Neurophysiology: Conduction Mechanisms

Which type of conduction involves step by step depolarization and repolarization of the plasma membrane?

What characteristic of myelinated axons allows for faster action potential propagation?

Which condition is likely to decrease the speed of action potential propagation in axons?

What area of myelinated axons has a high density of voltage-gated channels?

What factor contributes to faster propagation of action potentials along axons?

How do larger diameter axons affect the propagation of action potentials?

What mechanism primarily carries current along myelinated axons?

Which statement is true about continuous conduction?

Continuous Conduction

Involves step-by-step depolarization and repolarization of each adjacent segment of the plasma membrane.
Occurs in unmyelinated axons and muscle fibers.
Ions flow through voltage-gated channels in each segment of the membrane.
Action potentials propagate a short distance in a few milliseconds.

Saltatory Conduction

Special mode of action potential propagation along myelinated axons.
Occurs due to the uneven distribution of voltage-gated channels.
Few voltage-gated channels are present in myelinated regions.
Many voltage-gated channels are located at the nodes of Ranvier, where there is no myelin sheath.
Current flow across the membrane mainly happens at the nodes.
Action potential at one node generates ionic currents that open voltage-gated sodium channels at the next node.
This process repeats, leading to the propagation of the action potential.

Factors Affecting Propagation Speed

Myelination: Myelinated axons propagate action potentials faster than unmyelinated axons.
Axon Diameter: Larger-diameter axons propagate action potentials faster than smaller ones.
Temperature: Axons propagate action potentials at lower speeds when cooled.

Explore the mechanisms of continuous and saltatory conduction in neurons and muscle fibers. This quiz covers the differences between conduction types, their physiological significance, and factors affecting propagation speed. Test your knowledge on action potentials and membrane dynamics!