666 



THE LUMBAR PLEXUS. 



near the saphenous opening, and reaches down to the middle of the thigh. The 

 others appear beneath the skin lower down by the side of the vein ; one, larger than 

 the rest, passes through the fascia about the middle of the thigh, and extends to the 

 knee. In some instances, these small branches spring directly from the anterior crural 

 nerve, and they often communicate with each other. 



Fig. 440. Fig. 440. CUTANEOUS NERVES OP THE ANTERIOR 



AND INNER PART OF THE THIGH (from Sappey 

 after Hirschfeld and Leveille). | 



1, external cutaneous nerve ; 2, 2, middle cuta- 

 neous branch of the anterior crural passing through 

 the sartorius muscle and the fascia ; 3, 3, anterior 

 division of the internal cutaneous ; 4, filament to 

 the sartorius ; 5, inner or posterior division of the 

 internal cutaneous ; 6, its superficial branch to the 

 inside of the knee after perforating the fascia ; 7, 

 deep or communicating branch ; 8, superficial 

 branch of the musculo-cutaneous of the crural ; 9, 

 patellar branch of the internal saphenous nerve ; 

 10, continuation of the saphenous down the leg. 



(b) The anterior branch, descending in a 

 straight line to the knee, perforates the fascia 

 lata in the lower part of the thigh ; it after- 

 wards runs down near the intermuscular septum, 

 giving off filaments on each side to the skin, and 

 is finally directed over the patella to the outer 

 side of the knee. It communicates above the 

 joint with a branch of the long saphenous 

 nerve ; and sometimes it takes the place of the 

 branch usually given by the latter to the inte- 

 gument over the patella. 



This branch of the internal cutaneous nerve 

 sometimes lies above the fascia in its whole 

 length. It occasionally gives off a cutaneous 

 filament, which accompanies the long saphenous 

 vein, and in some cases it communicates with 

 the branch to be next described. 



The inner branch of the internal cutaneous 

 nerve, descending along the posterior border of 

 the sartorius muscle, perforates the fascia lata 

 at the inner side of the knee, and communicates 

 by a small branch with the internal saphenous 

 nerve, which here descends in front of it. It 

 gives some cutaneous filaments to the lower 

 part of the thigh on the inner side, and is dis- 

 tributed to the skin upon the inner side of the leg. Whilst beneath the fascia, this 

 branch of the internal cutaneous nerve joins in an interlacement with offsets of the 

 obturator nerve below the middle of the thigh, and with the branch of the saphenous 

 nerve nearer the knee. 



D. INTERNAL SAPHEXOUS NERVE. 



The internal or long saphenous nerve is the largest of the cutaneous 

 branches of the anterior crural nerve. In some cases it arises in connection 

 with one of the deep or muscular brandies. 



This nerve is deeply placed as far as the knee, and is subcutaneous in the 

 rest 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 



