THE QUADRICEPS EXTEHSOR CRURIS. 155 



The SUPERFICIAL FEMORAL VEIN corresponds closely with the Superficial 

 femoral artery in its relations and its branches. vein 



Dissection. The superficial femoral artery and vein are to be To expose 

 cut across just below the origin of the profunda, and are to be 

 thrown downwards preparatory to the deeper dissection. After- femur. 

 wards all the fat, and all the veins, are to be carefully removed 

 from amongst the branches of the profunda artery and anterior 

 crural nerve. Unless this dissection is fully carried out, the upper 

 part of the vastus interims and crureus will not be prepared for 

 examination. 



The TENSOR FASCLrE FEMORIS *. FASCLffi LAT.E (fig. 62, L, p. 165) Tensor 



occupies the upper third of the thigh. It takes origin from the a! 



front of the crest of the ilium at the outer aspect, from the anterior arises from 



superior spine and from the edge of the notch between this and the P elvis ; 



inferior spine as far as the attachment of the sartorius (fig. 47, p. 1 13). 



Its fibres form a fleshy belly about two inches wide, and are inserted 



into the ilio-tibial band of the fascia lata about three inches below, ends in 



and rather in front of the line of, the great trochanter of the femur. * ascia lata 



At its origin the muscle is situate between the sartorius and parts 

 the glutens medius. Beneath it are the ascending offsets of the ex- 

 ternal circumflex artery; and a branch of the superior gluteal nerve 

 enters its under surface. A strong sheath of fascia surrounds the 

 muscle. 



Action. Supposing the limb moveable the muscle abducts the use on 

 thigh, and may help in rotating inwards the femur. 



When the limb is fixed it will support the pelvis, and assist in on pelvis ; 

 balancing the latter on the femur in walking. 



The chief function of the tensor vaginae femoris is, however, to on knee, 

 act with the glutens maximus in tightening the ilio-tibial band so 

 as to support the extended knee. 



Dissection. After the tensor has been learnt, the slip of fascia Cut through 

 extending from it to the knee may be cut through ; and when it is fa s e c i a . n 

 detached from the muscles around, the rectus may be followed 

 upwards to its origin from the pelvis. 



The QUADRICEPS EXTENSOR CRURIS Consists of four parts Or Great exteu- 



heads, one long or superficial (rectus), which springs from the sor of knee ' 

 pelvis, and three short or deep (mstus internus, crureus, and vastus 

 externm) which arise from the femur : all are united below in a 

 common tendon. 



The RECTUS FEMORIS (fig. 59, l3 ) gives rise to a fleshy promi- Rectus has 

 nence on the front of the thigh. It arises from the pelvis by two ori^rfat 

 tendinous heads ; one, the anterior, is attached to the anterior pelvis ; 

 inferior iliac spine ; and the other, posterior, is fixed to a rough 

 mark on the outer surface of the ilium close above the acetabulum 

 (fig. 47, p. 1 13) : near their origin they join to form a single tendon, insertion 

 The fleshy fibres terminate below in another tendon, which joins the m n tendon, 

 aponeuroses of the other muscles in the common tendon. 



The rectus is larger in the middle than at the ends ; and its fibres i s 

 are directed from the centre to the sides, giving rise to the condition 



called penniform. Its upper end is covered by the tensor fasciae except 



above. 



