HomeostasisSpec 2.81
- Homeostasis
- The maintenance of a constant internal environment.
Conditions inside the body change when we eat, exercise, or move between hot and cold places. The body responds to keep the conditions inside the body constant.
| Condition | Example of a change |
|---|---|
| Body water content | Sweating, or drinking a lot |
| Body temperature | Hot or cold surroundings, or exercise |
This matters because enzymes and cells work best in a narrow range of conditions. If conditions move too far from normal, reactions in cells slow down or stop.
Exam tip:
Constant does not mean the level never changes. It means the body brings it back to a set level, so say 'kept within narrow limits'.