We are really embracing all the fun and easy hands-on ideas we are finding to do with our homeschool unit study on the human body.
Homeschool Unit Study Human Body
This second project which is a model heart pump or a model of one of the heart’s chambers was a bit time consuming, but well worth it and I’ll share a few of our mistakes too.
This is a great project for middle school kids.
(Note: I filled the bottle back up on the right side so you could see it in the picture, but the bottle on the right side will empty into the other bottle.)
All of these items we had on hand, though we had to change it around some.
Look at this list:
- One empty plastic bottle about 16 oz.
- Two plastic bottles the same size. (We could have used glass glasses too and it’s easier if they are shorter than the 16 oz. bottle.)
- 3 bendy straws.
- 3 medium size balloons.
- glue gun.
- red food coloring.
- small dish.
- ear syringe (too, don’t do like us and use a small one. It was hard for us to get our heart pumping. Use one of those ear syringes with the long neck. But, then we had to use what we could find here in Ecuador.)
First, make two valves. Cut a small slit on one balloon, just big enough for the straw to fit through and for it to be tight.
We made the mistake of cutting the hole too big.
The balloon needs to be snug around the straw. Pull the straw through the mouth of the balloon.
One valve (top shown above) keep the bottom of the straw in the balloon.
For the second valve (second one shown above), keep the bendy part in the straw. Also cut some of the top part off the balloon to make a wider mouth.
Next you will need to cut two holes in the plastic bottle. One hole will be half way down on one side and the other hole will be about a third of the way up on the opposite side.
Cut them large enough for straws to fit through, but not too big. If you make the holes too big, you can seal it with the hot glue gun.
This next part is a bit hard and our balloon came off the straw inside the bottle. So we had to use another balloon.
But first put the “bottom valve” (Picture 2 above), which has part of the balloon mouth cut off, stick it through the top hole you made on the plastic bottle.
We had to gently twist the balloon and take our time.
The other valve goes in the bottom hole on the other side of the plastic bottle.
Stick the straw end into the hole.
Use the third straw to bend the valve (straw) inside the bottle to point down so the water will flow correctly.
Here you can see where we made a mistake because we intended on using the measuring cup turned over to elevate the plastic bottle, but our other two bottles were too tall.
We solved the problem by finding a pitcher. It worked great.
So that is what I mean when I said earlier that you could use glasses shorter than your plastic bottle.
We elevated the right side with a dish and made sure our straw was pretty good ways in.
The other bottle we stuck the balloon end from the straw in it.
Too, you will notice on this part, that we taped everything down as good as we could get it. That also helped for the bottles to not move.
I even taped the bottle on the right side to the dish.
Then a hot glue gun solves everything. I glued this part for Tiny.
I just glued around the straw and hole to seal any holes we had made too big.
This also helped the straws to stay in place after we bent them.
Then fill the container up on the right side with water. Add some red food coloring.
I think Tiny added like 8 drops (5 would of done, but whatever) or so and make sure the water is well above the straw’s end.
Next, take the third balloon and cut off some of the mouth and a very small hole at the closed end, just big enough for the neck of the ear syringe to fit in.
You are making a band that will fit tight and snug over the ear syringe when it is pulled up over it when the ear syringe is in the neck of the bottle. Lay it aside for just one minute.
Next, add water to your middle bottle and enough to cover the bottom straw about two inches over.
Next, the third balloon that you cut the mouth off and that has a small opening on the other side, place over the middle plastic bottle mouth.
Stick the syringe through the bottle and pull the balloon up over the up to make a seal between the bottle and the syringe.
(Note: Tiny already took off the seal for our syringe because we had a pretty tight seal without the balloon seal.)
The pump is ready. Squeeze and release the “heart”. The heart squeezes to pump blood.
The water should be going from one side or from the filled bottle to the empty bottle. When you squeeze the ear syringe, air pushes on the water and on the balloon inside the middle bottle.
The water exited through the straw on the left side and air pressure closed the balloon (valve) inside the middle bottle.
When you let go of the syringe, air pushed water on the two outside bottles.
The difference in pressure, pulled water into the balloon inside the middle bottom and closed the balloon (valve) on the right bottle.
Free Heart Minibook
Hugs and love ya,