Question

If A 34-year-old female presents to her doctor with a slight enlargement in the anterior portion of her neck. The doctor suspected a goiter, so tests are ordered to try to determine the cause. The results showed that TRH levels were low, TSH levels were high, and T3 and T4 levels were high.

Given these results, which endocrine organ is the problem?
a. Anterior pituitary gland
b.thryroid gland
c.posterior pitutary gland
d. hypothalamus

Answer 1

Given the test results indicating low TRH, high TSH, and high T3 and T4 levels, the endocrine organ likely to be the problem is the hypothalamus, which isn't properly regulating the negative feedback loop to inhibit TSH secretion.

Step-by-step explanation:

The student's question involves a 34-year-old female with an enlarged neck, suggestive of a goiter, and her hormonal levels indicating an endocrine issue. The test results showed low thyrotropin-releasing hormone (TRH) levels, high thyroid-stimulating hormone (TSH) levels, and elevated levels of T3 and T4. In the context of these results and given the provided options, the problem seems to be with the hypothalamus.

TRH is secreted by the hypothalamus and TSH by the anterior pituitary gland. The elevated TSH despite high levels of T3 and T4 suggests that the negative feedback loop which should normally inhibit TSH secretion when T3 and T4 levels are high is not functioning properly. Since TRH from the hypothalamus stimulates the anterior pituitary to release TSH, and the TSH level is inappropriately high for the elevated thyroid hormones, it indicates that the hypothalamus may not be providing the correct signals to suppress TSH release.