Approximately how fast can nerve impulses travel?

Approximately how fast can nerve impulses travel?

• A. 200 mph
• B. 20 mph
• C. 2 mph
• D. 100 mph

Answer: (A)

Nerve impulse speed depends on the fiber’s insulation and size. Large-diameter, myelinated axons transmit signals much faster because the impulse jumps between the nodes of Ranvier in a process called saltatory conduction, skipping much of the axon as it propagates. In the fastest fibers, conduction can reach around 100 meters per second or more, which is roughly 200 miles per hour. That makes about 200 mph a good approximate upper speed for nerve impulses. Slower speeds occur in unmyelinated or smaller fibers, so 2 mph or 20 mph are typical for those, while 100 mph is possible but not the upper limit.

Nerve impulse speed depends on the fiber’s insulation and size. Large-diameter, myelinated axons transmit signals much faster because the impulse jumps between the nodes of Ranvier in a process called saltatory conduction, skipping much of the axon as it propagates. In the fastest fibers, conduction can reach around 100 meters per second or more, which is roughly 200 miles per hour. That makes about 200 mph a good approximate upper speed for nerve impulses. Slower speeds occur in unmyelinated or smaller fibers, so 2 mph or 20 mph are typical for those, while 100 mph is possible but not the upper limit.