Pathology cell injury

• General pathology studies the basic reactions of cells and tissues to abnormal stimuli and inherited defects that underlie all diseases.
• Special or systemic pathology studies specific responses of specialized organs and tissues which are responsible for disorders.
• Etiology, a core aspect of disease process, is the cause of a disease.
• Clinical manifestations are the functional consequences of these changes.
• Genetic etiology involves inherited mutations and disease-associated gene variants, or polymorphisms.
• Acquired etiology can be infectious, nutritional, chemical, or physical.
• Idiopathic disease is a disease of unknown cause.
• Pathogenesis is the sequence of cellular, biochemical, and molecular events that follow the exposure of cells or tissues to an injurious agent.
• Metaplasia is a condition where one differentiated cell type is replaced by another cell type, often changing from cells sensitive to stress into cells able to withstand an adverse environment.
• Reduction in size of uterus after parturition is a pathologic condition known as Atrophy.
• Fatty Change is characterized by lipid vacoules.
• Liquefactive Necrosis is characterized by the digestion of the dead cells, focal bacterial or, occasionally, fungal infections, and Pus - creamy yellow necrotic material.
• Cellular Swelling (Hydropic Change/Vacoular Degeneration) is the first manifestation of almost all forms of injury to cells.
• Coagulative Necrosis is characterized by the architecture of dead tissues being preserved, affected tissues exhibiting a firm texture, and the injury denaturing not only structural proteins but also enzymes and so blocking the proteolysis of the dead cells.
• Fat Necrosis is characterized by focal areas of fat destruction, from the release of activated pancreatic lipases, acute pancreatitis (fat saponification), and Ghost fat cells, calcium deposits, inflammation.
• Caseous Necrosis is characterized by foci of tuberculous infection, a friable white appearance of the area of necrosis, and granuloma.
• sequence of cellular, biochemical, and molecular events that follow the exposure of cells or tissues to an injurious agent— pathogenesis
• General – studies basic reactions of cells and tissues to abnormal stimuli and inherited defect that underlie all diseases
• Genetic - inherited mutations and disease- associated gene variants, or polymorphisms
• Acquired - infectious, nutritional, chemical, physical
• Multifactorial - arise from the effects of various external triggers on a genetically susceptible individual (atherosclerosis, cancer)
• A symptom is a feeling which is noticed by a patient, indicating the presence of disease or abnormality.
• A sign is a manifestation that is noted by an observer
• Hypertrophy

  • Increase in size of cells→ increase in size of organ
• Hyperplasia

  • Increase in the number of cells in an organ or

  tissue→increased mass of the organ or tissue
• Atrophy - Reduced metabolic needs of the cells sufficient for it to survive
• Metaplasia

  • One differentiated cell type (epithelial or mesenchymal) is replaced by another cell type
• columnar to squamous -most common

  epithelial metaplasia
• Barrett’s esophagus→intestinal metaplasia
• Cellular Swelling (Hydropic Change/Vacoular Degeneration) - first manifestation of almost all forms of injury to cells
• Irreversible Cell Injury

  • denaturation of intracellular proteins and enzymatic digestion of the lethally injured cell
• Coagulative Necrosis architecture of dead tissues is preserved

  • affected tissues exhibit a firm texture
• Liquefactive Necrosis

  • digestion of the dead cells

  • Pus-creamy yellow necrotic material
• Liquefactive Necrosis

  • focal bacterial or, occasionally, fungal infections
• Caseous Necrosis (cheeselike)

  • foci of tuberculous infection

  • friable white appearance of the area of necrosis

  • granuloma
• Fat Necrosis

  • focal areas of fat destruction

  • from release of activated pancreatic lipase