A regulator uses internal control mechanisms to control internal change in the face of external fluctuation (river otter) A conformer allows its internal condition to vary with certain external changes (largemouth bass) Organisms use homeostasis to maintain a steady state or internal balance regardless of external environment. In humans, body temperature, blood ph, and glucose concentration are each maintained at a constant level. Mechanisms of homeostasis moderate changes in the internal environment. For a given variable, fluctuations above or below a set point serve as a stimulus; these are detected by a sensor and trigger a response. The response returns the variable to the set point. Homeostasis in animals relies largely on negative feedback, which helps to return a variable to a normal range. Positive feedback amplifies a stimulus and does not usually contribute to homeostasis in animals. Homeostatic processes for thermoregulation involve form, function, and behavior. Thermoregulation is the process by which animals maintain an internal temperature.