adrenal physiology Flashcards
what is produced in the zona glomerulosa
aldosterone
what is produced in the zona fasciculata
cortisol
what is produced in the zona reticularis
dihydrotestosterone
what is cortisol and androgen production regulated by
hormones produced by hypothalamus and anterior pituitary
what is aldosterone production regulated by
renin-angiotensin system and plasma potassium
regulation of cortisol/androgen production
- illness, stress, time of day triggers hypothalamus to release CRH
- this then stimulates the anterior pituitary to release ACTH
- which stimulates the adrenal cortex to produce cortisol
- cortisol negatively feedbacks to anterior pituitary and hypothalamus
how does renin-angiotensin system work
- Major regulator of aldosterone production
- Activated in response to decreased blood pressure
- Leads to production of Ang II which causes direct (vasoconstriction) and indirect (aldosterone) methods of BP elevation
mechanism of action of corticosteroids
Bind intracellular receptors
Receptor/ligand complex binds DNA to affect transcription
what are the 6 classes of steroid receptors
- glucocorticoid
- mineralocorticoid
- progestin
- oestrogen
- androgen
- vit D
effect of cortisol on circulatory/renal
- increase cardiac output
- increase blood pressure
- increase renal blood flow and GFR
effect of cortisol on CNS
- mood lability
- euphoria/psychosis
- decreased libido
effect of cortisol on bone/connective tissue
- accelerates osteoporosis
- decrease serum calcium
- decrease collagen formation
- decrease wound healing
effect of cortisol on immune system
- decrease capillary dilatation/permeability
- decrease leucocyte migration
- decrease macrophage activity
- decrease inflammatory cytokine production
cortisol effects on metabolism
- increase blood sugar
- increase lipolysis
- increase proteolysis
clinical use of corticosteroids
- reduce inflammation
- suppress immune system
- replacement treatment
