VENOUS CIRCULATION. 99 



two branches in its course, and these at its termination: 

 1, the epigastric, and, 2, circumflexa ilii. 



The femoral artery, commencing at Poupart's ligament, 

 is to he found at a point half way between the anterior supe- 

 rior spinous process of the ilium, and the symphysis puhis, 

 situated behind this ligament and upon the common union 

 of the psoas magnus, and iliacus internus muscles; thence 

 it crosses the pectinalis, adductor brevis and longus, along 

 the inner edge of the rectus, and behind the sartorius to the 

 tendon of the adductor magnus, which it perforates. There 

 it becomes popliteal and continues such to the aperture in 

 the interosseous ligament of the leg, where it divides into 

 anterior and posterior tibial arteries, supplying the leg 

 and foot. The femoral arteries give off each four principal 

 branches to the thigh ; the popliteal, five to the knee-joint, 

 and the two terminating branches of the popliteal, to the 

 leg and foot. The whole number of primary branches 

 supplying the lower extremity, is about 28. 



The whole number to the body is 132 66 to the trunk, 

 and 66 to the extremities. 



This is the most usual way in which the arterial system 

 is distributed, but we shall frequently find varieties in the 

 origin, course, size, and number of the primary branches. 



The venous tree has its commencement where the arte- 

 rial terminates, or more properly, from the capillaries, the 

 connecting link between the two. The venous system con- 

 sists of two trunks, called the inferior or ascending, and 

 the superior or descending cava. 



These two trunks, with the coronary vein, return to the 

 heart all the blood of the body. We trace the primary 

 branches of the venous trunks in a direction contrary to 

 the arterial, that is, from the circumference to the heart, 

 instead of from the heart to the circumference. 



In the inferior extremity, commencing in the foot, we 

 trace the venous radicles, forming the superficial and deep- 

 seated veins. 



The superficial are the external and internal saphena, 

 the former rising upon the anterior and external part of the 



