Three different sequences of events that result in inflammation or in the enhancement of inflammation

The inflammatory response is triggered whenever body tissues are injured by physical trauma, intense heat, irritating chemicals, or infection and begins when a flood of inflammatory chemicals are released into the extracellular fluid. Macrophages bear surface membrane receptors called Toll-like receptors (TLRs) that play a central role in triggering immune response. Each TLR is recognized for a specific class of attacking microbe. Once activated, a TLR triggers a release of cytokines that promote inflammation and …

…bacteria by increasing pressure. Redness and heat result from the dilation of capillaries. Pain results from a response to prostaglandins and swelling. In severely infected areas, a mixture of dead or dying neutrophils, broken down tissue cells, and dead pathogens (pus) accumulates in the wound. In the inflammatory mechanism fails to clear the area of debris, the sac of pus may form an abscess, which would have to be surgically drained so healing could occur.