You get a new skeleton every 10 years
During your whole life, your bones are replacing themselves. They adapt in shape, size, and place to fit all the amazing things you do.
So about every 10 years, you have a whole new skeleton.
But why do we even need bones? And how do they change so much? Let’s see!
Why do we have bones?
Every bone in our body has a special job. But if you had to know just two, these are the main ones:
1) Bones protect our organs
Our bodies can take some hits and blows because we have a shield inside us —
The skull is like a helmet that protects our brain. The ribs are like armor that protects our heart and lungs. And so with other organs, such as our kidneys and liver.
2) Bones help us move
They hold up our muscles so we can run, jump, and play! Without them, we might crawl like snails or wiggle like worms.
How do bones work?
1) Bones are like builders working day and night
They fix themselves and grow.
Imagine building with LEGO bricks. When some bricks get old and cracked, we replace them with new ones.
That’s just what bones do!
1. First, bone cells go to areas where bones are worn-out or cracked.
2. Those cells fuse and dig a cavity in the old bone.
3. Then, the fused cells leave, taking the old bone’s nutrients where our bodies can reuse them.
4. Other types of bone cells pave the cavity with minerals and proteins, making new bone.
Guess what? Our bones are super smart
They balance themselves with minerals that keep them tough, and with proteins that make them flexible.
If our bones had only minerals, they would be brittle and break like twigs. If they had only protein, they would be soft as jelly.
2) Bones become stronger when you use them
For example, if you play tennis, your arms will develop thicker bones. Or if you play soccer, you’ll end up with thicker leg bones.
If you traveled to space for too long, your bones would turn into little sticks!
Without gravity, they wouldn’t get enough exercise.
As long as you exercise and eat healthy foods, your bones will keep growing strong — so you can do even mightier things.