Fill in the blanks: A rise in free T3 and T4 would be expected to produce a(n)______ in TRH and TSH secretion. A decrease in free T3 and T4 would be expected to produce a(n)_____in TRH and TSH secretion.

Video transcript

Hey, everyone. Let's take a look at this question together which of the following can cause an elevation in TSH levels. Is it answer choice? A low iodine levels, answer choice B, low thyroxine, answer choice C, low triiodothyronine or answer choice D all of the above. Let's work this problem out together to try to figure out which of the following answer, choices can cause an elevation in TSH levels. So in order to solve this question, we have to recall what we have learned about TSH, which we know that TSH stands for thyroid stimulating hormone. And we note that thyroid stimulating hormone triggers the thyroid to release hormones which impacts the body's metabolism. And since we are focused on an elevation in TSH levels, specifically, what can cause that elevation in TSH levels. We know that high TSH or thyroid stimulating hormone levels usually indicates hypothyroidism, which is low T three and T four, which we know that hypothyroidism is when there is low thyroid hormone levels, which those low thyroid hormone levels can be attributed to an iodine deficiency. Therefore, an elevation in TSH levels refers to low T three, which is true ido thyronine and low T four, which is thyroxine and a deficiency of iodine. So low iodine levels, low thyroxine and low triiodothyronine can all cause an elevation in TSH levels. So answer choice. D all of the above is the most appropriate answer choice and all other options individually are incorrect. I hope you found this video to be helpful. Thank you and goodbye.