BRANCHES OF THE FEMORAL ARTERY. 579 



The profunda gives off the following named branches : 



External circumflex. Internal circumflex. Four perforating. 



The External Circumflex Artery supplies the muscles on the front of the thigh. 

 It arises from the outer side of the profunda, passes horizontally outward, between 

 the divisions of the anterior crural nerve and behind the Sartorius and Rectus 

 muscles, and divides into three sets of branches ascending, transverse, and de- 

 scending. 



The ascending branches pass upward, beneath the Tensor fasciae femoris muscle, 

 to the outer side of the hip, anastomosing with the terminal branches of the gluteal 

 and deep circumflex iliac arteries. 



The descending branches, three or four in number, pass downward, behind the 

 Rectus, upon the Vasti muscles, to which they are distributed, one or two passing 

 beneath the Vastus externus as far as the knee, anastomosing with the superior 

 articular branches of the popliteal artery. These are accompanied by the branch 

 of the anterior crural nerve to the Vastus externus. 



The transverse branch, the smallest, passes outward over the Crureus, pierces 

 the Vastus externus, and winds round the femur to its back part, just below the 

 great trochanter, anastomosing at the back of the thigh with the internal circum- 

 flex, sciatic, and superior perforating arteries. 



The Internal Circumflex Artery, smaller than the external, arises from the inner 

 and back part of the profunda, and winds round the inner side of the femur, be- 

 tween the Pectineus and Psoas muscles. On reaching the upper border of the Ad- 

 ductor brevis it gives off two branches, one of which passes inward to be distrib- 

 uted to the Adductor muscles, the Gracilis, and Obturator externus, anastomosing 

 with the obturator artery ; the other descends, and passes beneath the Adductor 

 brevis, to supply it and the great Adductor ; while the continuation of the vessel 

 passes backward and divides into an ascending and a transverse branch (Fig. 257). 

 The ascending branch passes obliquely upward upon the tendon of the Obturator 

 externus and under cover of the Quadratus femoris toward the digital fossa, where 

 it anastomoses with twigs from the gluteal and "sciatic arteries. The transverse 

 branch, larger than the ascending, appears between the Quadratus femoris and 

 upper border of the Adductor magnus, anastomosing with the sciatic, external cir- 

 cumflex, and superior perforating arteries (" the crucial anastomosis"). Opposite 

 the hip-joint, the artery gives off an articular vessel, which enters the joint beneath 

 the transverse ligament ; and, after supplying the adipose tissue, passes along the 

 round ligament to the head of the bone. 



The perforating arteries (Fig. 316), usually four in number, are so called from 

 their perforating the tendon of the Adductor magnus muscle to reach the back of 

 the thigh. They pass backward close to the linea aspera of the femur, under cover 

 of small tendinous arches in the Adductor magnus. The first is given off above 

 the Adductor brevis, the second in front of that muscle, and the third immediately 

 below it. 



The first perforating artery passes backward between the Pectineus and Ad- 

 ductor brevis (sometimes perforates the latter) ; it then pierces the Adductor mag- 

 nus close to the linea aspera. It gives off branches which supply the Adductor 

 brevis, the Adductor magnus, the Biceps, and Gluteus maximus muscles, and anas- 

 tomoses with the sciatic, internal and external circumflex, arid middle perforating 

 arteries. 



The second perforating artery, larger than the first, pierces the tendons of 

 Adductor brevis and Adductor magnus muscles, and divides into ascending and 

 descending branches, which supply the flexor muscles of the thigh, anastomosing 

 with the first and third perforating. The second artery frequently arises in com- 

 mon with the first. The nutrient artery of the femur is usually given off from this 

 branch. 



The third perforating artery is given off below the Adductor brevis; it pierces 

 the Adductor magnus, and divides into branches which supply the flexor muscles 



