Thirst Center

the totality of structures in the brain that regulate thirst and drinking reactions, thus determining the body’s requirement for water.

Stimulation and inhibition of the thirst center, which are manifested in the development or cessation of thirst, depend on the physicochemical state of the body’s internal environment and on signals from the exteroceptors and interoceptors (chemoreceptors and mechanoreceptors in the mouth, throat, stomach, and carotid sinuses and volume receptors in the circulatory channel). The various structures included in the thirst center are located in different parts of the central nervous system: the hypothalamus, the limbic system, and the cerebral cortex.

Receptors in the hypothalamic areas react to changes in the volume and osmotic pressure of extracellular fluids and to their content of Na ions and biologically active substances. There is a link between the thirst center and the level of secretion of vasopressin, angiotensin, renin, aldosterone, thyroid hormones, and insulin. Thus, the thirst center is involved in regulating metabolism, the work of the kidneys, and the circulation of the blood. Damage to certain structures of the thirst center may produce an intensification of thirst (hyperdipsia) or its suppression (hypodipsia and adipsia).

The cortical areas of the thirst center are very important as the site of the formation of complex reflex reactions that regulate the body’s intake of water. The thirst center is closely connected with the appetite, or hunger center.