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

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

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

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

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

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

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

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

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

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

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