monocyte

monocyte /mono·cyte/ (mon´o-sīt) a mononuclear, phagocytic leukocyte, 13μ to 25μ in diameter, with an ovoid or kidney-shaped nucleus, and azurophilic cytoplasmic granules. Formed in the bone marrow from promonocytes, monocytes are transported to tissues, such as the lung and liver, where they develop into macrophages.monocyt´ic

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mon·o·cyte (mn-st)

n.

A large, circulating, phagocytic white blood cell that has a single well-defined nucleus and very fine granulation in the cytoplasm and that constitutes from 3 to 8 percent of the white blood cells in humans.

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mono·cytic (-stk), mono·cytoid (-stoid) adj.

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Monocyte

White blood cell that increases during a variety of conditions including severe infections. It removes debris and microorganisms by phagocytosis.

Mentioned in: AIDS, AIDS Tests, White Blood Cell Count and Differential

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monocyte

[mon′əsīt]

Etymology: Gk, monos + kytos, cell

a large mononuclear leukocyte, 13 to 25 μm in diameter with an ovoid or kidney-shaped nucleus, containing chromatin material with a lacy pattern and abundant gray-blue cytoplasm filled with fine, reddish, and azurophilic granules. See also monocytosis. monocytic, adj.

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monocyte (mon´osīt),

n a large mononuclear leukocyte with an ovoid or kidney-shaped nucleus, containing chromatin material with a lacy pattern and abundant gray-blue cytoplasm filled with fine, reddish, and azurophilic granules. They are produced by the bone marrow from hematopoietic stem cell precursors called monoblasts and circulate in the bloodstream for about 1 to 3 days and then typically move into tissues throughout the body. They make up 3% to 8% of the leukocytes in the blood. In the tissues, monocytes mature into different types of macrophages at different anatomic locations. They are responsible for phagocytosis (ingestion) of foreign substances in the body. They can perform phagocytosis using intermediary (opsonising) proteins such as antibodies or complement that coat the pathogen, as well as by binding to the microbe directly via pattern-recognition receptors that recognize pathogens. They are also capable of killing infected host cells via antibody, termed
antibody-mediated cellular cytotoxicity. They can increase in amount with certain disease. See also monocytosis.

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monocyte

a mononuclear, phagocytic leukocyte, 13 to 25 μm in diameter, having an ovoid or kidney-shaped nucleus and azurophilic cytoplasmic granules. Monocytes are derived from promonocytes in the bone marrow. They circulate in the blood for about 24 hours before migrating to the tissues, as in the lung and liver, where they develop into macrophages.

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monocyte leukemia

see monocytic leukemia.

monocyte-macrophage system

see reticuloendothelial system.

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monocyte

Hematology A phagocytic WBC that arises in BM from a common progenitor, CFU-GM; 'daughter' monocytes circulate in the blood, forming resident and transient populations in various sites; resident monocytes–histiocytes include Kupffer cells–liver, Langerhans cells–dermis, microglial cells–brain, pleural, peritoneal, alveolar macrophages and osteoclasts; monocytes normally constitute 2%–8% of peripheral WMCs, measure 12-25 µm, have a reniform nucleus with lacy chromatin, an N:C ratio of 4:1 to 2:1, and gray blue cytoplasm containing lysosomal enzymes–eg, acid phos, arginase, cathepsins, collagenases, deoxyribonuclease, lipases, glycosidases, plasminogen activator and others, and surface receptors–eg, FcIgG and C3R; monocytes are less efficient in phagocytosis than PMNs, but have a critical role in antigen processing. See CFU-GM, White blood cell.