384 MUSCLES OF THE THIGH. 



2. Semimembranosus, 



Arises, tendinous, from the upper and posterior part of the 

 tuberosity of the os ischium ; sends down a broad flat tendon, 

 which ends in a fleshy belly, and, in its descent, runs at first 

 on the forepart of the biceps, and lower, between it and the 



semitendinosus. 







Inserted, tendinous, into the inner and back part of the head 

 of the tibia. 



Use. To bend the leg, and bring it directly backward. 



N. B. The two last form what is called the inner hamstring. 



3. Biceps Flexor Cruris, 



Arises by two distinct heads. The first, called longus, arises, 

 in common with the semitendinosus, from the upper and pos- 

 terior part of the tuberosity of the os ischium. The second, 

 called brevis, arises from the linea aspera, a little below the 

 termination of the gluteus maxirnus, by a fleshy acute begin- 

 ning, which soon grows broader as it descends to join with the 

 first head, a little above the external condyle of the os femoris. 



Inserted, by a strong tendon, into the upper part of the head 

 of the fibula. 



Use. To bend the leg. 



JV. B. This muscle forms what is called the outer ham- 

 string ; and between it and the inner, the nervus popliteus, 

 the arteria and vena poplitea, are situated. 



4. Popliteus, 



Arises, by a round tendon, from the lower and back part of 

 the external condyle of the os femoris, then runs over the liga- 

 ment that involves the joint; firmly adhering to it, and part of 

 the semilunar cartilage. As it runs over the joint, it becomes 

 fleshy, and the fibres run obliquely inwards, being covered 

 with a thin tendinous membrane. 



Inserted, broad, thin and fleshy, into a ridge at the upper 

 and internal edge of the tibia, a little below its head. 



Use. To assist in bending the leg, and to prevent the cap- 



