THE THIGH 263 



insertion, which is prolonged for some distance proximally, 

 on its deep surface, in the form of an aponeurosis. As it 

 nears the knee the tendon of the rectus femoris joins the 

 other tendons of the quadriceps, and forms with them a 

 common tendon which is inserted into the proximal border 

 of the patella. The rectus femoris is supplied by the femora? 

 nerve. 



M. Vastus Lateralis. The lateral vastus muscle forms 

 the greater part of the prominent mass on the lateral side of 

 the thigh. Its surface is covered by a glistening aponeurosis. 

 The descending branch of the lateral circumflex artery con- 

 stitutes the best guide to its anterior border, and when that 

 margin is raised it will be seen that the muscle lies upon, and 

 is partially blended with, the vastus intermedius. 



The vastus lateralis arises ( i ) from the upper part of the 

 intertrochanteric line; (2) from the front of the trochanter 

 major, distal to the insertion of the glutaeus minimus; (3) 

 from the inferior part of the trochanter major distal to the 

 insertion of the glutaeus medius ; (4) from the lateral part 

 of the gluteal tuberosity, anterior to the insertion of the 

 glutaeus maximus ; (5) from the proximal part of the linea 

 aspera ; and (6) from the lateral intermuscular septum (Figs. 

 117, 1 1 8, 121). The fleshy fibres are for the most part 

 directed distally and forwards. By means of the common 

 tendon of insertion the muscle gains attachment to the patella 

 and, at the same time, gives an expansion to the capsule of the 

 knee joint. It is supplied by the femoral nerve. 



Dissection. Divide the rectus femoris about its middle, and 

 pull the distal part forcibly towards the foot. The narrow 

 interval between the tendons of the vastus intermedius and 

 vastus medialis will then become apparent, and will serve as a 

 guide to the line along which the muscles must be separated. 

 Another guide to the line of separation is the long, slender 

 nerve of supply to the articular muscle of the knee ; it runs 

 along the medial edge of the vastus intermedius. When the 

 anterior border of the vastus medialis is raised from the vastus 

 intermedius the medial surface of the body of the femur will be 

 seen to be almost bare. Few muscular fibres arise from that 

 bony surface. The fleshy mass of the vastus medialis may now, 

 with advantage, be divided transversely about two inches proximal 

 to the patella. The muscle can then be thrown medially, and 

 its origin studied. 



M. Vastus Medialis. The vastus medialis is intimately 

 connected with the vastus intermedius, but not to such an 

 extent as might be inferred from a superficial inspection. In 



