The Principles Of Feedback Mechanisms

Question 0

What would happen if the information from an effector is not fed back to the receptor?

Answer 0

The receptor will continue to stimulate the effector, leading to an over-correction and causing a deviation in the opposite direction

Question 1

What is important to happen once an effector has corrected any deviation and returned the system to the set point?

Answer 1

It is important that this information is fed back to the receptor

Question 2

When does negative feedback occur?

Answer 2

When the feedback causes the corrective measures to be turned off so that a system is returned to its normal level

Question 3

Give some common examples of negative feedback in the body

Answer 3

Temperature regulation and the control of blood glucose levels

Question 4

When does positive feedback occur?

Answer 4

When the feedback causes the corrective measures to remain turned on, causing the system to deviate even more from the normal level

Question 5

Give an example of positive feedback

Answer 5

One example occurs in neurones when a stimulus causes a small influx of sodium ions which increases the permeability of the neurone to sodium ions so more ions enter, causing a further increase in permeability and even more rapid entry of ions which results in the rapid build up of an action potential that allows for an equally rapid response to a stimulus