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Jessi is getting a haircut later, but what makes it so that your hair doesn't hurt when you go to get it cut?

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SOURCES:

http://kidshealth.org/en/kids/brain.html
http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?id=2612&np=152&p=335
https://askabiologist.asu.edu/explore/how-do-we-feel-touch
http://www.biology-pages.info/M/Mechanoreceptors.html
http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=2726
It’s that time again!

I’m getting a haircut later today. lots of people get them Sometimes people decide to cut their hair much shorter, and sometimes they just get a trim, like I am. Even Squeaks had a little trim when he got a piece of gum stuck his fur, remember, Squeaks? [Squeaks squeaks] But there’s something that all haircuts have in common: They don’t hurt!

When you think about it, it might seem kind of weird that they don’t. I mean, if you get a cut on almost any other part of your body, like your finger, it definitely hurts! But when someone cuts your hair, as long as you hold very still, it doesn’t hurt at all!

There’s also another place on our bodies that it doesn’t hurt to cut, and we do it all the time. Can you guess what it is, Squeaks? [Squeaks guesses] That’s right — our nails! The reason it doesn’t hurt to cut your hair, toenails, or fingernails is that they don’t have nerves inside them.

A nerve is a type of body part you have all over the inside of your body, kind of like how you have muscles all over. These nerves have a special job to do: they carry messages between different places in your body. Now, you have lots of body parts.

So nerves have lots of jobs. But one of the biggest jobs nerves have is to help you sense the world around you. Nerves are the reason you can see, hear, smell, taste … and yes, feel things!

Nerves are a big part of the sense of touch. Squeaks, can I touch your nose to show how this works? [Squeaks squeaks] When you touch something [taps Squeaks on the nose], it brushes up against your skin. And, like most parts of your body, your skin has nerves in it.

When something touches your skin, it activates, or kind of ‘turns on’ the nerves. These nerves can feel all kinds of different things. Some of them feel whether something is warm or cold.

Others can help us tell if something is smooth or rough. And there are also some that are in charge of sensing pain. When I tap Squeaks’ nose, some of the nerves in my finger get switched on, and each one sends a message.

Those messages travel through my hands … up my arm … through a big bundle of nerves that’s in my back … and all the way to my brain! Then, my brain decodes the messages. It checks if I’ve ever touched anything like this before, and combines that with any other information it can get, like if I can see the thing I’m feeling.

This all happens really fast, which is how I can figure out what I’m touching right away — Squeaks’ nose! [Squeaks sneezes] Oh, I’m sorry ! I guess your nose is kinda ticklish, Squeaks! So, our sense of touch takes more than just our hands.

It also takes our nerves, and our brains, too! But what about our hair? Well, try this.

Pat the top of your head. Just like the skin that’s on your fingers, the skin that’s under your hair has nerves. So your fingers can feel the top of your head, and your head can feel your fingers touching it!

Just like how Squeaks felt my finger with his nose. Now find the very end of a piece of hair and try squeezing it, without pulling on it at all. Your fingers can feel your hair, but your hair can’t feel your fingers!

That’s because there are no nerves inside your hair. And as long as you’re not pulling on your hair, or moving it around too much, you’re not going to feel a thing. The same goes for the very ends of your fingernails and toenails.

They don’t have nerves in them either. No nerves means no sense of touch, so they don’t feel anything. And if there’s no sense of touch, there’s no pain.

So the next time you get a haircut, now you’ll know why it doesn’t hurt! [Squeaks squeaks] Yikes, you’re right Squeaks — I should go if I don’t want to be late for my haircut! Thanks for joining us! If you want to keep learning and having fun with Squeaks and me, hit the subscribe button, and we’ll see you next time here at the Fort!