|
Varicose and spider veins are common medical complaints that result when blood flow from outlying parts of the body back to the heart becomes compromised. Veins in the leg are the most commonly affected, particularly on the back of the calf. These veins contain a series of leaflet valves that allow only upward blood movement. Transport of blood up the leg to the heart proceeds via ladder-like steps through this series of valves. Varicose and spider veins result when vein walls develop poor tone, causing valve malfunction. Blood then stalls out on its upward journey and may even move down the leg. Valve malfunction in smaller vessels produces spider veins. In larger ones, varicose veins result. The characteristic color of varicose and spider veins, observable only for veins near the surface, derives from the bluish-red tint of oxygen-depleted venous blood.
|
