Homeostasis

Question 1

What factors are important in maintaining homeostasis?

Answer 1

Temperature
Blood glucose concentration
Blood salt concentration
Water content
Blood pressure
Blood carbon dioxide partial pressure (blood pH)

Question 2

What is negative feedback?

Answer 2

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

Question 3

what is the importance of stable blood glucose concentration?

Answer 3

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

Question 4

how can a positive feedback loop affect homeostasis?

Answer 4

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