Thyroid

Question 1

what is the main raw material of thyroid hormone

how do we get this raw material

what happens next

Answer 1

inorganic iodide

provided by the diet

extracted from the blood and converted to organic iodine

Question 2

iodide ingested and taken into the blood is converted to

• -> ___ + ___
• -> ____ + ____
• -> ____

Answer 2

iodine which binds to tyrosine

which forms monoiodtyrosine which binds with iodine

which forms diiodotyrosine

Question 3

what forms T4

Answer 3

diiodotyrosine + diiodotyrosine = tetra/thyroxin

Question 4

what is another name for T4

Answer 4

thyroxin

tetraiodothyronine

Question 5

what forms T3

Answer 5

monoiodotyrosine + diiodotyrosine

Question 6

what is another name for T3

Answer 6

triiodothyronine

Question 7

what is thyroid hormone stored in? as what ?

Answer 7

acini

thyroglobulin

Question 8

most of thyroid hormone in circulation is what type

Answer 8

T4 90%

Question 9

99% of T4 and T3 are bound to what in the blood

Answer 9

protein

Question 10

most of T4 is bound to what

most of T3 is bound to what

Answer 10

TBG (thyroid binding globulin)

TBG and albumin

Question 11

thyroid binding globulin is what type of protein

Answer 11

alpha 1 globulin

Question 12

1% of T4 and T3 is found where

Answer 12

FREE or unbounded

metabolically active in cells

Question 13

free T4 is converted to

where

Answer 13

T3

in the liver cells for utilization

Question 14

what percent of daily T3 is converted and utilized by the liver

Answer 14

80%

Question 15

80% of __ is converted and utilized by the liver

Answer 15

T3

Question 16

decreased levels of T3 and T4 cause what to happen

Answer 16

TRH production in hypothalamus

Question 17

increased levels of T3 and T4 cause what to happen

Answer 17

inhibit TSH and TRH

Question 18

TSH high, T3 and T4 are low indicate what

Answer 18

primary hypothyroidism

hashimotos

Question 19

TSH is normal or low
T3 and T4 are low
indicates what

Answer 19

secondary hypothyroidism

Question 20

why is TSH normal or low in secondary hypothyroidism

Answer 20

pituitary doest respond to TRH or low T3/T4 doesnt trigger TRH response

Question 21

TSH is low and

T3 and T4 are high indicates what

Answer 21

hyperthyroidism

Question 22

is T3 or T4 more elevated in hyperthyroidism

Answer 22

T3

Question 23

what causes hyperthyroidism

Answer 23

due to autonomous hyperfunction or thyroid stimulators in the blood

Question 24

what is graves disease

Answer 24

hyperthyroidism

Question 25

what is another name for graves disease

Answer 25

diffuse toxic goiter

Question 26

what are the requirements to have graves disease

Answer 26

hyperthyroidism and one of the following: goiter exophthalmous pretibial myxedema

Question 27

what causes graves disease

Answer 27

due to circulating antobodies against TSH receptors which causes continuous secretion of T3/T4

Question 28

what is the most common cause of hyperthyroidism

Answer 28

graves disease

Question 29

what results from the ingestion of thyroid hormone

Answer 29

thyrotoxicosis factitia

Question 30

calcitonin is made by what cells of the thyroid gland

Answer 30

C cells of thyroid

Question 31

what does calcitonin do

Answer 31

reduce Ca in the blood decrease absorption in GI decrease osteoclasts decrease Ca and phosphate reabsorption in the kidney

Question 32

parathyroid hormone is secreted by what

Answer 32

parathyroid glands found inside the thyroid gland

Question 33

what does PTH do

Answer 33

increase Ca in the blood increase absorption in GI increase osteoclasts increase Ca and phosphate reabsorption in the kidney

Question 34

what is the 5th most abundant element in the body

Answer 34

Calcium

Question 35

calcium is the __ most abundant element in the body

Answer 35

5th

Question 36

adults have calcium content of what

Answer 36

1kg | 2% of body weight

Question 37

all but __% of calcium is found in the bone where is this % found

Answer 37

1% intra and extracellular space

Question 38

in blood, all calcium is found in the

Answer 38

plasma

Question 39

what percent of calcium is free what is this also called

Answer 39

50% ionized calcium

Question 40

what percent of calcium is bound to protein

Answer 40

40% 80% - albumin 20% - globulins

Question 41

what percent of calcium exists as anions examples

Answer 41

10% bicarbonate lactate citrate

Question 42

what is normal serum calcium levels

Answer 42

8.5 to 10.5 mg

Question 43

what form of calcium is the only form that is regulated by calciotropic hormones

Answer 43

free or ionized calcium

Question 44

decisions of total serum calcium concentration should not be made without considering what

Answer 44

albumin | plasma proteins

Question 45

total serum calcium is easier or harder to measure than ionized/free calcium

Answer 45

easier ..but make sure to consider the protein concentrations to determine the difference bound to protein and free/ionized

Question 46

in patients with multiple myeloma, the ___ concentration is often increased, which leads to excessive binding of Ca to ____ which may elevate total serum calcium concentration, yet the ___ level may be normal

Answer 46

globulin monoclonal paraprotein ionized calcium

Question 47

when is ionized free calcium considered useful to diagnose a patient

Answer 47

multiple myeloma

Question 48

serum calcium levels above what usually cause symptoms critical levels = medical emergency =

Answer 48

11.5 mg 12mg 15mg (severe hypercalcemia)

Question 49

hypercalcemia results from what

Answer 49

increased mobilization of calcium from bones or increased intestinal absorption primary hyperparathyroidism or bone metastasis from breast, prostate, thyroid, lung

Question 50

what are the symptoms of hypercalcemia

Answer 50

ACUTE confusion fatigue lethargy > 13 mg

Question 51

what are the symptoms of chronic hyperparathyroidism

Answer 51

``` stones - kidney moans - abdominal pain groans - myalgia bones - bone pain psychiatric overtones ```

Question 52

PTH and PTHrP levels are normal indicates what

Answer 52

rule out PT adenoma suggest malignancy, hypervitaminosis A or D, milk alkali syndrome, granulomatous disease, meds, lithium, thiazides

Question 53

hypocalcemia results from what

Answer 53

absent or impaired parathyroid glands OR impaired vitamin D synthesis

Question 54

what causes primary hypothyroidism

Answer 54

failure of thyroid gland - hashimotos thyroiditis - MC iodine deficiency enzymatic defects