Block 13 Thyroid Parathyroid Steroid Adrenal MCQ's

21 Questions | Total Attempts: 472

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Block 13 Thyroid Parathyroid Steroid Adrenal MCQ

Review of thyroid disorders, steroids, adrenal drugs and parathyroid


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.   Rate of atrial pacemaker depolarization Expression of cardiac Na2+/exchanger Expression of cardiac b-adrenergic receptors Expression of Cardiac Na+,K+-ATPase A Increase Decrease Decrease Increase B Decrease Increase Increase Decrease C Increase Increase Decrease Decrease D Increase Increase Increase Increase E Decrease Decrease Increase Increase F Decrease Increase Decrease Increase G Increase Increase Increase Decrease
    • 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 the release of TRH and TSH?   T3 & T4 TRH TSH A Increase Increase Decrease B Decrease Increase Increase C Decrease Decrease Decrease D Increase Increase Increase E Increase Decrease Increase F Decrease Decrease Increase
    • 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. 
    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 into 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.

  • 5. 
    Which of the following statements about thyroid follicles is FALSE?
    • A. 

      They contain thyroglobulin

    • B. 

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

    • C. 

      Their lining includes parafollicular cells that release calcitonin into the colloid

    • D. 

      They are surrounded by a fenestrated capillary network

    • E. 

      They are stimulated by TSH

  • 6. 
    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

  • 7. 
    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).   I II III A Euthyroid 1˚ hypothyroidism 2˚ hypothyroidism B 1˚ hypothyroidism 2˚ hypothyroidism Euthyroid C 1˚ hypothyroidism Euthyroid 2˚ hypothyroidism D 2˚ hypothyroidism Euthyroid 1˚ hypothyroidism E 2˚ hypothyroidism 1˚ hypothyroidism Euthyroid
    • A. 

      A

    • B. 

      B

    • C. 

      C

    • D. 

      D

    • E. 

      E

  • 8. 
    Which of the following statements is characteristic of the thyroid gland?
    • 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

  • 9. 
    A routine laboratory test for cardiovascular risk factors in a normal 60-year-old man shows that his levels of both T3 and T4 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

  • 10. 
    Which of the following statements best explains the mechanism of actions of thyroid hormones?
    • A. 

      They inhibit the synthesis of Na+/K+ ATPase in cell membranes

    • B. 

      They modulate transcription of selected genes in the nucleus

    • C. 

      They inhibit assembly of selected ribosomes on the rough endoplasmic reticulum

    • D. 

      They inhibit turnover of selected lipids in the Golgi complex

    • E. 

      They activate the synthesis of lipocortin

  • 11. 
    Most of the known effects of corticosteroids are mediated by actions on which of the following molecular targets?
    • A. 

      G-protein coupled receptors

    • B. 

      Tyrosine kinase receptors

    • C. 

      Specific nucleotide sequences of the DNA

    • D. 

      Ion channel coupled receptors

    • E. 

      Specific nucleotide sequences of RNA

    • F. 

      Specific nucleotide sequences of ribosomes

  • 12. 
    Which of the following actions most likely contributes to the antiinflammatory effects of glucocorticoids?
    • A. 

      Inhibition of ACTH release

    • B. 

      Increased catabolism of prostaglandins

    • C. 

      Increased capillary permeability

    • D. 

      Increased release of interleukin-1

    • E. 

      Induction of lipocortin synthesis

  • 13. 
    Which of the following actions most likely contributes to the immunosuppressive effect of glucocorticoids ?
    • A. 

      Increased plasma levels of free fatty acids

    • B. 

      Increased gluconeogenesis

    • C. 

      Reduced production of TNF in macrophages

    • D. 

      Increased protein synthesis in the liver

    • E. 

      Decreased calcium absorption from the intestine

  • 14. 
    Which of the following statements regarding the pharmacokinetics of corticosteroids are correct? (Check all that apply)
    • A. 

      Oral bioavailability is generally very good

    • B. 

      Substantial absorption does occur through the skin

    • C. 

      They distribute into peripheral tissues but cross the blood-brain barrier with difficulty

    • D. 

      Their biological half-lives can be long (up to 72 hours)

    • E. 

      They are mainly excreted unchanged by the kidney

  • 15. 
    Which of the following are effects of glucocorticoids upon carbohydrate metabolism? (Check all that apply)
    • A. 

      Decreased gluconeogenesis in liver

    • B. 

      Increased glucose uptake by skeletal muscle

    • C. 

      Increased glycogen synthesis in liver

    • D. 

      Decreased glucose uptake by adipose tissue

    • E. 

      Increased glucose utilization in peripheral tissues

  • 16. 
    A 55-year-old man with Addison’s disease presented to the hospital complaining of episodic weakness, paresthesias, and constipation. He had been taking cortisol and fludrocortisone for several months. On admission his blood pressure was 160/98 mm Hg and an ECG showed prolongation of Q-T interval. Lab results revealed a plasma K+ level of 2.5 mEq/L. Which of the following events best explains the patient syndrome?
    • A. 

      Cortisol induced hyperglycemia

    • B. 

      Fludrocortisone excess

    • C. 

      Inadequate therapy of adrenal insufficiency

    • D. 

      Cortisol induced myopathy

    • E. 

      Essential hypertension

  • 17. 
    A 42-year-old man presented to the hospital with a complaining of weight gain, mild but continuing facial acne, and decreased muscle strength. On physical examination he was found to be a plethoric, red-faced male with violaceus pigmented striae on a protuberant abdomen and relatively thin extremities. Serum potassium levels on admission were 4.5 mEq/L. A CT scan disclosed an adrenal adenoma in the left adrenal gland and the patient was scheduled for surgery. Which of the following drugs was most likely given during and after surgery to this patient?
    • A. 

      Fludrocortisone

    • B. 

      Spironolactone

    • C. 

      Cortisol

    • D. 

      Aminoglutethimide

    • E. 

      Mifepristone

    • F. 

      Ketoconazole

  • 18. 
    In pheochromocytoma, 3-methoxy-4-hydroxymandelic acid  is formed enzymatically as a breakdown product of norepinephrine. The formation of this metabolite would be slowed down not only by inhibitors of MAO or COMT, but also by a:
    • A. 

      Glutamate decarboxylase inhibitor

    • B. 

      COX-2 inhibitor

    • C. 

      Tricyclic antidepressant

    • D. 

      Tryptophan hydroxylase inhibitor

    • E. 

      Tyrosine hydroxylase inhibitor

  • 19. 
    Of these drugs, the one best suited for the treatment of pheochromocytoma is a
    • A. 

      Glutamate decarboxylase inhibitor

    • B. 

      COX-2 inhibitor

    • C. 

      Tricyclic antidepressant

    • D. 

      Tryptophan hydroxylase inhibitor

    • E. 

      Tyrosine hydroxylase inhibitor

  • 20. 
    65 year old man presents with bone pain and is found to have increased parathyroid hormone. A SPECT scan finds all four of the parathyroid glands enlarged. Serum calcium is high and phosphate is low. Serum creatinine is normal. Which of the following is the most probable cause of this patient’s illness?
    • A. 

      Parathyroid adenoma

    • B. 

      Chronic renal failure

    • C. 

      Parathyroid carcinoma

    • D. 

      Primary hyperplasia

    • E. 

      Lung carcinoma

  • 21. 
    Thyroid hormone (T3 or T4) receptors:
    • A. 

      Bind T3 or T4 in the blood plasma, but do not enter cells.

    • B. 

      Facilitate the entry of T3 or T4 in the cell.

    • C. 

      Are integral membrane proteins that bind T3 or T4 on their extracellular domains.

    • D. 

      Bind T3 or T4 with their leucine zipper domain.

    • E. 

      Bind T3 or T4 with their ligand binding domain and function in the nucleus.

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