THE ANTERIOR CRURAL XERVE. 60 r 



of its course. In the thigh it accompanies the femoral vessels, lying at first 

 somewhat to their outer side, but lower down approaching close to them, and 

 passing beneath the same aponeurosis. "When the vessels pass through the open- 

 ing in the adductor muscle into the popliteal space, the saphenous nerve separates 

 from them, and is continued downwards beneath the sartorius muscle to the 

 inner side of the knee ; where, haviiag first given off, as it lies near the inner 

 condyle of the femur, a branch wliich is distributed over the front of the patella, 

 it becomes subcutaneous by piercing the fascia between the tendons of the sar- 

 torius and gi'acilis muscles. 



The nerve then accompanies the saphenous vein along the inner side of the 

 leg, and passing in front of the ankle is distributed to the inner side of the foot. 

 In the leg it is connected with the internal cutaneous nerve. 



The distribution of the branches is as follows. 



A communicnthi'i hranch is given off about the middle of the thigh to join in 

 the interlacement formed beneath the fascia lata by this nerve and branches of 

 the obturator and internal cutaneous nerves. After it has left the aponeurotic 

 covering of the femoral vessels, the internal saphenous nerve has, in some cases, 

 a further connection %vith one or other of the nerves just referred to. 



The branch to the integuincnt i it, front of the patella perforates the sartorius 

 muscle and the fascia lata ; and, ha\'ing received a communicating offset from 

 the internal cutaneous nerve, spreads out upon the fore part of the knee ; and, by 

 uniting with branches of the middle and external cutaneous nerves, fonns a 

 plexus — plexus patella. 



A branch to the inner ankle is given oflf in the lower third of the leg, and 

 descends along the margin of the tibia, and some small filaments pierce the tarsal 

 ligaments. 



Su-m:!j:ae,y. — The anterior crural nerve is distributed to the skin 

 upon the fore part and inner side of the thigh, commencing below the 

 termination of the ilio-inguinal and genito-crnral nerves. It furnishes 

 also a cutaneous nerve to the inner side of the leg and foot. All the 

 muscles on the front and outer side of the thigh receive their nerves 

 from the anterior crural, and the pectineus is also in part supplied by 

 this nerve, and in part by the obturator. The tensor muscle of the 

 fascia lata is supplied fi'om a different source, viz., the superior gluteal 

 nerve. Lastly, two branches are given from the anterior crural nerve 

 to the knee-joint 



FIFTH LUMBAR NERVE. 



The anterior branch of the fifth lumbar nerve, having received a 

 fasciculus from the nerve next above it, descends to join the first 

 sacral nerve, and forms part of the sacral plexus. The cord resulting 

 from the union of the fifth with a part of the fourth nerve, is named 

 the lumdo-sacral i\Qr\e. 



Superior Gluteal Nerve. — Before joining the first sacral nerve the 

 lumbo-sacral cord gives off from behind the superior gluteal nerve ; 

 this offset leaves the pelvis through the large sacro-sciatic foramen, 

 above the pyriformis muscle, and divides like the gluteal artery into 

 two branches, which are distributed chiefly to the smaller gluteal 

 muscles and tensor of the fascia lata. 



(a) The upper branch runs with the gluteal artery along the origin of the 

 gluteus minimus, and is lost in it and in the gluteus medius. 



(b) The lower branch crosses over the middle of the gluteus minimus between 

 this and the gluteus medius, and supplying filaments to both those muscles, is 

 continued forwards, and terminates in the tensor muscle of the fascia lata. 



