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Hi, I'm Jared, welcome to "Fun Science Demos".
How's everybody doing? How did I do that?
Well, that's part of the big idea today. If I feel my arm,
I can feel bones and I can feel muscles.
And the big idea is that muscles move bones.
So how does our arm work? Well, you can feel your arm
and I'll feel my arm and I feel around and I feel a bone.
I feel this squishy muscle and I notice
it changes when I raise my arm up and lower it down.
When I raise my arm up the muscle bunches together,
gets bigger; when I lower it, it stretches and loosens out.
But I can't peel my arm and look inside of it.
So we have this really cool model
for you to check out. So let's take a closer look at this really cool model.
You can see that our upper arm has one bone,
and our lower arm actually has two bones,
and then in our wrist and fingers we have lots a tiny little bones.
These straws and this balloon work just like our muscle.
And through science we've discovered that these little ropes
attach the muscle to the bone, and scientists call those
tendons. So now let's see this thing work. Now, think back to your arm. Remember how
the muscles seem to bunch up and get bigger when we brought our arm up?
Watch what happens to our lower arm when her muscles up here
bunch together and get bigger. We're gonna see if we can make it wave.
Here we go.
Did you see the arm move up?
Well, it moved because the muscles were pulling the bones.
And it doesn't just happen in our arm, muscles move bones
throughout my whole body. My head, it moves because muscles are pulling the
bones. My mouth,
it moves because muscles are pulling the bones. My fingers move because muscles
pull the bones.
Everything in my body moves because the muscles are pulling
the bones. We'd like to thank Ed for building such a cool model
so you can see how muscles and bones work in your arm. Don't forget to check
out our links in the video description.
Science is so cool. Thanks for watching, see you next time!
I'm