Reticuloendothelial system
- Reticuloendothelial system
The reticuloendothelial system (RES), part of the immune system, consists of the phagocytic cells located in reticular connective tissue, primarily monocytes and macrophages. These cells accumulate in lymph nodes and the spleen. The Kupffer cells of the liver and tissue histiocytes are also part of the RES.
Mononuclear phagocytic system and lymphoreticular system are synonymous with RES.
The reticuloendothelial system is divided into "primary" and "secondary" lymphoid organs.
Primary lymphoid organs
Primary (or "central") lymphoid organs - the sites where the cells of the RES are "produced". The cells of the RES are produced in the bone marrow.
The thymus is also included as it is the required site for T cell maturation.
econdary lymphoid organs
Secondary (or "peripheral") lymphoid organs - the sites where the cells of the RES "function". This includes the lymph nodes, tonsils, spleen, and "MALT" (mucosa-associated lymphoid tissue).
*MALT is further divided into the "GALT" (gut-associated lymphoid tissue) and the "BALT" (bronchus-associated lymphoid tissue).
*The Kupffer cells of the liver act as part of this system but are not organized into a tissue; rather, they are dispersed throughout the liver sinusoids.
*The microglia of the Central Nervous System (CNS) can be considered a part of the reticuloendoethelial system. They are scavenger cells that proliferate in response to CNS injury.
Function
The secondary lymphoid structures function to survey all entering or circulating antigen and to mobilize an immune response against foreign antigen upon its discovery. The GALT and BALT are privy to a myriad of antigen entering the gastrointestinal and respiratory tracts, respectively. All extracellular fluid must filter through lymph nodes as it traverses the lymphatics on its way back to the systemic circulation. Antigen residing in the interstitium is thus swept to the lymph nodes for processing.
Finally, the spleen filters the blood in search of antigen. Upon the discovery of foreign antigen, all of these tissues react in a similar manner to amass an appropriate and multifaceted immune response.
Clinical significance
Lymphoma of the reticuloendothelial system is called reticuloendotheliosis.
External links
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2010.
Look at other dictionaries:
reticuloendothelial system — n a diffuse system of cells of varying lineage that include esp. the macrophages and the phagocytic endothelial cells lining blood sinuses and that were orig. grouped together because of their supposed phagocytic properties based on their ability … Medical dictionary
reticuloendothelial system — Immunol. the aggregate of the phagocytic cells, including certain cells of the bone marrow, lymphatic system, liver, and spleen, that have reticular and endothelial characteristics and function in the immune system s defense against foreign… … Universalium
reticuloendothelial system — noun a widely distributed system consisting of all the cells able to ingest bacteria or colloidal particles etc, except for certain white blood cells • Syn: ↑RES • Hypernyms: ↑system • Part Holonyms: ↑immune system • Part Meronyms: ↑ … Useful english dictionary
reticuloendothelial system — noun Date: circa 1923 mononuclear phagocyte system; broadly the mononuclear phagocyte system plus certain other cells now known to be pinocytic or only weakly phagocytic … New Collegiate Dictionary
reticuloendothelial system — The phagocytic system of the body, including the fixed macrophages of tissues, liver and spleen. Rather old fashioned term that is coming back into use; ‘mononuclear phagocyte system’ is probably better when only phagocytes are meant … Dictionary of molecular biology
reticuloendothelial system — reticuloendothe′lial sys tem n. imu the aggregate of the phagocytic cells that have reticular and endothelial characteristics and function in the immune system s defense against foreign bodies Abbr.: RES … From formal English to slang
reticuloendothelial system — RES a community of cells – phagocytes – spread throughout the body. It includes macrophages and monocytes. The RES is concerned with defence against microbial infection and with the removal of worn out blood cells from the bloodstream. See also:… … The new mediacal dictionary
reticuloendothelial — Denoting or referring to reticuloendothelium. See r. system. * * * re·tic·u·lo·en·do·the·li·al ri tik yə lō .en də thē lē əl adj of, relating to, or being the reticuloendothelial system <reticuloendothelial tissue> <reticuloendothelial… … Medical dictionary
system — systemless, adj. /sis teuhm/, n. 1. an assemblage or combination of things or parts forming a complex or unitary whole: a mountain system; a railroad system. 2. any assemblage or set of correlated members: a system of currency; a system of… … Universalium
reticuloendothelial — adjective Etymology: New Latin reticulum + endothelium Date: circa 1923 of, relating to, or being the reticuloendothelial system … New Collegiate Dictionary
