AP BIOLOGY

Detailed explanation-1: -All of the above would be normal responses to excessive loss of body heat in a cold environment. The dermal blood vessels would become constricted, the sweat glands would become inactive, and the skeletal muscles would contract involuntarily. These responses all prevent the body from becoming hypothermic.

Detailed explanation-2: -When liquid sweat changes to a vapour and evaporates from the skin surface, it takes heat away from the body. If the body is cold, the sweating mechanism is inhibited. Temperature regulation is controlled by a part of the brain called the hypothalamus responding to the core temperature of the blood.

Detailed explanation-3: -Eccrine sweat glands primarily respond to thermal stimuli; particularly increased body core temperature [40], but skin temperature and associated increases in skin blood flow also play a role [9, 46–49].

Detailed explanation-4: -Humans exhibit two major physiological responses to cold exposure. Peripheral vasoconstriction limits heat loss. Shivering, physical activity, or both increase heat production.

Detailed explanation-5: -The eccrine sweat gland, which is controlled by the sympathetic nervous system, regulates body temperature. When internal temperature rises, the eccrine glands secrete water to the skin surface, where heat is removed by evaporation.