Question

describe a negative feedback loop and explain why this mechanism is so common in regulating animal body functions

Answer 1

There are two kind of feedback loops that regualte the body- postive and negative.

Negative feedback mechanism is aminly involved in slowing down or reversing a process/ change in the body. Examples of negative feedback include regulation of body temperature, blood glucose levels, water balance, ionic balance and so on.

Let us consider the example of regulation of blood sugar here and discuss it. The ideal blood glucose level is maintained at a constant range between 80-140mg/dL (depending on the time of the day). If there is any change, i.e., increase or decrease in the level, negative feedback comes into play to reverse this change. The machanism is summarized in the figure below. You can elaborate it in words. The black and red arrows indicate two different negative feedback loops.

We can see that negative feedback loops are more common as there is need to maintain homeostatic conditions. It reverses the temporary changes in the internal environment, bringing back the body to normal conditions. It helps in ensuring that the small changes do not get too large, such that body balance is harmed.