494 



THE ARTERIES OF THE LOWER LIMB. 



A. The muscular branches are divided into a superior and an inferior group. 



1. The superior muscular branches, three or four in number, are distributed 

 to the lower parts of the adductor magnus and hamstring muscles, and anastomose , 

 with the perforating and upper articular arteries. Small offsets pass from these 

 branches to the internal popliteal nerve and to the skin, and also communicate above 

 with the branches of the perforating arteries. 



2. The inferior muscular or sural arteries, generally two in number, and 

 of considerable size, arise from the back of the popliteal artery, a little above the 

 knee-joint, and enter, one the outer, and the other the inner head of the gastrocne- 

 mius muscle, which they supply, as well as the plantaris and the upper part of the 

 soleus muscle. 



Over the surface of the gastrocnemius, on each side and in the middle of the 

 limb, are slender branches, which descend a considerable distance along the calf of 



Fig. 391. VIEW OP THE POPLITEAL ARTERY AND ITS BRANCHES IN 

 THE RIGHT LEO. (Tiedemann.) 



a, biceps muscle ; b, semimembranosus ; c, semitendinosus ; 1, pop- 

 liteal artery, 2, 3, superficial sural branches ; 4, outer, 5, inner superior 

 articular branch ; 6, superior muscular ; 7, median superficial artery. 



the leg and supply the integument. These small vessels 

 (superficial sural) may arise either from the popliteal trunk 

 or from its sural branches. 



B. The articular arteries are five in number. Two of 

 these pass off nearly at right angles from the popliteal artery, 

 one on each side, above the condyles of the femur ; two 

 others have a similar arrangement below the knee-joint ; 

 and the fifth passes directly forwards into the centre of the 

 joint. 



1. The superior internal articular artery is di- 

 rected inwards just above the inner head of the gastro- 

 cnemius, and beneath the inner hamstring muscles, to all of 

 which it famishes small offsets. Winding round the inner 

 side of the femur, between the bone and the tendon of the 

 adductor magnus, it divides under cover of the vastus 



internus muscle into branches, which anastomose with the deep part of the anas- 

 tomotic, the upper external articular, and the lower articular arteries. The size of 

 this artery varies inversely with that of the deep part of the anastomotic branch 

 of the femoral. 



2. The superior external articular artery (v), larger than the internal, 

 runs outwards above the outer head of the gastrocnemius, under cover of the biceps, 

 and, perforating the intermuscular septum, enters the lower part of the crureus 

 muscle. Its branches anastomose above with the descending branch of the external 

 circumflex artery, below with the lower external articular artery, and internally with 

 the upper internal articular artery and the deep branch of the anastomotic, forming 

 with the last a considerable arch at the upper border of the patella. 



3. The inferior internal articular artery (v), the larger of the two lower 

 branches, inclines at first downwards and inwards along the upper margin of the 

 popliteus muscle, to which it gives branches, and then passes forwards below the 

 inner tuberosity of the tibia, between the internal lateral ligament and the bone. 

 Its offsets ramify over the inner and fore part of the joint, as far as the patella and 

 its ligament, and anastomose with the superficial branch of the anastomotic, the 

 upper internal articular, and lower external articular arteries. 



