This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Vein used in bypass Surgery: 
Select and explain. 
A. Great saphenous vein, B. Sho saphenous vein, C. Femoral vein, D. Brachial vein
A: Great saphenous vein
Answer: A: Great saphenous vein 
Explanation: In patients with occlusive coronary disease caused by atherosclerosis, the diseased aerial segment can be bypassed by inseing a graft consisting of a poion of the great saphenous vein.The venous segment is reversed so that its valves do not obstruct the aerial flow. Following removal of the great saphenous vein at the donor site, the superficial venous blood ascends the lower limb by passing through perforating veins and entering the deep veins.The great saphenous vein can also be used to bypass obstructions of the brachial or femoral aeries.