Endocrinology: Adrenal Hormones Flashcards
What is the role of the adrenal cortex?
Mediates the stress response via the production of
- Mineralocorticoids
- Glucocorticoids
What are the 3 layers of the adrenal cortex and what do they each produce?
- Zona glomerulosa (produces mineralocorticoids)
- Zona fasciculata (produces glucocorticoids)
- Zona reticularis (produces weak androgens)
What are adrenal hormones synthesised from?
They are all synthesised from cholesterol
What do glucotcorticoids include?
- Cortisol
- Corticosterone
What are the actions of glucocorticoids on protein catabolism?
- Inhibit DNA synthesis
- Inhibit RNA and protein synthesis (except in the liver)
What is the action of glucocorticoids on metabolism?
- Formation of ATP
- Increases gluconeogenesis
- Inhibits peripheral glucose usage
- Increases lipolysis
What is the action of glucocorticoids on connective tissue and bone?
- Inhibits fibroblasts
- Loss of collagen
- Increases bone resorption
What is the action of glucocorticoids on the renal system?
- Increases excretion of Na+ and water
- Increases GFR
What is the action of glucocorticoids on the stomach?
Increases secretion of stomach acid
What is the action of glucocorticoids on blood?
- Decreases lymphocyte count
- Increases neutrophil count
What type of hormone is aldosterone?
Mineralocorticoid
What is the function of aldosterone?
Part of the Renin-Angiotensin System
1. Reabsorption of Na+ from DCT and collecting ducts
2. Excretion of H+ and K+ via kidneys
3. Acts on posterior pituitary to release ADH
What 6 factors regulate aldosterone secretion?
- Renin-angiotensin system
- Sympathetic nerves
- Juxtaglomerular appatatus
- Carotid artery baroreceptors
- Plasma concentration of K+
- Plasma concentration of Na+
When is adrenarche in boys vs. girls?
- Males = 7-9 yrs old
- Females = 6-7 yrs old
What does the adrenal cortex secrete during adrenarche?
Weak androgens such as:
- DHEA
- Dehydroepiandrosterone sulphate (DHEAS)
- Androstenedione
