694 



THE VASCULAR SYSTEMS 



Boundaries. The popliteal space is a lozenge-shaped space, widest at the 

 back part of the knee-joint, and deepest above the articular end of the femur. 

 It is bounded externally, above the joint, by the Biceps, and below the joint by the 



Jlantaris and external head of the Gastroc- 

 nemius. Internally, above the joint, by the 

 Semimembranosiis, Semitendinosus, Gracilis, 

 and Sartorius; below the joint, by the inner 

 head of the Gastrocnemius. 



Above, it is limited by the apposition of the 

 inner and outer Hamstring muscles; below, 

 by the junction of the two heads of the Gas- 

 trocnemius. The floor is formed by the lower 

 part of the posterior surface of the shaft of 

 artend the femur, the posterior ligament of the 

 knee-joint, the upper end of the tibia, and 

 the fascia covering the Popliteus muscle, and 

 the space is covered in by the fascia lata. 



Contents. It contains the popliteal vessels 

 and their branches, together with the termi- 

 nation of the external saphenous vein, the 

 internal and external popliteal nerves and 

 /some of their branches, the lower extremity 

 of the small sciatic nerve, the articular branch 

 from the obturator nerve, a few small lymph 

 nodes, and a considerable quantity of loose 

 )se tissue. 



-Anterior peroneal. 



m 



FIG 483.-The 



Position of Contained Parts. The in- 

 ternal popliteal nerve descends in the middle 

 line of the space lying superficial and cross- 

 ing the artery from without inward. The 

 external popliteal nerve descends on the 

 outer side of the upper part of the space, 

 lying close to the tendon of the Biceps 

 muscle. More deeply at 'the bottom of the 

 space are the popliteal vessels, the vein lying 

 superficial to the artery, to which it is closely 

 united by dense areolar tissue; it is a thick- 

 walled vessel, and lies at first to the outer 

 side of the artery, and then crosses it to gain 

 the inner side below; sometimes the vein is 

 double, the artery lying between the two 

 venae comites, which are usually connected 

 by short transverse branches. More deeply 

 and, at its upper part, 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 artic- 

 ular filament from the great sciatic nerve. 



The popliteal lymph nodes, four or five 

 in number, are found surrounding the artery; 



^J'^^terior tibial. and Qne usua Jly l| es superficial to the VCSSel I 



