Question

Topic 1: Feedback loops.

Define & give real-life physiological examples of a negative and positive feedback loop, in your answer include.

• Definitions for the negative and positive feedback loop

• Physiological examples of each

• A general description of the four major components of the feedback loop and what those components are in each of your examples

• A drawing of the feedback loop including where the negative and positive feedback occurs.

Answer 1

Negative feedback loop

it is a mechanism that reduces the changes in the output andaand input and maintains the balance

Negative feedback mechanism is more common ,helps the body to maintain homeostasis.

Example; when the body temperature starts to change.when it is cold out ,and body temperature decreases below the set point range and body temperature decreases below the set point,the negative feedback loop will cause the body to Shiver producing heat and ultimately the body temperature is maintained.

The negative feedback mechanism also decreses the body temperature by sweating when the outside temperature is high.

Positive feedback loop;

It is defined as mechanism which enhances the input larger . positive feedback leads system instability.

It do not help in maintaining homeostasis .

It amplify the change that occuring in the body.

Example; when there is a cut in the vessel wall positive feedback mechanism starts and platelets arrives and slow blood occurs and platelets release chemical and blood clot is formed and positive feedback stops.

Four major components of feedback loop are

​​​​​​Stimulus

Sensor

Control and

Effector.

Positive feedback examples include - Child birth,blood clotting, ovulation.

Negative feedback examples include- regulated of body temperature,blood pressure and fluid content.