MYOLOGY. 71 



2. Muscles of the fore part and sides of the Thigh. These are 

 eleven in number. 



Tensor vagincß femoris arises from tlie exterior internal part of the anterior 

 superior spinous process and crest of the ilium, and is inserted into a dupli- 

 cature of the fascia lata on the outside of the thigh, about three or four inches 

 below the great trochanter. Use : to make tense the fascia, to compress 

 the vastus externus, to rotate the thigh inwards, and to assist in flexing and 

 abducting it. 



Sartorius^ or the tailor's muscle, is the longest muscle in the body. Thin 

 and flat, like a ribbon, it is situated obliquely along the anterior and inner 

 side of the thigh, arising from the anterior superior spine of the ilium and 

 from the notch below that process. It extends obliquely across the thigh to 

 its inner side, and descending perpendicularly to the knee, it passes behind 

 the condyle of the femur. It then turns forwards and outwards towards the 

 inner side of the upper end of the tibia, into which it is inserted below the 

 tubercle. Use : to flex the leg on the thigh and the thigh on the pelvis, to 

 cross the lower extremities, &c. 



Rectus femoris is a long and flat muscle, placed vertically on the fore part 

 of the thigh. It arises by two tendons, one from the anterior inferior spinous 

 process of the ilium, the other from the superior and external border of the 

 acetabulum. These soon unite into a strong fleshy belly ending in a flat 

 tendon, which is inserted into the upper edge of the patella. Use: to extend 

 the leg on the thigh and to flex the leg on the pelvis. Its action is greatly 

 facilitated by the patella, which enables it to act at greater mechanical 

 advantage. This muscle is internally united to three others subjacent to 

 it ; the four, in fact, form a single quadriceps muscle. Of these the ex- 

 ternal is called vastus externus, the middle, crurseus, and the internal, vastus 

 internus. 



The vastus externus arises from the root and anterior part of the great 

 trochanter, from the outer edge of the linea aspera, and from the oblique 

 ridge which leads to the external condyle. It is inserted into the external 

 surface of the tendon of the rectus, and into the patella. It extends the 

 knee, and rotates the leg outwards. 



Vastus internus arises on the anterior edge of the femur, and is inserted 

 into the inner edge of the tendon of the rectus and into the patella. Use : 

 to extend the knee and turn the leg a little inwards. 



Grurceus^ between the two last, arises from the anterior and external part 

 of the femur, and is inserted into the upper and anterior edge of the patella. 

 It assists the vasti and rectus in extending the leg. 



Gracilis, situated at the inner side of the thigh, beneath the integuments 

 and fasciae, arises from the lower half of the symphysis and from the 

 inner edge of the descending ramus of the pubes. It is inserted into 

 the superior part of the internal surface of the tibia. Use: to abduct 

 the leg and thigh, to bend the knee, and turn the leg and foot in- 

 wards. 



PectinoRus arises from the linea innominata and the convex surface below 

 it on the horizontal ramus of the pubes, and is inserted into the rough ridge 



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