Believe it or not, there’s something a lot like this inside of you and inside me, too!
It’s a skeleton!
You may have seen skeletons in a museum -- like the ones they have of dinosaurs -- or maybe
plastic models of human skeletons, like this.
Maybe you’ve even seen dancing skeletons around Halloween.
But do you know how important, and cool, and powerful your skeleton really is?
Let’s get to know your bones -- from how they help you move, to the different
kinds of bones you have, and even a super special job they have to do!
Let’s get started!
One of a skeleton’s super important jobs is, of course, to hold your body up!
Your muscles are strong, but they need a frame, something to hold on to. Without a skeleton,
you’d be all loosey goosey, and you wouldn’t be shaped like …you!
And it goes both ways! Without your muscles, your skeleton would just be a pile of bones.
It’s only by squeezing and relaxing your muscles that you’re able to move your bones
around.
So that silly dancing Halloween skeleton? It’s just pretend -- because it doesn’t
have muscles!
So, your bones are hard enough to hold the weight of the rest of your body.
But they’re also hard enough to act like a protective shield around your soft, squishy
organs.
Your ribs, for example, are bones that protect your lungs and heart so that even when you
get a great big bear hug, your insides don’t get squeezed too!
And speaking of strong--the strongest bone in your body is also the biggest, the longest
and the heaviest one you have.
It’s the bone that goes from your hip to your knee, called the femur!
And that bone has to be big and strong -- because when you run, jump, walk, or even just stand
still, a lot of the weight of your body falls on the femur.
Now, where do you think your smallest bone might be?
The very smallest bone you have is actually in your ear.
This little bone, called the stapes, looks kind of like a stirrup. Even in adults,
it’s only about the size of a grain of rice.
But this tiny bone has a big job. When sounds enter your ear, they make this little bone
move back and forth. Those vibrations are what your ears pick up as sound. So, without
this teeny bone, you wouldn’t be able to hear.
Now I have a question, how many bones do you think we have?
Well … it kinda depends.
It sounds crazy, but you have fewer bones now than when you were born!
Newborn babies have about 300 bones, but -- by the time you’re finished growing -- you’ll
have only 206.
So, where did all those extra bones go?
Nowhere! As babies grow, some of their bones grow together, or fuse, into one bigger bone.
For example ... your skull!
Your hard noggin is actually 21 bones that are fused together, plus one bone that always
remains separate -- your jaw!
Your skull starts out as a bunch of separate bones, because that leaves lots of room for
your brain to get bigger.
And once you’re fully grown, the fused parts make an incredibly strong shield to protect
your precious brain.
One final fun fact about your skeleton? Your bones … are alive!
Even though we often think of skeletons as not living -- like the ones we see in a museum,
or in this model --your bones are full of living cells.
Some of these cells are what make your bones grow, and repair them if they get hurt.
And other cells -- which are tucked away in a thick spongy layer deep inside your bones
-- have a very special job: They make your blood.
That’s right! Most of the stuff that’s in your blood is actually made inside of your
bones!
It’s because your bones are alive that they’re able to grow -- like they are, in you, right
now! And they won’t be done until you’re about 25 years old.
But even then, your bones will still be busy holding you up, helping you hear, and making
your blood.
So bones in museums are cool, and Halloween skeletons are fun -- don’t get me wrong.
But nothing’s more scary-powerful than your own living skeleton and all the great stuff
it does for you!
Do you have a question about animals with big bones, small bones, or no bones at all?
just let us know by getting help from a parent, and leaving a comment below or emailing us
at kids@thescishow.com.
See you next time!