Peripheral Nervous System And Synaptic Pharmacology 2: Nervous Conduction

26 Questions | Total Attempts: 35

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Nervous System Quizzes & Trivia

Lecture 2


Questions and Answers
  • 1. 
    Which of the following statements is correct?
    • A. 

      The Em for a RBC isn't -20mV

    • B. 

      The outside of a cell is always negative with respect to the outside

    • C. 

      The inside of a cell is always negative with respect to the outside

    • D. 

      The Em for a neuron isn't -70mV

  • 2. 
    The resting membrane potential results from...
    • A. 

      A high level of Cl- entering the cell

    • B. 

      Active transport of ions across a membrane

    • C. 

      An unequal distribution of ions across a selectively permeable membrane

    • D. 

      Electrogenicity of NaK-ATP-ase

  • 3. 
    Na+...
    • A. 

      Diffuses into the cell

    • B. 

      Diffuses out of the cell

  • 4. 
    K+...
    • A. 

      Diffuses into the cell

    • B. 

      Diffuses out of the cell

  • 5. 
    Cl-...
    • A. 

      Diffuses into the cell

    • B. 

      Diffuses out of the cell

  • 6. 
    Ca2+...
    • A. 

      Diffuses into the cell

    • B. 

      Diffuses out of the cell

  • 7. 
    In depolarization...
    • A. 

      The Vm becomes more positive than the resting potential

    • B. 

      The Vm becomes more negative than the resting potential

    • C. 

      The Vm moves back to the resting potential following depolarisation

    • D. 

      The Vm remains constant

  • 8. 
    In repolarization...
    • A. 

      The Vm becomes more positive than the resting potential

    • B. 

      The Vm becomes more negative than the resting potential

    • C. 

      The Vm moves back to the resting potential following depolarisation

    • D. 

      The Vm remains constant

  • 9. 
    In hyperpolarization...
    • A. 

      The Vm becomes more positive than the resting potential

    • B. 

      The Vm becomes more negative than the resting potential

    • C. 

      The Vm moves back to the resting potential following depolarisation

    • D. 

      The Vm remains constant

  • 10. 
    Graded potentials...
    • A. 

      Serve as short distance signals

    • B. 

      Are 'all or nothing'

    • C. 

      Serve as long distance signals

    • D. 

      Do not act in muscles (end plate potentials)

  • 11. 
    Which of the following statements is untrue?
    • A. 

      The change in voltage in a graded potential is greatest underneath a synapse

    • B. 

      The signal of a graded potential is decromental

    • C. 

      The larger the initial active area, the larger the decromental spread

    • D. 

      The signal of a graded potential is undiminishing

  • 12. 
    The first stage of generating an action potential is...
    • A. 

      At peak of action potential voltage approaches Na+ equilibrium potential

    • B. 

      Depolarization to the threshold potential activates voltage-gated Na+ channels. A positive feedback loop causes Na+ channels to further open.

    • C. 

      Rapid depolarization occurs due to Na+ moving down its concentration and electrochemical gradient. Na+ channels rapidly inactivate.

    • D. 

      Resting membrane potential; cell is permeable to K+

  • 13. 
    The second stage of generating an action potential is...
    • A. 

      At peak of action potential voltage approaches Na+ equilibrium potential

    • B. 

      Depolarization to the threshold potential activates voltage-gated Na+ channels. A positive feedback loop causes Na+ channels to further open.

    • C. 

      Rapid depolarization occurs due to Na+ moving down its concentration and electrochemical gradient. Na+ channels rapidly inactivate.

    • D. 

      Resting membrane potential; cell is permeable to K+

  • 14. 
    The third stage of generating an action potential is...
    • A. 

      At peak of action potential voltage approaches Na+ equilibrium potential

    • B. 

      Depolarization to the threshold potential activates voltage-gated Na+ channels. A positive feedback loop causes Na+ channels to further open.

    • C. 

      Rapid depolarization occurs due to Na+ moving down its concentration and electrochemical gradient. Na+ channels rapidly inactivate.

    • D. 

      Resting membrane potential; cell is permeable to K+

  • 15. 
    The fourth stage of generating an action potential is...
    • A. 

      At peak of action potential voltage approaches Na+ equilibrium potential

    • B. 

      Depolarization to the threshold potential activates voltage-gated Na+ channels. A positive feedback loop causes Na+ channels to further open.

    • C. 

      Rapid depolarization occurs due to Na+ moving down its concentration and electrochemical gradient. Na+ channels rapidly inactivate.

    • D. 

      Resting membrane potential; cell is permeable to K+

  • 16. 
    The fifth stage of generating an action potential is...
    • A. 

      Voltage gated K+ channels inactivate

    • B. 

      The NaK-ATP-ase gradually restores the ionic gradients

    • C. 

      Voltage gated K+ channels open causing repolarization

    • D. 

      Resting membrane potential is restored

  • 17. 
    The sixth stage of generating an action potential is...
    • A. 

      Voltage gated K+ channels inactivate

    • B. 

      The NaK-ATP-ase gradually restores the ionic gradients

    • C. 

      Voltage gated K+ channels open causing repolarization

    • D. 

      Resting membrane potential is restored

  • 18. 
    The seventh stage of generating an action potential is...
    • A. 

      Voltage gated K+ channels inactivate

    • B. 

      The NaK-ATP-ase gradually restores the ionic gradients

    • C. 

      Voltage gated K+ channels open causing repolarization

    • D. 

      Resting membrane potential is restored

  • 19. 
    The eighth stage of generating an action potential is...
    • A. 

      Voltage gated K+ channels inactivate

    • B. 

      The NaK-ATP-ase gradually restores the ionic gradients

    • C. 

      Voltage gated K+ channels open causing repolarization

    • D. 

      Resting membrane potential is restored

  • 20. 
    When a voltage-gated Na+ channel is closed...
    • A. 

      Its activation and inactivation gates are open

    • B. 

      Its activation and inactivation gates are closed

    • C. 

      Its activation gate is open and its inactivation gate is closed

    • D. 

      Its activation gate is closed and its inactivation gate is open

  • 21. 
    When a voltage-gated Na+ channel is open...
    • A. 

      Its activation and inactivation gates are open

    • B. 

      Its activation and inactivation gates are closed

    • C. 

      Its activation gate is open and its inactivation gate is closed

    • D. 

      Its activation gate is closed and its inactivation gate is open

  • 22. 
    When a voltage-gated Na+ channel is inactive...
    • A. 

      Its activation and inactivation gates are open

    • B. 

      Its activation and inactivation gates are closed

    • C. 

      Its activation gate is open and its inactivation gate is closed

    • D. 

      Its activation gate is closed and its inactivation gate is open

  • 23. 
    Which two of the following statements is true about absolute refractory periods?
    • A. 

      The neuron cannot be restimulated

    • B. 

      Na+ channels are inactivated

    • C. 

      Greater stimulation required to trigger acion potential

    • D. 

      K+ channels are still activated

  • 24. 
    Which two of the following statements is true about relative refractory periods?
    • A. 

      The neuron cannot be restimulated

    • B. 

      Na+ channels are inactivated

    • C. 

      Greater stimulation required to trigger acion potential

    • D. 

      K+ channels are still activated

  • 25. 
    The conduction velocity of a neuron depends on which two of the following?
    • A. 

      Neuron class

    • B. 

      Axon diameter

    • C. 

      Myelination

    • D. 

      Concentration of Na+ within the cell

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