THE LOWER LIMB 477 



Boundaries — External. — The vastus intemus, closely covering the 

 inner surface of the femur as far back as the inner lip of the linea 

 aspera. Internal and Posterior. — ^The adductor longus and subse- 

 quently the adductor magnus, both of which extend back to the 

 inner hp of the linea aspera, where they meet the vastus intemus and 

 so form the apex of the triangle. Anterior or Superficial. — ^This 

 boundary is commonly called the roof of the canal. It represents 

 the base of the triangle, and is formed by an aponeurotic expansion 

 which extends from the adductor longus and adductor magnus on 

 the inner side to the vastus intemus on the outer side. Superficial 

 to this expansion in its whole length is the middle portion of the 

 sartonus, and the subsartorial plexus of ner\'es lies between the 

 two in the middle third of the thigh. The aponeurosis is com- 

 paratively weak over the upper half of the canal, but over the lower 

 half it is strong, and, below, it is continuous \vith the anterior 

 margin of the femoral opening in connection with the adductor 

 magnus. 



Contents. — ^These are sls follows : the superficial femoral artery in 

 the second part of its course, and its branches ; the first portion 

 of the femoral vein, and its tributaries ; the long saphenous nerve ; 

 and the nerve to the vastus intemus muscle in the upper half of the 

 canal. 



Femoral Artery. — ^This vessel extends from the lower border of 

 Poupart's ligament to the posterior margin of the femoral opening, 

 which is in connection with the adductor magnus. It is the direct 

 continuation of the external ihac artery, and at its termination 

 becomes the pophteal. It occupies the upper three-fourths of the 

 thigh, and its direction is downwards and inwards. The coiuse of 

 the vessel is indicated in the following manner : the thigh being 

 partially flexed upon the abdomen, and at the same time shghtly 

 abducted and rotated outsvards, draw a line from a point midway 

 bet^veen the anterior superior ihac spine and the symphysis pubis 

 to the adductor tubercle of the femur, or, if this tubercle cannot be 

 felt, to the internal tuberosity on the inner surface of the internal 

 condyle. This line over its upper three-fourths represents the 

 course of the vessel. 



At a point about 3 J inches below Poupart's Ugament the sartorius 

 takes up a position over the artery, and from this point onwards 

 that muscle continues to lie over the vessel. For at least the first 

 i^ inches of its course the vessel corresponds in size with the 

 external iliac artery. WTien, however, it reaches a point from i^ 

 inches to 2 inches below Poupart's hgament it gives off a large 

 branch, called the arteria profunda femoris, after which it under- 

 goes a sudden diminution in size. The part of the vessel between 

 Poupart's ligament and the origin of the arteria profunda femoris 

 is known as the common femoral ; the part beyond the origin of 

 that large branch is called the superficial femoral ; and the arteria 

 profunda femoris is spoken of as the deep femoral ; that is to say, 

 the common femoral artery is regarded as dividing into superficial 



