What is a White Blood Cell?
White blood cells are the body’s sentries, serving as the backbone of the immune system. White blood cells are found throughout the body, in both the blood and the lymphatic system. White blood cells have a density of about 4-11 billion per liter of blood. The scientific name for a white blood cell is leukocyte, simply meaning “white cell.” White blood cells get their name from their color – white. This color was first discovered when blood was put into high-speed centrifuges and separated into its components. In healthy individuals, white blood cells make up about 1% of the blood. In sick individuals, this percentage increases substantially. The ratio of white blood cells in the blood can be used as a diagnostic of illness. There are several different types of white blood cells, all with subtly varying functions. Some of the most common are neutrophils (65%), lymphocytes (25%), monocytes (6%), eosinophils (4%), and basophils (1%). White blood cells originate from stem cells in bone ma
