Principles of Homeostasis + Negative Feedback Flashcards
1
Q
What is homeostasis?
A
The maintenance of an internal environment within restricted limits in an organism.
2
Q
What is positive feedback?
A
When a stimulus causes a deviation from the optimum point and results in further deviation.
3
Q
What is negative feedback?
A
When a change produced by a control system leads to a chance in stimulus detected by the receptor and so turns the sytem off.
4
Q
What things need to be maintained by homeostasis?
A
- Temperature
- Oxygen
- Water levels (balance)
- Tissue (pH / fluidity)
- Composition of blood (glucose, salt)
5
Q
Why is homeostasis important?
A
- Independence: stops organisms being reliant on the external environment
- Enzymes: sensitive to pH + temperature changes (denaturation)
- Blood glucose: helps maintain water potential + also gives cells a constant supply of glucose for respiration
- Water potential: changing this blood / tissue fluid could make cells shrink or even burst
