25.15 : 炎症反応

An inflammatory response is a localized, non-specific immune reaction marked by redness, swelling, heat, pain, and occasional loss of function.

Any damaging stimulus, like an abrasion, chemical irritants, pathogens, or extreme temperatures, usually triggers the inflammatory response.

Soon after the injury or infection, the damaged tissue and immune cells secrete inflammatory chemicals. For example, tissue mast cells release histamine and prostaglandins into the extracellular fluid.

These chemicals increase the dilation and permeability of vessels, resulting in local redness and heat.

These changes can accelerate enzyme reactions, boost phagocyte activity, and help damage foreign proteins.

With additional blood influx, leaking plasma fluid swells the tissue and builds pressure.

The increased pressure, along with the prostaglandins, triggers nerve endings to induce pain.

The inflammatory chemicals act as chemotactic agents to attract phagocytes, including neutrophils and macrophages.

These phagocytes squeeze through the permeable blood vessels and reach the injury site.

They clear the debris and dead cells from the injury and release cytokines to stimulate tissue fibroblasts, initiating tissue repair.