THE POPLITEAL ARTERY. 637 



anastomosing with the superior and inferior perforating. The nutrient artery of the 

 femur is usually given off from this branch. 



The third or inferior perforating artery is given off below the Adductor brevis ; 

 it pierces the Adductor magnus, and divides into branches which supply the flexor 

 muscles of the thigh, anastomosing above with the perforating arteries, and below 

 with the terminal branches of the profunda and the muscular branches of the 

 popliteal. 



Muscular branches are given off from the superficial femoral throughout its 

 entire course. They vary from two to seven in number, and supply chiefly the 

 Sartorius an<l Vastus internus. 



The Anastomotica Magna arises from the femoral artery just before it passes 

 through the tendinous opening in the Adductor magnus muscle, and divides into a 

 superficial and deep branch. 



The superficial branch accompanies the long saphenous nerve beneath the 

 Sartorius. and. piercing the fascia lata, is distributed to the integument. 



The deep branch descends in the substance of the Vastus internus, lying in 

 front of the tendon of the Adductor magnus. to the inner side of the knee, where it 

 anastomoses with the superior internal articular artery and anterior recurrent 

 branch of the anterior tibial. A branch from this vessel crosses outward above 

 the articular surface of the femur, forming an anastomotic arch with the superior 

 external articular artery, and supplies branches to the knee-joint. 



Popliteal Artery. 



The popliteal artery commences at the termination of the femoral at the 

 opening in the Adductor magnus. and. passing obliquely downward and outward 

 behind the knee-joint to the lower border of the Popliteus muscle, divides into 

 the ant: r //<</ and posterior tibial arteries. A portion of the artery lies in the 

 popliteal space : but above, to a slight extent, and below, to a considerable extent, 

 it is covered by the muscles which form the boundaries of the space, and is therefore 

 beyond the confines of the hollow. 



THE POPLITEAL SPACE (Fig. 377). 



Dissection. A vertical incision about eight inches in length should be made along the 

 back part of the knee-joint, connected above and below by a transverse incision from the inner 

 to the outer side of the limb. The flaps of integument included between these incisions should 

 be reflected in the direction shown in Fig. 328, page 514. 



Boundaries. The popliteal space. is lozenge-shaped, widest at the back part of 

 the knee-joint. It is bounded externally, above the joint, by the Biceps, and, 

 below the joint, by the Plantaris and external head of the Gastrocneinius ; in- 

 ternally, above the joint, by the Semimembranosus and Semitendinosus. the latter, 

 however, lying on (posterior to} the former, whose edge is the real boundary; below 

 the joint, by the inner head of the Gastrocnemius. 



Above, it is limited by the apposition of the inner and outer hamstring 

 muscles: beLw. by the junction of the two heads of the Gastrocnemius. 

 The floor is formed by the lower part of the posterior surface of the shaft of 

 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 termination 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 lymphatic glands, and 

 a considerable quantity of loose adipose tissue. 



Position of Contained Parts. The internal popliteal nerve descends in the 

 middle line of the space, lying superficial and crossing the artery from without 

 inward. The external popliteal nerve descends on the outer side of the space, 



