154 LABORATORY MANUAL FOR VERTEBRATE ANATOMY 



insertion, by a strong tendon on the greater trochanter of the femur; action, 

 abductor of the thigh. Along the anterior border of this muscle the origin of 

 the tensor fasciae latae passes internally toward the ilium. 



f) Sartorius. This muscle forms the anterior margin from the lateral view 

 of the thigh. It is folded over the margin and on following it to the medial 

 or inner surface of the thigh will be found to cover the anterior half of the medial 

 surface. Origin, crest, and ventral border of the ilium; insertion, proximal 

 end of the tibia and the patella and the fascia and ligaments between; action, 

 adductor and rotator of the thigh and extensor of the shank. 



g) Vastus lateralis. Cut through the fascia lata by a longitudinal slit 

 extending to the patella. Separate well the sartorius from underlying parts. 

 The tensor fasciae latae is now well exposed. The large stout muscle which was 

 covered by the fascia lata is the vastus lateralis. Origin, greater trochanter and 

 surface of the femur. 



ti) Rectus femoris. At its anterior margin the vastus lateralis will be found 

 partly separable from a stout muscle lying on its medial side and covered exter- 

 nally by the sartorius. The sartorius may be cut across the middle. The muscle 

 in question is the rectus femoris. Origin, ilium near the acetabulum. 



i] Vastus medialis. This is on the medial side of the thigh posterior to 

 the rectus femoris which its anterior margin partly covers. It also is covered 

 externally by the sartorius. Origin, femur. 



j} Vastus intermedius. On widely separating the rectus femoris from the 

 vastus lateralis a muscle will be seen deep down next to the shaft of the femur; 

 Origin, surface of the femur. 



The rectus femoris and the three vastus muscles are more or less united to 

 each other and constitute the great quadriceps femoris muscle. Its origins have 

 been described; all its parts are inserted on the patella and adjacent ligaments, 

 action, extensor of the shank. 



k] Gracilis. This is the large flat muscle forming the posterior half of the 

 medial surface of the thigh. Origin, ischial and pubic symphyses; insertion by 

 an aponeurosis which passes to the tibia; action, adductor of the leg. 



/) Adductor longus and adductor femoris. Cut through the middle of the 

 gracilis and separate each half from the underlying muscles. The latter consist 

 of three muscles passing from the median ventral line to the femur. The most 

 anterior of the three is quite small; this is the adductor longus. Origin, pubis; 

 insertion, femur; action, with the next. The middle muscular mass is the large 

 adductor femoris (corresponding to adductor magnus and brevis of other mam- 

 mals). Origin, pubis; insertion, femur; action, adductor of the thigh. 



m) Semimembranosus. The large posterior part of the mass which was 

 covered by the gracilis. Origin, ischium; insertion, medial epicondyle of the 

 femur and proximal end of the tibia; action, extensor of the thigh. The muscle 

 is more or less divisible into two parts. 



