Scientific Method and Homeostasis Flashcards
1
Q
Why is it important to maintain the constancy of the internal environment?
A
The body needs the ECF to be maintained in a state compatible with the survival of the individual cells
2
Q
What percentage of the ECF is ISF?
A
80%
3
Q
What percentage of the ECF is plasma?
A
20%
4
Q
Describe the principles of negative feedback control systems
A
- change e.g. in temperature is detected by receptors
- receptors feed change to integrating centre where it is compared to reference level
- if there is a difference from the reference level, a signal is sent to an effector and the change is negated
5
Q
What is the magnitude of the error signal sent in negative feedback control systems proportional to?
A
The size of the response and the deviation from the reference level
6
Q
Explain feed forward control
A
- more sophisticated version of negative feedback
- more sensors are involved
- changes can be anticipated and negated before significant changes occur
- e.g. sensors in skin detect minor changes in temp. before the core temp. is affected
7
Q
What percentage of total body water is the ECF?
A
33%
8
Q
What percentage of total body water is ICF?
A
66%
