Flashcards in Thyroid Deck (54)
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1
what is the main raw material of thyroid hormone
how do we get this raw material
what happens next
inorganic iodide
provided by the diet
extracted from the blood and converted to organic iodine
2
iodide ingested and taken into the blood is converted to
--> ___ + ___
--> ____ + ____
--> ____
iodine which binds to tyrosine
which forms monoiodtyrosine which binds with iodine
which forms diiodotyrosine
3
what forms T4
diiodotyrosine + diiodotyrosine = tetra/thyroxin
4
what is another name for T4
thyroxin
tetraiodothyronine
5
what forms T3
monoiodotyrosine + diiodotyrosine
6
what is another name for T3
triiodothyronine
7
what is thyroid hormone stored in? as what ?
acini
thyroglobulin
8
most of thyroid hormone in circulation is what type
T4 90%
9
99% of T4 and T3 are bound to what in the blood
protein
10
most of T4 is bound to what
most of T3 is bound to what
TBG (thyroid binding globulin)
TBG and albumin
11
thyroid binding globulin is what type of protein
alpha 1 globulin
12
1% of T4 and T3 is found where
FREE or unbounded
metabolically active in cells
13
free T4 is converted to
where
T3
in the liver cells for utilization
14
what percent of daily T3 is converted and utilized by the liver
80%
15
80% of __ is converted and utilized by the liver
T3
16
decreased levels of T3 and T4 cause what to happen
TRH production in hypothalamus
17
increased levels of T3 and T4 cause what to happen
inhibit TSH and TRH
18
TSH high, T3 and T4 are low indicate what
primary hypothyroidism
(hashimotos)
19
TSH is normal or low
T3 and T4 are low
indicates what
secondary hypothyroidism
20
why is TSH normal or low in secondary hypothyroidism
pituitary doest respond to TRH or low T3/T4 doesnt trigger TRH response
21
TSH is low and
T3 and T4 are high indicates what
hyperthyroidism
22
is T3 or T4 more elevated in hyperthyroidism
T3
23
what causes hyperthyroidism
due to autonomous hyperfunction or thyroid stimulators in the blood
24
what is graves disease
hyperthyroidism
25
what is another name for graves disease
diffuse toxic goiter
26
what are the requirements to have graves disease
hyperthyroidism and one of the following:
goiter
exophthalmous
pretibial myxedema
27
what causes graves disease
due to circulating antobodies against TSH receptors which causes continuous secretion of T3/T4
28
what is the most common cause of hyperthyroidism
graves disease
29
what results from the ingestion of thyroid hormone
thyrotoxicosis factitia
30
