What is the negative feedback mechanism in the regulation of body temperature?

The term "thermoregulation" describes how our body regulates its temperature. It can be external or internal. Our skin has receptors called peripheral receptors that detect changes in temperature, and our brains have central receptors that sense changes in blood temperature as blood flows through the brain.

Now, your receptors sense a change in temperature, and when they do, they send a message to the hypothalamus, which is the control center in charge of thermoregulation. The anterior hypothalamus regulates body temperature; the posterior hypothalamus regulates body temperature. The hypothalamus interprets the message from the receptors, and then sends it to the appropriate effectors.

Sweat glands and muscle tissue in arterioles (blood vessels) are effectors that release heat when temperatures rise too high. The anterior hypothalamus stimulates sweat glands to release sweat, which cools the body through evaporative cooling. Additionally, arterioles dilate to increase blood flow to the skin, which causes heat loss (this process is known as vasodilation).

Effectors that contract in response to low temperatures include the muscles in your skin called erectors and the muscle tissue in arterioles. The posterior hypothalamus triggers the contraction of erector muscles, which causes goosebumps and rises hairs, thereby preventing heat loss and creating a layer of warm air that "traps" beneath your skin. It also triggers the constriction of arterioles, which lowers blood flow to the skin and causes heat retention (vasoconstriction).

The hypothalamus is responsible for monitoring changes in body temperature. When the temperature exceeds the set point, the hypothalamus signals for responses like sweating and vasodilation to cool the body down. When the temperature falls below the set point, the hypothalamus triggers responses like shivering and vasoconstriction to increase heat production and conserve warmth. When the body reaches the set point again, the hypothalamus ceases to signal for these responses, preserving homeostasis.