566 DISSECTION OF THE THIGH. 



The external circumflex branch of the profunda artery lies amongst the 

 muscles and supplies them with branches ; and a large nerve, the anterior 

 crural, furnishes offsets to them. 



Dissection. To proceed with the deep dissection, the limb is to be 

 retained in the same position as before, and the flaps of skin on the front 

 of the thigh are to be thrown aside. The fascia lata is to be cut along 

 the middle line of the thigh and knee, and to be reflected to each side 

 nearly to the same extent as the skin. Over the knee-joint the student is 

 to note its attachment to the edges of the patella, and its union with a 

 prolongation from the tendon of the extensor muscle to the leg. 



In raising the inner piece of the fascia the narrow muscle appearing 

 (sartorius) should be followed to its insertion into the tibia : and to pre- 

 vent its displacement, it should be fixed with stitches along both edges. 

 Care should be taken of the small nerves in contact with the sartorius ; 

 viz., a plexus beneath it at the middle of the thigh from the saphenous, 

 internal cutaneous, and obturator ; two branches of the internal cutaneous 

 below its middle, one crossing the surface, and the other lying along the 

 inner edge of the muscle ; and the trunk of the great saphenous escaping 

 from beneath it near the knee, with the patellar branch of the same per- 

 forating it rather higher. 



Internal to the sartorius some strong muscles (adductors) are inclined 

 downwards from the pelvis to the femur. The student is to lay bare the 

 fore part of those muscles ; and beneath the most superficial (adductor 

 longus), near where it touches the sartorius, he is to seek a branch of the 

 obturator nerve to the plexus before mentioned in the middle of the 

 thigh. On the outer side of the sartorius is the large extensor of the 

 knee. For its dissection the knee is to be bent, to make tense the fibres : 

 and an expansion below from the common tendon to the fascia lata and 

 the knee-joint is not to be removed now, its arrangement will be noticed 

 after. 



The little muscle at the upper and outer part of the thigh, tensor of 

 the fascia lata, is to be cleaned ; and a strip of the fascia, corresponding 

 with its width, should be left along the outer aspect of the thigh. After 

 this slip has been separated, the rest of the fascia on the outer side of the 

 thigh is to be divided by one or two transverse cuts, and is to be followed 

 backwards to its attachment to the femur. 



The SARTORIUS (fig. 196, *) is the longest muscle in the body, and 

 extends from the pelvis to the leg. It arches over the front of the thigh, 

 passing from the outer to the inner side of the limb, and lies in a hollow 

 between the extensor on the one side, and the adductors on the other. 



Its origin is tendinous from the upper anterior iliac spinous process of 

 the hip bone, and from about half the interval between this and the infe- 

 rior process. The fibres constitute a ribbon-like muscle, which ends in a 

 thin tendon below the knee, and is inserted into the inner surface of the 

 tibia mainly into a slight depression by the side of the tubercle for an 

 inch and a half, but also, by its upper edge, as far back as the internal 

 lateral ligament of the knee-joint. 



The muscle is superficial throughout, and is perforated by some cuta- 

 neous nerves and vessels. Its upper part is oblique, and forms the outer 

 boundary of the triangular space containing the femoral artery : it rests 

 on the following muscles, iliacus, B, rectus, D, and adductor longus, G, as 

 well as on the anterior crural nerve and the femoral vessels. The middle 

 portion is vertical, and lies in a hollow between the vastus internus E, and 



