Flashcards in Thyroid gland Deck (30):
what temporarily connects the developing thyroid gland to the foramen cecum of tongue?
what cares blood vessels, lymphatic vessels, and nerve fibers deep into glands?
What covers the posterior surface of thyroid gland
What does T3 and T4 regulate
cell and tissue metabolism, head production
what does calcitonin regulate
blood calcium levels
how does the follicular epithelium change in response to activity?
low: simple squamous
High active:simple columnar
what secretes calcitonin
parafollicular cells ( C cells)
when is calcitonin released?
released when blood calcium are high. It LOWERS blood calcium level to normal
How does calcitonin regulate calcium levels
-inhibit bone breakdown by osteoclasts
-Promote calcium deposition in bones (osteoid calcification)
-increase Ca excretion
What hormone travels down to thyroid gland to initatiate T3 and T4 production
Where are vesicles formed in the follicluar cell?
What does each thyroglobulin molecule contain when it exocytose?
120-140 tyrosine residues
How does the iodide get into the thyroid gland
enters folliclular cell via active transport via Na/iodide symportersat the basal membrane of follicular cells
when Triiodinated tyrosine and tetraiodinated tyrosine gets cleaved from thyroglobulin, what does it become?
T3 and T4
How is T4 produced?
thyroid follicular cell
How is T3 produced?
Conversion of T4 by kidney, liver
what are some signs of hyperthyroidism? and what disease does it cause?
Graves disease: exophthalamos, enlarged thryoid
what cells synthesize and release parathyroid hormone?
what is the function of Parathryoid hormone (PTH)
regulates calcium and phosphate levels in the blood
PTH in bone effect
PTH attaches to osteoblast receptors-->cause osteoblast to release OsteoCLAST-stimulating factor-->osteoclast activity breaking down bone-->freeing calcium from bone to enter blood stream
PTH in Kidney effect
PTH: conserves Ca and excretes phoshpate.
initiate calcitriol synthesis.
reasborption of Ca from filtrate
PTH in GI
regulate formation of vit D in kidneys, PTH controls rate of calcium (via VItamin D, because VItamin D facilitates Ca absorption in GI)
which hormone decreases elevated blood Ca++ levels to normal?
what happens when you completely remove parathyroid gland?
drop in blood calcium level causing Hypoparathryoidism-->hypocalcemia-->tetany
cause hypercalcemia-->urinary tract stone (calcification)
which cells synthesize glucagon in pancreas
which cell synthesize insulin in pancreas?
what increases blood glucose level? decrease blood glucose level
What do delta cells synthesize? and what is its function?
reduce smooth muscle contraction of digestive tract and gall bladder
decrease insulin and glucagon