Block 5 Endo Thyroid Gland MCQ's

22 Questions | Total Attempts: 1135

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Block 5 Endo Thyroid Gland MCQ

Questions and Answers
  • 1. 
    Thyroid hormones can increase cardiac output.  From the following table, pick the row that correctly lists the mechanisms by which T3 increases cardiac output.  
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

    • F. 

      F

    • G. 

      G

  • 2. 
    What is the correct relationship between changes in plasma levels of T3 & T4 and release of TRH and TSH?
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

    • F. 

      F

  • 3. 
    A patient presents with signs of hypothyroidism. To investigate the matter, you measure the levels of T4 and TSH. If the patient suffers from iodine deficiency,  you can expect the following results:
    • A. 

      T4 reduced, TSH reduced

    • B. 

      T4 elevated, TSH reduced

    • C. 

      T4 elevated, TSH elevated

    • D. 

      T4 reduced, TSH elevated

    • E. 

      T4 reduced, TSH normal

  • 4. 
    What is the unique feature of the antibody produced in Graves' disease that stimulates growth of the thyroid gland?
    • A. 

      Enhanced secretion of thyroid stimulating hormone (TSH).

    • B. 

      Suppression of TSH secretion

    • C. 

      Enhanced secretion of adrenocorticotropic hormone (ACTH).

    • D. 

      Blockade of the TSH receptor on thyroid follicular cells.

    • E. 

      DON’T KNOW THE ANSWER TO THIS QUESTION…..

  • 5. 
    A patient presents with signs of hyperthyroidism (thyrotoxicosis).  To investigate the matter, you measure the levels of T4 and TSH. If the patient has a benign thyroid adenoma ("toxic nodule"), you can expect the following results:
    • A. 

      T4 reduced, TSH reduced

    • B. 

      T4 elevated, TSH reduced

    • C. 

      T4 elevated, TSH elevated

    • D. 

      T4 reduced, TSH elevated

    • E. 

      T4 reduced, TSH normal

  • 6. 
    The concept map below can be used as a basic algorithm for the determination of thyroid dysfunction. In the following table, pick the correct association of I, II, and III with conditions of euthyroidism,  primary hypothyroidism  (1° hypothyroidism),  and secondary hypothyroidism (2° hypothyroidism).
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

  • 7. 
    Which of the following statements regarding thyroid hormone synthesis is correct?
    • A. 

      In the thyroid gland, iodine is oxidized by type II deiodinase

    • B. 

      Thyroid peroxidase catalyzes the coupling of two DITs to form T4.

    • C. 

      Transport of iodide in to the thyroid gland is facilitated by anions such as perchlorate.

    • D. 

      Plasma iodide is transported into the thyroid by facilitated diffusion.

    • E. 

      Proteolysis of iodinated thyroglobulin is inhibited by TSH.

  • 8. 
    The most common cause of Hashimoto's thyroiditis is
    • A. 

      Therapeutic radiation

    • B. 

      Thyroid resection

    • C. 

      Hypopituitarism

    • D. 

      Autoimmune destruction

    • E. 

      Polyglandular failure syndrome.

  • 9. 
    In Grave's disease, enlargement of the thyroid gland is caused by
    • A. 

      Constitutive activation of the Gs-protein as a result of a somatic mutation

    • B. 

      An antibody that stimulates TSH receptors

    • C. 

      Abnormally elevated TSH levels

    • D. 

      A transport defect for iodine in the membrane of the follicular cell

    • E. 

      Reduced feedback inhibition of the thyrotrophs in the pituitary gland

  • 10. 
    You are working in a Medicins Sans Frontieres clinic in a mountainous region in the South Eastern part of Africa. A 50 year-old female comes to see you complaining of tiredness and a constant feeling of being cold. Despite no change in her dietary habits she and a constant you has gained weight and also suffers frequent muscle cramps. On physical examination, you notice that her skin is dry, and you detect moderate enlargement of the thyroid gland. You measure her pulse and find that it is 52 beats per minute at rest. Her blood pressure is 101/65mmHg. You send a blood sample to Cape Town. The results of these blood tests reveal that serum TSH is elevated, T3 andT4 levels marginally below normal. The patient's serum is negative for TSH receptor antibodies but positive for thyroid antibodies. This patient's symptoms are most likely to be ameliorated by administration of: .
    • A. 

      Thyroid stimulating hormone (TSH)

    • B. 

      Dietary iodine supplementation

    • C. 

      Thyroxine

    • D. 

      TSH receptor antibodies

    • E. 

      TRH

  • 11. 
    Which of the following statements about thyroid follicles is FALSE?
    • A. 

      They contain thyroglobulin

    • B. 

      They are line by epithelial cells that vary in appearance with the activity of the gland

    • C. 

      Their lining includes Para follicular cells that release calcitonin into the colloid

    • D. 

      They are surrounded by a fenestrated capillary network

    • E. 

      They are stimulated by TSH

  • 12. 
    Which of the following statements is characteristic of the thyroid gland? pharyngeal pouch
    • A. 

      It is derived from the 3rd pharyngeal pouch

    • B. 

      It secretes parathyroid hormone

    • C. 

      Chief cells are involved in the production of calcitonin

    • D. 

      Colloid is primarily composed of calcitonin and T3

    • E. 

      Thyroid follicular cells secrete T4 hormone

  • 13. 
    A 55-year-old woman with thyrotoxicosis was treated with radioactive iodine. One month later, she had elevated TSH levels. Which of the following drugs was she most likely prescribed at this point in time?   
    • A. 

      Potassium iodide

    • B. 

      Levothyroxine

    • C. 

      Diiodotyrosine

    • D. 

      Monoiodotyrosine

    • E. 

      Reverse triiodothyronine

  • 14. 
    Few days after a normal delivery, a new born baby boy became lethargic, had respiratory difficulties, hoarse cry, and sucks poorly. Physical examination revealed large fontanelles, macroglossia, a distended abdomen, a cyanotic skin, hypotonia, slow reflexes and hypothermia. Which of the following drugs would be appropriate for this baby?
    • A. 

      Methimazole

    • B. 

      Somatrem

    • C. 

      Levothyroxine

    • D. 

      Theophylline

    • E. 

      Potassium iodide

    • F. 

      Prednisone

  • 15. 
    A 75-year-old woman came to the clinic for her regular checkup. Her only complaints included very dry skin and constipation which she treats with milk of magnesia. She had no other medical problems and took no other medications. Routine laboratory tests are within normal limits except for a TSH of 15 mIU/mL (normal0.5-5.5). Further lab exams indicated the presence of thyroid peroxidase antibodies. Which of the following drug would be appropriate for this patient?
    • A. 

      Potassium iodide

    • B. 

      Propranolol

    • C. 

      Methimazole

    • D. 

      Loperamide

    • E. 

      Levothyroxine

    • F. 

      Diltiazem

  • 16. 
    A routine laboratory test for cardiovascular risk factors in a normal 60-year-old man shows that his levels of both T3 andT4 are only about 20% of normal. TSH is in the normal range, and the thyroid gland is of normal size without palpable masses. There are no clinical signs of abnormal thyroid function.  Which of the following proteins is most likely deficient in this patient?
    • A. 

      The TSH receptor

    • B. 

      The T3 receptor

    • C. 

      Thyroxin-binding globulin in the blood

    • D. 

      Thyroglobulin in the thyroid gland

    • E. 

      Pendrin

  • 17. 
    Which of the following drugs can block most effectively the conversion of T4 to T3 by the liver?
    • A. 

      Levothyroxine

    • B. 

      Diiodotyrosine

    • C. 

      TSH

    • D. 

      Propylthiouracil

  • 18. 
    Iodine deficiency used to be a common cause of thyroid enlargement (goiter) in some parts of the world. Which abnormality in chronically iodine-deficient patients is most directly related to the enlargement of the thyroid gland?  
    • A. 

      Reduced activity of thyroperoxidase

    • B. 

      Impaired conversion of T4to T3

    • C. 

      Reduced level of cAMP in the thyroid follicular cells

    • D. 

      An antibody that binds to the TSH receptor in the thyroid gland

    • E. 

      Elevated TSH level

  • 19. 
    A 28-year-old woman with hypothyroidism has missed her menstrual period this month. Pregnancy test is positive. She has been on levothyroxine for one year. Which of the following modification in her therapy is required for the normal development of the fetus and to control her symptoms?
    • A. 

      Increase levothyroxine dose

    • B. 

      Substitute levothyroxine dose with triiodothyronine

    • C. 

      Decrease levothyroxine dose

    • D. 

      Stop therapy with levothyroxine

  • 20. 
    A 37-year-old who presented with symptoms of hyperthyroidism was diagnosed with Grave's disease. He was started on propylthiouracil and propranolol. Which of  the following is a serious toxicity that can occur, though rarely, in patients taking propylthiouracil?
    • A. 

      Myopathy

    • B. 

      Cardiac arrhythmias

    • C. 

      Agranulocytosis

    • D. 

      Dry mouth

    • E. 

      Weight loss

  • 21. 
    Which of the following describes the effect of high dose of iodides on thyroid gland?
    • A. 

      It blocks the release of THS from pituitary gland

    • B. 

      It inhibits thyroid hormone release from follicular cells

    • C. 

      It increases the vascularity of thyroid gland

    • D. 

      It causes necrosis of thyroid follicular cells

  • 22. 
    Which of the following drugs is most appropriate to be used for replacement therapy in a hypothyroid patient?
    • A. 

      Propranolol

    • B. 

      Levothyroxine

    • C. 

      Triiodothyronine

    • D. 

      Propylthiouracil

    • E. 

      Lithium

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