ABO Blood Groups: Red cells that have both 'A' & 'B' protein(antigen) are called to be of AB group. A person's blood never changes throughout his life. They are classified according to the protein (antigen) present in the red blood cell membrane. Red cells that have "A" Protein (antigens) are called A Group. Red cells that have "B" Protein (antigens) are called B Group. Red cells that do not have these antigens are called "O" Group.
Rhesus Blood Group (Rh): Rh group is named after Macacus Rhesus Monkey, as it resembles the proteins in the red blood cells of Rhesus Monkey. If this Rh protein (antigens) is present in red blood call of human beings it is called Rh+ve. If this Rh protein (antigen) is absent it is Rh-ve. 95 - 98% of Indians are Rh+ve and 2-5% are Rh-ve.
Other Blood Groups. There are number of other blood groups which do not have much practical importance like MNSS,P,Lu, Le, Wr, etc.
Blood Cells Are Produced In Marrow. Red cells, white cells and platelets are made in the marrow of bones, especially the vertebrae, ribs, hips, skull and sternum. These essential blood cells fight infection, carry oxygen and help control bleeding.
Plasma Carries Blood Cells. Plasma is a pale yellow mixture of water, proteins and salts. One of the functions of plasma is to act as a carrier for blood cells, nutrients, enzymes and hormones.
Red Cells Deliver Oxygen. Red cells are disc-shaped cells containing hemoglobin, which enables the cells to pick up and deliver oxygen to all parts of the body.
White Cells Defend The Body. White cells are the body's primary defense against infection. They can move out of the blood stream and reach tissues being invaded.
Platelets Help Control Bleeding. Platelets are small cells in the blood that control bleeding. They form clusters to plug small holes in blood vessels and assist in the clotting process