Which statement about signal conduction in the nervous system is true?

• A. Information is conducted along axons as action potentials
• B. Information diffuses passively through brain tissue
• C. Signals travel only via chemical diffusion between neurons
• D. Neurons do not transmit electrical signals

Answer: (A)

Signal conduction in the nervous system relies on electrical impulses called action potentials that travel along axons. These all-or-none spikes are generated by voltage-gated ion channels and propagate along the neuron to reach synapses, delivering information to other neurons. The speed and reliability of this signaling are enhanced by myelin and axon diameter, which is why the nervous system can communicate quickly over long distances. Diffusion of signals through brain tissue would be far too slow and imprecise to support rapid communication. While neurotransmitters at synapses mediate the next step of signaling, they rely on the preceding action potential to trigger release. Neurons do transmit electrical signals, so the statement that they do not is incorrect.