CUTANEOUS NERVES OF THIGH. 557 



thigh. It is divided into two branches (anterior and inner), which perfo- 

 rate the fascia in separate places. 



The anterior branch becomes cutaneous in the lower third of the thigh, 

 in the line of the inner intermuscular septum (fig. 192, 3 ), along which it 

 is continued to the knee. This branch is distributed in the lower third 

 of the thigh, as well as over the patella and the inner side of the knee- 

 joint, and is united with the patellar branch of the internal saphenous 

 nerve. 



The inner branch (fig. 207, 8 ) perforates the fascia at the inner side of 

 the knee behind the internal saphenous nerve, with which it communi- 

 cates ; it furnishes offsets to the inside of the knee, and to the upper half 

 of the leg on the inner surface. 



Other small offsets of the nerve supply the inner side of the thigh, and 

 appear by the side of the saphenous vein. One or two come into view 

 near the upper part of the vein, and reach as far as the middle of the 

 thigh ; and one, larger in size than the rest, becomes cutaneous where the 

 others cease, and extends as far as the knee. 



The internal saphenous (fig. 192, 4 ), a branch of the anterior crural, is 

 continued to the foot, but only a small part of it is now visible. The 

 nerve pierces the fascia on the inner side of the knee; and. after commu- 

 nicating with the inner branch of the internal cutaneous, gives forwards 

 some offsets over the knee-joint. Finally it accompanies the saphenous 

 vein to the leg and foot. 



Its patellar branch (fig. 192, 5 ) appears on the inner side of the knee 

 above the preceding, and is soon joined by the internal cutaneous nerve. 

 It ends in many branches over the patella ; these communicate with offsets 

 from the middle and external cutaneous nerves, and form an interlace- 

 ment plexus patellce over the joint. 



Dissection. Let the fat and the inguinal glands be now removed from 

 the surface of the fascia lata, the cutaneous nerves being thrown aside to 

 be traced afterwards to their trunks. 



At the upper part of the thigh the student is to define the saphenous 

 opening in the fascia lata by detaching the superficial fascia. The inner 

 side is easily shown. But the outer border is blended with the superficial 

 fascia and with the subjacent crural sheath ; and it is only after the 

 uniting fibrous bands are broken or cut through that its semilunar edge 

 comes into view. 



The fascia lata is the deep aponeurosis of the thigh. It surrounds the 

 limb with a firm sheath, and sends inwards septa between the different 

 muscles. This membranous investment is of a bluish-white color, but in 

 fat bodies is sometimes so slight as to be taken away with the subcu- 

 taneous fat. 



It is much stronger on the outer than the inner aspect of the limb where 

 it receives the insertion of the tensor vaginae femoris, and the greater part 

 of the gluteus maximus muscle. This thickened part (ilio-tibial band) is 

 attached above to the hip-bone and below to the bones of the leg, and 

 helps the extensor muscle to keep the knee-joint straight in standing. 



Numerous apertures exist in the fascia for the transmission of the cuta- 

 neous nerves and vessels ; and the largest hole is near Poupart's ligament, 

 to permit the passage of the internal saphenous vein. 



Processes prolonged from the under surface form septa between, and 

 fibrous sheaths around the several muscles. Two of the processes are 

 larger than the rest, and are named outer and inner intermuscular septa of 



