Hi! Your heart is a strong muscle that works like a pump.
Think of it like a little squishy ball or a sponge:
- When the heart relaxes: The heart opens up and fills with blood, just like a sponge soaking up water. This is the resting part. The blood comes from the body and from the lungs.
- When the heart squeezes: The heart pushes the blood out, like you squeezing the sponge. The blood goes into the blood vessels — some goes to the lungs to pick up oxygen, and some goes to the rest of your body to give it oxygen and energy.
There are tiny doors called valves that make sure the blood goes the right way and doesn’t go backwards.
Try this fun activity:
- Put two fingers on your wrist or on your neck to feel your pulse.
- Count how many beats you feel in 15 seconds and then multiply by 4 to see how many times your heart beats in one minute.
- Run in place for 30 seconds and then feel your pulse again — it will be faster because your heart is working harder and squeezing more often.
That’s it — the heart relaxes to fill and squeezes to push the blood around, all day and night to keep you alive and active!