442 



POPLITEAL ARTERY. 



it is separated by an interval from the flat or somewhat hollowed triangular 

 surface at the lower end of the bone ; it then rests on the posterior ligament 

 of the knee-joint, and afterwards on the popliteus muscle. 



Edation to Veins. The popliteal vein lies close to the artery, behind 

 and somewhat to the outer side till near its termination, where it crosses the 

 artery and is placed somewhat on the inner side. The vein is frequently 

 double along the lower part of the artery, and, more rarely, also at the 

 upper part. The short saphenous vein, ascending into the popliteal space 

 over the gastrocnemius muscle, approaches the artery as it is about to ter- 

 minate in the popliteal vein. 



Relation to the Nene. The internal popliteal nerve lies at first to the 

 outer side of the artery, but much nearer to the surface than the vessel : 

 the nerve afterwards crosses over the artery, and is placed behind and to 

 the inner side below the joint. 



BRANCHES. The branches of the popliteal artery may be arranged in two 

 sets, viz. the muscular and the articular. 



1. The muscular brandies are divided into a superior and an inferior 

 group. 



(a) The superior branches, three or four in number, are distributed to the lower 

 ends of the hamstring muscles, and also to the vasti muscles, and anastomose with the 

 perforating and articular arteries. 



Fig. 302. 



Fig. 302. VIEW OF THE POPLITEAL ARTERY AND 

 BRANCHES IN THE RIGHT LEG (from Tiedemann). 



ITS 



a, biceps muscle ; Z>, semimembranosus ; c, semi- 

 tendinosus ; 1, the popliteal artery ; 2, 3, the superficial 

 sural branches ; 4, the outer, 5, the inner superior 

 articular branch ; 6, the superior muscular ; 7, the 

 inferior muscular or deep sural branches. 



(b) The inferior muscular branches, or sural arteries, 

 usually two in number, and of considerable size, arise 

 from the back of the popliteal artery, opposite the 

 knee-joint, and enter, one the outer, and the other the 

 inner head of the gastrocnemius muscle, which they 

 supply, as well as the fleshy part of the plantaris 

 muscle. 



Over the surface of the gastrocnemius will be found 

 at each side, and in the middle of the limb, slender 

 branches, which descend a considerable distance along 

 the calf of the leg, and end in the integument. These 

 small vessels (superficial sural) arise separately from 

 the popliteal artery, or from some of its branches. 



2. The articular arteries. Two of these pass 

 off nearly at right angles from the popliteal 

 artery, one to each side, above the flexure of 

 the joint, whilst two have a similar arrange- 

 ment below it, and a fifth passes from behind into the centre of the joint. 



(a) The upper internal articular artery winds round the femur just above 

 the inner condyle ; and, passing under the tendon of the great adductor and 

 the vastus internus, divides into two branches ; one of these, comparatively 

 superficial, enters the substance of the vastus, and inosculates with the anas- 

 tomotic branch of the femoral, and with the lower internal articular artery. 



