(“homeostasis” is the property of a system within the body of an organism in which a variable, such as the concentration of a substance in solution, is actively regulated to remain very nearly constant)
(examples of “homeostasis” include the regulation of the body temperature of an animal, the pH of its extracellular fluids, or the concentrations of sodium (Na+), potassium (K+) and calcium (Ca2+) ions as well as that of glucose in the blood plasma, despite changes in the animal’s environment, or what it has eaten, or what it is doing (for example, resting or exercising))
(each of these variables is controlled by a separate “homeostat” (or regulator), which, together, maintain ‘life’)
(“homeostats” are energy-consuming physiological mechanisms)
(the concept was described by French physiologist ‘Claude Bernard’ in 1865 and the word was coined by ‘Walter Bradford Cannon’ in 1926)
(the term “cybernetics” is applied to technological control systems such as thermostats, which function as “homeostats”, but is often defined much more broadly than the biological term “homeostasis”)
(“homeostasis” is an almost exclusively biological term, referring to the concepts described by ‘Bernard’ and ‘Cannon’, concerning the constancy of the internal environment (or ‘milieu intérieur’) in which the cells of the body live and survive)