242 MYOLOGY. 



spine, and from it springs the aponeurotic expansion termed the 

 fascia lata. (See Fasciae of the Posterior Lirnb, p. 255.) 



Relation. Internally with the iliacus, rectus femoris, and 

 vastus externus ; externally with the skin ; posteriorly with the 

 gluteus maximus and externus ; anteriorly with the precrural 

 lymphatic glands. 



Action. It assists in flexing the femur, raising the limb ; and 

 it tenses the fascia lata. 



CRURAL MUSCLES. 



The remaining muscles of this region, being all of them 

 inserted to the patella, may be described as a single muscle, the 

 triceps or quadriceps cruralis ; or the rectus may be regarded 

 as a single muscle, and the other three described together as the 

 triceps cruralis ; or, again, they may be considered as separate 

 muscles. The above names being borne in mind, the last is 

 perhaps the simplest method, and is the one adopted here. 

 These muscles are considerably blended, and cannot well be 

 perfectly separated without cutting muscular fibre. 



RECTUS FEMORIS. 



(Ilio-rotuleus.} 

 (PL. TIL 34 ; FIG. 76. I.) 



Situated on the anterior part of the thigh, between the two 

 vasti, it is thick, elongated, and fusiform, consisting of two short, 

 flat tendons of origin, and a fleshy intersected belly, terminating 

 in a conical aponeurotic envelope. It is directed downwards and 

 forwards. 



Origin. From two depressions, one on each side of the iliac 

 shaft, just before the acetabulum. 



Insertion. To the upper part of the patella. 



Relation. It lies between the vasti, and above the crureus, 

 and superiorly between the iliacus and the tensor fasciaa latas, 

 with which it is related anteriorly. A pad of fat occupies the 

 space between its tendons of origin and the capsular ligament of 

 the hip joint. 



Action. To flex the femur, and extend the leg. 



