A blood cell is any cell of any type found in blood. There are three main types of blood cells in mammals:

• Red blood cell-carries oxygen
• White blood cell-kills bacteria and cleans up debris
• Platelet-helps heal wounds. Platelets are really thrombocytes. These are small fragments (pieces) of a cell called a megakaryocyte. The platelets take part in blood clots when injury occurs.

Discovery

Jan Swammerdam a scientist from the Netherlands was the first person to observe red blood cells under a microscope. Antoni van Leeuwenhoek, another scientist from the Netherlands, was the first to draw an illustration of "Red Blood Cells".

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