Plasma is the liquid part of the blood, it is mainly made up of water. The function of plasma is to carry the blood around the body. Plasma carries dissolved nutrients, hormones, carbon dioxide and urea, it also distributes heat around the body.
Red blood cells
Red Blood Cells are biconcave (concave on both sides), disk-like cells with no nucleus. There are millions of red blood cells in each millimetre cubed of blood. The function of red blood cells is to transport oxygen around the body. Red blood cells contain mainly haemoglobin, which loads oxygen in the lungs and unloads it in other regions of the body.
White Blood Cells: Lympocytes
Lymphocytes are a type of white blood cell. Lymphocytes are approximately the same size as red blood cells, with a large spherical or lobed nucleus. The function of a lymphocyte is to produce antibodies which destroy microorganisms - some lymphocytes persist in our blood after infections and reward us with immunity to specific diseases.
White Blood Cells: Phagocytes
Phagocytes are much larger cells with a large spherical or lobed nucleus. Phagocytes' function is to engulf bacteria and other microorganisms that have infected our bodies. They are the smallest cells - made u
Platelets are the smallest cells – they are made up of fragments of other cells. Platelets release chemicals to make our blood clot when we cut ourselves.