Cellular Injury II: Classification

Cellular injury is any process that disrupts a cell’s ability to maintain homeostasis, causing structural or functional changes.

Cellular injury is commonly classified by its etiology, that is, the cause and mechanism of damage.

Hypoxic injury results from reduced oxygen delivery to tissues because of inadequate blood supply, most often from arterial obstruction. For example, a coronary artery thrombosis can cause ischemia of the heart muscle, leading to a myocardial infarction.

Chemical injury results from toxic agents that damage cells either directly, like mercury or strong acids, or indirectly through harmful metabolites, as in acetaminophen overdose.

Physical injury from trauma, extreme temperatures, or radiation can mechanically damage or kill cells.

Infectious injury is caused by bacteria, viruses, fungi, or parasites that damage cells directly or trigger an inflammatory response during the immune system's reaction.

Immunologic injury results from abnormal immune responses, including allergies or autoimmune diseases like lupus.