Outcomes of Acute and Chronic Inflammation

Restoration of the site of acute inflammation to normal, involves removal of cellular debris by macrophages and resorption of edema fluid by lymphatics. Usually occurs when injury is limited or short-lived, there is little tissue destruction, and damaged cells can regenerate.

Replacement of damaged tissue with fibrous connective tissue, occurs when there is substantial tissue destruction, tissues incapable of regeneration are damaged, or there is abundant fibrin exudation that cannot be cleared.

The process of resolving inflammatory exudates by fibrosis where connective tissue grows into the area of damage or exudate.

A type of acute inflammation characterized by the production of pus, which is a thick, yellowish fluid composed of dead neutrophils, bacteria, and other debris.

Factors that influence the outcome of acute inflammation, including the type of injury, the severity of injury, the specific tissue involved, and the body's ability to respond.

A type of inflammatory reaction characterized by the formation of granulomas, which are collections of immune cells, often surrounded by a rim of fibrosis.

Small, round masses of immune cells, frequently found in granulomatous inflammation.

Macrophages that have taken on an epithelial-like appearance, often seen in granulomas.

Large, multinucleated cells formed by the fusion of macrophages, often present in granulomas.

Granulomas that form in response to foreign objects that cannot be readily phagocytosed.

Granulomas that form in response to poorly degradable antigens, usually involving T cell-mediated immune responses.

The systemic changes associated with inflammation, often involving fever and the production of acute-phase proteins.

The transition from an acute inflammatory response to a long-term, chronic state. This happens when the initial injury persists or healing is disrupted, leading to sustained inflammation and tissue damage.

Chronic inflammation is a prolonged inflammatory process lasting weeks or months, characterized by simultaneous inflammation, tissue destruction, and healing.

Chronic inflammation can arise after acute inflammation as part of the normal healing process, due to persistent stimuli, or even without prior acute inflammation.

Infections by persistent microbes, particularly those that live inside cells, can trigger chronic inflammation.

Hypersensitivity reactions, including autoimmune diseases, can lead to chronic inflammation. These reactions involve an abnormal response to self-antigens or harmless substances.

Prolonged exposure to toxic substances, either from the environment (e.g., silica) or the body itself (e.g., lipids), can cause chronic inflammation.

Chronic inflammation is characterized by an infiltration of specific immune cells, tissue destruction, and attempts at healing by fibrosis.