Welcome to Excitement of Science 2010
Introduction
This year’s event is all about various aspects of blood flow around our bodies, how we measure it, how we control it, why it’s important, what happens when things go wrong and how it works in elite athletes.
Our cardiovascular system is made up of a pump (the heart) from which a series of tubes (the arteries) arise and then these divide and get smaller and smaller in diameter as they deliver blood to our organs and muscles. The following graphic shows a cross-section of the heart.
There's an excellent animation which shows how the heart is able to pump blood around the body.
Click here to view the animation and then return to this page.
Ultimately, deep down in our muscles these blood vessels are so small that their walls are only one cell thick and they lie alongside muscle cells so that oxygen can be delivered and energy created for the muscles to move. The really neat thing about our body is that when we need energy, signals are sent from the muscles to the heart so that more blood, and therefore oxygen, can be delivered to where it is needed.
This requires a very high degree of control of our physiology, particularly for the athlete, since if any component of the system does not fully work, then performance will be affected. For example, the elite marathon runner must increase the pumping of the heart and increase the diameter of blood vessels in the muscles so that more blood can be delivered and more energy produced.
The heart beats around 3 billion times in the averages person's life. About 8 million blood cells die in the human body every second, and the same number are born each second. Within a tiny droplet of blood, there are some 5 million red blood cells. It takes about 20 seconds for a red blood cell to circle the whole body. Red blood cells make approximately 250,000 round trips of the body before returning to the bone marrow, where they were born, to die. Red blood cells may live for about 4 months circulating throughout the body, feeding the 60 trillion other body cells.
This year’s project will examine a number of interesting things about how our bodies work, particularly the physiological changes which take place when we are exercising. We are going to ask you to look at a number of things, especially:
to look at ways to measure how the cardiovascular system works
to look at how the heart works
to look at how blood vessels change their diameter to allow more blood flow
to look at how all this is controlled
to look at how the cardiovascular system works in the elite athlete and what goes wrong in disease
This year’s project is run by Tim Cable, who is Professor of Exercise Physiology at Liverpool John Moores University.
Tim is an expert in how the cardiovascular system works and how it changes during exercise and what happens to make it perform better after athletic training. He has extensive experience of working with from a broad range of sports that include football and athletics. He also works with patients with cardiovascular diseases and uses exercise to make their cardiovascular systems healthier.
Simple Experiments to Get You Started
In order to get you started it would be great if you could arrange to make the following measurements with your teachers on as many classmates as possible. Once you have taken these measurements, you need to carefully record them so please be sure to save them as we would like to upload as much of this data as possible to help us work out how fit young people in the UK actually are.
However, before taking these tests, there are two important points to make:
1. Every person's fitness changes throughout their lives and our objective is to conduct scientific research, not to encourage anyone to change their lifestyles. This project is about the science of fitness and not necessarily about promoting fitness for fitness's sake; and
2. Inappropriate exercise can, in very rare cases, be dangerous; there is even a suggestion that joggers do more harm than good, to things like their knee joints, for example! It is your responsibility to ensure that you are physically able to do some of the more strenuous experiments. If you have any doubts, ask your doctor first: he or she will be pleased to advise. Importantly, most of you are not trying to become an elite athlete, so if you feel unwell while doing the experiments - stop and if you do not quickly recover, seek medical assistance.
Now, click on the Body Mass Index tab at the top of the page to look at the first measurement we'd like you to make.