2. Granulocytes have segmented nuclei and are described as polymorphonuclear leukocytes (PMNLs). Depending on the cell type, the mature nucleus may have 2-7 lobes connected by thin strands of nucleoplasm. Granulocyte types are most easily distinguished by their size and staining properties and by the appearance (as seen by EM) of the abundant specific granules in their cytoplasm. These granules are all membrane-limited and bud off the Golgi complex.

In addition to a small Golgi complex, each granulocyte contains a few mitochondria and free ribosomes and sparse RER. a. Neutrophils are the most abundant leukocytes in the blood. They usually constitute 60-70% of the white blood cells, with a limited range of normal variation (50-75%). They are also found outside the bloodstream, especially in loose connective tissue. Neutrophils are the first line of cellular defense against the invasion of bacteria. Once they leave the bloodstream, they spread out, develop ameboid motility, and become active phagocytes. Unlike lymphocytes, neutrophils are all terminally differentiated cells and so are incapable of mitosis.