homeostasis /hō′mē·əstā″sis/ [Gk, homoios + stasis, standing still] , a relative constancy in the internal environment of the body, naturally maintained by adaptive responses that promote healthy survival. Various sensing, feedback, and control mechanisms function to effect this steady state. Some of the key control mechanisms are the reticular formation in the brainstem and the endocrine glands. Some of the functions controlled by homeostatic mechanisms are heartbeat, hematopoiesis, blood pressure, body temperature, electrolytic balance, respiration, and glandular secretion. −homeostatic, adj.
