Dictionary Meaning and Definition on 'Leukocyte'
n : blood cells that engulf and digest bacteria and fungi; an
important part of the body's defense system [syn: leucocyte,
white blood cell, white cell, white blood corpuscle,
white corpuscle, WBC]
Wikipedia Meaning and Definition on 'Leukocyte'
White blood cells, or leukocytes (also spelled "leucocytes," "leuco-" being Greek for white), are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five
The number of WBCs in the blood is often an indicator of disease. There are normally between 4×109 and 1.1×1010 white blood cells in a litre of blood, making up approximately 1% of blood in a healthy adult. An increase in the number of leukocytes over the upper limits is called leukocytosis, and a decrease below the lower limit is called leukopenia. The physical properties of leukocytes, such as volume, conductivity, and granularity, may change due to activation, the presence of immature cells, or the presence of malignant leukocytes in leukemia.
The name "white blood cell" derives from the fact that after centrifugation of a blood sample, the white cells are found in the buffy coat, a thin, typically white layer of nucleated cells between the sedimented red blood cells and the blood plasma. The scientific term leukocyte directly reflects this description, derived from Greek λευκό (white), and κύτταρο (cell). Blood plasma may sometimes be green if there are large amounts of neutrophils in the sample, due to the heme-containing enzyme myeloperoxidase that they produce.[See more about Leukocyte at Dictionary 3.0 Encyclopedia]