636 THE ARTERIES. 



PLAN OF THE RELATIONS OF THE PROFUNDA ARTERY. 



In front. 



Femoral and Profunda veins. 

 Adductor longus. 



Outer side. 

 Vastus internus. 



Behind. 

 Iliacus. 

 Pectin eus. 

 Adductor brevis. 

 Adductor niagnus. 



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 

 descending. 



The ascending branches pass upward, beneath the Tensor vaginas femoris 

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

 the gluteal and 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 extern us 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 branches, the smallest and least numerous, pass outward over 

 the Crureus, pierce the Vastus externus, and wind round the femur to its back 

 part, just below the great trochanter, anastomosing at the back of the thigh with 

 the internal circumflex, 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, 

 between the Pectineus and Psoas muscles. On reaching the upper border of the 

 Adductor brevis it gives off two branches, one of which passes inward to be dis- 

 tributed to the Adductor muscles, the Gracilis, and Obturator externus, anasto- 

 mosing 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, between the Quadratus femoris and upper border of 

 the Adductor magnus, anastomosing with the sciatic, external circumflex, and 

 superior perforating arteries (" the crucial anastomosis "). Opposite the hip-joint 

 this branch gives off an articular vessel, which enters the joint beneath the trans- 

 verse ligament, and, after supplying the adipose tissue, passes along the round 

 ligament to the head of the bone. 



The Perforating Arteries (Fig. 375), usually three in number, are so called from 

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

 the thigh. The first is given off above the Adductor brevis, the second in front 

 of that muscle, and the third immediately below it. 



The first or superior perforating artery passes backward between the Pectineus 

 and Adductor brevis (sometimes perforates the latter) ; it then pierces the Adductor 

 magnus close to the linea aspera, and divides into branches which supply the 

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

 anastomosing with the sciatic, internal and external circumflex, and middle per- 

 forating arteries. 



The second or middle perforating artery, larger than the first, pierces the 

 tendons of the Adductor brevis and Adductor magnus muscles, and divides into 

 ascending and descending branches, which supply the flexor muscles of the thigh, 



