The heart, your amazing pump

Put your hand on your chest and you will feel a soft, steady beat. It is your heart, a muscle the size of your fist that works day and night without resting for a single second. What is it for and how does it work?

An amazing pump

The heart is a pump that pushes blood around the whole body through tubes called blood vessels. Blood carries oxygen and nutrients to every corner of your body, from the brain to your toes, and collects waste to remove it.

Four rooms

Inside, the heart has four chambers: two at the top, called atria, and two at the bottom, called ventricles. Blood comes in at the top and leaves at the bottom. Small doors called valves open and close so that blood always flows in the same direction.

The journey of the blood

Blood without oxygen reaches the heart, which sends it to the lungs. There it picks up oxygen and returns to the heart, which pumps it to the rest of the body. Then it comes back to start again. This round trip is called circulation.

Why it beats

Each heartbeat is a squeeze of the heart: it tightens to push the blood and relaxes to fill up again. At rest, a child heart beats roughly 70 to 100 times a minute, a little faster than an adult heart. When you run, it beats faster because your muscles need more oxygen.

How to look after your heart

Exercising, eating fruit and vegetables, sleeping well and not sitting all day help your heart stay strong, like any other muscle.

Experiment: measure your pulse

Place two fingers on your wrist, next to the thumb, and count the beats for 15 seconds; multiply by four to get the beats per minute. Jump 30 times and measure again: you will see it has gone up.

💡 Your heart is about the size of your fist.