“Even when we’re resting and daydreaming, internal activity is nonstop,” writes Bob Berman in the science magazine Discover.
And a lot of that activity is happening at quite a pace. Neural signals travel between the brain and other parts of the body at a range of speeds, from a mere five kilometres an hour for pain signals (“low-priority”, says Berman) to 400 km/h – the “nerve transmission speed for essential stuff”, which tends to involve avoiding the source of pain in the first place.
Among Berman’s other bodily speed tests:
Blood flows around the body at a range of velocities, averaging about 5-6 km/h.
Lymph fluid moves at about 60mm a minute.
Food travels through the oesophagus at about 2cm a second
And the fastest sneeze ever recorded raced into the world at 164 km/h.