Adrenal Physiology Flashcards
What are the 3 layers of the outer adrenal cortex?
What does each layer produce?
(nice little mnemonic for this)
Go Find Rex, Make Good Sex
zona Glomerulosa -> mineralcorticoids e.g. aldosterone
zona Fasciculata -> glucocorticoids e.g. cortisol
zona Reticularis -> sex -> androgens
What is the thickest layer of the adrenal cortex?
Zone fasciculata
What is secreted by the adrenal medulla?
Noradrenaline
Adrenaline
What is the starting block of all adrenal hormones?
Cholesterol
What is responsible for the secretion of cortisol, androgens and aldosterone?
Aldosterone -> K+ dependant - RAAS
Cortisol/Androgens -> ACTH dependant
What hormone stimulating the secretion of ACTH?
CRH
What receptor does aldosterone act on?
Mineralocorticoid receptor (MR)
What are the 3 effects of aldosterone?
Sodium/potassium balance
- Na+ absorption (increase levels)
- K+ excretion (decrease levels)
Blood pressure regulation
Regulation of extracellular volume
What will the blood biochem results look like if you have too much aldosterone (Conn’s disease)?
Low K+
High Na+
What effect do steroids have on the adrenal physiology?
Suppress ACTH secretion
How does aldosterone work to increase BP?
Via Na+/K+ pumps in distal convoluted tubules
Increases Na+ in blood -> Increases H20 in blood -> Increases BP
What effect does cortisol have on the body?
Increases: Gluconeogenesis Proteolysis Lipolysis BP Blood sugar
Decreases immune response
What are the names of the androgens produced by the zona reticularis?
What are they converted into?
DHEA + androstenedione
Testosterone + oestrogen
What is noradrenaline and adrenaline derived from?
Dopamine
What cell in the adrenal medulla produces noradrenaline and adrenaline?
Chromaffin cells
