Lecture 5 MCQ

Which of the following is a circulating form of thyroid hormone?

T3
TGL-T3
T4 (correct)
TGL-T4

What is the functional sensitivity of a TSH assay?

The ability of TSH to regulate thyroid hormone synthesis
The ability to measure TSH levels accurately
The ratio of TSH to thyroid hormone concentrations
The lowest concentration of TSH that can be measured with a given assay (correct)

Why should thyroid function testing be avoided in the critically ill?

Thyroid function tests can be influenced by non-equilibrium states and drugs (correct)
Thyroid function is not affected by critical illness
Thyroid function tests are not accurate in critically ill patients
Thyroid function tests are unnecessary in critically ill patients

Which test is useful if a radioactive iodine uptake scan is not possible?

TSH Receptor Antibodies (C) Signup and view all the answers

Which antibodies are assayed to check for interference in the assay for Thyroglobulin?

Antithyroglobulin antibodies (A) Signup and view all the answers

Which drug inhibits iodine uptake and thyroid hormone release?

Amiodarone (C) Signup and view all the answers

What is the functional sensitivity of the TSH assay?

0.004 mU/L (B) Signup and view all the answers

Which of the following is true about the levels of T4 and T3 in the body?

Approximately 99% of T4 and T3 are bound to transport proteins. (A) Signup and view all the answers

Which of the following is the predominant secretory product in the body?

T4 (B) Signup and view all the answers

Which of the following is true about the biological activity of T3?

T3 has greater biological activity compared to T4. (C) Signup and view all the answers

Which of the following is true about the regulation of T4 and T3 secretion?

TSH stimulates T4 and T3 secretion. (A) Signup and view all the answers

Which of the following is a symptom of thyroid storm?

Tachycardia (D) Signup and view all the answers

What is the most likely disease in Case Example 1?

Hashimoto's (D) Signup and view all the answers

What type of disorder is present in Case Example 2?

Primary hyperthyroidism (A) Signup and view all the answers

What will happen to TSH levels once T4 returns to normal in Case Example 2?

TSH will remain low (C) Signup and view all the answers

Which of the following is a biochemical definition of subclinical hyperthyroidism?

Normal T4 & T3 and suppressed TSH (D) Signup and view all the answers

Which of the following is a risk associated with subclinical hypothyroidism?

General well-being, depressive illnesses (A) Signup and view all the answers

What is the primary cause of primary hyperthyroidism?

Autonomous TSH secretion (D) Signup and view all the answers

What is the recommended monitoring parameter for therapeutic efficacy in the long term for hyperthyroidism?

TSH levels (C) Signup and view all the answers

Which of the following is NOT a clinical feature of hyperthyroidism?

Weight gain (A) Signup and view all the answers

Which of the following is a primary cause of hyperthyroidism?

Graves Disease (D) Signup and view all the answers

Which of the following is NOT a cause of hypothyroidism?

Toxic adenoma (D) Signup and view all the answers

Which of the following is a treatment option for hyperthyroidism?

All of the above (D) Signup and view all the answers

Which of the following is a possible interference in the Roche fT4 assay and its effect on the result?

High dose of biotin, which can cause streptavidin antibodies to form, leading to blocking or negatively interfering heterophilic antibodies (D) Signup and view all the answers

Which of the following drugs can increase Thyroid Binding Globulin (TBG) levels?

Oestrogens, methadone, heroin, tranquilisers, clofibrate, 5-fluorouracil (D) Signup and view all the answers

Which of the following is a method used to measure Total T4 levels?

Measure total T4 and measure binding protein levels to express results as an index (C) Signup and view all the answers

Which of the following is a possible effect of drugs that decrease Thyroid Binding Globulin (TBG) levels?

Decreased total T4 levels (C) Signup and view all the answers