Action potentials move along axons ________.
A) more slowly in axons of large than in small diameter
B) by activating the sodium-potassium "pump" at each point along the axonal membrane
C) more rapidly in myelinated than in unmyelinated axons
D) by reversing the concentration gradients for sodium and potassium ions

Question

Quizplus · Accepted Answer

Myelination allows for saltatory conduction, where action potentials jump between the nodes of Ranvier, increasing the speed of propagation along the axon. Thus, action potentials move more rapidly in myelinated than in unmyelinated axons.

Note: A is incorrect, as larger diameter axons actually conduct action potentials more rapidly. B is incorrect, as the sodium-potassium pump is not involved in generating action potentials but rather in restoring the resting membrane potential after an action potential. D is incorrect, as action potentials move along axons by opening and closing voltage-gated ion channels, not by reversing concentration gradients.

Action Potentials Move Along Axons ________