570 DISSECTION OF THE THIGH. 



mostly from the outer side of the femoral artery ; they enter the sartorius, 

 the vastus interims, and the adductor longus. 



The FEMORAL VEIN corresponds closely with the femoral artery in its 

 connections with the parts around, and in its branches. 



Dissection. The femoral artery and vein are to be cut across below the 

 origin of the profunda, and are to be thrown downwards preparatory to 

 the deeper dissection. Afterwards 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 completed, the upper part 

 of the vastus internus will not be prepared for learning. 



The TENSOR VAGINJS FEMORis (fig. 198, L ) occupies the upper third of 

 the thigh, and is the smallest and most external of the outer set of mus- 

 cles. It takes origin from the front of the crest of the hip bone at the 

 outer aspect ; from the anterior upper iliac spine, and from part of the 

 notch between this and the inferior spine as far as the attachment of the 

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

 inserted into the fascia lata about three inches below, and rather in front 

 of the line of the great trochanter of the femur. 



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

 medius. Beneath it are the ascending offsets of the external 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 movable the muscle abducts the thigh, 

 making tense at the same time the fascia lata ; and finally it will help in 

 rotating inwards the femur. 



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

 the same on the femur in walking. 



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

 from it to the knee may be cut through ; and when it is detached from 

 the muscles around, the head of the rectus may be followed upwards to 

 the pelvis. 



The TRICEPS EXTENSOR of the knee (fig. 197) consists of three fleshy 

 parts or heads, outer (vastus externus), inner (vastus internus), and mid- 

 dle (rectus), which are united below in a common tendon. 



The RECTUS FEMORIS gives rise to a fleshy prominence on the front of 

 the thigh (fig. 197, 13 ). At its origin from the pelvis the muscle consists 

 of two tendinous pieces : one arises from the anterior inferior iliac spinous 

 process ; the other (to be afterwards seen) is fixed into a depression on 

 the back of the hip bone, close above the acetabulum. The fleshy fibres 

 terminate inferiorly in another tendon, which joins the aponeurotic parts 

 of the other two muscles in the common tendon. 



The rectus is larger at the middle than at the ends ; and its fibres are 

 directed from the centre to the sides, as in a quill, giving rise to that con- 

 dition called penniform. It is subcutaneous, except above where it is 

 overlaid by the sartorius. It conceals branches of the external circumflex 

 artery and anterior crural nerve, and rests on the vasti. The upper ten- 

 don of the rectus readiest furthest on the anterior surface where the s;ir- 

 torius touches, whilst the lower tendon is most extensive on the posterior 

 aspect, or towards the subjacent vasti. 



Dissection. To see the remaining muscles, cut across the rectus near 

 the lower end, and raise it without injuring the branches of vessels and 

 nerves beneath. The muscular mass on the front of the femur is to be 

 divided into two, above, along the situation of some descending vessels and 



