Lesson 4: Cellular Degeneration and Infiltrations

• What do degenerations and infiltrations indicate about a cell?

  The cell is sick
• What is degeneration in cellular terms?

  Accumulation of metabolites in damaged cells
• What does infiltration refer to in cellular responses?

  Overloading normal cells with excessive materials
• What are the three main groups of cellular degeneration and infiltration?

  1. Water Overload
  2. Metabolite Overload
  3. Storage Loading
• What is hydropic degeneration?

  Acute cellular swelling due to mitochondrial damage
• What causes increased osmotic pressure in hydropic degeneration?

  Failure of sodium pump and ATP production
• How does hydropic degeneration affect cellular membranes?

  It causes influx of water molecules
• What happens to the Na-K pump after cell injury?

  Decreased ATP leads to Na influx
• What is the gross appearance of organs affected by hydropic degeneration?

  • Swelling of cells
  • Enlarged pale and heavy organ
  • Best observed in liver, kidneys, brain
• What microscopic changes occur in cells with hydropic degeneration?

  Vacuoles appear in the cytoplasm
• What are common causes of hydropic degeneration?

  Common response to most types of injury
• In which conditions is hydropic degeneration observed to be severe?

  Toxic and febrile conditions
• What happens to cells infected with viruses like FMD?

  Vacuoles coalesce and cells burst
• What is metabolite overload?

  Excessive accumulation of normal metabolic products
• What is fat overload in cellular terms?

  Accumulation of lipids in parenchymal cells
• Which cells are primarily affected by fat overload?

  Liver, kidney, and myocardial cells
• What can cause fat overload in cells?

  High fat diet and impaired protein production
• What is the gross description of an organ affected by fat overload?

  Uniformly pale and greasy appearance
• How does diabetes mellitus contribute to fat overload?

  It causes abnormal fat metabolism
• What is fatty change in cells?

  Presence of small fat droplets in cytoplasm
• What is the microscopic description of fatty change?

  Vacuoles appear foamy in cytoplasm
• What characterizes fatty infiltration (steatosis)?

  Single globule of fat displacing the nucleus
• Where does fatty infiltration commonly occur?

  Myocardium and skeletal muscles
• What is hyaline change in cells?

  Pink staining, glassy cytoplasmic droplets
• What is fibrinoid accumulation?

  Spherical protein accumulation resembling fibrin
• Where is fibrinoid found?

  Degenerating blood vessel walls and connective tissues
• What does fibrinoid consist of?

  Plasma proteins including fibrin and albumin
• What is the appearance of fibrinoid material?

  Amorphous, bright, eosinophilic material
• What is fibrinoid associated with?

  Necrosis of connective tissue and blood vessels
• What is fibrinoid?

  A spherical type of protein accumulation
• Why is it called "fibrinoid"?


  It resembles coagulated fibrin
• Where is fibrinoid found?

  In degenerating blood vessel walls
• What proteins are included in fibrinoid?

  Fibrin, albumin, globulins, and complement
• How does fibrinoid appear microscopically?

  As amorphous, bright, eosinophilic material
• What is fibrinoid associated with?

  Necrosis of connective tissue and blood vessels
• What characterizes amyloidosis?

  Deposition of proteinaceous material
• Where is amyloidosis typically seen?

  In renal glomeruli and liver sinusoids
• What does mucopolysaccharidosis involve?

  Secretions of epithelial cells
• What is the appearance of tissues in mucopolysaccharidosis?

  Transformed into jelly-like structures
• What is the gross appearance of affected organs in mucopolysaccharidosis?

  Gelatinous appearance and consistency