Homeostasis and health: analysis from a standpoint of the control theory

Homeostasis, the most important property of complex biological systems, was analyzed from a standpoint of the control theory. Homeostasis or the constancy of the internal environment arises in the biosystems upon feedbacking the control loop responsible for stationarity. Consideration was given to the mechanism of temperature homeostasis exemplifying such constancy. Presented was a concept of health as preservation of homeostasis. It was treated as the ability of the organism to maintain homeostasis and return to it after violations caused by external disturbances. A three-stage scheme of the life cycle where health is characteristic only of one stage was proposed.