POPLITEAL FOSSA 317 



arises from one of the sural muscular branches, and supplies 

 the integument over the proximal part of the calf of the leg. 

 It lies in the groove between the two heads of the gastro- 

 cnemius, with the medial cutaneous nerve of the calf. 



The genicular arteries are five in number, viz., two superior, 

 two inferior, and one middle or azygos. 



Arterise Genu Superiores (Superior Articular Arteries). 

 The two superior genicular arteries spring from the main trunk 

 in the interval between the condyles of the femur. One pro- 

 ceeds from each side of the popliteal artery, and they are called 

 medial and lateral, according to the direction which they take. 

 They were found resting directly upon the popliteal surface 

 of the femur, and will be observed to incline slightly upwards, 

 and then to wind round the bone immediately proximal 

 to the condyles. The lateral artery is the larger of the two. 

 The student is apt to mistake a muscular branch for one or 

 other of these vessels ; but their close apposition to the 

 femur should in all cases be sufficient to distinguish them. 



The superior lateral genicular artery runs laterally under 

 cover of the biceps femoris, and disappears from the popliteal 

 fossa by piercing the lateral intermuscular septum and enter- 

 ing the substance of the vastus intermedius. The superior 

 medial genicular artery proceeds medially under cover of the 

 semimembranosus, and leaves the popliteal fossa by piercing 

 the posterior intermuscular septum ; then it passes forwards, 

 under cover of the tendon of the adductor magnus, to reach 

 the deep surface of the vastus medialis. 



Arterise Genu Inferiores (Inferior Articular Arteries). 

 The two inferior genicular arteries arise from the popliteal as 

 it lies against the distal part of the oblique popliteal ligament. 

 The lateral inferior genicular artery takes a transverse course 

 laterally, under cover of the plantaris and lateral head of the 

 gastrocnemius, to gain a point on the lateral side of the knee, 

 immediately proximal to the head of the fibula. It proceeds 

 onwards under cover of the fibular collateral ligament of the 

 knee joint. The medial inferior genicular artery takes an 

 oblique course, distally and medially, under cover of the medial 

 head of the gastrocnemius, and along the proximal border of 

 the popliteus muscle, to gain the medial side of the tibia 

 distal to the medial condyle. There it turns forwards under 

 cover of the tibial collateral ligament of the knee. 



Arteria Genu Media (O.T. Azygos Articular Artery). The 



