Which vessel is NOT a tributary of the popliteal vein? Gastrocnemius veins Posterior tibial veins Great saphenous vein Small saphenous vein

The Great saphenous vein is NOT a tributary of the popliteal vein. Here's why:

1. The popliteal vein is a deep vein of the leg, located in the popliteal fossa at the back of the knee.

2. The gastrocnemius veins and the posterior tibial veins are tributaries of the popliteal vein. They drain blood from the calf muscles and the posterior compartment of the leg, respectively, and feed into the popliteal vein.

3. The small saphenous vein also drains into the popliteal vein. It runs up the back of the lower leg and drains blood from the lateral surface of the leg and the heel.

4. However, the great saphenous vein is not a tributary of the popliteal vein. It is the longest vein in the body, running from the foot to the groin. It drains blood from the medial surface of the leg and thigh and feeds into the femoral vein, not the popliteal vein.