Superficial veins of the udder of a dairy cow.
Superficial veins are not paired with an artery, unlike the deep veins, which typically have an artery with the same name close by.
Superficial veins are important physiologically for cooling of the body. When the body is too hot the body shunts blood from the deep veins to the superficial veins, to facilitate heat transfer to the surroundings. Superficial veins can be seen under the skin. Those below the level of the heart tend to bulge out. This can be readily witnessed in the hand: raised above the heart and the blood should drain; lowered below the heart and it will fill. Veins become more visually prominent when lifting heavy weight, especially after a period of proper strength training.
Physiologically, the superficial veins are not as important as the deep veins (as they carry less blood) and are sometimes removed in a procedure called vein stripping, which is used to treat varicose veins.
Some named superficial veins
- cephalic vein - glides along the biceps: the "signature vein" of bodybuilders
- median cubital vein - often used to draw blood (venipuncture).
- basilic vein - usually the largest vein in the arm: often used for dialysis access
- The Veins of the Lower Extremity, Abdomen, and Pelvis - Gray's Anatomy.
- Varicose vein therapy - medlineplus.org