Learning About the Skeletal System

We started out with this life size printable juvenile skeleton, cutting it out and piecing it back together on another life size body outline that we drew - I think we might make these into a huge book when we are done with our human body science studies. Whilst we pieced them together we chatted about the skeleton and I asked the girls what they knew about the skeleton and what they wanted to know. As usual, there were some answers that surprised me!

We talked about the functions of the skeletal system, with a few leading questions and some knowledge from our previous sessions on the cardiovascular system the girls were able to summarise that the skeletal system provides a frame, protects vital organs, manufactures red blood cells and allows movement in conjunction with the muscles.

I reminded the girls about one of the functions of blood - transporting nutrients and minerals around the body and explained that the bones were living and had a really good blood supply. Eve jumped in and asked if it was so the bones could grow..... yes, and repair themselves, I asked her if she knew what the most important  mineral was for bones and she knew it was calcium. We did a little experiment on some chicken bones to show how important calcium is. The bones were washed and dried and the girls tried bending them to see how strong they were. They put them into a jar full of vinegar and we left them for a few days. When we brought them out they were really bendy (shown above held in cling film as the girls didn't want to handle them without it!). It was amazing just HOW bendy they were without the calcium!

The next day we built a 1.2m high cardboard skeleton (I got it on offer from The Works at Christmas for a lot less) and as we did so compared and categorised the different types of bones - long bones, short bones, flat bones, irregular bones and sesamoid bones.

We moved on to looking at the function of the long bones in producing red blood cells for the body. we made a model inspired by this post on the blog 'science matters'. We started by rolling some red fabric to be the red marrow in the centre, then rolled a piece of yellow dish cloth around it to represent the fatty yellow marrow around it.......

...... we added a piece of natural sponge around that to show the honeycomb structure of the spongy bone around the yellow marrow. Lengths of red and blue embroidery floss represent the arteries and veins that bring a rich blood supply to the red marrow and remove by-products and red blood cells....

..... to finish up we wrapped white paper covered cardboard tube around the sponge to show the dense bone which is the final layer and around the outside.

As a final session, we talked about how bones and muscles work together to allow movement. There are different types of joint, we talked about the major ones of ball and socket, slightly movable such as the vertebrae in the spine (below, idea came from here)......

..... and made a model of the elbow hinge joint, with red balloons to show the muscles contracting and relaxing, instructions can be found here. We actually did most of this a few weeks ago but there was a short delay before we could complete our hinge joint after I realised that you really can't blow modelling balloons up without a pump...... and then I had to locate the infrequently used pump!! I was really pleased with how well the children remembered the information. We recap at the beginning of each session and then build on that information, linking it together and making it relevant to their own bodies, it was good to see them recalling and using the things we had learned previously.

The google docs printout of this topic with all four sessions full of all the information that we went through is available here! I hope that you find it useful!