Question

Why is it important to check TSH when you suspect abnormal thyroid levels?

A) LoW T3 and T4 will stimulate increased TSH levels from pituitary
B) Target organs produce TSH hormone when stimulated by T3 or T4
C) Posterior pituitary hormones activate TSH release, lowering T3 and T4 levels
D)The pituitary may be producing too much hormone

Answer 1

It is important to check TSH when suspecting abnormal thyroid levels because low T3 and T4 stimulate increased TSH production, target organs produce TSH to stimulate the thyroid gland, and the pituitary gland may produce excessive TSH.

Step-by-step explanation:

The pituitary gland produces thyroid-stimulating hormone (TSH) which stimulates the thyroid gland to secrete thyroid hormones T3 and T4. When there are abnormal thyroid levels, it is important to check TSH because:

1. Low T3 and T4 levels stimulate increased TSH production from the pituitary gland. This is due to the negative feedback loop where low thyroid hormone levels signal the hypothalamus to release thyrotropin-releasing hormone (TRH), which prompts the pituitary gland to secrete more TSH.
2. The target organs produce TSH hormone. T3 and T4 exert their effects on target organs, and when their levels are low, the target organs produce more TSH in response to stimulate the thyroid gland to produce more T3 and T4.
3. The pituitary gland may be producing too much hormone. In some cases, when there is abnormal thyroid function, the pituitary gland may produce excessive TSH in an attempt to stimulate the thyroid gland to produce more T3 and T4.