Nerve Action Potential propagation

Unreliable facts

Instructions: Select the 3/12 correct sentences

  1. Electrotonic flow of current along a neuron has the advantage of being regenerative but is slow.
  2. The propagation of an Action Potential allows for a rapid transmission of information from one point along the neuron along the neuron’s length.
  3. In Action Potential propagation, an individual AP physically transports its charge along the length of the neuron to arrive at the neuron’s terminals with amplitude intact.
  4. Unidirectional transmission of Action Potentials is ensured by the refractoriness of each part of the neuron that has just produced an AP.
  5. As a fail-safe mechanism, Action Potentials only occur when the resting membrane potential reaches the threshold for the chemically-gated ion channels to be activated by neurotransmitter inputs.
  6. An AP is regenerative in the sense that the current flowing into a neuron during an AP can spread electrotonically along to trigger another AP just-adjacent to the starting depolarization.
  7. AP regeneration reconstitutes the information of the initial AP triggering event to cause a flow of that information and also speeds it up.
  8. The conduction velocity of neural information flow is enhanced by increasing axon diameter which allows the neuron to produce a larger influx of Na+ ions and thereby produce a larger AP.
  9. The conduction velocity of neural information flow is enhanced by covering the entire axon with a myelin sheath with no interruptions in the sheath along the neuron’s length.
  10. The neurons with the fastest conduction velocity are those with large axon diameters as well as uninterrupted longer myelin sheaths.
  11. The neurons with the slowest conduction velocity have the smallest axon diameters and are also devoid of myelin sheaths.
  12. Of the factors that increase conduction velocity of neural information flow, the major factor is AP regeneration, followed by the presence of a myelin sheath, and finally the axon diameter size.