Science -- Your Future, Scotland's Future
SCI-FUN Roadshow Exhibits -- Heartbeat Monitor
SCI-FUN Roadshow Exhibits -- Heartbeat Monitor
In this exhibit you learn about the movement of the muscles in your heart, and how we can measure that using electricity.

Your heart is amazing. It pumps blood around your body all day and all night. Your blood takes lots of useful things to the cells around your body, such as oxygen and sugar, and removes waste products, like carbon dioxide. Blood is vital, and so is your heart.

The heart is made up of two pumps. The one on the right pumps blood to your lungs, whilst the bigger left pump pumps the blood around your body. Your cells need oxygen from the air to make energy in a reaction called respiration. Respiration produces carbon dioxide as a waste product, so your body needs to get rid of that too. Your heart and lungs work together to make sure that your blood is able to move around your body, and can get new oxygen and get rid of carbon dioxide.

The heart itself is made up of muscles, called cardiac muscles. Cardiac muscles keep beating continually, so long as they are supplied with blood (if you take a cardiac muscle out of a body and bathe it in blood, you’ll see it beating away). So your heart needs its own blood supply. This blood is supplied by coronary arteries.

A heart attack happens when a coronary artery gets blocked. This means that some of the cardiac muscles do not get the blood supply they need and stop beating; sometimes those muscles might even die. One of the main ways that a coronary artery can get blocked is by cholesterol, a kind of fat. This is why heart attacks commonly occur in people who are overweight or obese.

Questions
1 Your heart pumps __________ around your body all day and all night.
2 How many pumps are there in your heart?
3 What do your cells need oxygen for? Can you name the reaction?
4 What do we call the muscles in your heart?
5 Why are heart attacks most common in people who are overweight?
6 How do you think you can keep your heart healthy?

Activities
1

Find out how your heart rate changes in response to exercise. Relax completely, then measure your pulse. You can find your pulse on your wrist (you should be able to feel your tendons down the centre of your wrist, your pulse will be on the thumb side of the tendons) or on your neck (just to the side of your wind-pipe). Count the number of beats in a minute, using a timer. Now do some exercise (try running, cycling, swimming or a brisk walk) and measure your pulse rate again. It will be faster. Try out different kinds of exercise for different amounts of time, and see how your pulse rate changes.
2

Learn how to carry out First Aid for hearts. A First Aid course will teach you how to do CPR (a technique to keep someone’s blood pumping when their heart has stopped) and what to do if someone has a heart attack. See if you can enrol on a course, or if your school or youth group could organise one. With this knowledge, you could save someone’s life.

NEVER practise doing CPR on a person.