Granulocytes are a category of white blood cells characterised by the presence of granules in their cytoplasm. They're also called polymorphonuclear leukocytes (PMN or PML) because of the varying shapes of the nucleus, which's usually lobed into three segments. In common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil granulocytes, the most abundant of the granulocytes. Granulocytes or PMN are released from the bone marrow by the regulatory complement prote… (More on Granulocytes)