homeostazë

Homeostazë, also known as homeostasis, is the process by which living organisms maintain a stable internal environment despite changes in the external surroundings. It describes the regulatory mechanisms that keep physiological variables within narrow ranges necessary for proper cellular function and survival.

Regulated variables commonly include body temperature, pH, fluid and electrolyte balance, blood glucose, and the levels of oxygen and carbon dioxide. The maintenance of these variables involves a system of sensors, control centers, and effectors. Receptors detect deviations from set points, integrators or control centers compare the information to a desired value, and effectors enact responses to restore balance. Negative feedback is the most common mechanism, working to counteract disturbances. Positive feedback occurs in specific situations to amplify a response, such as during childbirth or blood clotting.

Examples of homeostatic processes include thermoregulation, which maintains core body temperature; osmoregulation, managed by the kidneys and thirst mechanisms; glucose homeostasis coordinated by insulin and glucagon; and acid–base balance regulated by the lungs and kidneys.

Disruptions to homeostazë can lead to illness or dysfunction, including conditions like diabetes, dehydration, or metabolic and respiratory disorders. Homeostatic regulation operates at cellular, tissue, organ, and whole-organism levels and is fundamental to physiology, medicine, and biology.