Homeostasis Flashcards
What factors are important in maintaining homeostasis?
Temperature Blood glucose concentration Blood salt concentration Water content Blood pressure Blood carbon dioxide partial pressure (blood pH)
What is negative feedback?
Reversal of a change in the environment to return to the optimum position
Receptor detects the change
Communication systems inform the effectors
The effector reacts to reverse the change
Eg: maintaining blood pressure
what is the importance of stable blood glucose concentration?
There must be enough glucose in the blood to supply the demands of respiring cells
If there is too much glucose in the blood:
Water potential of blood is low
Water moves by osmosis out of tissues/ECF and into the blood
Individual becomes dehydrated
Blood pressure becomes too high
Therefore blood glucose concentration must be within the appropriate range
how can a positive feedback loop affect homeostasis?
Response causes change to increase Destabilizes the system Usually more harmful Does not lead to homeostasis Can be useful in certain situation Eg: childbirth - uterine contractions
