Endocrinology: hypopituitary adrenal axis - diagram in Cats (Felis) | Vetlexicon
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Endocrinology: hypopituitary adrenal axis – diagram

ISSN 2398-2950

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Endocrinology: hypopituitary adrenal axis - diagram

  1. Adrenocorticotrophic releasing hormone (CRH) is released from the hypothalamus and stimulates anterior pituitary release of ACTH.
  2. ACTH stimulates the adrenal gland to produce cortisol.
  3. Rising cortisol concentrations has a negative feedback control on both the anterior pituitary and the hypothalamus to decrease further ACTH production.
  4. In hyperadrenocorticism  Hyperadrenocorticism the negative feedback system breaks down. In pituitary dependent disease a pituitary neoplasia or hyperplasia is present which continues ACTH production in the abscence of CRH and does not respond to the excess cortisol concentrations.
  5. In adrenal dependent disease an adrenal tumor is present and this autonomously produces cortisol in the absence of ACTH. The contralateral normal adrenal gland will be inactive due to a lack of ACTH stimulation.
  6. In hypoadrenocorticism the adrenal cortex is atrophied and cortisol is not produced despite massively increased ACTH concentrations.