Homeostasis Flashcards
Importance of maintaining constancy of the internal environment
To ensure fundamental life processes are able to take place optimally
Process of negative feedback
- Magnitude of change is sensed by receptor
- This information is fed back to integrating centre (hypothalamus)
- Compared to reference level
- Any difference between reference level generates another signal
- This signal is fed to an effector mechanism which produces a response to correct original change
`Explain feed-forward control
Changes made in the anticipation of change
Homeotherms
Maintain a constant core temperature over a wide range of external temperatures
Describe the principles behind negative feedback control systems
Oscillation around the set point
Cannot prevent it from happening but restores variable after displacement
Examples of feed-forward control
Changes in heart rate and respiratory rate before exercise
Skin detects external temperature change before change in core temperature occur
Positive Feedback Mechanism
In the output exaggerates or enhances the original stimulus
Homeostatic control of blood glucose
Depolarisation
Daily water balance in man
60% of body weight is water
1/3 ECF
2/3 ICF
40 L of fluid
Different body fluid compartments
ICF
(ISF
Plasma)- ECF
Insensible loss
moisture lost from the body through sweat and breath
ICF
Fluid within the cells
ISF
Fluid that bathes the outside of the cells
Plasma
Fluid component of blood
Plasma exchanges components with____
ISF
All 3 compartments are freely permeable to______ but not_____
Water, gases and glucose not ions
