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Innate Immunity Cellular Responses (view source)
Revision as of 10:06, 1 May 2012
, 10:06, 1 May 2012→Macrophages
==[[Macrophages|Macrophages]]==
==[[Macrophages|Macrophages]]==
[[Image:Monocytes.jpg|thumb|right|150px|Monocytes - J. Bredl, RVC 2008]]
[[Image:Monocytes.jpg|thumb|right|150px|Monocytes - J. Bredl, RVC 2008]]
The innate cellular response begins with recognition and phagocytosis by macrophages that precide in the tissue where the wound occurs. The populations of distinct, tissue-specific macrophages that are present are the:
* Alveolar macrophages (lung)
* Tissue histiocytes
* Glomerular macrophages (kidney)
* Hepatic Küpffer cells (liver)
* CNS microglia (Central Nervous System: Brain and Spinal Cord)
* Sinus-lining macrophages of the lymph nodes and spleen
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When [[Phagocytosis|phagocytosis]] of the bacteria or fungi by the tissue macrophages occurs they release a number of [[Cytokines|cytokines]] that have a number of effects. The first being the activation of the endothelium that results in the expression of adhesion molecules that allow leukocytes, in particular the [[Neutrophils|neutrophils]] to bind to the endothelium from the bloodstream and the subsequent extravasation (movement out of the bloodstream). Once the leukocytes are out of the bloodstream, the cytokines released by the tissue macrophages act as chemoattractants that enable the chemotaxis of the leukocytes to the site of infection.
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The [[Monocytes|'''Monocytes''']] are immature macrophages that are circulating phagocytes. They circulate for 6-8 hours and function as phagocytes within the blood and as newly migrated cells in tissues. Their primary function, however, is function to replace the various tissue macrophage populations at the latter stages of the immune response.
==[[Neutrophils|Neutrophils]]==
==[[Neutrophils|Neutrophils]]==