Inflammation

Inflammation is the reaction manifested by the tissues to injury. The classical signs of inflammation are redness, swelling, heat, and pain. The arteries supplying an inflamed part dilate, and the flow of blood in them is retarded; fluid escapes from the capillaries involved in the inflammatory processes. [Exudation Fluid.] White blood corpuscles make their way through the capillary walls, and proliferation of these cells or of the connective tissue cells of the affected parts occurs. Such formation of new cells, if excessive, may result in suppuration, or the formation of pus, the pus corpuscles being the degenerate descendants of proliferating cells. Inflammation may terminate in resolution with absorption of the inflammatory products, or such resolution may be complicated by suppuration and the formation of abscesses, or by ulceration where the parts affected lie superficially. When the inflammation is severe, it may involve the death of considerable portions of tissue (gangrene or necrosis). The cause of inflammation may be some mechanical injury, or the introduction of some chemical irritant, or an infective agent or organism.