Thump thump… thump thump… or maybe lub dub… lub dub… lub dub… Sounds you can make to mimic the sound of your beating heart! But what do you know about your heart? Do you know how your heart works? Can you actually listen to your own heart?
Here are four of our favorite experiments for you to learn more about the human heart. You can discover *how* a heart works, how to see evidence of the pumping blood through your body, make a stethoscope to listen to your heart (or others who say you can!), and then see if you can affect your heart rate… can you?
- Your hand
- Red Food Coloring (optional)
- Shape your hand into a fist, then open it up slightly keeping your fingers touching, but allowing an opening in the center tocollect water.
- Put your hand in a basin of water (sink, bathtub, swimming pool, etc) and squeeze tightly.
- Return to the original position and squeeze again.
- Repeat in a rhythm like a heartbeat.
What do you notice?
Can you “pump” water through your hand?
When your hand is open slightly, the water collects inside of it, and when you squeeze it quickly and tightly the water is forced out. When you repeat this motion it simulates how the heart muscle pumps the blood throughout your body.
- Ball of clay or play dough
(about the size of a super ball, 1″ in diameter)
- A straw
- Soften the clay by kneading it in your hand.
- Roll it into a small ball and then flatten the ball a bit so it is more like a disk
- Stick the straw into the flattened ball.
- Lay on the floor with your head turned to the side. Place the flattened clay on your neck along your aorta – where you feel your heartbeat the strongest.
You can “watch” your heart beat!
You can also do this by placing the clay on your wrist.
Did you know: your aorta is the largest artery in your body! It is over an inch in diameter! When your blood pumps through it, you can feel it right through your skin. Using the clay and a straw, you can actually “see” the rhythm of the blood pumping through your aorta!
Tube and Funnel Stethoscope
- A large funnel
- A small funnel
- 2 feet of tubing that fits over the small ends of both funnels
- Electrical tape
- Push the tubing onto the small ends of each of the funnels, connecting them.
- Cut the mouth off of the balloon and stretch the balloon over the opening of the larger of the two funnels.
Be sure to stretch the balloon so that it is completely flat and stretched onto the widest opening of the funnel.
- Put the large funnel – balloon side down – onto your chest near your heart.
- Put the small funnel to your ear and listen for your heartbeat!
Sound travels through vibrations. As your heart beats, it squeezes tight then contracts moving in your chest. As this happens it pushes blood through your aorta and throughout your body. This movement causes a vibration that can be felt through your body. When that movement hits the balloon it vibrates as well. That vibration travels through the tube and up to the other funnel which then travels into your ear and to your eardrum sending a signal to your brain that you hear something. That something is your heart beat!
Track Your Heart Rate
- Your wrist and your pointer and middle finger on your other hand
- A stopwatch or a clock with a second hand
- Lay your wrist on a flat surface.
- Using your pointer and middle finger on your opposite hand, push down on the space on the side of your wrist just under your thumb. This spot is on the inside of the bone that runs from your thumb down your arm.
- Look at a stopwatch or a clock that has a second hand and count the number of times your heart beats in 10 seconds.
- Multiply that number by 6 and you will have the number of times your heart beats in a minute. This is your pulse rate.
- You can also do this for 15 seconds then multiply the number by 4 to get your pulse rate.
- Do this when you’re at rest and you will get your resting heart rate.
- NOW, try doing some exercises and see if it changes your heart rate!
- Try other activities such as dancing or jumping jacks – or any other active activity – for 1-2 minutes, then check it again.
Is it the same? Different? Higher? Lower?
When you exercise, your muscles need more oxygen to move, so your heart has to send out more blood to carry the oxygen through your body to get it to the muscles that need it! That is why your heart rate increases when you exercise.