THE POPLITEAL AETEEY. 951 



artery, usually the former ; an additional nutrient branch may also be supplied by the first or 

 fourth perforating arteries. 



(5) The arteria genu suprema (O.T. anastomotic) arises near the termination 

 of the femoral artery, in the distal part of the adductor canal, and divides, almost 

 immediately, into a superficial, saphenous, and a deep (musculo- articular) branch ; 

 indeed, very frequently the two branches arise separately from the femoral trunk. 



(a) The saphenous branch passes through the distal end of the adductor canal with 

 the saphenous nerve, and appears superficially, on the medial side of the knee, between 

 the gracilis and the sartorius. It gives twigs to the integument of the proximal and 

 medial part of the leg, and it anastomoses with the inferior medial genicular artery. 

 (6) The musculo-articular branch runs towards the knee,> in the substance of the vastus 

 medialis, along the anterior aspect of the tendon of the adductor magnus. It anastomoses 

 with the superior medial genicular artery, and it sends branches laterally, one on the 

 surface of the femur and another along the proximal border of the patella, to anastomose 

 with the descending branch of the lateral circumflex, the fourth perforating artery, the 

 superior lateral genicular, and the anterior tibial recurrent. 



AETERIA POPLITEA. 



The popliteal artery is the direct continuation of the femoral. It commences 

 at the medial and proximal side of the popliteal fossa, under cover of the semi- 

 membranosus, and terminates at the distal border of the popliteus muscle, and on 

 a level with the distal part of the tuberosity of the tibia, by dividing into the 

 anterior and the posterior tibial arteries. 



From its origin the artery passes distally, with a lateral inclination, to the 

 interspace between the condyles of the femur, whence it is continued vertically to 

 its termination. 



Relations. Anterior. It is in contact in front and proximo-distally with the 

 popliteal surface of the femur, the posterior part of the capsule of the knee-joint, and the 

 fascia covering the posterior surface of the popliteus. 



Posterior. The artery is overlapped behind, in the proximal part of its extent, by the 

 lateral border of the semimembranosus ; it is crossed, about its middle, by the popliteal 

 vein and the tibial (O.T. internal popliteal) nerve, the vein intervening between the 

 artery and the nerve ; whilst, in the distal part of its extent, it is overlapped by the 

 adjacent borders of the two heads of the gastrocnemius, and is crossed by the nerves 

 to the soleus and popliteus and by the plantaris muscle. 



Lateral. On its lateral side it is in relation, proximally, with the tibial nerve and the 

 popliteal vein, then with the lateral condyle of the femur, and, distally, with the lateral 

 head of the gastrocnemius and the plantaris. 



Medial. On the medial side it is in relation, proximally, with the semimembranosus, in 

 the middle with the medial condyle of the femur, and, distally, with the tibial nerve, the 

 popliteal vein, and the medial head of the gastrocnemius. Popliteal lymph glands are 

 arranged irregularly around the artery. 



Branches. (1) Muscular branches are given off in two sets, proximal and distal. 



The proximal muscular branches are distributed to the distal parts of the hamstring 

 muscles, in which they anastomose with branches of the profunda artery. 



The distal muscular, or sural, arteries enter the proximal parts of the gastrocnemius, 

 the plantaris, the soleus, and the popliteus muscles, and they anastomose with branches 

 of the posterior tibial artery and the lower genicular arteries. 



(2) The genicular branches are five in number viz., superior and inferior lateral, 

 superior and inferior medial, and a median branch. 



(a) The superior lateral genicular artery passes laterally, proximal to the lateral 



iondyle, behind the femur and in front of the biceps tendon, into the vastus lateralis, 



where it anastomoses with the arteria genu suprema, the descending branch of the lateral 



circumflex, and the fourth perforating artery ; it also sends branches distally to anastomose 



ith the inferior lateral genicular and with the anterior tibial recurrent. 



(6) The superior medial genicular artery passes medially, proximal to the medial 

 condyle, behind the femur, and anterior to the tendon of the adductor magnus, into the 

 vastus medialis. It anastomoses with branches of the arteria genu suprema and of the 

 superior lateral genicular artery. 



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