Dr Gawad Course Online Exam - Excitable - Lec 2 (Action Potential, Compound Action Potential, All Or None Rule)

9 Questions | Total Attempts: 196

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Dr Gawad Course Online Exam - Excitable - Lec 2 (Action Potential, Compound Action Potential, All Or None Rule)

9 MCQs (Only one correct answer)Each MCQ: 1 mark, Total mark: 9Allowed time: 10 minGood Luck


Questions and Answers
  • 1. 
    The main cause of depolarization of nerve is:
    • A. 

      K outflux

    • B. 

      Na influx

    • C. 

      Cl outflux

    • D. 

      None of the above

  • 2. 
    At stage of complete depolarization of action potential of the curve
    • A. 

      K out flux is the major change

    • B. 

      Na out flux is the major change

    • C. 

      The potential difference between outer and inner surface is Zero

    • D. 

      Na-K pump is acting with full capacity

  • 3. 
    Reversal of polarity, which is true:
    • A. 

      Outer membrane is more negative than inner membrane.

    • B. 

      Action potenial is – 50 mv

    • C. 

      Potential magnitude is + 35 mv

    • D. 

      None of the above

  • 4. 
    Repolarization of nerve coincides with:
    • A. 

      Influx of Na

    • B. 

      Out flux of K

    • C. 

      Out flux of Cl

    • D. 

      Impermeability of the membrane to protein

  • 5. 
    Ascending limb of nerve action potential is due to Na movement through
    • A. 

      Leak channels

    • B. 

      Ligand gated channels

    • C. 

      Voltage gated channels

    • D. 

      None of the above

  • 6. 
    Which of the following is a representation of hypopolarized state:
    • A. 

      Stage of rapid depolarization

    • B. 

      After depolarization

    • C. 

      After hyperpolarization

    • D. 

      All after potential stages

  • 7. 
    Which of the following is false regarding compound action potential:
    • A. 

      The largest the diameter the fastest velocity conduction

    • B. 

      Myleinated (medullated) nerves are faster than non myleinated

    • C. 

      The larger the diameter the longer the duration of the spike

    • D. 

      - the larger the diameter the bigger the magnitude of action potential

  • 8. 
    Which of the following is not applying all or none rule:
    • A. 

      Single nerve fiber

    • B. 

      Single nerve fiber of mixed nerve

    • C. 

      Whole skeletal muscle

    • D. 

      Cardiac muscle

  • 9. 
    The main cause of after hyperpolarization is
    • A. 

      Delayed Na channel closure

    • B. 

      Massive inward movement of Cl ions

    • C. 

      Delayed voltage K channels closure

    • D. 

      Na-K pump activation

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