Caption: Granulocytic white blood cells (neutrophils), T-lymphocytes and a red blood cell. Granulocytes are leukocytes with granules in their cytoplasm that contain destructive chemicals. Neutrophils are involved in inflammation and other immune responses. They assist in cellular defense (phagocytosis) of pathogenic microorganisms. Neutrophils travel from a capillary to infected regions where antibody / antigen complexes are located. A neutrophil destroys an antigen by engulfing it and injecting lethal chemicals. Macrophages will arrive later to consume any remaining debris. Neutrophils are involved in cellular defense (phagocytosis) of small pathogenic microorganisms. Lymphocytes are involved in the specific immune response and are composed mainly of precursor T cells and B cells (pre-T cells and B cells). Pre-T cells and B cells are subsets of lymphocytes that originate in the red bone marrow from hematopoietic stem cells. Pre-T cells (also known as T lymphocytes) circulate in the blood before migrating to the thymus where they develop into specialized cells (helper T cells and killer T cells) that are able to identify antigens and infected tissue cells. Platelets are cell fragments in the blood that play an essential role in blood clotting and wound repair. Platelets can also activate certain immune responses.
Magnification*: x1,600
Type: SEM
Copyright 2008 Dennis Kunkel Microscopy, Inc.
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