The Science of Skeletons
Google Slides of Classroom Activities: Moon; Star; Sun
Your Squiz Kids Shortcut to … Halloween: https://www.squizkids.com.au/squiz-kids-shortcuts/halloween/
Interactive human skeleton: https://www.dkfindout.com/us/human-body/skeleton-and-bones/skeleton/
They come out every Halloween… only 2 per cent of animal species have them… and without them, humans just wouldn’t be human. This is your Squiz Kids Shortcut to Skeletons—the podcast where we dive into the who, what, when, where, why and how of the big news stories. I’m Amanda Bower.
And I’m Bryce Corbett.
Bryce, I don’t know about you, but I love Halloween. Any excuse to dress up! And every Halloween, you are SURE to see skeletons. Of course, it’s pure fiction that a skeleton could walk around without a brain to control it, nerves to send messages from the brain, and muscles, ligaments, and tendons to receive those messages and move the bones.
Which is a good thing… I don’t like the idea of a REAL skeleton walking around by itself! A kid in a skeleton costume, no problem! Today, we’ll take you through WHAT our skeletons do; WHY babies have more bones than adults; and HOW we can take care of our skeletons.
Listen carefully – there’s a Squiz at the end!
So Bryce, what do YOU think skeletons do? I’ll give you some spooky Halloween music to think to… and Squiz Kids, you have a think too. You may even want to pause the podcast to share your ideas!
Okay Bryce, what have you got?
Well, our skeletons hold us up! Without a skeleton, we’d just collapse into a skin bag, filled with organs and muscles and other goop.
That’s absolutely true! And quite the mental image… what else?
Hmm… well if I put my hand where my heart is, on the left hand side of my chest, I feel my ribs. Those bones are protecting my heart, aren’t they?
Correct again. Doctors often divide the skeleton into two parts, and the one that gives us protection is the axial skeleton. That starts at your skull, then travels down to include your ribs and spine. Some people also include your pelvis. There are about 80 bones involved, and they protect your brain, your spinal cord – which sends all the messages from your brain to the rest of your body – and most of your important organs, like your heart and lungs.
So what’s left are basically the arms and legs, correct?
Yep! That’s called your appendicular skeleton… Appendicular comes from the word “appendage”, which means arms or legs. Doctors LOVE to use long words for simple things. Anyway, the appendicular skeleton’s main job is to move us around, using our joints.
Joints, of course, are where bones JOIN up, right?
That’s right, and we have 360 joints in our body! They don’t all work the same way, though. Bryce, why don’t you stand up, and give that rugby ball I bet Flynn has left lying around a big kick.
(woohoo! Through for a conversion!)
Don’t you love fantasy football? Your knee joint is the reason you were able to kick that ball. It’s called a hinge joint, because it’s like a hinge on a door. Just like you can only open a hinged door in one direction, you can only move the joint in one direction.
mmm…aggghh… yep, no way I can bend my knee up towards my head.
But when you celebrated your conversion by waving your arms in the air, you were able to swing your arm all the way around… that’s because you have a different kind of joint in your shoulder. It’s called ball and socket, because the head of your upper arm bone is ball shaped, and it fits into a bowl-shaped bone in your shoulder.
So our bones hold us up, protect us, and allow us to move. Our bones are also a factory that makes our blood. Inside our bones is our bone marrow, which produces the white blood cells we need to fight infection, the red blood cells we need to carry oxygen, and the platelets we need to stop bleeding. The adult skeleton is made up of 206 very busy bones.
I noticed you said “adult” skeleton there, Amanda… WHY do kids have more bones than adults?
Your skeleton starts forming about three months into a baby growing in its mum’s uterus, but it doesn’t finish that process until you’re older. For example, there’s a bone called the sacrum. It’s at the bottom of our spine, and connects to our pelvis. In you and me, Bryce, the sacrum is one bone that’s shaped like a shield. But in a baby, it’s five separate bones. Over time, they fuse together to form one big bone. When they’re born, babies have around 300 parts to their skeletons.
Now I remember when my kids were born, we had to be extra careful of their heads, because there were gaps between the skull bones..
Exactly right. Those gaps are there to make it easier for the baby’s head to be born. Once they’re out, the skull bones start growing – or fusing – together. Once that skull jigsaw has grown together, there’s only one bone left in the skull that can actually move. Can you guess which one?
Um… let me just have a sip of my coffee while I think… hmmm…
Let me give you a clue. How were you able to talk to me, and drink your coffee?
Oh yes! My lower jaw has a joint that allows it to move!
Believe it or not, Bryce, there’s only ONE bone in your whole body that’s not connected to another bone.
Go on, tell me.
It’s called the hyoid bone. It’s horseshoe shaped, and muscles hold it in your throat. It’s REALLY important – it’s what allows us to move our tongues around. Next time you swallow, or speak, or stick your tongue out at someone… thank your hyoid bone.
That IS an important bone! Although I suspect they’re probably all pretty crucial. HOW do we take care of our 206 bones?
Have you ever heard of the bone disease osteoporosis?
Oh yes! My grandmother had that. It’s a disease that weakens your bones, and if you fall, there’s a good chance they’ll break.
That’s it. Some doctors call osteoporosis a CHILDHOOD disease with adult consequences. That’s because when you’re a kid, your bones are growing—and how well they grow affects whether you end up with osteoporosis when you get old and gray.
So what do we need to do to grow good bones?
Doctors say that the two most important bone health habits are proper nutrition, and plenty of physical activity. And when they’re talking about nutrition, the bone foods are ones that contain lots of calcium and Vitamin D. We’re talking dairy, soybeans, leafy greens, salmon, baked beans… I’ll put a list in your episode notes. Weirdly, FIGS also have a ton of calcium and Vitamin D.
And it’s also important to get a little sunlight, to activate that Vitamin D in your diet. We all know that too much sun is a problem – but no sun is, too. Humans and other animals with skeletons – called vertebrates – make up only two percent of the animal kingdom. So our bones are really special, and worth taking care of!
I’ll eat a fig to that.
This is the part of the podcast where you get to test how well you’ve been listening…
1. What does the axial skeleton do?
2. What makes the hyoid bone special?
3. What are the two things we need to do to take care of our bones?