692 THE VASCULAR SYSTEMS 



Peculiarities of Origin of the Prof unda. This vessel occasionally arises from the inner 

 side, and, more rarely, from the back of the common trunk; but the more important peculiarity, 

 from a surgical point of view, is that which relates to the height at which the vessel arises from the 

 femoral. In three-fourths of a large number of cases it arose between one to two inches below 

 Poupart's ligament; in a few cases the distance was less than an inch; more rarelv, opposite the 

 ligament; and in one case, above Poupart's ligament, from the external iliac. * Occasionallv, 

 the distance between the origin of the vessel and Poupart's ligament exceeds two inches, and in 

 one case it was found to be as much as four inches. 



Branches. The profunda gives off the following-named branches: 



External circumflex. Four perforating. 



Internal circumflex. Muscular. 



The external circumflex artery (a. circumflexa femoris lateralis) 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 femoral nerve and 

 behind the Sartorius and Rectus muscles, and divides into three sets of branches 

 ascending, transverse, and descending. 



The ascending branch (ramus ascendens) passes 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. It sends out muscular 

 branches. 



The descending branch (ramus descendens) passes downward, behind the Rectus, 

 upon the Vasti muscles, to which its branches 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 femoral nerve to the Vastus externus. 



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

 the Vastus externus, and winds around 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 (a. circumflexa femoris medialis}, smaller than 

 the external, arises from the inner and back part of the profunda, and winds 

 around 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 muscular branches, 

 one of which passes inward to be distributed 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; whfle the continuation of the vessel passes backward and divides into 

 an ascending and a transverse branch (Fig. 389). The ascending branch (ramus 

 profundus] 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 (ramus super ficialis), larger than the ascending, appears between the 

 Quadratus femoris and upper border of the Adductor magnus, anastomosing with 

 the sciatic, external circumflex, and superior perforating arteries, the crucial anas- 

 tomosis. Opposite the hip-joint the artery gives off an articular vessel (ramus 

 acetabuli), which enters the joint beneath the transverse ligament; and, after sup- 

 plying the adipose tissue, passes along the round ligament to the head of the bone. 



The perforating arteries (Figs. 472 and 47t\), usually three 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. 



