Hormones Flashcards
describe the simple endocrine pathway and give an ex of it
a stimulus acts on endocrine cell that releases a hormone to th effector
ex, BGL
describe the simple neuroendocrine pathway and give an ex of it
stimulus that acts on part of the brain (hypothalamus or pituitary) to release hormones into blood to target effectors(stimulus–> hypothalamus–> hormone to endocrine cell(posterior put) –> target)
ex, suckling of breast stimulates hypothalamus to posterior pituitary to release oxytocin into blood that targets smooth muscles in breast to contract and release milk
describe the hormone cascade pathway and give an ex
hypothalamus releases a releasing hormone to the portal blood vessel which triggers AP to release the hormone that goes to the effectors
ex, hypothalamus releases prolactin releasing hormone to portal blood vessels to stimulate AP to release prolactin to mammary glands to produce milk
ex of hormones that uses transmembrane receptors
peptides/amines, oxytocin, FSH/LH, glucagon/insulin, thyroxine/epinephrine
ex of hormones that use cytoplasmic receptors
steroids, cortisol, NO
epinephrine effect on intestinal blood vessel, skeletal muscle blood vessel, liver cells:
intestine: vessel constricts
Skeletal: vessel dilates
Liver: release glucose
What endocrine pathway is posterior and anterior pituitary associated with
Posterior: neuroendocrine
Anterior: hormone cascade
where are neuroendocrine hormones synthesized?
hypothalamus
which hormones are released from the posterior pituitary
ADH, oxytocin
detail the regulation of ADH
osmoreceptors in hypothalamus detect rise in blood osmolarity &ntrigger release of ADH from posterior pituitary and travels through blood to kidneys where more water is absorbed, blood osmolarity decreases.
What blocks release of ADH
ethanol
list tropic hormones
FSH/LH, GH, ACTH, TSH
list nontropic hormones
prolactin, MSH, endorphins, GH
define tropic and nontropic
nontropic: directly regulates tissues that are not endocrine glands
tropic: regulates endocrine glands to release another hormone
detail the tropic and nontropic pathway for GH
Non-tropic: GH secreted from AP to all cells for aa uptake
Tropic: GH secreted from AP to liver cells to release IGF to simulate bone and cartilage growth
underproduction of GH in childhood results in _________
overproduction of GH in childhood results in _________
overproduction of GH in adulthood results in ________
pituitary dwarfism
gigantism
acromegaly
function of thyroxine/thyroid
inc basal metabolic rate, fat breakdown cold stimulates TRH release from hypothalamus
what is thyroxine made from
tyrosine
T/F: Thyroid produces mostly T3
False, it produces more T4 but T3 is more active b/c its receptors have higher affinity. T4 can be converted to T3 by an enzyme in blood
What causes iodine deficiency?
production of inactive thyroxine (non-iodated), inactive form can’t turn off by neg fdbk, working hard to produce more–> goiter
hypothyroidism symptoms/conditions/causes
not enough active thyroxine
low metabolism, goiter, lethargic, cold intolerance, cretinism in children
results from iodine deficiency or genetics
hyperthyroidism symptoms/conditions/causes
too much active thyroxine
goiter, high metabolism, weight loss
neg fdbck fails from Grave’s- incorrect antibody is synthesized from a mutagenic TSH receptor and can induce conformational change–> thyroid thinks there is thyroxine but its just the mimic antibody
adrenal medulla & cortex
medulla: under nervous system control, produces epinephrine & norepinephrine
cortex: under hormonal control, secretes cortisol when recepts ACTH
Catecholamine pathway
tyrosine–> L-dopa–> dopamine–> norepinephrine–> epinephrine
What two diff types of receptors do epinephrine and norepinephrine bind to. Which ones for each?
alpha and beta GPCRs
Epinephrine binds to beta and alpha equally, norepinephrine tends to alpha
what are beta blockers
drugs that only inactivate beta adrenergic, leaves alpha alone so norepinephrine can regulate bp
what does the cortex use as a backbone to produce sex steroids, mineralocorticoids, and glucocorticoids?
cholesterol
detail release of cortisol
frightening stimulus releases CRH from hypothalamus to AP which releases ACTH to adrenal cortex which releases cortisol
provide an ex of a glucocorticoid and its funciton
cortisol; promotes gluconeogenesis
why is the cortisol response slower than epin/norepin
adrenal medulla is connected to the nervous system
adrenal cortex is connected to the hormonal system
what are short term symptoms of stress signal
inc bp, heart & metabolic rate, glycogen breakdown
-blocked by beta blockers
long term effects of stress
inc blood glucose, immune suppressed, fats break down
what causes cretinism
hypothyroidism in children
