580 A MANUAL OF ANATOMY. 



downward to supply the front and outer side of the muscles 

 of the thigh. A long branch reaches to the outer side of 

 the knee and anastomoses with the superior external 

 articular branch from the popliteal. Other branches in 

 front extend to the knee joint and at the inner side anasto- 

 mose with the deep branch of the anastomotica magna. 



(2) The Internal Circumflex arises from the inner and 

 back part of the profunda artery near its origin. It passes 

 backward between the tendon of the psoas and pectineus, 

 then between the adductor brevis and the obturator ex- 

 ternus, and continues between the quadratus femoris and 

 the adductor magnus to the back of the thigh, where it 

 anastomoses with the sciatic, external cutaneous, and the 

 first perforating artery of the profunda, thus forming the 

 "crucial anastomosis." In its course the internal circum- 

 flex supplies the muscles adjacent to it, the hip joint, 

 anastomoses with the obturator artery, and gives off a 

 branch of considerable size which follows the tendon of 

 the obturator externus muscle to the back of the hip joint 

 (above and behind the quadratus femoris) to anastomose 

 with the sciatic, and gluteal arteries. 



(3) The Perforating- Arteries. There are three of these 

 given off from the profunda, and counting the termination 

 of that vessel itself, makes four. The three perforating 

 are branches from the profunda as it lies behind the ad- 

 ductor longus muscle. They all pass through the adductor 

 magnus (the two upper ones iii addition piercing the ad- 

 ductor brevis) by means of aponeurotic openings close to 

 the bone, and appear upon the back of the adductor mag- 

 nus where they form a chain of anastomoses with each 

 other. In addition the first artery anastomoses with the 

 sciatic, internal circumflex and the external circumflex, the 

 third perforating with the termination of the profunda, 



