lecture 21 and 22- thyroid and adrenal hormones Flashcards
what is the chloride-iodide counter-transporter that allows iodide to be transported across apical membrane of cell into follicle
pendrin
what creates thyroxine
DIT + DIT
what creates triiodothyronine
DIT + MIT
what catalyzes the organification of iodine
peroxidase
is T3 or T4 more active
T3
what is the most released thyroid hormone
thyroxine
what do most thyroid hormones entering blood bind to
plasma proteins synthesized in liver
where does TSH come from
anterior pituitary
where does TRH come from
hypothalamus
how does TSH act on follicular cells
via adenylate cyclase-cAMP mechanism
what are the causes of hyperthyroidism
graves disease and adenoma
what is the treatment for hyperthyroidism
surgical removal of most of thyroid gland or treatment with radioactive iodine
what are the causes of hypothyroidism
hashimoto disease, endemic goiter, cretinism
what causes cretinism
extreme early hypothyroidism
what are symptoms of hypothyroidism (besides the opposite of hyper)
myxedema and atherosclerosis
what do thiocyanate ions do
inhibit iodine uptake
what does propylthiouracil do
inhibits peroxidase
what do iodides do
decrease thyroid activity when present in very high concentrations
what does the medulla of the adrenal gland secrete
epinephrine and norepinephrine
what is the medulla of the adrenal gland functional related to
sympathetic nervous system (backup for it)
what does the cortex secrete
corticosteroids
what increases the number of LDL receptors
ACTH
where is cholesterol converted to pregnenolone
in mitochondria
what is the enzyme needed for conversion of cholesterol to pregnenolone
cholesterol desmolase
what factors increase the conversion of cholesterol to pregnenolone
ACTH and angiotensin II
what is the half life for aldosterone
20 minutes
what do principal cells do
increase sodium reabsorption and potassium by kidney tubules (with help of aldosterone)
how does hyperkalemia affect aldosterone secretion
it increases it
what do intercalated cells do
increase hydrogen secretion by kidneys
what part of the adrenal gland secretes mineralocorticoids
zona glomerulosa
what is the major glucocorticoid
cortisol
what is the secretion of cortisol controlled by
ACTH
what is the second messenger for CRH and ACTH
cAMP
what part of the adrenal gland secretes cortisol
zona fasciculata
what part of the adrenal gland secretes androgenic hormones
zona reticularis
how does increased potassium effect aldosterone secretion
it greatly increases it
how does increased angiotensin II effect aldosterone secretion
greatly increases it
what maintains vascular response to catecholamines
glucocorticoids
what resists/controls inflammation
glucocorticoids
what is the primary cause of addisons disease
injury to adrenal cortex
what is secondary cause of addison’s disease
impaired function of pituitary gland
what are disturbances associated with addison’s disease
due to mineralocorticoid and glucocorticoid deficiency, melanin pigmentation
