Do myelinated nerves conduct impulses faster or slower than unmyelinated nerves?

• A. Faster
• B. Slower
• C. The same
• D. They stop conduction

Answer: (A)

Myelination speeds up nerve impulse conduction through saltatory conduction. The myelin sheath acts as insulation, increasing membrane resistance and reducing membrane capacitance. This causes the depolarizing current to leak less and travel farther between the gaps called nodes of Ranvier. At each node, a cluster of voltage-gated Na+ channels re-energizes the signal, so the impulse effectively jumps from node to node rather than moving continuously along every tiny segment. That jumping dramatically accelerates transmission compared with unmyelinated fibers, where the impulse must be regenerated along every point of the membrane. So myelinated nerves conduct impulses faster.