This demonstration uses a balloon, jar, and straws to create a simple model that mimics how the heart pumps blood through the body. The balloon acts as the heart muscle, and the straws represent blood vessels, showing one-way flow similar to valves in the heart.

1. Fill a small jar halfway with water and add a few drops of red food coloring to represent blood.
2. Cut the neck off a balloon and stretch the remaining portion tightly over the top of the jar.
3. Use a toothpick to poke two small holes in the balloon, about an inch apart.
4. Push a bendy straw through each hole so that the bendy parts stick upward.
5. Take the cut-off balloon neck and place it over the opening of one straw to act as a valve.
6. Place a cup under the open straw to catch the “blood.”
7. Push down firmly on the balloon surface between the straws to pump the liquid up and out of the open straw.

Make A DIY Heart Model | Human Body | Experiment | Arts & Crafts | Science For Kids - Big Bang Academy Kids:

📄 Easy Heart Pump Model: Cardiovascular STEM for Kids - Team Cartwright: https://team-cartwright.com/heart-pump-model/

• Use this on Valentine's day for a themed demonstration.
• Use larger jars and thicker straws for a bigger model.
• Add tape or glue around the straw holes to prevent air leaks and improve pumping efficiency.
• Try adding two jars connected by tubing to simulate blood moving between heart chambers.

• Adult supervision is required when cutting the balloon and poking holes.
• Food coloring may stain surfaces, so protect work areas.
• Avoid vigorous pumping near electronics or delicate surfaces to prevent spills.

• How does the balloon act like the muscles of the heart? (It squeezes down to push the liquid, just as the heart contracts to pump blood.)
• Why does the balloon neck on one straw act like a valve? (It allows liquid to flow one way but prevents it from going backward.)
• How is this model different from a real human heart? (The human heart has four chambers and multiple valves, while the model is simplified with only one pump and two “vessels.”)