OBTURATOR NERVE. 473 



accompanies the femoral artery to the aponeurotic canal formed by the 

 adductor longus and vastus internus muscles. It then quits the 

 artery, and, passing between the tendons of the sartorius and gracilis, 

 descends along the inner side of the leg with the internal saphenous 

 vein, crosses in front of the inner ankle, and is distributed to the 

 integument on the inner side of the foot as far as the great toe. 



The internal saphenous nerve receives from the obturator nerve two 

 branches of communication, one near its upper part, which passes 

 through the angle of division of the femoral artery, and the other at 

 the internal condyle. The branches which it gives off in its course 

 are, a femoral cutaneous branch, at about the middle of the thigh, 

 distributed to the integument of the inner and posterior aspect of the 

 limb, and communicating with other cutaneous filaments from the 

 saphenous below the knee ; a tibial cutaneous branch proceeding from 

 the nerve a little above the internal condyle, passing between the 

 sartorius and gracilis and descending the inner aspect of the leg to the 

 ankle ; an articular branch of small size, proceeding from the nerve, 

 while in the aponeurotic canal of the femoral artery and passing 

 directly to the knee-joint to supply the synovial membrane ; an ante- 

 rior cutaneous branch proceeding from the saphenous at the inner con- 

 dyle, perforating the sartorius, and dividing into a number of filaments 

 which supply the integument over the patella and around the joint, 

 and the integument of the front and outer aspect of the leg as far as 

 the ankle ; lastly, cutaneous filaments below the knee to supply the 

 inner side and front of the leg and foot, and articular branches to the 

 ankle-joint. 



The OBTURATOR NERVE is formed by a branch from the third, 

 and another from the fourth lumbar nerve. It passes downwards among 

 the fibres of the psoas muscle, through the angle of bifurcation of the 

 common iliac vessels, and along the inner border of the brim of the 

 pelvis, to the obturator foramen, where it joins the obturator artery. 

 Having escaped from the pelvis it gives otf two small twigs to the 

 obturator externus muscle and divides into four branches, three ante- 

 rior, which pass in front of the adductor brevis, supplying that muscle, 

 the pectineus, the adductor longus, and the gracilis ; and a posterior 

 branch which passes downwards behind the adductor brevis, and 

 ramifies in the adductor magnus. 



From the branch which supplies the adductor brevis, a communi- 

 cating filament passes outwards through the angle of bifurcation of the 

 femoral vessels to unite with the long saphenous nerve. From the 

 branch to the adductor longus a long cutaneous nerve proceeds, which 

 issues from beneath the inferior border of that muscle, sends filaments 

 of communication to the plexus of the short saphenous nerve, and 

 descends to the inner side of the knee, where it pierces the fascia and 

 communicates with the long saphenous nerve. It is distributed to the 

 integument upon the inner side of the leg. From the posterior branch 

 an articular branch is given off which pierces the adductor magnus 



