Endocrinology Flashcards
what happens to receptors when there is too much hormone?
down regulation, pulls in receptors and degrades them
what happens to receptors when there is too little hormone?
up regulation, make more receptors
what happens to receptors to desensitize them?
adds a phosphate to decrease or reduce the function
which hypothalamic nucleus forms ADH?
supraoptic
which hypothalamic nucleus forms oxytocin?
paraventricular
what is the neurohypophysis?
posterior pituitary gland
where are the “releasing hormones” made?
ventral hypothalamus
where is one place where hormones don’t travel a long distance?
hypothalamic-pituitary system
what is the infundibulum?
stalk that connects hypothalamus to pituitary
what is significant about the pars nervosa (post. pit)?
contains axons
what are the two target tissues of oxytocin?
uterus (contraction during labor)
milk let down
what are the target tissues of ADH?
kidneys (retain water-principle cell)
sweat glands (decreases water loss)
arterioles (contracts to increase blood pressure)
what can cause decreases secretion of ADH?
alcohol
what can cause increased secretion of ADH?
diabetes insipidus
what is the adenohypophysis?
anterior pituitary
what is the precursor of the anterior pituitary?
Rathke’s pouch from the oral mucosa
is there a direct connection between ant pit and hypothalamus?
no, releasing hormones travel through blood
what is the pro hormone?
pro-opiomelanocortin (POMC)
what is POMC the precursor for?
ACTH
MSH
enkephalin and endorphin
which cells produce thyroid hormone?
follicular cells
what is present in a thyroid follicle?
colloid (contains tyrosine)
what is the pathway of T3/T4?
TRH - TSH - T3, T4
hypo - A. pit - thyroid gland
what nutrient is required to form thyroid hormone?
iodide
what is iodide trapping?
moving iodide across follicular cell into colloid with Na where it is trapped because it is so large
where is thyroglobulin formed?
follicular cell
where is thyroid hormone formed?
follicular cells and then transported into the blood
where is thyroxine binding globulin present?
in the blood
what does thyroglobulin do?
transports tyrosine into the follicular cell and uses iodine to form T3 and T4
what is the calorigenic effect?
body processes produce heat
which hormone does T3 have a potentiating affect on?
catecholamine
which receptors are up regulated by T3?
beta adenergic receptors
what system does thyroid hormone influence during growth and development?
nervous system
what is cretinism?
hypothyroidism in fetal and infant development causes developmental issues and mental retardation
what is weird about Grave’s dz?
antibodies against TSH ramp up production of T3/T4
how do you treat Grave’s dz?
remove or ablate thyroid and do hormone replacement for the life
what situation is cortisol good for?
stress situation
-increase blood glucose
-increase blood pressure
natural anti-inflammatory
