REB 13. Effects of Adrenal Hormones Flashcards
Each adrenal is composed of 2 endocrine organs which are…
[1] Adrenal Cortex (80%)
[2] Adrenal Medulla (20%)
What percentage is the adrenal cortex?
80%
What percentage is the adrenal medulla?
20%
What are the 3 layers of the adrenal cortex?
[1] Zona Glomerulosa
[2] Zona Fasciculata
[3] Zona Reticularis
What are the hormones that are produced in the adrenal glands? First general term, then the 3 branches
Adrenocortical Hormones:
[1] Mineralocorticoids (aldosterone)
[2] Glucocorticoids (cortisol)
[3] Sex Hormones (dehydroepiandrosterone)
Where in the cortex is Aldosterone synthesized?
Zona Glomerulosa
Where in the cortex is Cortisol synthesized?
Zona Fasciculata (primary source) \+ Zona Reticularis
Where in the cortex is the Adrenal Sex Hormones synthesized?
Zona Fasciculata + Zona Reticularis
- produced in greater abundance in the gonads
Where is the adrenal sex hormones synthesized in the greatest abundance?
the gonads
Why are there only small amounts of aldosteroe, cortisol and DHEA found in the adrenocortical cells at any given time?
This is because the hormones are not stored in there, they are rather secreted on demand
Describe the characteristics of adrenocortical hormones? (are the lipophobic, lipophilic…) How do these hormones move through the blood?
they are lipophilic - so they can diffuse into the blood after synthesis
- they are extensively bound to plasma proteins (such as CBG and albumin)
- binding prevents hormone entering a cell + being excreted
What is the average daily production of cortisol in the adrenal cortex?
20 mg/day
What is the average daily production of aldosterone in the adrenal cortex?
0.1 mg/day
What is the average daily production of DHEA in the adrenal cortex?
30 mg/day
What are the 2 main functions of aldosterone?
[1] Acts as Distal + Collecting Tubes of Kidney
- Na+ retention and K+ elimination during urine formation
- promotion of Na+ retention secondarily induces osmotic retention of water, expanding ECF volume
[2] Essential for Life
- without aldosterone, death results from circulatory shock due to fall in plasma volume caused by excessive loss of H2O-holding Na+