Cortisol is secreted by the adrenal cortext in response to stress. In addition to its function in a stress response, it functions in negative feedback by

Options

A. Inhibiting hypothalamus to secrete corticotropin releasing hormone or CRH
B. Inhibiting anterior pituitary's ability to respond to CRH
C. Both A and B
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Cortisol's Role**: Cortisol is a steroid hormone produced by the adrenal cortex in response to stress. It plays a crucial role in the body's stress response and helps regulate various physiological processes.

2. **Negative Feedback Mechanism**: Hormones like cortisol often utilize a negative feedback mechanism to maintain homeostasis. This means that when cortisol levels rise, they signal the body to reduce further production of cortisol.

3. **Inhibition of the Hypothalamus**: Cortisol binds to receptors in the hypothalamus. When cortisol levels are high, it inhibits the hypothalamus from secreting corticotropin-releasing hormone (CRH). This is the first part of the negative feedback mechanism.

4. **Inhibition of the Anterior Pituitary**: In addition to inhibiting the hypothalamus, cortisol also acts on the anterior pituitary gland. It reduces the pituitary's ability to respond to CRH, which further decreases the secretion of adrenocorticotropic hormone (ACTH).

5. **Conclusion**: Since cortisol inhibits both the hypothalamus's secretion of CRH and the anterior pituitary's response to CRH, it effectively reduces its own production through a negative feedback loop. Therefore, the correct answer to the question is that cortisol functions in negative feedback by inhibiting both the hypothalamus and the anterior pituitary.

**Final Answer**: Both A and B.

---