Thursday, April 17, 2014

Let's Take A Trip Through The Cardiovascular System!

Check it out, we made a heart!

For the past two weeks, Kat and I have been learning about the cardiovascular system and how it works to keep our body alive and healthy. We've done some really great projects to demonstrate how the heart works, and we've even dissected a pig heart in our home! All of this will culminate into a visit with the American Red Cross, where we will learn more about human anatomy relating to the circulatory system, Kat will learn some basic CPR, and I will donate a pint of blood to the Red Cross!

In this post, I'll talk about how the heart works, and share some of the wonderful projects we've been working on as we learned about the heart!



Hand drawn diagram of the human heart.
Free hand drawing of the Usborne Illustrated Dictionary of Biology diagram, Kat's labels!

When we breathe air into our lungs, tiny air sacs within the walls of the lungs (called alveoli) allow the oxygen to pass into the blood stream. This oxygenated blood travels from the lungs into into the left atrium. The heart muscles contract, pulling the valves open, allowing the blood to be dumped into the left ventricle. The valve then slams shut, preventing the blood from flowing backwards into the bloodstream. When the heart contracts again, it opens the valve from the left ventricle to the aorta, sending freshly oxygenated blood to the rest of the body!





Actual placement of the organs in the human body may differ from that shown above.

Materials Needed:
1. Scissors                        
2. Large flat surface
3. Printed pictures of red blood cells
4. Printed pictures of the heart and other body organs


1. Turn on your "safe search" filters and do a Google Image Search for diagrams of various organs. Exercise your child's knowledge of anatomy by inviting him/her to choose the organs you search for!

2. Save and print your pictures. We printed ours as 3.5 x 5, so they would all be the same size. You will want to print several copies of the red blood cells, since you'll be using a lot of them to represent blood.

3. Cut out your pictures!


5. Using the red blood cells, make a path from the left side of the heart to the rest of the organs! As you move the blood cells about, talk about how they're carrying oxygen to the organs.





Materials Needed:

1. Beaker or wide mouthed jar
2. Water
3. Red Food Coloring
4. 2 Flexible straws
5. Tape
6. Balloon
7. Toothpick or scissors
8. Large pan or sink
9. Scissors








7. Point the open straw downward and start pumping! The neck of the balloon over one of the straws acts as a valve, blocking any of your blood from flowing back through the "plumbing system". The other straw allows blood flow to pass through, where in a heart, it will continue through the aorta to the body or pulmonary arteries to the lungs!

Kat loved using this pump! 
Now we had a much better understanding of how the heart beats to pump blood throughout our bodies! We've moved blood cells around in circulation and made our own pump to represent the heart beating! But we still didn't have a precise knowledge of the anatomy of the heart. Really knowing that would help us greatly in really internalizing how it all works. To that end, we made our own anatomical model of the human heart!


Our model of the human heart!

Before you begin, it helps to look at a diagram of the human heart for proper placement of the arteries. We used our copy of Usborne's Illustrated Book of Biology to help us with our placement. You can use any medical reference book, or search for diagrams on the internet.

Materials Needed:

1. Modeling clay (red and blue)
2. Aluminum foil
3. Toothpicks
4. Hot glue gun
5. Pipe cleaners
6. Red crepe paper (you can also use paper mache)
7. Rolling pin
8. Milkshake straw


1. Take some big chunks of aluminum foil and make three balls out of them. The first ball should be about the size of a tennis ball, while the other two should be about the size of a golf ball.

2. Poke three toothpicks into the upper left corner of the larger ball. Use the hot glue to secure them in place. Then attach one of the smaller balls to it. Do the same for the other side until you have a sort of "Mickey Mouse" shape.

3. Take some chunks of red clay and roll them flat with your rolling pin. We covered our rolling pin with foil so the clay wouldn't stick to it. Cover your foil pieces with clay until it begins to look like a human heart. Continue shaping and smoothing the foil and the clay until you are satisfied with how it looks.

4. Once you're finished with the shape of the heart, it's time to start on the aorta! Take 6 pipe cleaners and bend them in half so that they fold in on each other. Use the hot glue to secure the ends in place.

5. Bend the pipe cleaners into a U-shape. Wind the crepe paper around the pipe cleaners until they are fully covered. Use hot glue to secure. (Note, if using paper mache, follow normal paper mache instructions, then paint red once it is dry.)

6. Stick 3 toothpicks on one end of your aorta. Glue them in place and stick the aorta into the top of the right side of the heart (this is the left ventricle). Bend the U-shape so that it ends behind the heart and glue it into place.


8. Stick 3 toothpicks in one end of the pulmonary trunk. Use glue to secure in place and then attach it to the top of the left side of your heart. Bend the pulmonary trunk so that it hugs the aorta, and glue into place.

9. For the pulmonary arteries, take 2 pipe cleaners, and bend them together as you did for the aorta and pulmonary trunk, using glue to secure the ends together. This is going to fit through the loop of the aorta, and will hug the back of the pulmonary trunk. Use hot glue to secure in place.

10. Now it's time to work on the arteries! Grab a milkshake straw and cut it up! You'll need five 1/2 inch pieces, three 1 inch pieces, and two 2 inch pieces.

11. Put your 1/2 inch pieces on the ends of your arteries, as shown above. Two on each end of the pulmonary artery, and one on the end of the pulmonary trunk. The 1 inch pieces should be spaced evenly apart along the top of the aorta. Finally, the two inch pieces should stick out of the right side of the heart, just off the left atrium.

12. Finally, roll out some blue clay into thin strips, and line the left ventricle with posterior veins!

Now you're finished with your very own anatomical model of the human heart! Congratulations and great job!



We also learned even more when we dissected a heart in our kitchen! Due to the amazing experience we had with the dissection, that took a whole new blog post! Here's the link where you can see what we did and find out how to get your own heart dissection kit!



  1. How did you make your heart? I LOVE it!


  3. I love that you are doing science with your daughter. We need to get more girls excited about science! Great blog!


  4. I'm glad to see so many helpful tips right here. Thank you

  5. Wow this is an incredible post AND my 5 yr old even sat beside me to WATCH Thee entire video!! Amazing! She never Sista through educational videos well--this was perfect. She really understood it! Time for a heart mobile shopping trip!

  6. Can you use playdough instead of clay for the model heart?
