Patient Z tends to be hyperactive and thin. You are an endocrinologist, and you first determine that Z has high thyroid hormone levels in the blood. Your next step is to determine whether the problem lies at the level of the hypothalamus, anterior pituitary or the thyroid gland. What is the predicted level (high, normal, low) for TRH, TSH and thyroid hormone if the problem is:
a) due to a problem with secretion of TRH by the hypothalamus?
b) due to a problem with secretion of TSH by the anterior pituitary gland?
c) due to a problem with secretion of thyroid hormone by the thyroid gland?
Use this framework for your answer:
Condition a) (hypothalamus defect)
TRH levels:
TSH levels:
thyroid hormone levels:
Condition b) (anterior pituitary defect)
TRH levels:
TSH levels:
thyroid hormone levels:
Condition c) (defect at the level of the thyroid gland)
TRH levels:
TSH levels:
Thyroid hormone levels:
Assume that you determine that the problem is high secretion of TSH by the anterior pituitary, despite normal levels of TRH. Describe two possible causes of this problem, and how you could gather evidence for those causes. Assume that you can take small pieces of Xs anterior pituitary gland, keep it alive in a dish, and measure what you need to measure.
Possible cause #1 for high secretion of TSH by the anterior pituitary despite normal TRH:
Experimental evidence that would support this cause: (1 pt).
Possible cause #2 for high secretion of TSH by the anterior pituitary despite normal TRH:
Experimental evidence that would support this cause: