innervates the 

 anterior two thirds of the penis, including the glans, and sends off ventral branches which pass 

 around to the under surface of the organ. 



The dorsal nerve of the clitoris (n. dorsalis clitoridis)(Fig. 11 28), while much smaller than 

 the dorsal nerve of the penis, has a corresponding course and distribution. 



The dorsal nerve of the penis or clitoris communicates with the inferior pudendal branch 

 of the small sciatic. 



Variations. — The pudic may receive a root from the fifth lumbar, in the high form of plexus. 

 A root from the fifth sacral is described by Henle. The inferior hemorrhoidal may pierce either 

 the great or the small sacro-sciatic ligament, and the former of these ligaments may be perforated 

 by the lateral superficial perineal nerve. 



