Chapter 38

Question 1

structural and functional units of the thyroid gland

Answer 1

thyroid follies

Question 2

each thyroid folic is surrounded mainly by

Answer 2

simple cubodial epithelium

Question 3

each thyroid follicle is filled with a —- which is mainly composed of —–

Answer 3

colloid, thryoglobulin

Question 4

undertake thyroglobin production, iodide intake, and thyroid hormones release

Answer 4

colloid

Question 5

thyroid hormones are mainly synthesized in the

Answer 5

colloid

Question 6

two types of thyroid hormones

Answer 6

T3 and T4

Question 7

synthesis of thyroid hormones

Answer 7

• Iodide is uptake by Na/I symporter
• Iodide is oxidized by thyrodial peroxidase into iodine
• iodine iodinates tyrosine to form MIT and DIT (Iodine organification)
• coupling
• release

Question 8

type of thioamide drugs

Answer 8

thyroidal peroxidase

Question 9

how is the thyroid regulated

Answer 9

HPT axis

hypothalamic pituitary thyroid axis

Question 10

induces new proteins generation which produce effects

Answer 10

T3

Question 11

some of t4 are converted to t3 in

Answer 11

kidney and liver

Question 12

insufficiency of thyroid hormone

Answer 12

hypothyroid

Question 13

insufficiency of thyroid hormone in infant and child, results in irreversible mental retardation

Answer 13

cretinism

Question 14

excess thyroid hormone, sympathetic nervous over-activity

Answer 14

hyperthyroid

Question 15

antithyroid drug that blocks uptake of iodide (competitive inhibition)

Answer 15

perchlorate (anion inhibitors) — these can lead to anemia

Question 16

• antithyroid drug that has the mechanism of “Wolff-Chaikoff effect”
• inhibit hormone release and organification

Answer 16

iodides such as KI

Question 17

antithyroid drug that treats thyrotoxicosis, taken up and trapped in the same manner as I-

Answer 17

Radioactive Iodide

Question 18

antithyroid drug that has the mechanism of peripheral conversion

Answer 18

propylthiouracil

Question 19

effective for tremor, anxiety, nervousness accompanied with hyperthyroidism

Answer 19

propanolol (a beta receptor blocking agent)

Question 20

• inhibit peroxidase activity
• Inhibitors of thyroid hormone production
• Outcompete with thyroiglubilin for oxidized iodide
• Selective decrease in organification and coupling of thyroid hormone precursors

Answer 20

thioamides

Question 21

for treatment of thyrotoxicosis

Answer 21

radioactive iodine

Question 22

are effective in treatment of thyrotoxicosis.

Propranolol

Answer 22

beta-adrenoceptor blockers

Question 23

the hypothalamus releases —– then the anterior pituitary releases —— and the thyroid gland releases ——

Answer 23

TRH
TSH
T3 and T4

Question 24

stimulates T4 and T3 synthesis and release from the thyroid.

Answer 24

TSH

Question 25

inhibit both TRH and TSH synthesis and release.

Answer 25

t3 and t4

Question 26

hypothyroidism is treated as a whole with

Answer 26

thyroid hormones

Question 27

hyperthyroidism is treated as a whole with

Answer 27

anti-thyroid drugs

Question 28

4 main classifications of antithyroid drugs

Answer 28

- thioamides - iodides - radioiodine - beta receptor blocking agent

Question 29

PTU, or ends in -mazole

Answer 29

thioamides

Question 30

inhibits thyroid peroxidase, decrease thyroid hormone production

Answer 30

Thioamides 1. The major action is to prevent hormone synthesis by inhibiting the thyroid peroxidase-catalyzed reactions to block iodine organification. 2. They block coupling of iodotyrosines . 3. PTU (Propylthiouracil) can also prevent the conversion of T4 to T3.

Question 31

inhibit organificatian and hormone release.

Answer 31

iodides

Question 32

- used in thyroid hormone replacement therapy in patients with hypothyroidism

Answer 32

levothyroxine (t4)

Question 33

majority of t4 is deiodinated to

Answer 33

t3

Question 34

- used in short term suppression of TSH in patients undergoing surgery for thyroid cancer - initial therapy of myxedema

Answer 34

Liothyronine (T3)

Question 35

any condition caused by elevated levels of circulating free thyroid hormones

Answer 35

thyrotoxicosis

Question 36

- an autoimmune disease that causes the thyroid gland to produce too much thyroid hormone. - symptoms: goiter and bulging eyes - malfunction in which immune system releases abnormal antibodies that mimic TSH - overproduction

Answer 36

graves disease

Question 37

how is graves disease treated

Answer 37

Radioactive iodide, antithyroid drugs, beta blockers, thyroidectomy

Question 38

a life-threatening health condition that is associated with untreated or undertreated hyperthyroidism. Symptoms: individual’s heart rate, blood pressure, and body temperature can soar to dangerously high levels.

Answer 38

thyroid storm

Question 39

treatment of thyroid storm

Answer 39

PTU