Thermoregulatie

The body regulates core temperature through negative feedback mechanisms.

When the core temperature drops, thermoreceptors send signals to the hypothalamus, activating the heat-promoting center.

In response, the hypothalamus releases thyrotropin-releasing hormone, which stimulates the anterior pituitary to release the thyroid-stimulating hormone.

Together, these changes raise core temperature by several mechanisms.

Vasoconstriction of blood vessels in the skin reduces heat loss by retaining heat in the internal organs.

The release of hormones like epinephrine and norepinephrine, along with thyroid hormone increases cellular metabolism and heat production.

Shivering involves involuntary muscle contractions, elevating muscle tone and activating stretch receptors. This raises skeletal muscle activity, causing significant heat production.

In contrast, high core temperature leads to the inhibition of the heat-promoting center and, at the same time, activation of the heat-losing center, which regulates body temperature through two mechanisms:

Vasodilation of cutaneous blood vessels enables blood flow to the skin, allowing heat dissipation.

Increased sweating further leads to significant heat loss by evaporation.