THE NERVOUS SYSTEM. 325 



into the thigh, where it divides into an anterior or cutaneous 

 branch, and a posterior or muscular branch. It supplies a" 

 muscles and the front of the thigh, excepting the tensor 

 femoris, gives branches to the knee, and supplies the skin of tin 

 inner side in front of the thigh, and to the leg and foot. Its 

 branches are, from the anterior division : 



(a) Middle cutaneous, to sartorius muscle and skin of front of 

 thigh ; 



(b) Internal cutaneous, supplies the skin in the inner aspect of 

 the leg; 



'(<) Long saphenous, or internal saphenous, passes through 

 Hunter's can a 1 , " a c c o nTfmiTI es the internal saphenous vein, to supply the 

 skin of the inner side of the foot. 



From the posterior division: 



(a) Muscular, to the muscles of the anterior and lateral aspects 

 of the thigh; 



(b) Articular, to the knee-joint. 



THE SACRAL NERVES, five in number, divide into anterior 

 and posterior nerves. The four upper sacral nerves, with the 

 fifth lumbar, and a filament from the fourth, the two latter 

 forming the Jumbo-sacral cord, together form the sacral plexus. 

 It lies upon the anterior surface of the pyriformis muscle, and is 

 separated from the viscera, the sciatic and pudic branches of the 

 internal iliac artery, by the pelvic^ fascia. Its branches are : 



1. Muscular, supply the obturators, gemelli, quadratus 

 femoris, and pyriformis. 



2. Superior gluteal, supplies the glutei muscles and tensor 

 vaginaB femoris. 



3. Pudic, accompanies the internal pudic artery, passing 

 out of the great sacro-sciatic foramen, around the spine of the 

 ischium to re-enter the lesser sacro-sciatic foramen. It gives 

 off: 



(a) Inferior ha?morrhoidal, supplies the skin of the anus; 



(b) Perineal, folloAvs the course of the superficial perineal artery 

 to supply the perineal structures generally; 



(c) Dorsal nerve of the penis, follows the course of the correspond- 

 ing artery to supply the skin of the glans, prepuce, and penis generally. 



4. Small sciatic, supplies the skin of the thigh, leg, pcrin- / - 

 eum, and the glutens niaximus muscle. "Its branches are: CcJt** 



(a) Inferior gluteal, to the glutens maximus; 



(b) Internal cutaneous lira nclies. to the skin of the inner and upper 

 part of the thigh, and one branch, the inferior inuJrndul, supplies th'^ 

 skin of the scrotum in the male and labiuni in (lie female; 



