❤️ HEART: 4-CHAMBER PUMP
PAGE 1 OF 5 · YOUR NEVER-STOP ENGINE
BEAT
THE HEART NEVER RESTS
Your heart is a strong muscle about the size of your fist. It sits slightly left of centre in your chest. Day and night it squeezes and relaxes to push blood around your body. In a long lifetime it may beat billions of times, often around three billion as a rough estimate. Each beat sends oxygen and food to cells and carries waste away. You do not have to think about it. The heart keeps working while you sleep, play, and dream.
⚡ DID YOU KNOW?
A healthy adult heart often beats 60 to 100 times per minute at rest. Exercise, fear, and sleep all change the speed.
THUMP!
MUSCLE
💪 Heart muscle is special cardiac muscle that can keep contracting without getting tired like arm muscles.
⚡ Its own electrical system sets the beat so it does not wait for brain commands every time.
⚡ Its own electrical system sets the beat so it does not wait for brain commands every time.
SIZE
✊ Your heart is roughly fist-sized and grows bigger as you grow taller.
🫁 It sits behind the breastbone, protected by the rib cage.
🫁 It sits behind the breastbone, protected by the rib cage.