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Author(s): Wade Haaland

Necessary Components of a Homeostatic System

To maintain homeostasis, a system must have three components: 1) a receptor, 2) a control center, and 3) an effector.  All of these components do specific jobs that allow an organism to regulate its internal environment. 

A receptor detects external changes that could influence the internal environment. It then reports these changes to the control center, which, in turn, will activate an effector, whose function is to restore homeostasis. In the diagram above, the thermometer represents the receptor for this homeostatic system. It communicates with the thermostat (the control center) when there is a change in the external environment. The thermostat responds by directing the fan (the effector) to turn off or on. For example, if the thermometer informs the thermostat of a sudden increase in temperature, the thermostat will direct the fan to turn on to cool the area back to a comfortable temperature.

The central nervous system and the endocrine system are the major control systems in the body. Each is able to respond to signals from receptors and activate effectors accordingly.