If ACTH (adrenocorticotropic hormone) secretion is inhibited, which of the following is most likely to occur?

• A. Decreased cortisol production by the adrenal cortex
• B. Enhanced release of thyroid hormones
• C. Elevated blood glucose levels due to increased glucagon
• D. Increased secretion of aldosterone

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the role of ACTH (adrenocorticotropic hormone). ACTH is secreted by the anterior pituitary gland and stimulates the adrenal cortex to produce and release cortisol, a glucocorticoid hormone involved in stress response, metabolism, and immune regulation.
2. Step 2: Analyze the effect of inhibited ACTH secretion. If ACTH secretion is inhibited, the adrenal cortex will not receive the necessary stimulation to produce cortisol, leading to decreased cortisol levels in the body.
3. Step 3: Evaluate the options provided in the question. Consider how decreased ACTH secretion impacts each option: (a) Decreased cortisol production by the adrenal cortex, (b) Enhanced release of thyroid hormones, (c) Elevated blood glucose levels due to increased glucagon, and (d) Increased secretion of aldosterone.
4. Step 4: Eliminate options that are unrelated to ACTH inhibition. For example, thyroid hormone release is regulated by TSH (thyroid-stimulating hormone), not ACTH. Similarly, glucagon secretion is primarily regulated by blood glucose levels, and aldosterone secretion is influenced by the renin-angiotensin system rather than ACTH.
5. Step 5: Conclude that the most likely outcome of inhibited ACTH secretion is decreased cortisol production by the adrenal cortex, as cortisol synthesis is directly dependent on ACTH stimulation.