Thyroid

Question 1

Iodide is absorbed in the ____

Answer 1

Small intestine

Question 2

Iodide is converted to organic iodine by ____

Answer 2

Peroxidase

Question 3

The ____ (in thyroglobulin) are iodinated at one or two sites and then coupled to form the hormones T3 and T4

Answer 3

Tyrosines

Question 4

____, a glycoprotein containing T3 and T4 within its matrix, is taken up as colloid droplets by the thyroid cells

Answer 4

Thyroglobulin

Question 5

____ cleave T3 and T4 from thyroglobulin, resulting in the release of free T3 and T4

Answer 5

Lysosomes

Question 6

Secretion of hormone from the thyroid depends on the amount of circulating ___

Answer 6

TSH

Question 7

The level of TSH depends on the amount of ___ and on the level of free thyroid hormones in the circulation

Answer 7

TRH

Question 8

Under normal conditions, only about __% of thyroid hormone secretion is T3

Answer 8

15%

Question 9

80-85% of T4 and 70% of T3 are bound to this serum protein in the blood

Answer 9

TBG

Question 10

What serum protein is bound to about 30% of T3 (5% of T4)

Answer 10

Albumin (TBA)

Question 11

Only about __% of circulating T3 is produced by the thyroid

Answer 11

15%

Question 12

About __% of daily T3 production takes place by conversion of free T4 to T3

Answer 12

80%

Question 13

Protein-bound thyroid hormone is metabolically ____

Answer 13

Inert (inactive)

Question 14

____ increases the rate of energy exchange and oxygen consumption by all body tissues

Answer 14

Thyroid hormone

Question 15

Thyroid hormone stimulates the synthesis of ___ in virtually every body tissue

Answer 15

Protein

Question 16

PBI stands for

Answer 16

Protein Bound Iodine

Question 17

PBI is ___ in patients w/hyperthyroidism and ____ in patients w/hypothyroidism

Answer 17

Increased, decreased

Question 18

A common reason for a false increase in PBI?

Answer 18

Pregnancy (or oral contraceptives)

Question 19

Greater than normal levels of total T4 (thyroxine) indicate a ____ state, while decreased levels indicate the opposite

Answer 19

Hyperthyroid

Question 20

Actual name for T3?

Answer 20

Triiodothyronine

Question 21

Levels of carrier proteins (such as TBG) are concomitantly measured by T3 ____ studies (along with the usual Total T4 test)

Answer 21

Resin uptake

Question 22

Possible critical value of total T4 in newborns?

Answer 22

<7.0 micrograms/dL

Question 23

Critical values of total T4 for adults? (Both low and high)

Answer 23

<2.0 micrograms/dL (Myxedema coma possible)

>20 “ “ (thyroid storm possible)

Question 24

Hypothyroidism in infants

Answer 24

Cretinism

Question 25

Hypothyroidism in adults

Answer 25

Myxedema

Question 26

Most common cause of hyperthyroidism

Answer 26

Grave’s disease

Question 27

Most common cause of hypothyroidism

Answer 27

Hashimoto’s thyroiditis

Question 28

Drug that decreases TBG

Answer 28

Steroid

Question 29

Enlarged thyroid gland

Answer 29

Goiter

Question 30

Hyperthyroidism in adults

Answer 30

Thyrotoxicosis

Question 31

Hypothyroidism in a child

Answer 31

Juvenile

Question 32

This test requires the antibody to T4

Answer 32

T4 by radioimmunoassay (RIA)

Question 33

First thyroid test used

Answer 33

PBI

Question 34

The sensitivity of T4 assay is approximately __% for hyperthyroidism and __% for hypothyroidism

Answer 34

95%, 92%

Question 35

This test is one of the best for thyroid function and most accurately reflects thyroid status

Answer 35

Free Thyroxine Assay

Question 36

This test measures the capacity of TBG to bind (“take up”) labeled T3 at unsaturated T4 sites

Answer 36

T3 Uptake Test (T3U)

Question 37

In the T3 uptake test, high levels of uptake of 131 I-T3 by the resin (meaning low amounts were taken up by the open TBG sites) is indicative of ____thyroidism

Answer 37

Hyper

Question 38

Another way to say normal thyroid

Answer 38

Euthyroid

Question 39

This test is measured by multiplying the Total T4 result by the T3 uptake result. It was developed to correct the T4 assay for effects of thyroxine-binding protein alterations (i.e. increased/decreased TBG)

Answer 39

Free Thyroxine Index (FTI)

Question 40

This test measures total serum T3 directly by using anti-T3 antibody. It is used to detect T3 Thyrotoxicosis.

Answer 40

T3 by RIA (T3 assay)

Question 41

The ___ reflex is a good measure for tissue utilization of thyroxine (T4)

Answer 41

Achilles tendon

Question 42

This measurement is inversely proportional to thyroid status

Answer 42

Cholesterol

Question 43

The ___ concentration aids in differentiating primary from secondary hypothyroidism.

Answer 43

TSH (Thyroid Stimulating Hormone)

Question 44

Pituitary TSH secretion is stimulated by hypothalamic ____ hormone

Answer 44

Thyroid-releasing (TRH)

Question 45

An elevation in TRH and TSH would indicate a patient with ____ hypothyroidism

Answer 45

Primary (T3 and T4 are low, leading to increased stimulation of TRH and therefore TSH)

Question 46

A patient with secondary hypothyroidism would have __ levels of TRH and TSH

Answer 46

Low

Question 47

Decreased levels of TSH could indicate what two things?

Answer 47

1. Secondary hypothyroidism | 2. Hyperthyroidism

Question 48

What thyroid test is considered a good SCREENING test?

Answer 48

TSH test

Question 49

The American Thyroid Association recommends that adults be screened for thyroid dysfunction by measurement of TSH beginning at age ___ and every 5 years thereafter.

Answer 49

35

Question 50

Antithyroglobulin antibody and antithyroid microsomal antibody would both be increased in patient’s w/this hypothyroid disease

Answer 50

Hashimoto’s thyroiditis

Question 51

Treatment for patients w/primary hypothyroidism (cretinism, juvenile hypothyroidism, myxedema)

Answer 51

Thyroid hormone for life (synthetic thyroxine)

Question 52

ALP is ____ in hypothyroidism

Answer 52

Decreased

Question 53

Common name for Toxic diffuse goiter

Answer 53

Grave’s disease

Question 54

Common name for Toxic nodular goiter

Answer 54

Plummer’s disease

Question 55

The most common cause of goiter worldwide

Answer 55

Iodine deficiency