ABSTRACT
The effects of sleep deprivation are commonly interpreted in terms of the homeostatic regulation of some physiological variable that is as yet unknown. Walter Cannon introduced the term homeostasis in 1929 to describe physiological mechanisms found in many organisms that maintain a constant internal environment. Physiological variables that are homeostatically regulated by one or more types of organism include temperature, osmolarity, pH, body mass, density, blood pressure, respiratory rate, heart rate, and tissue concentrations of numerous nutrients, waste products, and other chemicals.
