- Mononuclear phagocyte system
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"Reticuloendothelial system" is an older term for the mononuclear phagocyte system. The mononuclear phagocyte system consists primarily of monocytes and macrophages. The spleen is the largest unit of the mononuclear phagocyte system. The monocyte is formed in the bone marrow and transported by the blood; it migrates into the tissues, where it transforms into a histiocyte or a macrophage. Macrophages are diffusely scattered in the connective tissue and in liver (Kupffer cells); spleen and lymph nodes (sinus histiocytes); lungs (alveolar macrophages); and central nervous system (microglia). The half-life of blood monocytes is about 1 day, whereas the life span of tissue macrophages is several months or years. The mononuclear phagocyte system is part of both humoral and cell-mediated immunity. The mononuclear phagocyte system has an important role in defense against microorganisms, including mycobacteria, fungi, bacteria, protozoa, and viruses. Macrophages remove senescent erythrocytes, leukocytes, and megakaryocytes by phagocytosis and digestion.
The mononuclear phagocyte system is a part of the immune system that consists of the phagocytic cells[1] located in reticular connective tissue. The cells are primarily monocytes and macrophages, and they accumulate in lymph nodes and the spleen. The Kupffer cells of the liver and tissue histiocytes are also part of the MPS.
Its functions include:
- Formation of new red blood cells (RBCs) and white blood cells (WBCs).
- Destruction of old RBCs and WBCs.
- Formation of antibody.
- Formation of plasma proteins.
- Formation of bile pigments.
"Reticuloendothelial system" is an older term for the mononuclear phagocyte system, but it is used less commonly now, as it is understood that most endothelial cells are not macrophages.[2]
References
- ^ MeSH Mononuclear+Phagocyte+System
- ^ Inderbir Singh (2006). Textbook of human histology. Jaypee Brothers Publishers. pp. 90–. ISBN 9788180618093. http://books.google.com/books?id=Ej22iANgNkoC&pg=PA90. Retrieved 12 November 2010.
External links
Myeloid immune response Myeloid lineage - Blood (WBC and RBC) Cellular/
HSCsCFU-GMHistiocytes · Kupffer cells · Alveolar macrophage · Microglia · Osteoclasts · Epithelioid cells · giant cells (Langhans giant cells, Foreign-body giant cell, Touton giant cells)CFU-DLCommonCFU-BasoCFU-EosCFU-MegCFU-ECFU-MastNoncellular Categories:- Immune system
- Immunology stubs
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