Neutrophilic granulocyte (peripheral blood, human)

Electron microscopy. Survey (A) and detail (B) of a neutrophilic granulocyte. Two nuclear lobes (1) of the segmented nucleus are visible in a cytoplasm with a moderate amount of organelles but with abundant granules (2, 3) of varying sizes. The detail shows in the cytoplasm large amounts of granules of varying forms, sizes and densities. The motile human neutrophil (9 - 14 m) appears to contain at least four types of granules. The primary granules (2) are spherical to ellipsoid (light microscopic) azurophilic granules, and are large (0.4 m). They contain e.g. acid hydrolases as acid phosphatase, arylsulfatase, beta-glucuronidase, but also myeloperoxidase as an antibacterial substance. The majority of smaller (3) granules of varying sizes and forms (diameter 0.2 m up to length 0.8 m) are the specific, or secondary granules, they contain substances like lysozyme, phagocytin to be secreted extra-cellularly involved in mobilization of inflammatory mediators and complement activation.