The fastest signals in the human nervous system run along thick, insulated nerve fibres. What speed do they reach, in metres per second?
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🫀 Human body · metres per second
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Answer
About 120 metres per second
Not every nerve is quick: the uninsulated fibres that carry dull, aching pain pass their messages along at only about 1 metre per second.
How to estimate it
This is a laboratory measurement, but daily life brackets it. A tap on your toe is felt almost instantly after travelling nearly 2 m to the brain. If the delay is under a twentieth of a second, the speed exceeds 40 m/s. Nerves are chemical, not wires, so they should be slower than sound at 340 m/s. Guess about 100. The measured top speed is about 120 metres per second.
Source: Purves et al., Neuroscience; Encyclopaedia Britannica
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