Homeostasis Flashcards
What is homeostasis?
The ability to maintain internal stability in an organism to compensate for environmental changes
What are the systems that interact with the internal environment, and help to achieve homeostasis?
- CVS
- Respiratory
- Excretory
- Alimentary
Why is homeostasis important?
- Cells function most effectively under ‘optimal’ environmental conditions
- Homeostasis operates to correct any changes in the cellular environment
What conditions are important in regulating homeostasis?
- Temperature
- pH
What are the 2 homeostatic control mechanisms?
- Feed-back control
- Feed-forward control
What is negative feedback control?
A change in a variable activates mechanisms that alter the level of that variable so as to COUNTERACT the change
What are Circadian ‘rhythm’s’
Physical, mental and behavioural changes that follow a daily cycle (occur in every 24 hours)
What is feedforward control?
Altering a behaviour before there is an obvious ‘error signal’
- It is an anticipatory action
What is positive feedback?
A change in a variable activates mechanisms that alter the level of that variable so as to increase the change
A small change is amplified and converted into a larger one
Which feedback control is not used in homeostatic control?
Positive feedback
What is interstitial fluid?
In between tissues
What is osmosis?
Diffusion of water along its concentration gradient
What is a hypotonic solution?
Higher concentration of water in solution
What I an isotonic solution?
Equal concentration of water in solution and cell
What is a hypertonic solution?
Lower concentration of water in solution
