Midterm 2 - Importance of Adrenal Hormones Flashcards
what are adrenals
paired organs capping the kidneys
what do the adrenals consist of
2 layers
what are the 2 layers of the adrenals
outer cortex and inner medulla
what is the outer cortex derived from
mesoderm
what is the inner medulla derived from
neural crest
what is the medulla a part of
ANS
what is the medulla equivalent to
a ganglion, but with postganglionic cells secreting catecholamines that diffuse in blood
catecholamines
epinephrine, norepinephrine
what are the 3 zones that compose the cortex
zona glomerulosa
zona fasciculata
zona reticularis
what does the zone glomerulosa secrete
mineralcorticoids
what does the zone fasciculata secrete
glucocorticoids
what does the zone reticularis secrete
androgens
what percentage of the adrenal glands mass is the cortex
90%
what hormones does the cortex produce
steroid hormones (adrenocortical hormones) required for survival
how are hormones from the cortex produced
by a stepwise conversion of cholesterol perviously absorbed from blood lipoproteins
what are major enzymes in the conversion of cholesterol
cytochrome-p450
what do cells from each zone of the cortex have
different enzymes while allows formation of different hormones
what is the most potent mineralcorticoid
aldosterone
what happens to mineralocorticoids after diffusion
they circulate loosely bound to cortisol binding globulin (CBG)
what is synthesis and secretion of mineralocorticoids stimulated by
angiotensin
direct actin of K+ concentration on cortical cells
does ACTH from pituitary have an impact on aldosterone production
minimal
what doe mineralocorticoids regulate
metabolism of important inorganic ions
what do mineralocorticoids stimulate
the reabsorption of Na+ and the secretion of K+ in the distal kidney tubules and collecting ducts
what does aldosterone do in target cells
binds to its receptor to modulate gene transcription
what does aldosterone do to gene transcription in Na+ and K+ pumps in basolateral membrane
increase
what does aldosterone do to gene transcription in Na+ channels in apical membrane
increase
what do glucocorticoids regulate
glucose metabolism
what is the most potent glucocorticoids
cortisol
what glucocorticoid has weaker activity
corticosterone
what does cortisol do after diffusing into blood
binds to CBG
what does the free hormone portion of cortisol do
enters target cells, binds to its receptors and stimulates or inhibits gene transcription