Why does our heart beat?

Put your hand on your chest and stay very still. Can you feel it? Thump-thump… thump-thump. That is your heart beating, all day and all night, even while you sleep.

A muscle that squeezes

Your heart is not really heart-shaped — it is a strong muscle about the size of your fist. It works by squeezing tight and then letting go, over and over. Each squeeze is one heartbeat.

When the heart squeezes, it acts like a little pump. It pushes blood out and sends it whooshing all around your body through tiny tubes.

Blood is a delivery driver

Why send blood everywhere? Because blood is a busy delivery driver! It carries oxygen from your lungs and food from your tummy to every single part of you — your toes, your brain, your fingertips.

Every part of your body needs these to stay strong and to grow. So your heart keeps pumping to make sure the deliveries never stop.

Faster and slower

When you run and jump, your body needs more oxygen, so your heart beats faster to deliver it quickly. When you rest, it slows down again. It always knows just what you need.

Wonder fact: Your heart beats around 100,000 times every day — and you never have to tell it to. It does the job all by itself!