False-colour scanning electron micrograph (SEM) of a sectioned varicose saphenous vein, 1 of 2 such superficial veins that drain blood from the foot (the long saphenous vein, the longest in the body, runs from the foot to the groin, where it joins the femoral vein). Varicose veins are veins that are distended, lengthened & tortuous. Causes include inherited tendency & obstruction to blood flow due to the narrowing of the interior lumen of the vein (as in this case). Complications include thrombosis (clot formation) & haemorrhage (leakage of blood). Treatment includes elastic support, stripping (avulsion) or surgical removal. Magnification: X 10 at 35mm size.