Heart Pump Experiment

Updated September 2023

To go with our homeschooling circulation week, I found this heart pump experiment on Pinterest from www.Team-Cartwright.com.

As usual I found a great idea and tried to make it my own, keep reading to see how our version of the heart pump experiment turned out.

Look here for more blood and circulation curriculum ideas

Materials Needed:
-1 or 2 balloons
-2 small cups (I used Take n’ Toss sippies)
-Toothpick
-2 bendy straws
-Tape
-water
-Red food coloring (optional but it makes it more realistic)
-Something to protect the area from flying “blood”

Step 1) Cut the neck off of the balloon

Step 2) Fill one of the cups 3/4 full with water & add food coloring should you choose. (There is a good chance some of the water will spray a bit, if you care about getting food coloring on your work surface I would do without.)

Step 3) Stretch the bottom part of the balloon over the cup you filled with water. I did not think this was going to work, but it does! We went through a few balloons before getting one to fit on the cup without breaking, so you may want an extra balloon or two on hand…

Step 4) Use the toothpick to poke the smallest hole possible into the center of the balloon. You will then poke another hole about half an inch away from the first, so be sure to leave room.

Step 5) Push straws into the holes with the bendy part on top. This was the trickiest part for us. The toothpick starter holes do work but it is still difficult to get the straws in without stretching the balloon. You want to be sure to have a tight seal around the straws.

Reusable straws on Amazon

Step 6) Use the other half of the balloon and tape it around one of the straws. Pull the balloon over the straw like a sock and tape around the straw to seal.

Step 7) Place the second cup underneath the uncovered straw. Honestly, you might just want to use a big bowl instead of a small cup. Aiming our blood flow complicated things and I think if we had a bigger place to aim for it may have been easier!

Step 8) Press quickly between the two straws until the blood starts to pump!

The Science of the Heart Pump Experiment:

By pushing on the balloon covering the cup, you are acting like the heart pumping blood. The balloon on the end of the straw acts as a heart valve. The blood can go up the straw but there is no back flow!

Want more activities for teaching kids about circulation and blood? Click here!