228 



INFERIOR EXTREMITY 



foramen it extends distally, with the inferior glutaeal artery, 

 under cover of the glutaeus maximus. Leaving the muscle 

 it proceeds distally, on the back of the thigh, immediately 

 subjacent to the deep fascia. It will afterwards be traced to 

 the posterior aspect of the calf of the leg. 



In the glutaeal region it gives off several cutaneous 



LIV 



^.Lumbo-sacral cord 



Superior glutaeal nerve 



Inferior glutaeal nerve 



S.I _ 



To piriformis __H 



To piriformi 



Nerve to quadratus femoris 

 Nerve to obturator internus 



-Sciatic nerve 



.Common 

 peronaeal nerve 



\ Tibial nerve 

 -. Post. cut. N. of thigh (O.T. small sciatic) 



Perineal N. and dorsal N. of penis \ Pudendal 

 Inferior haemorrhoidal nerve / nerve 



Perforating cutaneous nerve 

 - ' 



-^ ' Nerves to levator ani 

 Coccygeal branches 



FIG. 86. Diagram of Sacral Plexus. 



branches, viz. (i) inferior nerves of the buttock which wind 

 round the distal border of the glutaeus maximus to supply a 

 limited area of the skin of the buttock ; (2) a few twigs to the 

 skin to the medial region of the thigh ; and (3) the perineal 

 branches of which one is known as the long perineal nerve 

 (O.T. long pudendal). 



This branch turns medially round the origin of the 

 hamstring muscles to reach the perineum. 



