Homeostasis Flashcards
(9 cards)
1
Q
Define homeostasis.
A
Homeostasis refers to the body’s ability to maintain a stable internal environment, despite changes in the external environment.
2
Q
What does the human nervous system consist of?
A
- CNS (brain and spinal cord)
- Peripheral nervous system (all nerves)
3
Q
Why is it important that internal conditions are maintained?
A
- enzymes control reactions in organisms but only when in a suitable environment
- external and internal environments change
- multilcellular organisms must be able to respond to these changes to maintain a constant internal environment
4
Q
What makes a good control system?
A
- covers the whole body
- enables cells to communicate with each other
- enables rapid communication
- enables short term and long term responses
5
Q
What is cell signalling?
A
- One cell releases a chemical that is detected by another which will respond to this signal
6
Q
What are the two types of feedback?
A
- positive
- negative
7
Q
Describe positive feedback.
A
- takes conditions further from the norm
8
Q
Describe negative feedback.
A
- Brings back to norm to reverse changes and maintain environmental conditions
9
Q
Give an example of positive feedback.
A
Childbirth
