Acute Inflammation
Rapid onset, short lived inflammation (less than a week) characterized by edema, the emigration of leukocytes (often neutrophils). Can lead to chronic inflammation or repair.
Chronic Inflammation
Inflammation of long duration (with no end) characterized by the presence of lymphocytes, macrophages, and neovascularization. Can lead to fibrosis and tissue destruction.
Repair
Occurs after acute inflammation and is characterized by the emigration of monocytes that remove damaged tissue. Can lead to resolution (regeneration) or the development of granulation tissue followed by scar/fibrosis.
Granulation Tissue
A step during the repair process that is characterized by the proliferation of fibroblasts and endothelial cells.
Fibrosis
The deposition of collagen and other matrix proteins that fill-up an area of tissue damage incapable of regeneration, resulting in a scar.
Cirrhosis
Fibrosis of the liver following chronic injury. By definition, it involves fibrous entrapment of regenerated nodules of parenchyma. The fibrosis extends from portal to portal tract (or portal to central vein) and involves the entire liver.
Granuloma
A nodular, chronic inflammatory response consisting of lymphocytes, macrophages, giant cells, fibroblasts, and fibrous tissue. It occurs when macrophages encounter something that they cannot digest (e.g. foreign bodies, certain bacteria). Occurs in casseous and non-casseous types.
Caseous necrosis
Necrosis in which the tissue is soft, dry and cheesy. Usually occurs in the center of caseating granulomas in response to tuberculosis or fungi.
Multinucleated Giant Cell
Macrophages that fuse together forming a large multinucleated cell, often found around granulomas.
Coagulative Necrosis
Death of cells, the protoplasm of the cells becoming fixed and opaque by coagulation of the protein elements, the cellular outline persisting for a long time.
Contraction Bands
Fixed, hyper-contracted bands of contractile proteins in dead myocyte fibers. Seen within hours of an infarct.
Autolysis
The destruction of tissues or cells of an organism by the action of substances, such as enzymes, that are produced within the organism. Also called self-digestion. Frequently occurs port-mortem where is fails to elicit an inflammatory response.
Anthracosis
Accumulation of carbon in the lungs from inhaled smoke, coal dust, or soot. Mild form seen in "city dwellers" lung. Severe form seen in coal miners: "black" lung.
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