Explain how sweat glands and the capillary blood vessels of the skin function together to help the body thermoregulate itself.
When the body is too warm, the flow of perspiration from the sweat glands to the ducts to the surface of the skin increases. As the perspiration evaporates, heat is removed from the surrounding tissues in order to change the liquid to a gas, thus producing a cooling effect on the body. At the same time, the capillaries in the skin dilate, which increases the flow of blood to the skin. Because blood rapidly loses heat by radiation to the outside, the greater the blood flow to the skin, the greater the heat lost. Conversely, when the body is too cool, the capillaries constrict, thus reducing blood flow to and heat loss from the skin.
