Question

Inhibition of TRH release due to elevated levels of thyroid hormone would be an example of:

long-loop negative feedback

positive feedback

short-loop negative feedback

Answer 1

Answer: C. Short loop negative feedback

A negative feedback loop is one where the final product of a system inhibits the same system itself from further production of the product. As in our question the TRH hormone secretion by the anterior pituitary is inhibited by the level of thyroid hormones. Hence it is an example of negative feedback loop.

Now the negative feedback loop can be of three types:

1. Ultra short loop
2. Short loop
3. Long loop

Please see the image below to understand the different types of feedback loop and their level of system inhibition.

Hope this helps. Please let me know if you have any query.

Best wishes!!