Today Nurse Nanobot and I have been concentrating on the structure that enables our bodies to stand up – brilliant bones and the skeleton.
Without them we’d also just be wobbly blobby blobs!
Press the play button above to listen to us explore the world of bones and also read loads of interesting facts below!
Bones are mostly made of a mineral called calcium, which is hard and white, a bit like your teeth.
The outside of bones is a smooth and very hard layer called cortical bone, which makes your bones strong and hard, and under this hard layer is a spongy layer called trabecular bone.
Whilst this layer is still made of hard mineral, it has lots of tiny holes in it, just like a honeycomb, which makes your bones light in weight and allows for a network of blood vessels to carry blood delivering oxygen, nutrients and water to keep your bones healthy and strong.
They also to carry away waste products and bits of old bone. In many bones, this is where you will also find bone marrow, a thick, squidgy substance that makes 175 billion new red blood cells each day!
The Skeleton is the amazing framework of our bodies – just like planks of wood are the framework of a house.
The skeleton also protects your internal organs and all the squishy bits. For example, your skull, which is the hard thing you feel when you touch your head, protects the brain.
Your spine is one part of your skeleton that’s easy to check out – just touch the centre of your back and you’ll feel its bumps under your fingers. The spine lets you twist and bend, and it holds your body upright. It also protects the spinal cord, a large bundle of nerves that sends information between your brain and the rest of your body.
Your ribs protect your heart and lungs. Ribs are long, thin bones that surround your chest. You have 24 ribs (in 12 pairs), although some people have 13 pairs, and others only 11! Together with your sternum, the flat T-shaped bone in the middle of your chest, they form your ribcage. If you shut your eyes, and place you fingers on your chest, you can count them.
Our skeleton has joints where bones meet – these joints allow our bodies to bend and move. Some joints only bend in one direction, for example the knee joint only swings forwards and backwards like a hinge. Others can move in lots of different directions, such as your hip joint which can move in a big circle.
Bones at a joint are connected by tough straps called ligaments. And the end of each bone is covered with smooth, shiny cartilage which allows bones to slide against each other. Just imagine how hard it would be to move if you didn’t have joints. Try moving around without bending your knees or elbows – careful now. Now try and sit down. Can you get back up again. See how hard it is to move around!
Trepanning is a word that means drilling holes in your skull. Since the Neolithic period 12,000 years ago, people have been doing this to try to make themselves feel better. We know this because skulls have been found with perfectly circular or square holes cut in them. The funny thing is that surgeons today do similar activity to get to parts of the brain, but modern surgeons call this a craniotomy.
Did you know nurse, that whilst a baby is born with over 300 bones? As you grow, some of these fuse so by the time you’re an adult you will have on average 206 bones in your body. And more than half of your bones are found in your hands and feet – there are 27 bones in each hand and 26 bones in each foot.
And did you know that we all have a tail bone? You can feel a knobbly bone at the bottom of your back. This is called the coccyx.
Have you ever broken a bone? It is pretty easy to tell when you have – your arm or leg might look very wonky indeed and if you’re very unlucky some of the bone might be sticking out through your skin. Don’t worry, though, if it does happen. Its very easy to mend.
If you ever break a bone, you will need to visit the hospital, where with an X-ray machine (a bit like X-Ray specs) a doctor can look at broken bones in more detail. The first step of treating a broken bone is to put the pieces back in the right place. Once all the bits are in the right place, the bone is then held in place whilst it heals, with a cast made of plaster, plastic or fibre glass. Your body then takes over with all the blood vessels bringing all the good stuff to mend the bone – and bones are very good at mending.
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