Flashcards in Physio of the Adrenal Cortex Deck (15)
What are glucocorticoids predominantly prescribed for?
Effects leukocyte movement and function, decrease migration of inflammatory cells to the site of the injury, decreases prostaglandin production
Adrenal gland structure
Cortex and medulla
Cortex has 3 layers" zona glomerulosa, zona fasiculata, zona reticularis
What does each layer of the adrenal cortex produce?
What does the medulla produce?
Glomerulosa: mineralocorticoids (aldosterone)
Fasiculata: Glucocorticoids (cortisol)
Cholesterol for steroid hormone biosynthesis comes from what 2 souces
Circulating cholesterol (major source)
De novo synthesis from acetate
Why can't cells of the zona glomerulosa make cortisol or androgens?
Do not express 17a hydroxylase
Why can't cells of the zona fasiculata and reticularis make aldosterone?
Do not express aldosterone synthase
What type of receptors do steroids have?
They are lipid soluble so their receptors are intracellular
Bind to a hormone response element on DNA and cause gene transcription
How are steroid hormones metabolized
Inactivation mainly occurs in the liver, but also in the target tissues and kidney
Get converted to hydrophilic compounds
Eliminated as urinary metabolites (not recycled)
Binds to the mineralocorticoid receptor to regulate gene expression and induce rapid effects via non genomic mechanisms
Regulates reabsorption of Na and secretion to K to maintain blood volume and BP
Production is stimulated by AII
Functions of aldosterone
1. Rapid effects
2. Slower responses
1. Increased Na channel activity in CT and DCT (increasing availability/opening channels)
2. Upregulation of genes for Na channels, Na/K pumps, and kinases
ACTH acts on the cells of the adrenal cortex by what receptor?
Maintains adrenocortical cells
Regulates adrenal androgen secretion
What is the inactive form of cortisol?
Does D1 or D2 enzyme activate or inactive cortisol?
D1: converts inactive to active (liver)
D2: converts active to inactive (kidney)