THE PUDIC NERVE. 



329 



tained in a special sheath of the obturator fascia below the pudic vessels, and breaks 

 up into superficial and deep branches. 



The superficial 'perineal nerves are two in number, external and internal. The 

 external or posterior, which is the first to leave the perineal trunk, runs forwards 

 along the outer side of the perineal space to the scrotum, and sometimes gives a 

 branch to the adjacent part of the thigh. The iniernal or anterior branch is larger, 

 and runs forwards nearer the middle line, dividing into long slender offsets which 

 are distributed to the integument of the scrotum. The two branches communicate 

 freely together, and the external generally receives the connecting filaments from the 

 inferior pudendal and inferior haemorrhoidal nerves. The superficial perineal and 



Fig. 214. RIGHT SIDE OP THE INTERIOR OP 



THE MALK PELVIS, WITH THE PRINCIPAL 



NKRVES DISPLAYED. (Hhschfeld and Le- 

 veille.) i 



The left wall has been removed as far as the 

 sacrum behind and the symphysis pubis in 

 front ; the viscera and the lower part of the 

 right levator ani have been removed ; a, lower 

 end of the aorta ; a', placed on the fifth lumbar 

 vertebra, between the two common iliac arteries, 

 of which the left is exit short ; b, right external 

 iliac vessels ; c, symphysis pubis ; d, the divided 

 pyriformis muscle, close to the left auricular 

 surface of the sacrum ; e, bulb of the urethra 

 covered by the bulbo-cavernosus muscle ; the 

 membranous part of the urethra cut short is 

 seen passing into it ; 1, on the crest of the 

 ilium, the external cutaneous nerve of the thigh 

 passing over the iliacus muscle ; 2, on the psoas 

 muscle, the genito-crural nerve ; 3, obturator 

 nerve ; 4, 4, on the lumbo-sacral cords ; that of 

 the right side points to the gluteal artery cut 

 short ; 4'. superior gluteal nerve ; 5, on the 

 right sacral plexus, points by four lines to the 

 anterior divisions of the four ' upper sacral 

 nerves, which, with the lumbo-sacral cord, form 

 the plexus ; 5', placed on the fifth piece of the 

 sacrum, points to the fifth sacral nerve ; 5", 



visceral branches from the third and fourth sacral nerves ; 6, placed on the lower part of the coccyx, 

 below the coccygeal nerves ; 7, the nerve of the levator ani muscle ; 8, inferior hsemorrhoidal nerve ; 

 9, nerve of the obturator internus ; 10, pudic nerve : 10', muscular branches of the perineal nerve ; 

 10", superficial perineal nerves, and on the scrotum the distribution of these nerves and the inferior 

 pudendal nerve ; II, right dorsal nerve of the penis ; 11', the nerve on the left crus penis which is cut 

 short ; 12, small sciatic nerve; 12', its inferior pudendal branch. ; 13, on the transverse process of the 

 fifth lumbar vertebra, the lowest lumbar sympathetic ganglion ; 14, on the first piece of the sacrum, the 

 upper sacral sympathetic ganglia ; between 14 and 6, are seen the remaining ganglia and sympathetic 

 nervous cords, as well as their union with the sacral and coccygeal nerves, and at 6, the lowest ganglion 

 or ganglion impar. 



inferior pudendal nerves are sometimes named from their distribution long scrotal 

 nerves (nn. scrotales poster iores). 



In the female, both the superficial perineal branches terminate in the external 

 labium pudendi (nn. labiales posterior es). 



The deep branches generally arise by a single trunk, and are distributed mainly 

 to the muscles of the perineum. They supply the fore part of the external sphincter 

 and levator ani muscles, the transversus perinei, ischio-cavernosus and bulbo- 

 cavernosus. One branch passes inwards through the bulbo-cavernosus muscle, and 

 divides into slender filaments which penetrate the corpus spongiosum and reach the 

 mucous membrane of the urethra. 



(c) The dorsal nerve of the penis (2, 3, (1) s) is the deepest branch of the pudic 

 nerve, and accompanies the pudic artery in its course through the deep perineal 

 fascia (Vol. II, pp. 339 and 477), and between the layers of the suspensory liga- 



