The heart as a pump
Biology · Key Stage 2 · The School
A muscle that never stops
The HEART is a pump made of muscle. It sits in the middle of your chest. Unlike your arm muscles, it never gets to rest. It squeezes, again and again, every single second of your life, without you ever having to think about it. It has been beating like this since before you were born. By the time you are an adult, it will have beaten billions of times.
What the heart pumps
The heart pumps BLOOD. Blood carries oxygen and nutrients to every part of the body. It also carries waste away again. Without the heart pumping, blood would simply sit still, and none of that delivery would happen at all. Every cell in your body depends on this delivery to survive.
Feeling the pump at work
Every time the heart squeezes, it pushes a wave of blood through your blood vessels. You can feel that wave at your wrist or your neck. It is called a PULSE. Each pulse you feel is really one single heartbeat, arriving there. Doctors and nurses check a pulse to see how a heart is working.
Press two fingers gently on the inside of your wrist. Wait a moment. Feel a small beat, again and again. That is your pulse. Now count how many beats happen in one full minute. Sit still for a minute and count again. Now stand up, do some star jumps for one minute, then count once more. The number will be much higher. Your heart is pumping faster, pushing more blood around your body to keep up with your moving muscles.