128 LESSER ISCHIATIC NERVE. 



The Muscular branches supplied by the sacral plexus externally to the 

 pelvis are, a branch to the pyramidalis ; a branch to the gemellus supe- 

 rior ; and a branch of moderate size which descends between the gemelli 

 muscles and the ischium, and is distributed to the gemellus inferior, the 

 quadratus femoris, and the capsule of the hip joint. 



The GLUTEAL NERVE (superior gluteal) is a branch of the lumbo-sacral ; 

 it passes out of the pelvis with the gluteal artery, through the great sacro- 

 ischiatic foramen, and divides into a superior and an inferior branch. 

 The superior branch follows the direction of the superior curved line of 

 the ilium, accompanying the deep superior branch of the gluteal artery, 

 and sending filaments to the gluteus medius and minimus. The inferior 

 passes obliquely downwards and forwards between the gluteus medius 

 and minimus, distributing numerous filaments to both, and terminates in 

 the tensor vaginae femoris muscle. 



The INTERNAL PUDIC NERVE arises from the lower part of the sacral 

 plexus, passes out of the pelvis through the great sacro-ischiatic foramen 

 belo\v the pyriformis muscle, and takes the course of the internal pudic 

 artery. While situated beneath the obturator fascia it lies below that 

 vessel and divides into a superior and an inferior branch. 



The Superior nerve (dorsalis penis) ascends upon the posterior surface 

 of the ramus of the ischium, pierces the deep perineal fascia and accom- 

 panies the arteria dorsalis penis to 'the glans, to which it is distributed. 

 At the root of the penis this nerve gives off a cutaneous branch which 

 runs along the side of the organ, gives filaments to the corpus cavernosum, 

 and with its fellow of the opposite side supplies the integument of the 

 upper two-thirds of the penis and prepuce. 



The Inferior or perineal nerve pursues the course of the internal pudic 

 artery in the perineum and sends off three principal branches, an external 

 perineal branch, which ascends upon the outer side of the crus penis, and 

 supplies the scrotum ; a superficial perineal branch, which accompanies 

 the artery of that name and distributes filaments to the scrotum, to the 

 integument of the under part of the penis and to the prepuce ; and, thirdly, 

 the bulbo-urethral branch, which sends twigs to the sphincter ani, trans- 

 versus perinei, and accelerator urinae, and terminates by ramifying in the 

 corpus spongiosum. 



In the female the internal pudic nerve is distributed to the parts analo- 

 gous to those of the male. The superior branch supplies the clitoris ; and 

 the inferior the vulva and parts in the perineum. 



The LESSER ISCHIATIC NERVE passes out of the pelvis through the great 

 sacro-ischiatic foramen below the pyriformis muscle, and divides into 

 muscular and cutaneous branches. The muscular branches, inferior glu- 

 teal, are distributed to the gluteus maximus ; some ascending in the sub- 

 stance of that muscle to its upper border, and others descending. The 

 cutaneous branches are, several ascending filaments to the integument 

 over the gluteus maximus (n. cutanei clunium inferiores), perineal cuta- 

 neous, and middle posterior cutaneous. 



The Perineal cutaneous nerve (pudendalis longus inferior), curves around 

 the tuberosity of the ischium and ascends in a direction parallel to the 

 ramus of the ischium and os pubis to the scrotum, where it communicates 



