Thyroid

Question 1

how is T3 made

Answer 1

TRH released from hypothalamus
TSH released from anterior pituitary
acts on thyroid to release T4 the precursor of T3

Question 2

t4 half life

Answer 2

8 days

Question 3

t3 half life

Answer 3

1 day

Question 4

hypothyroid parameters*

Answer 4

low t4
low/normal ts
high TSH
low serum thyroglobulin

Question 5

hyperthyroid parameters

Answer 5

high t4 and t3
low TSH
high serum thyroglobulin

Question 6

cause of hasimotos thyroiditis

Answer 6

antibodies against thyroglobulin and thyroid peroxidase that destroy thyroid gland particles

Question 7

often misfdiagnosed as depression or anxiety

Answer 7

hasimotos thyroiditis

Question 8

diagnosis of hasimotos thyroiditis

Answer 8

enlarge thyroid gland detected by ultrasound or radioactive uptake scan
need aspiration of gland detects macrophages and leukocytes
antibodies in blood test

Question 9

caution of thyroid hormones

Answer 9

increase sensitivity to catecholamines

Question 10

cause of graves disease

Answer 10

activating antibodies for TSH

Question 11

contraindication for radio iodine

Answer 11

children and pregnancy

Question 12

precautions for radioiodine

Answer 12

hypothyroidism
thyroid cancer
radiation induced thyroiditis
delay in therapeutic response

Question 13

thioamide mechanism of action

Answer 13

inhibits thyroid hormone synthesis
interferes with organification of iodine
blocks conversion of MIT to DIT
inhibit coupling of iodinated tyrosines

Question 14

polythiouracil mechanism of action

Answer 14

inhibits conversion of T4 to T3

fast decrease in T3

Question 15

preferred treatment in pregnancy

Answer 15

polythiouracil

Question 16

thioamine drug side effects

Answer 16

arthritis like 
rash
fever
leukopenia - dont monitor WBC levels, stop therapy at first sign of sore throat
agranulocytosis

Question 17

what are symptoms of a thyroid storm

Answer 17

shortnss of breath 
anxiety 
increased body temp 
sweating
tachycardia 
chest pain

Question 18

drug to decrease cardiovascular symptoms

Answer 18

propranolol

Question 19

dexamethasone effects

Answer 19

inhibits conversion of t4 to t3

Question 20

lithium effects

Answer 20

inhibits secretion adn degradation in peripheral tissues

Question 21

sulfonamide effects

Answer 21

interfere with organification of iodine

Question 22

sodium nitroprusside effects

Answer 22

thiocyanate accumulation inhibits iodine reuptake by the thyroid

Question 23

amiodarone effects

Answer 23

contains lots of iodide

Question 24

iodide in large doses effects

Answer 24

decreases degranulation of thyroglobulin and gland vascularity, usefull prior to surgery