468 THE MUSCULATURE 



of the tela subcutanea and others a portion of the fascia lata. This fascia cribrosa contains 

 many openings for the passage of blood-vessels and lymphatics. The space which lies medial 

 to the femoral vessels between the femoral ring and the fossa ovalis is called the femoral canal 

 (crural canal). 



From the fascia intermuscular septa descend in between the underlying muscles. Of 

 these, the medial and lateral intermuscular septa are the best marked (fig. 410). 



The lateral intermuscular septum separates the extensor muscles from the hamstring 

 group. It extends from the tendon of the gluteus maximus to the lateral epicondyle. It is 

 composed chiefly of longitudinal fibres and is thickest distally. The vastus lateralis is united 

 to its ventro-lateral surface; the short head of the biceps, to its dorso-medial surface. 



It will be noted that this septum serves to divide primarily ventral from primarily dorsal 

 musculature, with the exception of the short head of the biceps, which, though primarily dorsal, 

 occupies a position, perhaps secondarily acquired, with the primarily ventral muscles. 



The medial intermuscular septum serves to divide the anterior extensor from the medial 

 adductor musculature. It is perhaps simplest in the region immediately distal to the ilio- 

 pectineal fossa (fig. 410 B). Here a well-marked septum may be seen extending to the femur 

 between the sartorius and quadriceps on the one side, and the adductor longus and brevis on 

 the other. The septum here, next the muscles, has on each side a membranous lamina. Be- 

 tween the two lamina there is a looser tissue in which run blood-vessels and nerves. A fibrous 

 membrane extends between the rectus and sartorius to the septum. 



More distally the sartorius comes to overlie the septum (fig. 410 C). The sheath of the 

 sartorius on the lateral margin becomes fused with the fascia of the vastus medialis, and on 

 the medial margin to a membrane that covers the ventral surfaces of the adductor longus and 

 magnus. Beneath the sartorius and between the adductor longus and the vastus medialis is a 

 triangular space bounded by the sheaths of these muscles, and filled with a loose areolar tissue 

 in which run the chief blood-vessels of the thigh. This space, first described by John Hunter, 

 is known as Hunter's canal, or the adductor canal. Still more distally the vessels with their 

 surrounding fibrous tissue pass through the hiatus tendineus, between the long tendon of the 

 adductor magnus and the femur, to the back of the thigh. The septum here passes behind the 

 posterior surface of the vastus medialis to the femur. 



MUSCLES 

 1. The Anterior Group 



(Figs. 411, 412) 



This group, which forms a semi-conical mass pointed upward, is composed of 

 the quadriceps femoris and the sartorius muscles, innervated by the femoral 

 nerve. 



The sartorius is a long, ribbon-like muscle which arises from the anterior 

 superior spine of the ilium and extends along the medial margin of the quadriceps, 

 passing obliquely across the upper part of the thigh, and then descending to the 

 dorse-medial side of the knee, whence its tendon curves forward to be inserted 

 into the ventro-medial surface of the superior extremity of the tibia. 



The quadriceps femoris is composed of four muscles differentiated from a com- 

 mon embryonic origin. Of these, the rectus femoris, which arises from the 

 ventro-lateral margin of the ilium, by two tendons, is the mott superficial and 

 the most completely differentiated. The vastus lateralis, which arises from the 

 superior extremity of the ventral surface of the shaft of the femur and from the 

 lateral lip of the linea aspera; the vastus medialis, which arises from the medial 

 lip of the linea aspera and from the intertrochanteric line; and the vastus inter- 

 medins (crureus), which arises between these two and beneath the rectus from the 

 surface of the femur, are less distinctly differentiated from one another. The 

 vastus intormcdius and vastus lateralis are partly fused at the insertion, the 

 intermedins and medialis at their origins. From the four muscles arises a tendon 

 which is inserted into the tuberosity of the tibia. In this tendon, which is 

 closely appli(,'d to the capsule of the knee-joint, lies a sesamoid l)on(!, the patella. 



The sartorius and the rectus flex the thigh; the (|uadriceps extends 

 the leg; the sartorius flexes the leg and rotates the thigh lateral ward and the 

 leg medialward. 



In the embryo the sartorius has an origin distinct from that of tlie quadriceps. In the 

 anthropoid apes it is riiucli more developed than in man. 



In addition to supplying the mu.scles of this group, the femoral nerve also gives branches 

 to the iliacus muscle (p. 4.')5) and the pectineus muscle (p. 472). 



The sartorius (fig. 411). — Origin. — From the anterior superior si)ine of the ilium and the 

 area immediately below this. 



Insertion.— into the medial surface of the til)ia near the tuberosity and into the neighbour- 

 ing fascia of the leg. 



