What is the neural impulse traveling down an axon called?

• A. Dendrite
• B. Axon
• C. Action Potential
• D. Metacognition

Answer: (C)

Action potentials are the electrical signals that travel along a neuron’s axon. They start when the neuron is stimulated enough to reach threshold, opening voltage-gated sodium channels and letting Na+ rush in. This depolarizes the membrane, making the inside briefly more positive. The signal then triggers potassium channels to open, letting K+ out and restoring the resting state. This sequence propagates along the axon, regenerating the impulse at each point. In myelinated fibers, the impulse speeds up by jumping between nodes of Ranvier. Dendrites receive signals, the axon carries the impulse away, and metacognition has to do with thinking about thinking, not neural signaling.