Which term describes rapid conduction of an action potential by jumping between nodes of Ranvier?

Which term describes rapid conduction of an action potential by jumping between nodes of Ranvier?

• A. Saltatory conduction
• B. Continuous conduction
• C. Retrograde conduction
• D. Synaptic conduction

Answer: (A)

Saltatory conduction describes rapid conduction of an action potential by jumping between nodes of Ranvier. In myelinated axons, the myelin sheath insulates the membrane and leaves gaps called nodes of Ranvier where voltage-gated Na+ channels cluster. The depolarizing current travels quickly through the insulated segments and is then regenerated at each node, so the action potential effectively “jumps” from node to node. This speeds up signal transmission compared with firing along every point of the membrane in unmyelinated fibers. Continuous conduction would be the slower wave of depolarization along unmyelinated axons. Retrograde conduction would mean the signal traveling backward, which isn’t the typical direction in normal propagation. Synaptic conduction refers to the transmission across a synapse, not along the axon itself.

Saltatory conduction describes rapid conduction of an action potential by jumping between nodes of Ranvier. In myelinated axons, the myelin sheath insulates the membrane and leaves gaps called nodes of Ranvier where voltage-gated Na+ channels cluster. The depolarizing current travels quickly through the insulated segments and is then regenerated at each node, so the action potential effectively “jumps” from node to node. This speeds up signal transmission compared with firing along every point of the membrane in unmyelinated fibers.

Continuous conduction would be the slower wave of depolarization along unmyelinated axons. Retrograde conduction would mean the signal traveling backward, which isn’t the typical direction in normal propagation. Synaptic conduction refers to the transmission across a synapse, not along the axon itself.