nervous system

You hear a buzz, and swat at a mosquito. In that fraction of a second, a series of messages just traveled along your nervous system! First, signals raced from your ear to your brain, where you processed the sound and determined a mosquito was nearby. Then your brain sent messages along the nervous system to the muscles in your arm and hand—and the pesky insect is history!

Image credits: main image, © AMNH/E.Hamilton.