phys I Flashcards
what hormones does the hypothalamus secrete
TRH, CRH, GnRH, GHRH, somatostatin, dopamine
what hormones does the anterior pituitary release
TSH, FSH, LH, ACTH, MSH, GH, Prolactin
what hormones does the posterior pituitary release
oxytocin, ADH
what hormones does the thyroid gland release
T3 T4 Calcitonin
what hormones do the paratyroid glands release
PTH
what hormones are released by pancreas
insulin, glucagon
what hormones are released by adrenal medulla?
cortex?
medulla is norepi and epi
cortex is cortisol, aldosterone
what hormones are secreted by kidneys
renin and 1-25 dihydroxycholecalciferol
estradiol gives what type of feedback( + or -) to what
positive feedback to the anterior pituitary
what are the negative feedback loops to hypothalamus
anterior pituitary and hormones like testerone
steroid and thyroid hormones work on what R
nuclear R, lipid soluble aka can cross membrane
how do most peptide hormones and biogenic amines signal
membrane R
how do water soluble hormones differ in intracellular signaling from lipid soluble
water soluble usually work through a 2nd messenger where lipid soluble stimulate synthesis of specific new proteins
describe storage of steroid and thyroid hormones
steroid made when needed, thyroid stored
describe storage of water soluble hormones
stored in vesicles
half life of lipid and water soluble hormones
lipid soluble are long and watersoluble is short
methods for measuring hormone levels
plasma analysis: reflective only of time of sampling
urine analysis: restricted to the measurement of catecholamines and steroid hormones
what are they primary thyroid dysfunction diseases
hashimoto thyroiditis and graves
TRH, TSH and T3T4 levels in graves and hashimotos
Graves: low TRH TSH high T3T4
hashimoto: high TRH, high TSH, low T3T4
what is an example of secondary thyroid failure and lab values?
pituitary failure form ishcemic necrosis
high TRH, low TSH low T3T4
example of tertiary thyroid failure and lab values
hypothalamic failure (hypothalamic tumor) low TRH low TSH and low T3T4
If pituitary hormone level is low but the target hormone is high what is most likely
autonomous secretion by target endocrine organ
if pituitary hormone level is low but the target hormone is low too what is most likely
pituitary failure
if pituitary hormone level is high and the target hormone is low what is goind on
primary failure of target endocrine hormone
if pituitary hormone level is high and the target hormone is also high what is going on
autonomous secretion of pituitary hormone or R to the target hormone action
What areas release posterior pituitary hormones
supraoptic nuclei and paraventricular nuclei
what releases the anterior pituitary hormones
the neurone in hypothalamus
ADH is released whtn
increased serum osmolality because causes and increase in water resorption by working on distal tubule in kidney
also induces contraction of vascular smooth muscle to protect against severe volume depletion
when is oxytocin released
milk letdown and uterine contraction
Action ADH
increase expression aquaporin 2 on principal cell sin distal tubule
What is neurogenic Diabetes inspidus
hypothalamic/central unregulated release ADH
what is diabestes insipidus characterized by
large volume urine that is hypotonic, dilute and tasteless
what is nephrogenic DI
unresponsive to ADH, problem in kidneys
what is primary polyuria
increased water intaked due to pathologic, habitual or psychiatric syndromes
Dx of DI is confirmed how
dehydration stimulus followed by inability to concentrate urine
plasma ADH levels in neurogenic DI? nephrogenic DI?
in neurogenic ADH plasma levels are low
in nephrogenic the plasma ADH levels are either high or normal
how will urine osmolality change after water deprivation in both DI
no change
how will plasma ADH change after water deprivation in both DI
in neurogenic there is no change
in nephrogenic there will be an increase
how will urine osmolality change after ADH administration in both types DI
in neurogenic it will increase
in nephrogenic there is no change
stimulatory factors for GH release
decreased glucose [ ] decreased FFA [ ] arginine fasting hormones of puberty exercise stress stage III and IV sleep alpha adrenergic agonists
what are the inhibitory factors for GH release
increased glucose increased FFA obesity senescence somatostatin somatomedins GH beta adrenergic agonists pregnancy
what are the effects of GH
insulin Resistance: dec glucose uptakes, increase blood glucose, increase lipolysis, increase blood insulin
increased protein synthesis and organ growth through IGF-I: increase aa uptae, increase DNA RNA synthesis, increase body mass and organ size
increase linear growth through IGF-I with altered cartilage metabolism
What does prolactin induce
dopamine synthesis
stimulatory factors for prolactin release
pregnancy, breast feeding, sleep, stress, TRH, dopamine antagonists
inhibitory factors for prolactin release
dopamine, bromocriptine
somatostatin
prolacitn (neg feedback)
What is definition prolactinoma
> 200ng/ml
describe effects of GnRH on FSH and LH
pulsatile secretion GnRH prevents downregulation of LH FSH Receptros
constant infusion GnRH causes decrease in LH and FSH
What is needed to activate T3 and T4
peroxidase to take it off thyroglobulin
What is needed for peroxidase to work on thyroglobulin
I(-) iodine
how is iodine transported to follicular lumen
electrochemical gradient, co transport with Na
What will proplythiouracil inhibit
oxidation of iodine
organificaiton of iodine into MIT and DIT
coupling reaction of DIT+DIt to T4 and DIT+MIT to T3
how do T4 and T3 circulate
bound to thyroid binding globulin and some to albumin and transthyretin
what is the more active thyroid hormone
T3 because 10 fold higher affinity for thyroid R
ration T4 to T3
10:1
people with no thyroid function will have what levels when given T4
only T3
What is euthyroid sick syndrome
hypothyroidism but problem is from increased diiodinase which forms inactive rT3
stimulatory factors for TH release
TSH, Thyroid stimulating Ig increased TBG (pregnancy)
what are inhibitory factors for thyroid hormone regulation
Iodoine deficiency deiodinase deficiency excessive iodine intake perchlorate proplythiouracil decreased TBG levels (liver disease)
what is wolff chaikoff effect
excessive iodine intake
what does perchlorate do
inhibit Na iodine cotransport
