Flashcards in thyroid histology Deck (27)
what is the first endocrine gland to develop?
what is the thyroid gland derived from?
is derived from endoderm in the floor of the primitive pharynx
when does the thyroid begin to fxn?
by the end of the 3rd month prenatally
what is the thyroid capsule derived from?
deep cervical fascia
what partitiions the gland into lobules?
which hormones does the thyroid gland synethesize?
T3, T4, Calcitonin
if cells in follicular epithelium are simple squamous, what level of activity?
if cells in follicular epithelium are simple cuboidal, what level of activity?
if cells in follicular epithelium are simple columnar, what level of activity?
thyroid follicles are surrounded by_____
what is in the follicular lumen?
what is in colloid?
thyrogloblin (T3 + T4)
where is calcitonin stored and released from?
parafollicular cells in the thyroid gland
synthesis of thyroid hormones is controlled by ____ and ____
TSH and iodide
thyroglobulin synthesis occurs in the ______, thyroglobulin glycosylation occurs in the _____&______
RER; RER & GA
how many tyrosine residues are found in each thyroglobulin molec?
what sort of transport is required for iodide to enter follicular cells?
the transepithelial pathway involves binding of thyroglobulin to ______
where is megalin located?
apical follicular cell membrane, facing the colloid
during the lysosome pathway or the transepithelial pathway does the T3 T4 get released when attached to thryoglobulin?
which pharyngeal pouches do the parathyroid glands arise from?
how are epithelial cells arranged in parathyroid gland parenchyma?
cords or clusters
which cells synthesize parathyroid hormone?
in bone, PTH attaches to _____ receptors, but triggers ______activity
osteoblast receptors, osteoclast activity
osteoclast = bone building or bone breakdown?
in kidney, PTH ____Ca loss in urine, ______phosphate loss in urine
prevents Ca loss, promotes phosphate loss