BLOOD You know what blood is. It is the red stuff that oozes out if you get a paper cut. The average person has about one to one and a half gallons or four to six litres of blood But what is blood really? And where does it come from? Your body’s cells need a constant supply of food, oxygen and other essentials as well as a prompt removal of wastes to stay alive. Blood provides this delivery and disposal service as it flows around the body. Billions of oxygen carrying red blood cells give blood it’s red color. Blood also contains white blood cells that defend your body against invading pathogens or germs. The average adult has about 10 pints or 5.7 litres of blood. But a newborn baby has only a cupful. Blood has the amazing ability to turn from liquid to solid in minutes and so helps mend cuts in your skin. A plaster can help a cut to heal by closing the skin and keeping out dirt. Plasters also stop you from scratching which can make a cut worse. There are four main types of blood called blood groups. A, O, AB, and B. Now that you know how important blood is what can you do? Kids generally aren’t allowed to donate blood. But, when you’re older, consider giving the gift of life.