NERVES OF THE INFERIOR EXTREMITY. 



781 



off many cutaneous branches to the posterior and lateral 

 parts of the thigh, as well as a communicating branch in 

 the ham, to the external saplienus nerve. 



The gluteal nerve comes out of the pel- p IG . g63. 

 vis, through the great sciatic foramen, 

 along with the gluteal artery, and divides 

 into a superior branch, which ascends to 

 supply the gluteus medius and minimus 

 muscles ; and an inferior branch, which 

 descends to supply, besides the glutei, the 

 tensor vaginas femoris. 



The internal pudic and. obturator nerves 

 are described in another place. 



The great sciatic or posterior crural 

 nerve (Fig. 263) is the principal trunk 

 from the sacral plexus, and the largest 

 nerve of the body ; it comes out of the 

 pelvis through the larger sciatic foramen, 

 below the pyriform muscle, sometimes 

 through it ; descends on the back of the 

 thigh, about midway between the tuber- 

 osity of the ischium and trochanter major, 

 over the small rotators, to about half way 

 down the thigh, where it divides* into the 

 popliteal and peroneal. This division some- 

 times occurs as high as the pelvis at the 

 plexus. Above it is concealed by the glu- 

 teus maximus, below by the hamstring 

 muscles. The sciatic nerve gives off fila- 

 ments to the hip joint, the various mus- 

 cles in its course, and the integuments. 



The popliteal nerve may be considered the continued trunk 



FIG. 263 represents the Sacral Plexus and its branches, a Lumbo sacral 

 nerve. 6 Gluteal nerve, c Anterior branches of the four upper sacral nerves. 

 d Sacral plexus, e Internal pudic nerve. / Lesser sciatic nerve, g Great 

 sciatic nerve, h External popliteal nerve, i Internal popliteal nerve, j Its 

 brandies to the calf of the leg. k Posterior tibial nerve. I Plantar nerves, 

 m Anterior tibial nerve, n Musculo cutaneous nerve, o Its cutaneous portion. 

 p External saphenus nerve. 



