Put a hand on your chest. Your heart is in there. Let's find out how it works.
Make a fist. Hold it up and look at it. The heart is an organ about that size. It pumps blood through your body.
Your heart is made of muscle. It has four chambers. Valves inside the heart keep blood moving the right way.
Each heartbeat sends blood to all of your body. The blood carries oxygen to every cell in your body.
Arteries carry blood away from the heart. Veins carry blood back to the heart.
A heartbeat makes a "lub-DUB" sound. Find your pulse on the inside of your wrist.
When you exercise, your heart beats faster. It does this to get more oxygen to your muscles.
Running and swimming are good for your heart.
Your heart pumps blood. It sends blood to every part of you. It beats faster when you exercise.
Words to know
- chambers: heart rooms
- valves: one-way doors
- arteries: blood vessels
- veins: blood vessels
- pulse: heartbeat feeling
