312 THE CIRCULATORY SYSTEM. 



sends several branches dorsad (toward the knee), and at about 

 the middle of the lower leg it divides into two main branches, 

 a dorsal branch (/'), passing- to the dorsum of the foot, and a 

 plantar branch (j), to the sole of the foot. The dorsal branch 

 is accompanied by the main saphenous nerve (^) and vein. It 

 sends one or two branches to the medial side of the ankle- 

 joint, passes then onto the dorsum of the foot, and divides into 

 four main branches. The medial one passes along the medial 

 side of the medial digit; the other three pass to the intervals 

 between the digits. Each divides into two branches which 

 supply the contiguous sides of the two digits between which 

 the interval lies. The dorsal branch thus supplies arteries to 

 the sides of all the digits except to the lateral side of the lateral 

 digit. This is supplied by A. suralis. 



The plantar branch (j) is larger than the dorsal. It passes 

 distad on the medial surface of the flexor longus hallucis, 

 accompanied by the tibial nerve, and across the space between 

 the tendon of Achilles and the flexor. It gives superficial and 

 deep branches to the structures about the ankle-joint, and 

 sends inward a branch from the lateral side (Fig. 128, d) 

 which joins the termination of A. tibialis anterior to form the 

 plantar arch. It then passes distad along the plantar surface 

 of the foot, nearer its medial border. Beneath the pad in the 

 sole of the foot it divides into three branches which supply the 

 interosseous spaces between the three digits. 



e. A. poplitea. — The main trunk of the femoral artery 

 passes between the vastus medialis and the semimembranosus 

 and then through the distal portion of the adductor femoris to 

 reach the popliteal space. This is the space ventrad (or 

 caudad) of the knee, between the biceps femoris on one side 

 and the semimembranosus on the other. Here the artery 

 receives the name A. poplitea, or popliteal artery. The pop- 

 liteal artery gives off a number of large branches as it passes 

 through the popliteal space, passes between the condyles of 

 the femur and underneath the popliteal muscle, and finally 

 turns dorsolaterad between the tibia and fibula, just distad of 

 the head of the fibula. It now receives the name A. tibialis 



