This is, But Why, a podcast for curious kids from Vermont Public.
I'm Jane Lindholm. On this show, we take questions from curious kids all over the world, and we find interesting people to help us answer them.
You've sent us so many amazing questions over the years, and we can see some themes in the kinds of questions you often want answers to.
A lot of you are really interested in animals, of course, but also many of you are interested in how things work, and in particular, how you work.
You want to understand your own body.
So today, we're going to tackle one crucial part of our insides, a part that helps us run and jump and stand up tall instead of being a wobbly blob on the ground.
We're going to talk about our bones.
Lots of you have sent us questions about bones, how they work, and why they sometimes break.
So we're going to start with how they work, and then we're going to talk a little bit about broken bones, why they break, and how they get fixed.
If that's something that makes you a little uncomfortable to think about, it's okay to stop listening when we get to that part.
I'll warn you when it's coming up.
For those of you ready to learn more, let's dive right in.
We're going to go under the skin, through our muscles, and right to the bone.
Hello, my name is Aubrey.
I am seven years old.
I live in North Carolina, and my question is, why do we have to have so many bones in our body?
My name is Emma. My question is, why the body made of bones?
I'm Mason. I'm from Disney City.
Why do we have bones?
Hi, my name is Cameron.
My question is, why do people have bones?
My name is Andrew. I'm five years old and I live in River, California, and my question is, why do we have bones?
Hi, my name is Stella, and I'm five and a half.
I live in Concha Hawk in Pennsylvania, and my question is, why do bones break and why do people have to have bones?
Let's tackle the why we have bones part first.
Our guest today is Melissa Raditz, a family nurse practitioner who works in the Duke Health System in North Carolina.
Melissa specializes in orthopedics.
Orthopedics is the branch of medicine that helps deal with problems in bones, muscles, joints, and tendons.
Okay, so, Melissa, why do we need bones?
Bones are how our body stands upright, and it helps us to move with our arms and our legs and our feet.
If you think about when you're working with bricks or you're playing with blocks, it's all the blocks of your body.
It's the foundation.
It's the start of everything in terms of your body moving and doing things like playing and jumping.
Yeah, they kind of give us our structure and our shape, and on this show, we've talked a lot, especially in recent episodes, about animals that have an exoskeleton, where the thing that keeps their bodies the shape that they are and strong is on the outside.
And humans and all other mammals and many other types of animals have internal skeletons, and so yeah, all of our skin and muscles sort of is formed on top of those bones, but our skeletons are on the inside, right?
Yes, so our skeletons are on the inside, and it's interesting because some of our muscles and our other tissues that aren't bone protect the bones, actually, from injury and harm.
So it is an advantage in some ways as opposed to other creatures and organisms in the ecosystem.
Hello, my name is Rosemary.
I'm five and a half.
I live in Canada. My question is, how many bones do I have?
Guess what, Rosemary?
It depends. Most adults have about 206 bones in their body.
But when you're born, you have a lot more.
Babies are born with about 270 bones.
So what happens to them?
You don't lose bones like you lose baby teeth.
As you grow up, some of your bones fuse together.
So two bones grow together into one solid bone.
By the time you're about 25 years old, your bones will be all done growing and fusing together.
My name is Joshua, and I'm five years old.
I live in Norwich, England, and my question is, how are bones made?
Hi, my name is Simone, and I'm nine years old.
I live in Waldorf, Maryland, and I want to know, what are bones made of?
Hi, my name is Luke, and I'm five years old, and I'm from Portland, Oregon.
And my question is, what are bones made out of?
Bones actually are made out of several different things.
On the inside of a bone, it is very much liquid, and that is where the bones start growing.
So it's called bone marrow, and it's the very inside of the bone.
The actual bone that we're more familiar with that is more on the outside of that inner growing area is usually white in humans.
And it is composed of calcium, which is really hard.
That's a good thing, because if it weren't, then we wouldn't be able to do all the things we do.
We'd be like a jellyfish or something.
My name is Ethan, and I live in Colorado, and I'm six years old, and I want to know how bones grow.
Hi, I am Jolene, and I'm six years old, and I live in Omaha, Nebraska.
And my question is, do bones grow?
Bones start growing before we're even born.
How do bones know when to stop growing?
There are these parts of your bone that remain soft and open as you're growing up, okay?
And so those are where you keep getting the length and some of the width of the bone, and they're called your growth plates, actually.
And so when you're younger, probably before you reach the age of being a teenager, those are still open.
The hormone system of the body, the one that you can't see, it's chemicals, that sends signals to the bones on when to stop.
And then the bone will not have any soft kind of opening like that and won't likely grow anymore unless there's some sort of a break or fracture, and the bone needs to repair itself.
My name is Darcy, and my question is, why do your bones not break when you bend your arms and legs?
Well, that's a great question, and the reason is because our body has joints.
And joints are like the connectors of the bones, and they're mobile, meaning that they can move, and they are made up of soft tissue that you can't see on an x -ray, and they're like rubber bands, but lots of rubber bands.
And kind of almost like tape, too, but very strong tape that can also kind of be a little bit more elastic.
And so that makes the bones move because the force between the bone can then allow it to rotate or bend like a hinge, like a door.
Or like when you see a ball inside of a cup, and it can move around in it.
Hi, I'm Aditya. I'm from half India and half America, and I live in Maryland.
And my question is, why does bones crack and make the sound?
Well, you're not necessarily cracking bone.
One, there could be air in the joint, and the air with cracking the knuckles or the joint can then be released.
So that might be one thing.
Bones have a shiny end to them.
It's called cartilage.
And if you look at a chicken drumstick or, you know, bone of another mammal, like we are a mammal, there's a shiny end to it.
And that's your cartilage.
And as you get older, like your grandparents age, the cartilage starts wearing down, kind of like when your shoes get old.
The surface of your shoe isn't as new anymore.
And so that surface gets rough.
And so you can hear cracking because the cartilage isn't smooth anymore.
So when your joints pop or crack, it's good to know that that doesn't mean they're breaking.
But sometimes bones do break.
Maybe some of you have experienced that.
They're hard, but they're not made out of steel.
So how does a bone break?
We'll learn all about it coming right up.
And if you don't want to think about broken bones, this is your cue to turn this episode off.
This is But Why. I'm Jane Lindholm, and today we're learning all about bones.
We're talking with Melissa Raditz, a nurse practitioner who focuses on orthopedics at Duke Health.
A lot of what Melissa deals with is people who have broken a bone.
It turns out it's really common.
The National Institutes of Health here in the United States wrote up a study that showed that in 2019, five years ago, people had 178 million broken bones.
So if you've ever broken a bone, you're in good company.
Bones break when there's a force on them, like the force of your body when you fall, that is greater than what the bone can hold.
Often you'll fall or have an accident where the bone just can't bend the way your body is moving, and it cracks.
There are different kinds of breaks.
Sometimes there's just a small crack in the bone, and sometimes the bones break into two or more distinct parts.
Now, pain is one way to know something is wrong in your body, and you should definitely tell an adult if you have a fall or you're experiencing pain.
But you still might not know if you got a bruise or pulled a muscle or broke a bone.
Melissa says that's where someone like her comes into the picture.
Typically if your bone is broken, you're moving and doing things, but you'll know if you can't move or do the things you used to before the injury happened to the bone.
You'll also know for sure if you go see somebody who works with bones at the clinic or at the hospital, and they take an x -ray of it.
And the x -ray is not scary.
It's just a tool they use to shine a light through your bones and see if there are any cracks in it that would indicate that your bone is broken.
Is that what a broken bone usually looks like?
A crack in the bone?
Yeah, it usually looks like a crack in the bone.
Sometimes if it's not severe, it could be small.
But if it's something that it was a pretty bad and painful injury or fall, then it might be pretty big.
And so sometimes we have to either put bones in a sling, it depends on which body part, or we put in a cast.
Or sometimes you wear a boot if it's on your foot or your ankle to give the bones protection in addition to the protection of your muscles and those wonderful things in your body.
Hi, my name is Kurt and I live in Nerf Bend, Washington.
And I want to know why do people need bandages when they get hurt?
We just need to make sure that the bones, especially if they're displaced, that they are in alignment so that they heal and it matches up with your other side.
Now, we also want to make sure because the bones are usually pretty strong as you have probably found out when you play and do different sports.
But when they have a break, they're a little bit more fragile and they need to be protected beyond your own body.
They need some extra reinforcement.
Hi, I'm Abby. I wonder like how do you itch under your cast because I have a broken bone.
We don't want you to put anything down the cast that could be harmful to your skin, right?
And so I wouldn't recommend just throwing anything into the cast.
We can take a hair dryer in a very cool setting and let the air just kind of go into the inside that way.
At least it moves any hair you have on that area or just can kind of make the skin feel a little bit better.
What I would suggest is if it's really bothering you, you could go back and get the cast changed.
And we do that really frequently with broken bones because as the bones grow, we often want to make sure that we're changing the cast, that it's still reinforcing things.
For example, if it gets wet, that it's still strong.
Or if it gets really dirty and smells, we don't want you to have to deal with that.
It's not a really big deal.
You don't need to worry if that's an issue.
It's not a problem.
Casts are pretty amazing.
Back when I was a kid, most people who got casts had a really thick, hard white cast that stayed on for a long time and you couldn't get it wet.
And these days there are lots of different kinds of cast materials.
Sometimes you can get them in bright colors or even two different colors.
Sometimes there are casts that you can even get wet.
It's kind of amazing how we've had this new technology that allows you to have different kinds of casts that let you live your life a little more easily than they did way back in my day.
That's true, yes. And they also have ones now that you can do through 3D printer.
It's pretty amazing.
But no, it's remarkable how much the materials have evolved and changed over the years.
And that also makes everything a little more comfortable as you're healing.
So it's a good thing.
It won't stop you from doing some of the things that you enjoy.
Sometimes you can have a bone that breaks or a couple of bones that break so badly that you need to have surgery.
And sometimes doctors will put in metal pieces to help make sure that that bone can stay straight and can heal correctly.
Yes, that's right. The bone needs maybe some more stability because the break is so big and maybe it's a little bit displaced, meaning maybe it's not at all in line anymore and it needs help getting back together so it can connect again.
So that is a time where you would need surgery.
And it's really like when you see a carpenter working on your house, they're just trying to kind of make sure everything lines up.
That's what the surgery is like.
They're just trying to make sure that everything is lining up again and that there's a support being there.
Hi, my name is Anna.
I'm eight years old.
I live in Waldorf, Maryland and I want to know how do bones heal when they break?
Hi, my name is Hannah.
I'm eight years old and I live in Baltimore, Washington.
And my question is, how do our broken bones heal?
So broken bones heal by basically having the blood carrying nutrients to the area where the bone had the break.
It's more chemicals that kind of then are added and kind of we call it a callus.
They're added to that area.
And then also if it goes all the way down to the bone marrow, the bone marrow reacts to that too and it helps to form the callus.
So it's kind of working in almost a 360 fashion.
Younger patients heal a lot more quickly when their bones break than our older patients do because they have faster cellular activity.
And so the cells divide and divide and a fracture could heal in four to six weeks.
Whereas a fracture in somebody who is your grandparents age might take eight to twelve weeks depending on their health.
Melissa, you mentioned that kids bones are generally pretty strong and they often heal faster because they have all of this great growth already happening.
So why do kids seem to break so many bones?
Kids tend to break more bones for a couple different reasons.
One being that quite simply kids are a lot more active typically than adults are or grandparents and they're doing a lot more dynamic activity in terms of running and jumping and high impact, high force activities.
So just by the nature of what you all get excited about and want to do, it's a little bit more risky for bones breaking than maybe what your parents or your grandparents might be interested in.
Have you ever broken a bone?
I've had probably at least five times broken bone.
I had a broken bone when I was younger.
I was running when I was about probably seven or eight and I slipped on ice and I fell on an outstretched arm.
We call it a foosh.
A foosh, I like that.
I didn't know that word.
And that means that you fell on an outstretched arm and you probably have a fracture of one of the bones in your forearm.
A foosh. Wow. So if you fall on an outstretched arm and have a fracture in one of those arm bones, that's called a foosh.
I've never heard that word.
I really like it. Although I wouldn't like to have it.
Melissa wanted to remind us that even though broken bones are pretty common, there are ways to protect yourself.
Of course, one way is to be careful and to know your limits if you're doing fun things like skiing or biking.
But accidents happen.
We can't prevent all of them.
So the best way to protect yourself is to make sure your bones stay healthy and grow really strong.
And that means eating a well -balanced diet with fruits and vegetables and protein, and of course getting enough sleep and rest.
Thanks to Melissa Raditz for chatting with us about bones and helping us better understand our own internal structure.
That's it for today.
If you have a question about anything, you can send it to us.
Have an adult help you record yourself asking your question and make sure to include your name, how old you are, and where you live.
Then your adult can send the file to questions at but why kids dot org.
If talking is hard or impossible for you or you just don't like to have your voice on, you can always have an adult just send us an email with that information as well.
Our show is produced by Melody Baudette, Kiana Niffen, and me, Jane Lindholm at Vermont Public and distributed by PRX.
Joey Palumbo works on our YouTube and video series, and Luke Reynolds wrote our theme music.
We'll be back in two weeks with an all -new episode.
Until then, stay curious.
