18. Thyroid Flashcards Preview

Tri 6 - Clinical Dx (Tom) > 18. Thyroid > Flashcards

Flashcards in 18. Thyroid Deck (44)
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1
Q

main raw material of thyroid hormone is ________ provided by the diet

A

inorganic iodide

2
Q

inorganic iodide is extracted from the blood and converted to

A

organic iodine

3
Q

iodine is incorporated into a tyrosine nucleus to form _________, and another is added to form _________

A

monoiodotyrosine, diiodotyrosine

4
Q

two molecules of diiodotryosine combine to form

A

tetraiodthyronine (thyroxin/T4)

5
Q

a monoiodotryosine combines with a diiodotryosine to form

A

triiodothyronine (T3)

6
Q

TH is stored in the acini as _________, and reconstituted as needed

A

thryoglobulin

7
Q

Over 90% of the TH in circulation under normal conditions is

A

T4

8
Q

99% of T4 and T3 is bound to

A

proteins

9
Q

most of T4 is bound to

A

thyroid binding globulin (TBG)

10
Q

TBG is an

A

alpha-1 globulin

11
Q

most T3 is bound to

A

TBG or albumin

12
Q

unbound/free T4 and T3 are metabolically

A

active

13
Q

free T4 is converted to T3, particularly in the

A

liver

14
Q

80% of daily T3 is converted and utilized in the

A

liver

15
Q

decreased T3/T4 cause hypothalamus to produce

A

TRH

16
Q

increased T3/T4 inhibit both

A

TRH and TSH

17
Q

High TSH, Low T3 and T4

A

primary hypothyroidism

18
Q

failure of the thyroid gland is usually from

A

Hashimoto’s thyroiditis

19
Q

TSH is low or absent from failure of pituitary to respond to TRH, or no TRH response to love T3/T4

A

secondary hypothyroidism

20
Q

Low TSH, High T4/T3

A

hyperthryoidism

21
Q

Graves disease, aka

A

diffuse toxic goiter

22
Q

Graves disease is characterized by hyperthyroidism and of of the fallowing…

A
  • goiter
  • exopthalmous
  • pretibial myxedema
23
Q

circulating antibodies against the TSH receptors resulting in

A

continuous secretion of T3/T4

24
Q

thyrotoxicosis factitia results from the ingestion of

A

TH

25
Q

hormone made by thryoid C cells and functions to reduce blood Ca levels?

A

calcitonin

26
Q

how does calcitonin reduce blood Ca levels?

A

DECREASE

  • intestinal absorption
  • osteoclastic activity
  • Ca and phosphorus reabsorption in kidney
27
Q

hormone that increases Ca levels in blood

A

parathyroid hormone (PTH)

28
Q

5th most abundant element in the body

A

calcium

29
Q

99% of adult calcium is contained in bones as

A

calcium hydroxyapatite

30
Q

in blood most calcium is present in

A

plasma

31
Q

50% of circulating calcium is free, known as

A

ionized calcium

32
Q

40% of serum calcium is bound to

A

proteins

  • albumin (80%)
  • globulins (20%)
33
Q

remaining 10% of serum calcium exists as various small

A

diffusible inorganic and organic anions

34
Q

total serum calcium concentration is normally between

A

8.5 - 10.5

35
Q

calciotropic hormones regulate what component of the total serum clalcium level?

A

ionized (free) calcium

36
Q

what should be considered when determining total serum calcium?

A

concentrations of plasma proteins (albumin)

37
Q

Total serum calcium is easier to measure than

A

ionized calcium

38
Q

what can cause excessive binding of calcium to the monoclonal paraprotein and occasional elevation of the total serum calcium?

A

increased globulin concentration in multiple myeloma

39
Q

in multiple myeloma patients, it’s helpful to assess

A

ionized calcium

40
Q

serum calcium levels above ___ mg/dL commonly cause symptoms

A

11.5

41
Q

calcium levels above 15 is a

A

meical emergency

42
Q

Confusion, fatigue, lethargy, and calcium level above 13

A

hypercalcemia

43
Q

stones (kidney), moans (abdomin), groans (myalgia), bones, and psychiatric overtones

A

chronic hyperparathyroidism

44
Q

impaired vitamin D synthesis or absent/impaired parathyroid glands will cause

A

hypocalcemia