A part of innate immunity, the Inflammatory Response occurs when injured tissues induce release of vasodilatory, opsonizing, and chemotactic mediators that attract macrophages and leukocytes to phagocytize and destroy foreign substances; dilate local blood vessels increasing local blood flow; increase capillary permeability; produce edematous swelling; and induce pain. Plasma- and cell-derived inflammatory mediators include Prostaglandins, Leukotrines, Cytokines, Lymphokines, Monokines, PAF, Histamine, Bradykinin, Complement, and Interferons.

The immediate defensive reaction (by vertebrate tissue) to infection or injury caused by chemical or physical agents. The process is characterized by local vasodilation, extravasation of plasma into intercellular spaces and accumulation of white blood cells and macrophages.