Plasma ACTH levels are high between these following hours
High-Yield Explanation
(B) 4 AM and 10 AM # ACTH the primary stimulator of adrenal cortisol production is synthesized by pituitary in response to CRH, which is released by hypothalamus.> Plasma ACTH and cortisol levels exhibit peaks at 6-8 AM and nadirs at 11 PM.> Referene values: 10-60 pg for AM values. No established reference values for PM.