1. Propagation of an Action Potential
Clicker Questions
Prepared by
Nora Hebert
Red Rocks Community College

3. The influx of sodium ions in one segment of an unmyelinated axon initiates which of the following events?
a. an action potential in that segment
b. a depolarizing current that brings the adjacent segment to threshold
c. a repolarizing current that brings the adjacent segment to threshold
d. all of the above
e. a and b
Answer: e. a and b

4. The influx of sodium ions in one segment of an unmyelinated axon initiates which of the following events?
a. an action potential in that segment
b. a depolarizing current that brings the adjacent segment to threshold
c. a repolarizing current that brings the adjacent segment to threshold
d. all of the above
e. a and b

6. The lighting effect, indicated by an arrow, in the previous slide denotes ________.
a. an action potential
b. a depolarizing current
c. the refractory period
Answer: a. an action potential

7. The lighting effect, indicated by an arrow, in the previous slide denotes ________.
a. an action potential
b. a depolarizing current
c. the refractory period

9. The refractory period occurs when ________.
a. voltage-gated sodium channels are open and potassium channels are closed
b. voltage-gated sodium channels are inactivated and potassium channels are open
Answer: b. voltage-gated sodium channels are inactivated and potassium channels are open

10. The refractory period occurs when ________.
a. voltage-gated sodium channels are open and potassium channels are closed
b. voltage-gated sodium channels are inactivated and potassium channels are open

12. Action potential propagation in myelinated axons is known as ________.
a. continuous conduction
b. gradual conduction
c. constant conduction
d. spontaneous conduction
e. saltatory conduction
Answer: e. saltatory conduction

13. Action potential propagation in myelinated axons is known as ________.
a. continuous conduction
b. gradual conduction
c. constant conduction
d. spontaneous conduction
e. saltatory conduction

15. In myelinated axons, action potential occurs ________ and they propagate ________.
a. in myelinated segments; slowly
b. in myelinated segments; rapidly
c. at nodes of Ranvier; slowly
d. at nodes of Ranvier; rapidly
e. in myelinated and unmyelinated segments; rapidly
Answer: d. at nodes of Ranvier; rapidly

16. In myelinated axons, action potential occurs ________ and they propagate ________.
a. in myelinated segments; slowly
b. in myelinated segments; rapidly
c. at nodes of Ranvier; slowly
d. at nodes of Ranvier; rapidly
e. in myelinated and unmyelinated segments; rapidly