POPLITEAL. 525 



or the vein may be double, the artery lying between the two venae comites, 

 which are usually connected by short transverse branches. More deeply, and 

 close to the surface of the bone, is the popliteal artery, and passing off from 

 it at right angles are its articular branches. The articular branch from the 

 obturator nerve descends upon the popliteal artery to supply the knee ; and 

 occasionally there is found deep in the space an articular filament from the 

 great sciatic nerve. The popliteal lymphatic glands, four or five in number, 

 are found surrounding the artery ; one usually lies superficial to the vessel, 

 another is situated between it and the bone, and the rest are placed on either 

 side of it. The bursas usually found in this space are : 1. On the outer side, 

 one beneath the outer head of the Gastrocnemius (which sometimes communi- 

 cates with the joint) and one beneath the tendon of the Popliteus, which is 

 almost always an extension of the synovial membrane. Sometimes also there 

 is a bursa above the tendon of the Popliteus, between it and the external lateral 

 ligament. 2. On the inner side of the joint there is a large bursa between the 

 inner head of the Gastrocnemius and the femur, which sends a prolongation 

 between the tendons of the Gastrocnemius and Semimembranosus, and lies in 

 contact with the ligament of Winslow. This bursa often communicates with 

 the joint. There is a second bursa between the tendon of the Semimembra- 

 nosus and the head of the tibia ; and sometimes a bursa between the tendons 

 of the Semitendinosus and Semimembranosus. 



The Popliteal Artery, in its course downwards from the aperture in the Ad- 

 ductor Magnus to the lower border of the Popliteus muscle, rests first on the 

 inner, and then on the posterior surface of the femur ; in the middle of its 

 course, on the posterior ligament of the knee-joint ; and below, on the fascia 

 covering the Popliteus muscles. Superficially, it is covered, above, by the 

 Semimembranosus; in the middle of its course, by a quantity of fat, which 

 separates it from the deep fascia and integument ; and below, it is overlapped 

 by the Gastrocnemius, Plantaris, and Soleus muscles, the popliteal vein, and the 

 internal popliteal nerve. The popliteal vein, which is intimately attached to 

 the artery, lies superficial and external to it, until near its termination, when it 

 crosses it and lies to its inner side. The popliteal nerve is still more superficial 

 and external, crossing, however, the artery below the joint, and lying on its 

 inner side. Laterally, the artery is bounded by the muscles which form the 

 boundaries of the popliteal space. 



PLAN OF KELAT-IONS OF POPLITEAL ARTERY. 



In front. 

 Femur. 



Ligamentum posticum. 

 Popliteus. 



Inner side. I popliteal \ Outer side. 



Semimembranosus. I Artery. I Biceps. 



Behind. 

 Popliteal vein. 

 Internal popliteal nerve. 

 Fascia. 



Peculiarities in point of division. Occasionally the popliteal artery divides prematurely into 

 its terminal branches ; this division occurs most frequently opposite the knee-joint. 



Unusual branches. The artery sometimes divides into the anterior tibial and peroneal, the 

 posterior tibial being wanting, or very small. In a single case, the popliteal was found to divide 

 into three branches, the anterior and posterior tibial, and peroneal. 



Surgical Anatomy. Ligature of the popliteal artery is required in cases of wound of that 

 vessel, but for aneurism of the posterior tibial it is preferable to tie the superficial femoral. The 

 popliteal may be tied in the upper or lower part of its course ; but in the middle of the ham the 



