Homeostasis literally means “same state” and it refers to the process of keeping the internal body
environment in a steady state, when the external environment is changed. The importance of this
cannot be over-stressed, as it allows enzymes etc to be ‘fine-tuned’ to a particular set of conditions,
and so to operate more efficiently. Much of the hormone system and autonomic nervous systems is
dedicated to homeostasis, and their action is coordinated by the hypothalamus. In Module 2 we
saw how the breathing and heart rates were maintained (N.B. Synoptic questions probable!).
Here we shall look at three more examples of homeostasis in detail: