Final answer:
Thermoregulation is the body's mechanism for maintaining a stable internal temperature in response to external temperature changes, involving processes like vasoconstriction and shivering when cold, and vasodilation and sweating when hot.
Step-by-step explanation:
The mechanism by which thermal receptors detect changes in body temperature, and the body responds through actions such as blood vessel constriction and muscle shivering, is known as thermoregulation. Thermoregulation is a critical homeostatic function that is managed by the hypothalamus in the brain. When it is cold, the skin's blood vessels undergo vasoconstriction to minimize heat loss, and shivering happens to generate heat, which raises body temperature.
On the other hand, when the body is overheated, processes such as vasodilation and sweat secretion increase. Vasodilation allows more blood to flow to the surface, releasing body heat, while sweating provides a cooling effect as the sweat evaporates from the skin. These responses are crucial for maintaining a steady internal environment, despite changes in external temperatures.