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Corticotrophin-Releasing Hormone

1. Describe the function of corticotrophin-releasing hormone (CRH) from the hypothalamus.
2. Explain why CRH levels would be low when ACTH levels are high. There is a negative feedback loop that inhibits CRH production when ACTH levels are high.
3. Steroid hormones fall into the lipid soluble category. What is the important of cholesterol to all steroid molecules? All steroid hormones are derived from cholesterol molecules.

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CRH
The corticotrophin-releasing hormone (CRH) is one of the hypothalamic releasing hormones that maintain homeostasis in the body by a negative feedback mechanism. The hypothalamic secretion of CRH stimulates the anterior pituitary to produce adrenocorticotropic hormone (ACTH) in the corticotrophs (constituting 15-20% of the cells of the anterior pituitary) by a proteolytic processing of of Prepro-opiomelanocortin a.k.a POMC (Khoo & Grossmam, 2011). ACTH main function is to regulate adrenal cortex and synthesis of adrenocorticosteroids (Owen,n.d.; Pralong, n.d.).

A) The negative feedback mechanism of CRH can be explained as follows:
Hypothalamus -> produces CRH -> stimulates the anterior pituitary -> increases production of ACTH -> stimulates adrenal cortex ->increases cortisol (a glucocorticoid).....(then).... an increase in cortisol->tells hypothalamus to stop CRH and the pituitary to stop ACTH productions.

B) Another feedback mechanism is that of ADH.
ACTH release is stimulated (in conjunction with CRH) by vasopressin or antidiuretic hormone (ADH) that is released by the posterior pituitary and reaches anterior pituitary via inferior ...

Solution Summary

The expert describes the functions of corticotrophin-releasing hormone from the hypothalamus. Why CRH levels would be low when ACTH levels are high are determined.

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