ENDORINE - part 2 Flashcards
also known as the butterfly shaped gland
thyroid gland
consist of two lobes located in the lower part of the neck, just below the voice box
thyroid gland
the 2 lobes of thyroid gland is connected by a narrow band called
isthmus
the fundamental structural unit of the thyroid gland
follicle
the site of the synthesis and storage of thyroid hormones
thyroid follicle
is a glycoprotein with a positive periodic acid schiff staining
thyroglobulin
it acts as a preformed matrix containing tyrosyl groups
thyroglobulin
types of cells in the thyroid gland
follicular cells (t3 and t4)
parafollicular or C cells (calcitonin)
is the neuroendocrine system that regulates the production and secretion of thyroid hormones
hypothalamic-pituitary-thyroid axis (HPTA)
by what week of gestation, which the gland begins to produce measurable amounts of thyroid hormones
11th week
TSH stimulates the synthesis of thyroid hormones through the cellular uptake of ___
dietary iodine
t4 is the prehormone of
t3
how t3 is produced as it says that its a prehormone of t4
in the cytoplasm from the removal of one iodine-outer ring of T4
the process of secretion into the circulation of T3 and T4 are all mediated by
TSH
is a biologically inactive metabolite of T4 and bound to TBG
reverse T3 (rT3)
if a mother has normal thyroid function, small amounts of maternal thyroid hormone crossing the placenta protect the fetus during development
what is the function of that small amount of thyroid hormone in fetus
critical in fetal NEUROLOGIC development
the actvity of thyroid hormones depends on the ____ of iodine atoms
location and number of iodine atoms
which type of thyroid hormone is metabolically active and which one is not
the metabolically active is the free thyroid hormone
the protein bound thyroid hormones are metabolically inactive
is the most important element in the biosynthesis of thyroid hormones
iodine
when iodide sources are diminished, ___ is produced in greater quantities, leading to increased T3 formation and release
MIT
iodine intake below _____ug/day is an indication of the deficiency of hormone secretion
50ug/day
it is a 32 amino acid monomeric peptide
thyrocalcitonin
is synthesized in the parafollicular cells from the cleavage and post translational modification of precalcitonin then procalcitonin
thyrocalcitonin
this maintains the balance of calcium and phosphorus in plasma
thyrocalcitonin