Adults have 5.5 litres. Red blood cells carry oxygen. Biconcave discs, live for 120 days, made in bone marrow. Note oxyhaemoglobin, carboxyhaemoglobin.
Platelets help in the clotting of blood.
Examine blood using the video-microscope and compare normal blood with eosinophilia and leukemia. Defence against disease Outline the defence mechanisms of the body, including the role of the skin and blood. Draw a diagram here. Produce a series of cartoons to describe the defense function of the blood. Explain how arteries carry blood at high pressure away from the heart.