❤️ How do our hearts pump blood?

Your heart is like a little pump inside your chest! ❤️ It goes "lub-dub, lub-dub" all day and night to send blood all around your body. Blood carries food and air to your muscles and brain so you can run, play, and think!

Imagine your heart is a squishy ball that squeezes and relaxes. When it squeezes, it pushes blood out, and when it relaxes, it fills up with more blood, just like a sponge!

Your heart is a super strong muscle that pumps blood through your body! ❤️ It has four rooms (called chambers): two atria (top) and two ventricles (bottom).

Here's how it works:
1. Blood without oxygen comes back to the heart.
2. The right side pumps it to the lungs to get oxygen.
3. The left side pumps the oxygen-rich blood to your body.
4. Valves (like little doors) open and close to keep blood flowing the right way!

The heart is a sophisticated double pump that keeps you alive! ❤️ Here's the science:

Structure:

• Atria: Receive blood (right = from body, left = from lungs)
• Ventricles: Pump blood out (right = to lungs, left = to body)
• Valves: Prevent backflow (tricuspid, mitral, pulmonary, aortic)

How it works:

1. Deoxygenated blood enters the right atrium → right ventricle → lungs (to get O₂).
2. Oxygenated blood returns to left atrium → left ventricle → aorta → body.
3. The SA node ("natural pacemaker") sends electrical signals to keep the rhythm (60-100 bpm).