White blood cell

White blood cells (also called leukocytes or immune cells) are a component of blood. They help to defend the body against infectious disease and foreign materials as part of the immune system. There are normally between 4x109 and 11x109 white blood cells in a litre of healthy adult blood.

Related Topics:
Blood - Infectious disease - Immune system - Litre

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As well as in the blood, white cells are also found in large numbers in the lymphatic system, the spleen, and in other body tissues. When this occurs, it is called emigration.

Related Topics:
Lymphatic system - Spleen

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Also a genetic Disease known as Alpha 1 Anti-trypsin deficiency can result in white blood cells attacking normal human cells

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