PATHO: CELLULAR INJURY

• Functional and morphologic changes are reversible if the damaging stimulus is removed

  REVERSIBLE CELL INJURY
• Becomes irreversible with continuing damage and Cell cannot recover and dies

  Irreversible Cell Injury
• Range from gross physical trauma of a motor vehicle accident to the single gene defect that results in a defective enzyme underlying a specific metabolic disease

  cause of cell injury
• OXYGEN DEPRIVATION

  hypoxia
• interferes with aerobic oxidative respiration“Oxygen Deficiency”

  hypoxia
• Loss of blood supply in tissue due to impeded arterial flow or reduced venous drainage -“Hypoxemia”- and it is MOST common cause of hypoxia

  ISCHEMIA
• A number of chemical substances can injure cells, Oxygen at sufficiently high partial pressures is toxic

  CHEMICAL AGENTS
• Oxygen at sufficiently high partial pressures is toxic

  CORROSIVE CHEMICALS
• vomited out of the body

  NON-CORROSIVE CHEMICALS
• Could be bacteria, viruses, or fungi

  INFECTIOUS AGENT
• Trauma, extremes of temperatures,radiation, electric shock, and sudden changes in atmospheric pressure all have wide-ranging effects on cells

  PHYSICAL AGENTS
• Cellular Senescence leads to alterations in replicative and repairabilities of cells and tissues

  NUTRIENT DEFICIENCY
• major pathway of cell death in many commonly encountered injuries

  NECROSIS
• active, energy-dependent, tightly regulated types of cell death seen in some specific situations “Programmed Cell Death”

  APOPTOSIS
• INFARCTS, IN ALL SOLIDS ORGANS EXCEPT THE BRAIN

  COAGULATIVE NECROSIS
• BRAIN (LIQUEFY THE TISSUE)

  LIQUEFACTIVE NECROSIS
• DIABETIC FOOD/USUALLY ONLIMB, GENERALLY ON LOWERLIMBLOWER LIMB

  GANGRENOUS NECROSIS
• TUBERCULOSIS (CHEESE-LIKE)

  CASEOUS NECROSIS
• PANCREATIC LIPASE/ ALCOHOL CAUSES PANCREATITIS

  FAT NECROSIS
• SEEN IN IMMUNE REACTIONS INVOLVING BLOOD VESSELS/“FIBRINOID” (FIBRIN-LIKE)/ LUPUS

  FIBRINOID NECROSIS
• it is defined as the paradoxical exacerbation of cellular dysfunction and death, following the restoration of blood flow to previously Ischaemic tissues.

  Reperfusion ischemic injury