Adrenal Physiology

Question 1

What are the main functions of the Adrenal Cortex?

Answer 1

Maintenance of Plasma Glucose, Immunosuppression and Regulation of Plasma Na and K, hence blood pressure.

Question 2

What is the outermost zone of the adrenal cortex? Function?

Answer 2

Zona glomerulosa. Synthesizes the mineralocorticoid aldosterone.

Question 3

What is the middle zone of the adrenal cortex? Function?

Answer 3

Zona fasciculata.

Question 4

What is the innermost zone of the adrenal cortex? Function?

Answer 4

Zona reticularis. Synthesizes the glucocorticoid cortisol and the androgens dehydroepiandrosterone (DHEA) and androstenedione.

Question 5

What is the adrenal medulla derived from?

Answer 5

Neural crest.

Question 6

What can the adrenal medulla be considered?

Answer 6

A modified sympathetic ganglion that directly releases catecholamines into the circulation.

Question 7

What is CRH?

Answer 7

Corticotropin releasing hormone

Question 8

What is ACTH?

Answer 8

Adrenocorticotrophic hormone

Question 9

What is cortisol?

Answer 9

The principle actor of glucocorticoids

Question 10

What are the traits of CRH?

Answer 10

41 AA mature polypeptide. Short half life, 9 min. Synthesized by hypothalamus. Anterior pituitary corticotrophins have CRH R1 receptor (Gs protein coupled receptor, stimulates adenylyl cyclase to inc. cAMP concentrations). Pro inflammatory cytokines and chronic stress promote release of CRH.