THE POPLITEAL ARTERY 693 



The first perforating artery (a. perforans prima) passes backward between the 

 Pectineus and Adductor brevis (sometimes perforates the latter); it then pierces 

 the Adductor magnus close to the linea aspera. It gives off branches which supply 

 the Adductor brevis, the Adductor magnus, the Biceps, the Gluteus maximus 

 . muscles, and anastomoses with the sciatic, internal and external circumflex, and 

 second perforating arteries. 



The second perforating artery (a. perforans secunda), larger than the first, pierces 

 the tendons of the Adductor brevis and Adductor magnus muscles, and divides 

 into ascending and descending branches, which supply the Flexor muscles of the 

 thigh, anastomosing with the first and third perforating arteries. The second 

 artery frequently arises in common with the first. The nutrient artery of the 

 femur (a. nutricia femoris) is usually given off from this branch. 



The third perforating artery (a, perforans tertia) 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 higher perforating 

 arteries, and below with the terminal branches of the profunda and the muscular 

 branches of the popliteal. 



A fourth perforating artery is represented by the termination of the profunda 

 femoris artery. 



Numerous muscular branches arise from the profunda; some of these end in the 

 Adductor muscles, others pierce the Adductor magnus, give branches to the Ham- 

 string muscles, and anastomose with the internal circumflex artery and with the 

 upper muscular branches of the popliteal. 



The anastomotica magna (a. genu supremo) (Figs. 481 and 482) arises from 

 the femoral artery just before it passes through the tendinous opening in the 

 Adductor magnus muscle, and immediately divides into a superficial and deep 

 branch. 



The superficial branch (ramus saphenus) pierces the aponeurotic covering of 

 Hunter's canal, and accompanies the long saphenous nerve to the inner side of the 

 thigh. It passes between the Sartorius and Gracilis muscles, and, piercing the 

 fascia lata, is distributed to the integument of the upper and inner part of the leg, 

 anastomosing with the inferior internal articular artery. 



The deep branch (ramus musculoarticularis) descends in the substance of the 

 Vastus internus. lying in front of the tendon of the Adductor magnus. to tho inner 

 side of the knee, where it anastomoses with the superior internal articular artery 

 and the anterior recurrent branch of the anterior tibial. A branch from this 

 vessel crosses outward above the articular surface of the femur, forming an anas- 

 tomotic arch with the superior external articular artery, and supplies branches to 

 the knee-joint. 



THE POPLITEAL ARTERY (A. POPLITEA) (Figs. 477 and 481). 



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 anterior 

 and posterior tibial arteries. A portion of the artery lies in the popliteal space; 

 but above 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 space. 



The Popliteal Space (Fig. 483). 



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. 386, p. 518. 



