If a patient's thyroid hormone (T4) production increases rapidly due to a thyroid adenoma, which consequence follows concerning the hypothalamic-pituitary-thyroid (HPT) axis feedback loops?

💡 Explanation

Elevated T4 triggers negative feedback on the hypothalamus and pituitary, causing a reduction in thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) secretion, because the body attempts to restore hormonal balance. Therefore, TRH and TSH decrease, rather than increase, as high T4 signals sufficient thyroid hormone levels.

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