586 A MANUAL OF ANATOMY. 



The Internal Annular Ligament. Fig. 131. 



This is the portion of the deep fascia reaching from the 

 internal malleolus to the inner lower and posterior borders 

 of the os calcis. 



For the relations of the important structures which pass 

 under this ligament, see page 632. 



The External (Short) Saphenous Vein. 



This begins at the outer side of the venous plexus found 

 upon the dorsum of the foot It passes backward along 

 the outer margin of the foot, below the external malleolus, 

 then upward over the back of the leg, perforates the deep 

 fascia of the leg at the lower part of the popliteal space and 

 empties into the popliteal vein. 



(For the dissection of the vein at the back of the leg, 

 see page 618.) 



The vein receives its tributaries from the outer side of 

 the foot, outer and back parts of the leg, and a large vein 

 from the lower part of the thigh just before it perforates 

 the deep fascia. 



The Internal (Long-) Saphenous Vein. 



This emerges from the inner side of the dorsal venous 

 arch of the foot. Its course is upward in front of the inter- 

 nal malleolus, along the antero-internal border of the leg 

 to the inner side of the knee, where it lies behind the inter- 

 nal condyle of the femur. Its further course and tribu- 

 taries are given on page 557. 



The internal saphenous receives the subcutaneous veins 

 from the inner side of the foot and leg. 



Both saphenous veins communicate with the venae com- 

 ites of the deep parts of the leg by veins which perforate 

 the deep fascia at irregular intervals. They also communi- 



