MCQS WITH ANSWERS-AMC -AUSTRALIAN MEDICAL COUNCIL EXAM

THYROID PHARMACOLOGY AND PHYSIOLOGY MCQS

1. Thyroid hormones exert pleiotropic effects in almost all tissues of the body .
2. Thyroid stimulating hormone (TSH) is produced by the thyrotroph cells in the posterior pituitary gland
3. TSH receptor are expressed on the thyroid para follicular cells.
4. A very small increases in thyroid hormone secretion reduce TSH secretion in a log-linear relationship.
5. T4 is the main regulator of TSH.

Answers
1. TRUE-This influences brain and somatic development in infants and metabolism in adults.
2. FALSE -TSH is an anterior pituitary hormone and secretes in response to negative feedback from circulating thyroid hormones.
3. FALSE-TSH receptors are expressed on thyroid follicular cells.
4. TRUE-The reason why the TSH is the most sensitive screening test for thyroid dysfunction
5. FAKSE – T3 is the main regulator since it binds to the thyrotroph nuclear thyroid hormone receptor while T4 acts via conversion to T3

THYROID PAHYSIOLOGY MCQS

1. 70 %TO 80% OF T4 is reabsorbed via enterohepatic circulation.
2. Cholestyramine can be used where rapid control of thyroid hormone is necessary
3. TBG(Thyroxine binding globulin) is a glycoprotein synthesized by the liver.
4. The affinity of TBG for T3 is very high.
5. Thyroid hormones enter cells in an unbound form.

Answers
1. TRUE
2. TURE-cholestyramine can be used effectively to bind T4 in its enterohepatic circulation.
3. TRUE
4. FALSE - affinity of TBG for T4 is very high.
5. TRUE

THYROID PHARMACOLOGY MCQS

The following can increase the TBG (Thyroxin binding globulin).
1. Oestrogens.
2. Glucocorticoids.
3 Heroin.
4. 5-Fluorouracil.
5. Methadone.
Answers
1. TRUE
2. FALSE-Decrease
3. TRUE
4. TRUE
5. TRUE

THYROID MCQS

THE FOLLOWING ARE TPO(THYROID PEROXIDASE ENZYME) INHIBITORS

1.Lithium
2.Amiodarone
3.Carbimazole
4.PTU(propylthiouracil)
5.Glucocorticoids

Answers
False-Iodide uptake inhibitor.
False-Blocks T3/T4 release from thyroid gland into circulation.
True-
True
True

1. Thyroid hormone receptors are encoded at two genomic loci, human chromosome 17 ,3.
2. Thyroid hormone resistance is seen in thyroid hormone receptor gene mutation.
3. Thyroid hormone resistance due to a gene mutation resulted in elevated fT3 and fT4 with normal or elevated TSH.
4. Aberrant TFT (thyroid function tests) in family is a clue to the diagnosis of thyroid hormone gene mutation.
5. If TSH is not suppressed in aberrant TFTs profile the diagnosis of hyperthyroidism is in doubt.

ANSWERS
1. TRUE
2. TRUE
3. TRUE
4. TRUE
5. TRUE

THYROID MCQS

1. Relative T3 to T4 excess is seen in amiodarone associated hyperthyroidism.
2. General hyperadrenergic symptoms are mediated by the actions of T3
3. In elderly the classic hyperadrenergic symptoms of hyperthyroidism may be blunted.
4. Atrial fibrillation occurs in 10-20 % of patients with untreated or partially treated hyperthyroidism.
5. Hyperthyroidism needs to be considered in and elderly patient with myopathy and weight loss.

ANSWERS
1. False-relative T4 to T3 excess thus hyperadrenergic symptoms may not be evident .
2. TRUE
3. TRUE
4. TRUE
5. TRUE

RADIONUCLIDE SCAN -THYROID GLAND
The following is/are true

1.Technetium 99 injected IV and images of thyroid obtained after 20 min.
2.The degree of radiation exposure is comparatively less than for CT abdomen and pelvis.
3. Pregnancy and breast feeding are absolute contraindications.
4.Technetium 99 mimics the behavior of iodide.
5.Avoid restaurant food before the test since there is no reasonable way to determine which one uses iodide salt.

Answers
1. TRUE.
2. TRUE-3.2 mSv and 15 msv respectively.
3. FALSE- Only pregnancy -advised to discard breast mild 24-26 hours post scan.
4. TRUE-Functional uptake scan.
5. TRUE-Need pre-preparation with avoidance of food and medications

RADIONUCLIDE SCAN -THYROID GLAND-MCQs

The following is/are true

1.Uptake of tracer is blocked if the patient has been exposed to thyroxine supplementation.
2.Is most useful in differentiating between hypothyroid conditions.
3. Painful thyroid is an absolute contraindication.
4.Homogenous radioiodine uptake is seen in Graves’ disease.
5.Absent or reduce uptake excludes hyperthyroidism.

Answers
1. TRUE.
2. FALSE-Hyperthyroid conditions.
3. FALSE- Differentials are subacute thyroiditis/Thyroid abscess
4. TRUE-
5. TRUE-A test for differentiation of Hyperthyroidism -results ranges from increased, reduced or absent uptake.

BIOTIN AND THYROID -MCQS

1. Biotin is a readily available supplement that is a part of the B-complex vitamins.
2. Biotin interferes with your thyroid medications.
3.Biotin affected thyroid function tests mirror the pattern seen in thyrotoxicosis
4.Need to stop taking biotin at least 3 days before the thyroid function tests
5. Repeat TFTs test 3 days after stop taking biotin is recommended.

Answers
1. TRUE-Can be purchased over the counter thus important to ask about supplements in medication history
2. FALSE-It affects your thyroid function tests (it is recommended to take thyroxine on an empty stomach in the morning 30 to 60 min before meals.)
3. TRUE-Elevated fT3/fT4 and suppressed TSH-(mimics Graves’ disease !)
4. TRUE-half life of biotin is 2 hours -depend on the dose its is recommended 72 hours of abstinence.
5. TRUE- Since it affects the test assay.

THYROID TREATMENT -MCQs

1. Propylthiouracil may cause fatal hepatic necrosis
2. Liver failure is less commonly associated with carbimazole/methimazole than propylthiouracil.
3. Propylthiouracil is the preferred antithyroid medication during first trimester of pregnancy.
4. Severe side effects from one medication is usually a contraindication to using other.
5. Agranulocytosis is an uncommon but serious side effect of antithyroid medications

ANSWERS
1.TRUE-especially during the first six months of treatment.
2.TRUE-both cholestatic and hepatitic pattern is seen.
3.TRUE-High risk of embryopathy with carbimazole
4. TRUE-since there is a significant cross reactivity of the two medications
5. TRUE-Uncommon but severe.

THYROID MCQS -GRAVES’ DISEASE


1. Graves disease is an organ specific autoimmune disease.
2. Characterised by the presence of Thyroid receptor antibodies (TRAb)
3. Thyroid receptor antibodies mimics the effects of TSH(thyroid stimulating hormone) and thereby exert a tropic effect on the thyroid gland
4. More common in men than women
5. Smoking is a risk factor.

Answers
1. TRUE -other examples are(Hashimotos thyroiditis,Type 1 diabetes)
2. TURE
3. TRUE-This include stimulation of follicular cell growth and activity, iodide uptake, and the synthesis of triiodothyronine (T3) and thyroxine (T4).
4. FALSE-More common in women(but hypokalaemic thyrotoxic periodic paralysis as a presentation of Graves’ disease is well recognised in Asian men)
5. TRUE-Important in history taking.

THYROTOXIC PERIODIC PARALYSIS -MCQS

1. The mechanism is thought to be due to increased tissue responsiveness to beta adrenergic stimulation by high thyroid hormone levels.
2. Characterized by depletion of total body potassium.
3. Characterized by muscle paralysis, acute hypokalaemia, and hyperthyroidism.
4. Often precipitated by a high carbohydrate meal, heavy exercise or fever
5. Treatment involves cautious potassium supplementation, beta blockade and definitive treatment of thyrotoxicosis.

ANSWERS
1. TRUE-Thus influx of potassium into cells
2. FALSE-Acute hypokalaemia without total body potassium deficit.
3. TRUE-Sudden onset of marked proximal limb muscle weakness.
4. TRUE
5. TRUE.

GRAVES’ DISEASE -MCQS

Manifestations specific to Graves’ disease include
1. Localized dermopathy
2. Ophthalmopathy
3. Thyroid acropachy
4. Hand tremors
5. Weight loss

Answers
1. TRUE-Pre- tibial myxoedema (a double misnomer as the lesions are seen in hyperthyroidism and are not limited to pretibial area, )
2. TRUE- Characterized by soft tissue swelling around the orbit, proptosis, extra-ocular muscle thickening and dysfunction, and in severe cases, blindness from optic nerve compression or significant corneal exposure.
3. TRUE-Digital clubbing(a rare manifestation )
4. FALSE.
5. FALSE.

GRAVES’ OPHTHALMOPATHY MCQS

TREATMENT OF GRAVES’ OPHTHALMOPATHY MAY INCLUDE

1. Corticosteroids
2. Orbital radiation
3. Decompressive orbital surgery
4. Immunotherapy
5. Smoking cessation

ANSWERS


1. TRUE
2. TRUE
3. TRUE
4. TRUE-Rituximab
5. TRUE-smoking leads to worsening of graves’ ophthalmopathy.

GRAVES’ DISEASE -PROGNOSIS MCQS

POOR PROGNOSTIC FACTORS INCLUDE

1. Female gender
2. Positive family history of autoimmune thyroid disease
3. Large goitre
4. Graves’ ophthalmopathy
5. High fT3 levels that are slow to settle.

Answers
1. FALSE-male gender
2. TRUE
3. TRUE
4. TRUE
5. TRUE-with severe hyperthyroidism.

THYROID SOLITARY FUNCTIONING NODULE -MCQS

1. Functioning solitary thyroid nodule can produce sufficient thyroid hormones to suppress TSH and thus suppress the remainder of the thyroid tissue
2. Likely to have a female predominance.
3. An important cause of hyperthyroidism.
4. Tc -99 Scan shows suppression of the rest of the rest of the thyroid gland.
5. Responds well to radioactive iodine and allows the rest of the thyroid gland to recover.

ANSWERS
1. TRUE-Functioning nodules are classified as hot nodules.
2. TRUE
3. TRUE
4. TRUE-functioning nodule shows a focus of Tc -99 isotope accumulation but the rest of the thyroid gland.
5. TRUE-thus allows the restoration of euthyroidism.

TOXIC MULTI NODULAR GOITRE-MCQS

1.Thyroid gland with at least 2 autonomously functioning nodules that secretes excess thyroid hormones.
2.Symptoms include dysphagia, dyspnoea dizziness and /or neck discomfort.
3.Tc -99 scan shows a homogeneous pattern.
4. Non contrast CT scan along with spirometry is useful to evaluate when there is a suspected tracheal compression.
5. Pemberton's sign is used to evaluate venous obstruction in patients with goitre


Answers
1. TRUE
2. TRUE-retrosternal goitre may cause dizziness when raising arms above the head.
3. FALSE-Heterogeneous pattern with many areas with hyperactivity and hypo-activity throughout the gland.
4. TRUE- Non contrast CT scan and inspiratory flow volume loop obtained during the spirometry manoeuvre may be helpful for functional evaluation of tracheal compromise.
5. TRUE-The sign is positive when bilateral arm elevation causes facial plethora