Block 5 Endo Hormone Synth MCQ's

13 Questions | Total Attempts: 634

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Block 5 Endo Hormone Synth MCQ

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Questions and Answers
  • 1. 
    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. 

      T4reduced, TSH normal

  • 2. 
    This structure is:  
    • A. 

      An estrogen

    • B. 

      An androgen

    • C. 

      A glucocorticoid

    • D. 

      A mineralocorticoid

    • E. 

      Progesterone

  • 3. 
    An elderly patient who takes aspirin for chronic arthritis complains about frequent pain in the stomach that can be relieved only by eating. One possible solution to the patient's problem is to
    • A. 

      Raise the aspirin dose to reduce the stomach pain

    • B. 

      Switch to a drug that has higher potency on COX-1relative to COX-2

    • C. 

      Switch to a drug that has higher potency on COX-2 relative to COX-1

    • D. 

      Use a selective inhibitor of prostaglandin E synthesis

    • E. 

      Use aspirin in combination with a converting enzyme inhibitor

  • 4. 
    During the synthesis of steroid hormones, side chain cleavage reactions occur in two biotransformations. These are:
    • A. 

      Glucocorticoids ---> mineralocorticoids and progestins --> androgens

    • B. 

      Progestins --> corticosteroids and androgens --> estrogens

    • C. 

      Cholesterol --> progestins and estrogens --> androgens

    • D. 

      Cholesterol --> progestins and progestins --> androgens

    • E. 

      Androgens --> corticosteroids and androgens--> estrogens

  • 5. 
    Thromboxane is formed in platelets, where it promotes platelet activation. The formation of thromboxane can be suppressed by inhibitors of:
    • A. 

      2l-hydroxylase

    • B. 

      COX-2

    • C. 

      5-lipoxygenase

    • D. 

      Desmolase

    • E. 

      COX-I

  • 6. 
    For a “classical" radioimmunoassay of insulin, you need
    • A. 

      Radiolabeled insulin receptor

    • B. 

      Radioactive insulin in the test tube

    • C. 

      Injection of radioactive insulin in the patient

    • D. 

      A radioactive antibody

    • E. 

      Two-dimensional electrophoresis

  • 7. 
    The antihypertensive drug captopril acts as an inhibitor of angiotensin converting enzyme. In addition to reducing the formation of angiotensin II, captopril will also reduce the level of circulating
    • A. 

      Cortisol

    • B. 

      Bradykinin

    • C. 

      Thromboxane

    • D. 

      Aldosterone

    • E. 

      Insulin

  • 8. 
    The nurse notices that a newborn girl has an unusually enlarged clitoris, and asks you whether this might be a disorder of sexual development. You notice that in addition to the large clitoris the labia are partially fused. Some tests are done. The hospital lab reports normal values for serum sodium, potassium and ACTH. An ultrasound scan shows normal sized adrenal glands. A buccal smear is sex chromatin negative (no Barr body). If this child has an enzyme deficiency, the missing enzyme is most Iikely
    • A. 

      Desmolase

    • B. 

      21-hydroxylase

    • C. 

      11-hydroxylase

    • D. 

      Aromatase

    • E. 

      5a-reductase

  • 9. 
    After several attacks of autoimmune thyroiditis, Mrs. O. has developed signs of hypothyroidism. Her hormone measurements will most likely show:
    • A. 

      HighT4, high TSH

    • B. 

      HighT4, low TSH

    • C. 

      Low T4, low TSH

    • D. 

      Low T4, high TSH

    • E. 

      Low T4, normal TSH

  • 10. 
    The hydroxylation reactions of steroid hormones in the endocrine glands require cytochromeP450, NADPH and
    • A. 

      Tetrahydrobiopterin

    • B. 

      Pyridoxal phosphate(vitamin B6)

    • C. 

      S-adenosyl-methionine

    • D. 

      Molecular oxygen

    • E. 

      Biotin

  • 11. 
    Insulin is synthesized from a larger precursor protein. The following events occur during insulin synthesis: (1) Formation of disulfide bonds; (2) Secretion by exocytosis; (3) Removal of the signal sequence (4) Removal of the C-peptide, In which sequence are these events most likely to occur?
    • A. 

      1--> 3 -->4 --> 2

    • B. 

      3 --> 2--> 1--> 4

    • C. 

      3 --> 1 --> 4 --> 2

    • D. 

      4 --> 3 --> 2 -->1

    • E. 

      4 --> 3 --> 1 --> 2

  • 12. 
    Selective COX-2 inhibitors have been developed, but they should be used with caution because they can increase the risk of
    • A. 

      Venous thrombosis

    • B. 

      Psychosis

    • C. 

      Gastric ulcer

    • D. 

      Acute myocardial infarction

    • E. 

      Inflammation

  • 13. 
    Low doses of aspirin are used to reduce the risk of acute myocardial infarction. Which enzyme is targeted when aspirin is used for this purpose?
    • A. 

      5-lipoxygenase

    • B. 

      12-lipoxygenase

    • C. 

      COX-1

    • D. 

      COX-2

    • E. 

      COX-3

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