homeostasis – the maintenance of a consistent internal environment in living organisms despite changes in external conditions

Note: All life must maintain homeostasis from salt levels, to temperature, to acid levels.  

To remember the meaning of homeostasis, use the following mnemonic:

At home, Romeo stays with his sister (homeostasis) and parents who maintain constant internal conditions.  

Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to external changes. This process is essential for survival as it keeps vital factors like body temperature, blood glucose levels and pH within narrow ranges that allow enzymes and other cellular processes to work efficiently. Homeostasis works through control systems that involve receptors (which detect change), coordination centres (like the brain or pancreas that process information), and effectors (muscles or glands that bring about responses to restore normal levels).

For example, when body temperature rises, the brain triggers responses like sweating to cool the body down, and when it falls, responses like shivering to help warm it up.

Without effective homeostasis, cells would be damaged by extreme conditions and the organism would not survive.