

MUSCLES OP THE THIGH. 759 



of the acetabulum. It forms a complete penniform mus- 

 cle, which, running in front of the thigh, is inserted, by a 

 strong, flat tendon, into the superior margin of the patella. 



Function. To extend the leg. 



The vastus externus (Fig. 249) arises, tendinous and 

 fleshy, from the root of the great trochanter, and from the 

 whole length of the linea aspera at its outer edge, from 

 the ridge leading to the external condyle, and from the 

 outer surface of the femoral hone. Its fibres descend ob- 

 liquely, and are inserted into the outer edge of the tendon 

 of the rectus, and outer edge of the patella. This is a large 

 muscle upon the outer thigh. Function. To extend the 

 leg, also to turn the knee outward. 



The vastus internus (Fig. 249) arises from the front of 

 the femur, at the trochanter minor, and covers all the 

 inner side of this bone ; arises also from the whole inner 

 edge of the linea aspera, and from the ridge going to the 

 inner condyle. Its fibres descend obliquely, and are in- 

 serted into the inner edge of the tendon of the rectus, and 

 inner edge of the patella. It is smaller and shorter than 

 the vastus externus. Function. To extend the leg. 



The crurceus arises fleshy from all the front of the femo- 

 ral bone and its outside, to the linea aspera. It is uncon- 

 nected with the bone, on its inner side; for about the 

 breadth of an inch, and extending thus nearly the whole 

 length of the shaft. It is behind the rectus, and over- 

 lapped by the two vasti. Its insertion is into the upper 

 edge of the patella, behind the tendon of the rectus. 



Function. To extend the leg. The last three muscles 

 receive the name of triceps extensor femoris , and, including 

 the rectus , are called quadriceps femoris. A few muscular 

 fibres of the cruraeus are seen going to the synovial mem- 

 brane of the joint, and take the name of sub-crurceus. A 

 large bursa is found behind the cruraaus, just above the 

 patella, and sometimes on the patella. 



The gracilis (Fig. 249) arises from the inner edge of the 

 descending ramus of the pubis and lower half of the sym- 

 physis, by a broad, thin tendon, which descends fleshy and 



