Question

An action potential traveling along an axon

• A. moves rapidly in both directions.
• B. moves faster than a neurotransmitter
• C. is slowed by myelin.
• D. travels through the blood.

Answer 1

The correct option is B

moves faster than a neurotransmitter

The correct option is B

Explanation of the correct option:

1. An action potential moves along a myelinated axon by saltatory propagation, which is faster and uses less energy.
2. Saltatory conduction is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.
3. Hence, an action potential traveling along an axon moves faster than a neurotransmitter.

Explanation of the incorrect options:

Option A

Action potentials are usually propagated in only one direction along an axon because a brief refractory period prevents depolarization from occurring in the direction from which the impulse came.

Option C

An action potential traveling along an axon does not slow down by myelin.

Option D

An action potential travels along an axon of a neuron, not through the blood.

Final answer: An action potential traveling along the axon moves faster than a neurotransmitter.