Thyroxin Negative Feedback Loop

Question 1

What does the negative feedback mechanism ensure?

Answer 1

• that the level of thyroxin in the blood is kept at the correct level at all times

Question 2

What is the 1st step in the thyroxine negative feedback loop?

Answer 2

1. The pituitary detects a decreased level of thyroxine in the blood, so it secretes more TSH

Question 3

What is the 2nd step in the thyroxine negative feedback loop?

Answer 3

2. The TSH stimulates the thyroid to secrete more thyroxin, returning its level to normal

Question 4

What is the 3rd step in the thyroxine negative feedback loop?

Answer 4

3. The higher levels of thyroxin inhibit further secretion of TSH from the pituitary