THE LEG 361 



Vena Saphena Parva. The small saphenous vein is 

 formed, in the lateral border of the foot, by the union of the 

 lateral digital vein of the little toe with the lateral end of the 

 dorsal venous arch of the foot. From its point of commence- 

 ment it runs backwards below the lateral malleolus, and 

 then upwards behind the lateral malleolus, in company with 

 the sural nerve, and superficial to the peroneal retinacula. 

 Afterwards it ascends, parallel with the lateral border of the 

 tendo calcaneus, where it is still associated with the sural 

 nerve. Above the level of the tendo calcaneus it ascends 

 along the median line of the calf to the lower part of the 

 popliteal region, where it pierces the popliteal fascia and 

 terminates in the popliteal vein. In the lower part of its 

 ascent along the median line of the calf it is associated with 

 the medial cutaneous nerve of the calf, and in the upper 

 part by the distal portion of the posterior cutaneous nerve 

 of the thigh. The small saphenous vein receives tributaries 

 from the lateral border of the foot, the heel, and the back 

 of the calf. It is accompanied by superficial lymph vessels 

 which commence in the areas in which the tributaries of 

 the vein arise, and which terminate in the popliteal lymph 

 glands (Figs. 163, 164). 



The two saphenous veins are connected together by the 

 medial femoral circumflex vein, which commences from the 

 small saphenous vein, immediately before it pierces the deep 

 fascia, and terminates in the great saphenous vein above the 

 middle of the thigh. In some cases the medial femoral 

 circumflex vein forms the direct continuation of the small 

 saphenous vein, and in those cases the small saphenous vein 

 has either only a very small connection, or no connection at 

 all, with the popliteal vein. 



The Lymph Vessels and Lymph Glands of the Inferior Extremity. 

 The lymph vessels of the inferior extremity cannot be displayed in an 

 ordinary " part," but some at least of the lymph glands are always found, 

 and as both lymph vessels and lymph glands are of great practical 

 importance, it is essential that the dissector should have a general know- 

 ledge of their positions and functions. The lymph vessels contain a 

 colourless fluid called lymph, which drains into their finer tributaries from 

 the surrounding tissues. Micro-organisms which have gained access to 

 the tissues, and the cells of malignant tumours growing in the tissues, may 

 enter the lymph vessels and so be carried onwards in the lymph stream. 

 The lymph carried by the lymph vessels eventually passes into two 

 terminal trunks, the tJioracic duct and the right lymph duct, each of which 

 terminates in a large vein ; therefore the lymph, and micro-organisms or 

 poisons formed by micro-organisms which have entered the lymph, are 



