Term
explain thyroid hormones from ingestion of iodine to T3/4 production and storage (7 steps) |
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Definition
1. ingest iodine 2. TSH stimulates iodine uptake and hormone production 3. iodine active transport into thyroid 4. activated with THYROID PEROXIDAZE (using Hb and H2O2) 5. monotyrostol and diiodotyrosyl are produced 6. THYROID PEROXIDASE links AA making T3 and T4 in a 1:4 ratio 7. T3 and T4 are stored in thyroglobulin |
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Term
explain thyroid hormone release from thyroglobulin to arrival at the tissues (7 steps) |
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Definition
1. thyroglobulin fuses with lysoosme
2. proteolytic enzymes break it into... - monotyrosyl and dioxotyrosyl which stay in thyroid - T3/T4 which go into blood - excess iodine which stays in thyroid
3. T3/4travel in blood on thyroxine binding globulin and albumin
4. T3/4 are released at tissues |
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Term
what motifications occur to T3/4 at the tissues (2) |
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Definition
diodinase enzymes remove 5' outer ring...
- 5-DI and 5-DII turn T4 to T3 (41% of T3)
- 5-DIII turns T4 into reverse T3 |
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Term
where are T3 and T4 degraded |
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Definition
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Term
what are the differences in T3 and T4 elimination |
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Definition
T3 is eliminated in 2 d due to increased protein binding increasing hald life
T4 is eliminated in 6-7d |
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Term
how does iodine regulate thyroid hormone production |
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Definition
decreased iodine decrease thyroid hormones which stimulate TSH causing thyroid hypertrophy (gioter) and selective T3 formation |
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Term
how does the production of thyroid hormone reulate itself |
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Definition
it doesnt
it stops TSH production but increases thyrotropin releasing hormone (TRH) production which cancel |
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Term
what is the difference in tissue binding and activity of T3 and T4 |
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Definition
T3 binds with 5x higher affinity
T4 binds with lower affinity |
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Term
what are the 6 areas in general thyroid hormones affect |
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Definition
growth and development basal metabolic rate released when cold to regulate body temp heart CNS cholesterol metabolism |
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Term
how does the thyroid effect growth and development (5) |
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Definition
differentiation and myelination of cnS
potentiation of GH, PTH, and calcitonin |
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Term
in what organs does the thyroid hormone effect on basal metabolic rate have the most effect (4) |
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Definition
heart, muscle, liver, kidney |
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Term
what changes do thyroid hormones cause in the heart (4) |
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Definition
sensitize it (synergistic) increase CO, HR, contractility |
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Term
what effects do thyroid hormones have on the CNS |
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Definition
sensitize catecholamine receptors (synergistic) |
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Term
what does thyroid hormone do to cholesterol metabolism |
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Definition
stimulates metabolism of cholesterol to bile acids
important! lack can cause hypercholesterolemia |
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Term
what is the name for adult hypothyroidism |
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Definition
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Term
what is the name for child hypothyroidism |
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Definition
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Term
what are the 9 signs of child hypothyroidism |
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Definition
impaired growth mental retardation pot belly dwarfism lethargy hypothermia slow HT poor appetite death if untreated |
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Term
what are the 8 signs of adult hypothyroiodism |
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Definition
pallid expression blank expression dry skin brittle nails weakness reduced CO fatigue cold intolerence |
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Term
what are two diseases of hyperthyroidism |
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Definition
graves and plummers disease |
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Term
what are 7 characteristics of graves disease |
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Definition
diffuse toxic goiter exophthalmos: big eyes hot moist skin forced rapid heart beat angina arrhythmia heart failure |
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Term
what are 4 causes of graves disease |
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Definition
autoimmune: IgG bind to TSH receptor
chorionic: placental secretion of TSG stimulates receptors in pregnancy |
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Term
what are 6 signs of plummer's disease |
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Definition
toxic nodular goiter hot moist skin forced rapid heart beat angina arrhythmia heart failure |
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Term
what are 5 general signs of hyperthyroidism |
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Definition
hot moist skin forced rapid heart beat angina arrhythmia heart failure |
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Term
what are the 3 treatments for hyperthyroidism |
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Definition
surgical removal of thyroid local radiation with radioactive iodine anti thyroid agents |
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Term
what causes a thyroid storm (7) |
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Definition
complication of hyperthyroidism triggered by stress, thyroid surgery, trauma, diabetic ketoacidosis, labor, heart disease, radioactive iodine |
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Term
what are the 7 treatments of a thyroid storm |
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Definition
fluids anti-pyretics cooling blankets propylithiouracil in large doses iodates B blockers and Ca can control tachyarrhytima dexamethasone |
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Term
what are the three thyroid hormone drugs, what hormone is each |
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Definition
desiccated thyroid - T3 and T4 levothyroxine - T4 liothyroxine - T3 |
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Term
what are the advantages of using liothyronlne over levothyroxine (4) |
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Definition
liothyroline does not have to be converted for full potential, fast onset, good absorption, good when someone has problem with T4 to T3 conversion enzyme |
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Term
what is the clinical use for thyroid hormones (3) |
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Definition
hypothyroidism non-toxic goiter replacement therapy |
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Term
what are the contraindications to thyroid hormones (3) |
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Definition
acute MI
increase anticoagulant effects
reduce digitalis effects |
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Term
what are the 3 side effects or problems with desiccated thyroid |
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Definition
antigenic because it comes from pork
highly variable biological activity
religous objections to treatment |
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Term
what are the two anti-thyroid or thiroureylenes |
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Definition
propylthiouracil and methimazole |
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Term
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Definition
stop iodiniation of throsyl in thyroglobulin
block thyroid peroxidae inhibiting coupling reaction
prophylthiouracil- blocks conversion of T3 to T4 |
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Term
what are the three side effects of anti-thyroids |
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Definition
agranulocytosis
marrow aplasic (improves on DC)
secreted into breast milk |
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Term
what can anti-thyroids be used to treat (7) |
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Definition
graves disease small goiters mild hyperthyroidism
deplete thyroid hormone before radiation hyperthyroidism in elderly
after radiation
prethyrodectomy- prevent surge in surgery
thyroid storm - prophylthiouracil due to T3 to T4 ability |
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Term
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Definition
saturated potassium iodide prevents thyroid hormone release
inhibits hormone synthesis by decreasing TSG and blcking its action (wolff chickoff effect) |
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Term
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Definition
rebound hyperthyroidism
angioedema
hypersensitivity
iodism |
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Term
what is iodism, what are 7 signs |
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Definition
chronic intoxication of iodine
burning bouth, throat, eyes, headache, productive cough, gastric irritation, skin lesions |
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Term
what are the three uses of iodine |
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Definition
reduce vascularity and increase gland firmness
thyroid storm prevention
pre surgery |
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Term
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Definition
gets trapped in thyroid and B-rays destory parenchyma B-rays only destory bad tissue |
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Term
what are three side effects of radioactive iodine |
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Definition
cannot use in pregnancy
delayed hypothyroidism
chromosomal abberations (cannot use in kids and pregnancy) |
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Term
what is the half life of radioactive iodine |
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Definition
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Term
what is the use of radioactive iodine |
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Definition
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Term
what is another name for radioactive iodine |
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Definition
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