monocyte


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monocyte

 [mon´o-sīt]
a mononuclear, phagocytic leukocyte, 13 μm 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 and circulate in the blood for about 24 hours before migrating to the tissues, such as the lung and liver, where they develop into macrophages. adj., adj monocyt´ic.

mon·o·cyte

(mon'ō-sīt),
A relatively large mononuclear leukocyte (16-22 mcm in diameter) that normally constitutes 3-7% of the leukocytes of the circulating blood and is normally found in lymph nodes, spleen, bone marrow, and loose connective tissue. When treated with the usual dyes, monocytes manifest an abundant pale blue or blue-gray cytoplasm that contains numerous fine, dustlike, red-blue granules; vacuoles are frequently present; the nucleus is usually indented, or slightly folded, and has a stringy chromatin structure that seems more condensed where the delicate strands are in contact. Monocytes that leave the bloodstream and enter the connective tissue spaces are called macrophages.
See also: monocytoid cell, endothelial leukocyte.
[mono- + G. kytos, cell]

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

mon·o·cyte

(mŏn′ə-sīt′)
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.

mon′o·cyt′ic (-sĭt′ĭk), mon′o·cy′toid′ (-sī′toid′) adj.

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.

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.

mon·o·cyte

(mon'ō-sīt)
A relatively large mononuclear leukocyte (16-22 mcm in diameter); monocytes normally constitute 3-7% of the leukocytes of the circulating blood; normally found in lymph nodes, spleen, bone marrow, and loose connective tissue. In stained smears, monocytes have abundant pale blue or blue-gray cytoplasm that contains numerous fine red-blue granules and vacuoles; the nucleus is usually indented, or slightly folded.
[mono- + G. kytos, cell]
Enlarge picture
MONOCYTES: (Orig. mag. ×640)

monocyte

(mon'o-sit?) [ mono- + -cyte],

MO

A mononuclear phagocytic white blood cell derived from myeloid stem cells. Monocytes circulate in the bloodstream for about 24 hr and then move into tissues, at which point they mature into macrophages, which are long lived. Monocytes and macrophages are one of the first lines of defense in the inflammatory process. This network of fixed and mobile phagocytes that engulf foreign antigens and cell debris previously was called the reticuloendothelial system and is now referred to as the mononuclear phagocyte system (MPS).
See: illustration; blood for illus.; macrophagemonocytic (mon-o-sit'ik), adjectiveillustration

Monocyte

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

monocyte

type of white blood cell; 2-10% of normal adult leukocytes; also located in lymph nodes, spleen, bone marrow and loose connective tissue; approximately 15-20μm diameter, with horseshoe-shaped nucleus and granular cytoplasm; they escape from dilated local blood vessels during acute inflammation, to form tissue macrophages (see macrophage)

mon·o·cyte

(mon'ō-sīt)
A relatively large mononuclear leukocyte that normally constitutes 3-7% of the leukocytes in circulating blood.
[mono- + G. kytos, cell]

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.

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.

monocyte leukemia
see monocytic leukemia.
monocyte-macrophage system
References in periodicals archive ?
Stephen Miller at Northwestern University in Illinois and his team found a method to use microparticles made of the biodegradable polymer PLGA to tag these monocytes in mice, New Scientist reported.
People have been thinking of targeting monocyte influx to treat atherosclerosis, but they need to consider macrophage proliferation as an additional or alternative approach, especially in established disease.
Berry will be further characterizing these changes in the monocyte populations in peripheral blood taken from patients over the course of their disease.

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