Question

if the pituitary gland is removed from a human subject, which of the following is likely to occur? multiple choice the adrenal gland will hypertrophy to increase cortisol production. the adrenal gland will atrophy and plasma cortisol levels will be reduced. the hypothalamus will secrete less crh. the subject will remain euthyroid. there will be increased negative feedback on growth hormone by insulin like growth factor 1 (igf - 1)

Explanation:

The pituitary gland secretes adrenocorticotropic hormone (ACTH). ACTH stimulates the adrenal gland to produce cortisol. Without the pituitary gland, ACTH is not produced. As a result, the adrenal gland, which depends on ACTH for stimulation, will atrophy (shrink due to lack of use/stimulation), and plasma cortisol levels (cortisol in the blood) will be reduced because there's no ACTH - induced cortisol production from the adrenal gland.
For the first option, without ACTH (from the pituitary), the adrenal gland won't hypertrophy (grow larger) to produce more cortisol. For the third option, when the pituitary is removed, the negative feedback on the hypothalamus (which secretes corticotropin - releasing hormone, CRH) from cortisol (low levels due to no ACTH) is removed, so the hypothalamus would secrete more CRH, not less. The fourth option is incorrect as the adrenal gland will be affected. The fifth option is about growth hormone regulation and is not relevant to the pituitary - adrenal - cortisol axis.

Answer:

The adrenal gland will atrophy and plasma cortisol levels will be reduced.