Iodine Flashcards
What form is the functional form of iodine
Iodide I-
sources of iodine
seafood, dairy, eggs, salt
iodide is absorbed throughout the
stomach and intestines (~100%)
70-80 % of bodys iodine concentration is in the
thyroid gland
there is a 40-50 x higher iodine concentration in ___ than blood
thyroid cells
True or False: Iodine requires a sodium dependent active transport system
true
functions of iodine
component of thyroid hormones
the formation of thyroid hormones
what are the the thyroid hormones iodine is a component of
thyroxine and triiodothryronine
what do thyroxine and triiodothryronine do
BMR, O2 cons, heat nervous sys dev growth organs antimicrobial
______ actively take up iodide through an Na+/K+- ATPase pump
thyroid cells
iodide is oxidized to what
iodine bound to tyrosine residue on thyroglobulin
iodine bound to tyrosine residue on thyroglobulin form what
thyroglobulin monoiodotyrosine (Thg-MIT)
Thg MIT + another iodine =
Thg DIT
2 ThgDIT =
T4
DIT + MIT =
T3
iodine is primarily excreted through the
kidneys - there is no mechanism kidneys to conserve iodide
Iodine deficiency is common in what part of the world
asia, africa
why is iodine deficiency low in NAmerica
iodized salt
who has an increased risk of deficiency
vegan/vegetarian
mothers who smoke
what is a goitrogen
substance that interferes with iodine metabolism and inhibit thyroid hormone production
what are some examples of goitrogens
- halide ions, thiocyanate, perchlorate
- lithium
polycyclic hydrocarbons and phenol compounds - plants - brassica, soy, millet, cassava
what is a goiter
enlargement of the thyroid gland
goiters are most often due to
overstimulation of thyroid gland by TSH iodine deficiency ( or ingestion of goitrogen)
what is crentism
caused by untreated congential deficiency of thyroid horomones
what causes crentism
maternal iodine deficiency
what two types of crentism are there
neurological
hypothyroid
signs and sx of neurological crentism
short stature MR hearing loss, deaf, mute spastic/ rigid mm caused by iodine def in 1 +2 trimester
signs and sx of hypothyroid crentism
short
MR
hypothyroidism
caused by iodine def in 3 trimester + several years following
clinical indications of iodine supplementation
treatment of fibrocystic breast changes
what is lugols solution
combination of iodine and potassium
signs and sx of iodine toxicity
- burning mouth, throat, ST
- incr saliva, swelling of salivary glands
- metallic taste
- severe headache
- acne form rash
- thyroid dysfunction
- pulmonary edema
- lymphadenopathy
- N/V/D
- thin hair
NaCl ______ iodine excretion
increases
______ is required for the conversion of T3- T4
Selenium
_____ inhibits absorption of iodine
calcium
_____ is associated with decrease iodine uptake by thyroid glands
vitamin A
Thyroid function tests what
TSH T3 T4
