The Thyroid Gland

Question 1

All of the following statements about iodine are true EXCEPT
a. Radioactive iodine treatment of Graves disease is effective in less than
40% of patients treated with this agent.
b. Iodine deficiency is one of the most common causes of hypothyroidism
in the world.
c. T4 has four iodine molecules.
d. RAIU is often useful in determining the cause of thyrotoxicosis.

Answer 1

a. Radioactive iodine treatment of Graves disease is effective in less than
40% of patients treated with this agent.

Question 2

2. The fetus
   a. Is dependent on thyroid hormone for normal neurologic development
   b. Does not develop a thyroid gland until the third trimester
   c. Is not susceptible to damage from radioactive iodine therapy given to
   the mother
   d. Will be born with hypothyroidism in approximately 1 of 400 births in
   developed countries

Answer 2

a. Is dependent on thyroid hormone for normal neurologic development

Question 3

The thyroid gland
a. Depends on TPO to permit iodination of the tyrosyl residues to make
MIT and DIT
b. Is an ineffective iodine trap
c. Depends on TPO to permit the joining of two DIT residues to form T3
d. Usually functions independent of TSH levels

Answer 3

a. Depends on TPO to permit iodination of the tyrosyl residues to make
MIT and DIT

Question 4

The thyroid gland produces all of the following EXCEPT
a. TSH
b. Thyroglobulin
c. T3
d. T4

Answer 4

a. TSH

Question 5

Hypothyroidism is generally associated with all of the following EXCEPT
a. TSH receptor antibodies
b. Depression
c. An elevation of TSH levels
d. TPO antibodies

Answer 5

a. TSH receptor antibodies

Question 6

6. A 34-year-old woman presents with goiter, tachycardia, and weight loss of 2
   months duration. TSH is undetectable and free T4
   is high. All of the
   following tests are useful in diagnosing the cause of the hyperthyroidism
   EXCEPT
   a. FNA biopsy of the thyroid gland
   b. TSH receptor antibodies
   c. RAIU
   d. TSH

Answer 6

a. FNA biopsy of the thyroid gland

Question 7

A 65-year-old woman presents with fatigue, hypothermia, pericardial
effusions, and hair loss. Her thyroid function tests show a significantly
elevated TSH and a low free T4
. All of the following laboratory test
abnormalities may be associated with her underlying condition EXCEPT
a. Elevated WBC
b. An elevated cholesterol level
c. Anemia
d. Elevated CPK levels

Answer 7

a. Elevated WBC

Question 8

A 26-year-old man presents with a 3-cm, right lobe, thyroid nodule and a
normal TSH. What is the next test that should be performed?
a. FNA of the nodule
b. Free T4
level
c. Thyroid ultrasound
d. Thyroid scan

Answer 8

a. FNA of the nodule

Question 9

The following are treatment options for hyperthyroidism associated with
Graves’ disease EXCEPT
a. Thyroid hormone
b. PTU
c. Beta-blockers
d. Radioactive iodine

Answer 9

a. Thyroid hormone

Question 10

All of the following abnormalities might be expected in a severely ill patient
EXCEPT
a. Low rT3
b. Low T4
c. Low T3
d. Low TSH

Answer 10

a. Low rT3

Question 11

Of the following thyroid hormones, which is considered the most
biologically active?
a. T3 bound to TBG
b. T4 bound to TBG
c. Free T4
d. Free T3
e. rT3

Answer 11

d. Free T3

Question 12

The primary serum test to screen for thyroid disease is
a. Free T4
b. rT3
c. Total T4
d. Autoimmune antibodies to thyroid tissue
e. TSH

Answer 12

e. TSH

Question 13

Of the following, which will MOST likely interfere with quantitation of
thyroglobulin?
a. Antithyroglobulin autoantibodies
b. Thyroid-stimulating antibodies
c. TSH receptor antibodies
d. Thyroid peroxidase antibodies

Answer 13

a. Antithyroglobulin autoantibodies