Adrenal Module Flashcards
what does the adrenal cortex produce
these hormones are synthesized from
- aldosterone
- cortisol
- androgens
- cholesterol
what does the adrenal medulla produce
these hormones are synthesized from
- catecholamines
- tyrosine
three layers of the adrenal cortex and what they produce
- zona glomerulosa - aldosterone (mineralocorticoids)
- zona fasciculata - cortisol (glucocorticoids)
- zona reticularis - androgens (DHEA, androstenedione)
primary targets of aldosterone
- kidney
- blood vessels
- heart
effects of aldosterone
where does this occur
- reabsorb Na+ into blood
- excrete K+ into urine
- BP regulation
- IN RENAL COLLECTING DUCT (PRINCIPAL CELL)
stimulatory factors of aldosterone
inhibitory factors of aldosterone
- AG II
- high K+
- low Na+
- decreased EC fluid volume
- decreased arterial pressure
- increased EC fluid volume
- increased arterial pressure
effects of cortisol
- Appetite (increase)
- BP (increase)
- Insulin resistance (increase)
- Gluconeogenesis (increase) and lipolysis/proteolysis
- Fibroblast activity (decrease)
- Immune function (decrease)
- Bone formation (decrease)
stimulatory factor of cortisol production
how so
inhibitor factor of cortisol production
- ACTH
- ACTH binds to receptors in fasciculata cells
- uptakes lipoproteins into fasciculata cells
- converts cholesterol to pregnenolone
- cortisol (negative feedback)
effects of androgens (in males/females)
FEMALES - development of pubic and axillary hair - contribute to libido MALES - bone/muscle growth - testosterone main androgen which is formed in the testes
stimulatory factor of androgens
how
- ACTH binds to receptors on reticularis cell
- converts cholesterol -> DHEA
effects of catecholamines
- cardiac stimulation
- BP increase
stimulatory factor of catecholamines
- sympathetic fibers (CNS)
synthesis of aldosterone
- cholesterol -> pregnenolone (cholesterol desmolase)
- pregnenolone -> progesterone (3-B-HSD)
- progesterone -> 11 deoxycorticosterone (21-B-hydroxylase)
- 11 deoxycorticosterone -> corticosterone (11-B-hydroxylase)
- corticosterone -> aldosterone (18-hydroxylase)
synthesis of cortisol
- cholesterol -> pregnenolone (cholesterol desmolase)
- pregnenolone -> 17-OH pregnenolone (17-hydroxylase)
- 17-OH pregnenolone -> 17-OH progesterone (3-B-HSD)
- 17-OH progesterone -> 11-deoxycortisol (21-B-hydroxylase)
- 11-deoxycortisol -> cortisol (11-B-hydroxylase)
synthesis of androgens
- cholesterol -> pregnenolone (cholesterol desmolase)
- pregnenolone -> 17-OH pregnenolone (17-hydroxylase)
- 17-OH pregnenolone -> DHEA (17,20-Des)
- DHEA -> androstenedione (3-B-HSD)
- androstenedione -> testosterone (17-B-HSD)
- testosterone -> estrogen (aromatase)`
synthesis of catecholamines
- tyrosine -> l-dopa
- l-dopa -> dopamine
- dopamine -> NE
- NE-> Epi (enzyme only in adrenal medulla)
breakdown product of Dopamine
- homovanillic acid (HVA)
breakdown product of NE
- VMA, normetanephrine
breakdown product of epinephrine
- metanephrine
CV action of dopamine
on which receptor
physiologic response
- vasodilation in heart, kidney, mesentery
- D1
- increase blood flow to vascular beds
CV action of norepinephrine
which which receptors
physiologic response
- intense vasoconstriction
- alpha and Beta 1
- increase PVR
CV action of epinephrine
with which receptors
physiologic response
- alpha - vasoconstriction in skin/viscera
- beta 2 - vasodilation in skeletal muscle
- stimulation of cardiac muscle cells - neutral on PVR
- increase CO, and HR
metabolic effects of catecholamines
- increase glycogenolysis/lipolysis
- decrease insulin release
aldosterone and androgens are most commonly measured when _____ secretion is suspected
- excess
