How does my hand tell my brain what it touches?

Close your eyes and rub your fingers over your blanket. Without peeking, you can tell it is soft and fuzzy. How does your hand tell your brain what it touches?

Your hand sits at the end of your arm, and your brain sits up inside your head. They are quite far apart, so the news about the soft blanket has a long way to travel.

Your skin is full of touch spots, far too small to see. Different spots notice different touches, like a gentle press or a tickle. They are there so your body can feel the world around it.

When the blanket presses on your fingertip, the touch spots there send out signals, which means quick little messages saying something is touching. Each signal starts right at the tip of your finger. How do you think a message gets from your fingertip all the way to your head?

It travels along your nerves, which are thin threads that carry messages through your body. Nerves run from every fingertip up through your hand and arm, like long strings. They are there to carry signals, one after another.

Up near your neck, the nerves from your arm join a thick bundle of nerves inside your backbone. That bundle carries the signals up to your brain. The whole trip takes less time than a blink!

Your brain gets signals from many touch spots at once. It checks which spots sent them, so it knows the touch is on your fingertip and not on your toe.

Next, it checks what kind of signals arrive. A soft blanket sends smooth, even signals, while a bumpy pebble sends signals that jump and change as your finger slides. From all of this, your brain works out what you are touching: a soft blanket!

Two words helped us today: signals and nerves. Touch spots in your skin send signals along your nerves to your brain, and your brain works out what your hand is touching.

Sleep well, and let your hands rest softly on your cozy blanket tonight.