Which structure does an action potential travel along?

Which structure does an action potential travel along?

• A. Dendrite
• B. Cell body
• C. Axon
• D. Nucleus

Answer: (C)

The action potential travels along the axon. The axon is the long, specialized conduit that transmits electrical signals away from the cell body to synaptic terminals. When a neuron fires, depolarization at the axon initial segment reaches threshold and an all-or-none spike is generated that propagates along the length of the axon as voltage-gated channels open sequentially. In myelinated fibers, this propagation speeds up through saltatory conduction, with the impulse leaping between gaps called nodes of Ranvier. Dendrites and the cell body are primarily for receiving and integrating inputs; they experience local, graded potentials that diminish with distance and generally do not support reliable long-distance propagation like the axon does. The nucleus houses genetic material and does not participate in electrical signaling.

The action potential travels along the axon. The axon is the long, specialized conduit that transmits electrical signals away from the cell body to synaptic terminals. When a neuron fires, depolarization at the axon initial segment reaches threshold and an all-or-none spike is generated that propagates along the length of the axon as voltage-gated channels open sequentially. In myelinated fibers, this propagation speeds up through saltatory conduction, with the impulse leaping between gaps called nodes of Ranvier.

Dendrites and the cell body are primarily for receiving and integrating inputs; they experience local, graded potentials that diminish with distance and generally do not support reliable long-distance propagation like the axon does. The nucleus houses genetic material and does not participate in electrical signaling.