Monday, 19 January 2015

How to make a model of a bone

So, the last few weeks my girls have been learning about bones.  This week we learnt about what bones are made up of and a bit about how bones are formed and more about how they help us keep healthy!




This time we made up a model of a bone to learn about what is inside our bones and what's going on inside them too. This was the end result.

If you fancy having a go too, read on for a STEP by STEP tutorial and some cool facts to learn as you go!

You will need:

  • A piece of red wool about 30cm long
  • A piece of blue wool about 30cm long
  • Some play dough - red or pink is best
  • A piece of bread with the crusts cut off, try not to take too much of the bread away though, just the crusts (you cannot eat this model)
  • A piece of cardboard ours was 15cm x 15cm, we only had black card today but it would have been cool to have it in a bone like colour, creamy beige.
  • Straws
  • PVA glue
  • Sticky tape
  • Scissors


STEP ONE

Flatten out your play dough a bit and place the blue wool and the red wool on top of it like so...


At this point you can talk about what these three objects represent in this model:  

  • The play dough is our bone marrow.  Bone marrow is a soft tissue that sits in the centre of our bone.  There are two types of bone marrow.  Red bone marrow - this makes blood cells and Yellow blood marrow - this contains fat cells. When we are born almost all our bone marrow is red, as we get older that changes and as adults only around half our bone marrow contains red bone marrow.
  • The blue wool represents a vein. The veins job is to transport blood back to the heart to collect more oxygen.
  • The red wool represents an artery. The artery's job is to bring fresh blood into the bone marrow.


STEP TWO

Roll your play dough, the bone marrow, around your wool, the vein and artery.  It should look something like this...


STEP THREE

Now we need our spongy bone.  

This is the part of your bone that is mostly made up of calcium salts, it has a structure full of holes to keep the bone strong but light.  If our bones were completely solid, it would be difficult to move as they would be so heavy!  

The bone marrow fits inside the spongy bone so, for our model I used a slice of bread to represent the spongy bone and wrapped it around our 'bone marrow'.


STEP FOUR

Around the spongy bone is a layer called the compact bone. This layer is full of hollow rods made of calcium mostly acting as a reinforcement to protect the bone marrow.  These hollow tubes are known as Haversian canals.  

If you want to learn more about how they make our bones so strong you might like the science project I recently posted: strong bones 

To represent the compact bone layer, I used a piece of thing cardboard, 15cm by 15cm.  We spread PVA glue all over one side of the cardboard and stuck down straws, all cut to 15cm in length.  We then used sticky tape to ensure it stayed stuck down.  

It should look something like this...


In a real bone, the compact bone is covered by the Periosteum, in our model the thin card is what we used to represent it - in our case it was black card, but a bone, as I am sure you know, would be more creamy in colour.

STEP FIVE

Roll the compact bone and periosteum, the straws and card, around the spongy bone layer so you have a finished model...



STEP SIX

We stuck our model together with a piece of sticky tape in the end and I was rather chuffed with it.  

The girls all learnt about what is really inside a bone and the purpose of all the different parts.  The best bit was that it entertained all of them from my 4 year old to my 12 year old.



MORE BONE FACTS...

YOUR BONES ARE ALIVE!!

Blood flows through your arteries to bring nutrients and oxygen and veins take waste away, this is to keep bones healthy and alive!  Yes, your bones are alive.  Still about 70% of your bones aren't living tissue but minerals, mostly calcium.

THE MARROW INSIDE YOUR BONES MAKE UP 4% OF YOUR BODY WEIGHT.

BONE MARROW IS ESSENTIAL TO KEEPING YOU HEALTHY AND ALIVE! Your immune system needs bone marrow.

CELLS CALLED OSTEOBLASTS FORM NEW BONE, KEEPING YOUR BONES STRONG AND HEALTHY. A single OSTEOBLAST can not form bone alone, they group together to do this.

THERE ARE ALSO CELLS CALLED OSTEOCLASTS, THESE DO THE OPPOSITE TO OSTEOBLASTS. OSTEOCLASTS break down bone.  They do this for the important reason to stop the bone becoming too hard.  The two types of cells balance each other out to keep the bone in good working order and to protect the bone marrow inside - osteoclasts resorb bone tissues and osteoblasts deposit new bone tissue.

We have 206 bones in our body.

Although your bones stop growing when you are 20 they are always rebuilding new cells.

Red bone marrow can produce up to 5 million new blood cells a day!

If you don't get enough calcium in your diet your body will take it from your bones, making your bones weaker so remember to eat a calcium rich diet!

4 comments:

  1. Woman, you are like a powerhouse of info! Ha ha. I love your blog - now I just need to shift my sorry backside and copy off, (I mean be inspired to take action)... your work. Excellent. Such great ideas.

    ReplyDelete
    Replies
    1. Thank you Fay, that is awesome to hear! I enjoying coming up with ways to make learning as fun as possible. :) x

      Delete
  2. What a great idea! We'll definitely be doing this on a homeschooling day soon :)

    ReplyDelete