SMALL SCIATIC NERYE. 



673 



clitoris, labia, and other corresponding parts in the female. It communicates 

 with the inferior pudendal branch of the small sciatic nerve. 



SMALL SCIATIC NERVE. 



The small sciatic nerve (tiervus ischiadicus minor) is chiefly a cutaneous 

 nerve, supplying the integument of the lower part of the buttock, the back 

 of the thigh, and upper part of the calf of the leg; it furnishes also branches 

 to one muscle the gluteus maximus. 



This nerve is formed by the union of two or more nervous cords, derived 

 from the lower and back part of the sacral plexus. Arising below the pyriform 

 muscle, it descends beneath the gluteus maximus, and at the lower border 

 of that muscle comes into contact with the fascia lata. Continuing its 

 course downwards along the back of the limb, it perforates the fascia a 

 little below the knee. 



Fig. 444. DEEP NERVES IN THE 

 GLUTEAL AND INFERIOR PUDENDAL 

 REGIONS (from Hirschfeld and Le- 

 veille). \ 



Fig. 441. 



, back part of the great trochanter ; 

 b, tensor vaginae feraoris muscle ; c t 

 tendon of the obturator internus muscle 

 near its insertion ; d, upper part of the 

 vastus externus ; e, coccyx ; f t gracilis 

 muscle ; between /"and cl, the adductor 

 magnus, semitendinosus, and biceps 

 muscles ; * placed at the meeting of the 

 crura penis above the urethia ; 1, 

 placed upon the ilium close above the 

 sacro-sciatic notch, marks the superior 

 gluteal nerve, and on the divided parts 

 of the gluteus meclius muscle, the supe- 

 rior branch of the nerve ; 1', on the 

 surface of the gluteus minimus muscle, 

 the inferior branch of the nerve ; 1", 

 branch of the nerve to the tensor vaginae 

 fernoris ; 2, sacral plexus and great 

 sciatic nerve ; 2', muscular twig from 

 the plexus to the pyriformis ; 2", mus- 

 cular branches to the geraellus superior 

 and obturator internus ; 3, lesser sciatic 

 nerve ; 3', placed on the upper and 

 lower parts of the divided gluteus 



maximus, the inferior gluteal muscular branches of the lesser sciatic nerve ; 3", the 

 cutaneous branches of the same nerve winding round the lower border of the gluteus 

 maximus ; 4, the continuation of the lesser sciatic nerve as posterior cutaneous nerve of 

 the thigh ; 4', inferior pudendal branch of the lesser sciatic ; 5, placed on the lower part 

 of the sacral plexus, points to the origin of the pudic nerve ; 6, its perineal division with, 

 its muscular branches ; b', anterior or superior superficial perineal branch ; 6", posterior 

 or inferior superficial perineal ; + + , distribution of these nerves and the inferior puden- 

 dal on the scrotum ; 7, dorsal nerve of the penis. 



The branches of tho small sciatic nerve are as follows. 



A. The inferior gluteal branches, given off under the gluteus maximus, supply the 

 lower part of that muscle. A distinct gluteal branch commonly proceeds from the 

 sacral plexus to the upper part of the muscle. 



B. The cutaneous branches of the nerve principally emerge from beneath the lower 

 border of the gluteus maximus, arranged iu an external and an internal set. Others 

 appear lower down. 



