Neutrophils are 
white blood cells and part of the 
immune system. They are the most common PMN (polymorphonuclear 
granulocytes[?]), constituting about 99% of them.  PMNs account for 70% of all leukocytes.  Neutrophils are active phagocytes capable of only one phagocytic event, expending all of their glucose reserves in an extremely vigorous 
respiratory burst[?].  Being highly-motile, neutrophils quickly congregate at a focus of 
infection.  They are much more numerous than the longer-lived monocytes/macrophages.  The first phagocyte a pathogen is likely to encounter is a neutrophil.  Some authorities feel that the short lifetimes of neutrophils is an evolutionary adaptation to minimize propagation of those pathogens that parasitize phagocytes.  The more time such parasites spend outside a host cell, the more likely they will be destroyed by some component of the body's defenses.
 
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