The Adrenal gland Flashcards
(45 cards)
structure of the adrenal gland

- 2 adrenal glands located on the superior poles of the kidneys
- 10g in mass
- Form a pyramidal shape
layers of the adrenal gland
capsule + cortex + medulla
capsule
fibrous layer on the outside of the adrenal gland
the adreanl cortex is made up of 3 layers called:
(GFR)
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
Zona glomerulosa secretes
mineralcorticoids
Zona fasciculata
Glucocorticoids
Zona reticularis
Glucocorticoids and small amount of androgens (sex)
name the mineralcorticoid secreted by the zona glomerulosa
Aldosterone- Salt
name the glucocorticoid secreted by the zona fasciculata
cortisol- sugar
name the androgens released by the zona reticularis
oestorgen and testosterone
how to remeber cortex layers
GFR: Salt Sugar Sex
the deeper you get the sweeter it gets
medulla is made up of
chromaffin cells- neural crest cells
- part of the sympathetic immune system
what does the medulla release
adrenaline and noradrenaline (20%)
all the hormones released by the 3 layers of the medulla are
corticosteroids
steroid horemones are synthesised from
cholersterol in the adrenal glands and gonads
features of steroid hormones
- Lipid soluble (intracellular receptors)
- Bind to receptors of the nucleus to modulate gene transcription
outline how corticosteroids exert their actions by regulating gene transcription
- Corticosteroids readily diffuse across the plasma membrane
- Binds to the glucocorticoid receptor
- Binding causes dissociation of chaperone protein
- Receptor ligand complex translocate to the nucleus
- Dimerization with other receptors can occur
- Receptor binds to glucocorticoids response elements (GRE) (DNA) or other transcription factors

Aldosterone (mineralocorticoid)
- Zona Glomerulosa
- Most abundant mineralocorticoid
- Synthesis and released by adrenal cortex
- Steroid hormone= lipophilic (intracellular receptro)
how is aldosterone transported in the blood
Carrier protein = mainly serum albumin and to a lesser extent transcortin
role of alsoterone
- Regulation of plasma Na+, K+ and arterial blood pressure
- Main action in distal tubules and collecting ducts
- Promotes expression of Na+/K+ pump promoting reabsorbing of Na+ and excretion of K+à water retention, blood volume and therefore blood pressure (RAAS)

main disorders associated with aldoseronehyperaldosteronism and hypoaldosteronism
Cortisol (corticosteroid)
- Zona fasciculata
- Most abundant corticosteroid and accounts for 95% pf glucocorticoid activity
- Synthesised and released in response to ACTH (Adrenocorticotropic hormone)
- Negative feedback to hypothalamus inhibits CRH and ACTH release
- Steroid hormone
carrier protein of cortisol
transcortin


