The acute inflammatory response can be stimulated by an infection, tissue necrosis, foreign bodies, or immune reactions. The stimulus is recognized by receptors on the surface phagocytes, dendritic cells, and epithelial cells. The two types of the receptors are the toll like receptors and the inflammasomes. The toll like receptors recognize bacterial and virus DNA and endotoxins and in response produce inflammatory mediators. The inflammasome recognizes microbial or dead cell products or components and elicits a cascade that activates caspase 1 leading to the activation of IL-1 beta and the inflammatory response. The chemical mediators like histamine induced vascular changes such as vasodilation to increase blood flow to the site of injury.
