keep the answer simple
2007-02-01 14:19:33 · 3 answers · asked by Volleyball_Playa_06 1 in Science & Mathematics ➔ Biology
Vaso dilatation: the blood vessels at the extremities (hand, feet) and those just under the skin get dilated, allowing a larger flow, which permit radiating more heat.
The exact opposite phenomenon occurs when subjected to cold temperature, as the blood vessels in the surface of the skin contract, restricting blood flow so that less heat is lost (which can cause some problem like frostbite in the end).
Further, in hot condition, the increased blood flow brings more fluid to the sweat glands, which can thus express more moisture and provide evaporative cooling.
2007-02-01 14:27:42 · answer #1 · answered by Vincent G 7 · 0⤊ 0⤋
The blood vessels nearest the surface of the skin dilate and allow more blood to pass through. Heat radiates out of the bloodstream, through the skin, and into the air. This cools the body.
That's why people who are hot have red faces.
2007-02-01 22:23:50 · answer #2 · answered by ecolink 7 · 1⤊ 0⤋
Your veins and arteries can become constricted or relaxed to help you regulate body tempature. Your blood vessels constrict and retreat deeper into your body to retain heat. When they relax and go close to the skin, they allow for cooling as they give off extra heat to the environment.
2007-02-01 22:30:48 · answer #3 · answered by greenhat1981 3 · 0⤊ 0⤋