Revision notes · Homeostasis and response
Homeostasis
Homeostasis4.5.1
Definition: Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes.
Homeostasis keeps body conditions stable so that cells and enzymes can function effectively.
- •Homeostasis maintains optimal conditions for enzyme action and all cellular functions.
- •In the human body, key controlled conditions include blood glucose concentration, body temperature, and water levels.
- •Control systems can involve nervous responses or chemical responses using hormones.
- •If body temperature rises too high, human enzymes will denature, stopping vital metabolic processes.
| Component | Role |
|---|---|
| Receptors | Detect a stimulus (a change in the environment) |
| Coordination centre | Processes the information (e.g. brain, spinal cord, pancreas) |
| Effector | Carries out the response (a muscle or gland) |
⚠️ Common mistake: Thinking homeostasis keeps internal conditions fixed at a single constant value at all times, rather than maintaining them within a narrow optimal range.
🧠 Remember: Remember RCE: Receptors detect the stimulus, Coordination centres process the information, and Effectors carry out the response.
Feel like you’ve got it?
Practise it now →