cell injury + adaptation

• What does aetiology refer to in medicine?

  Cause of disease
• What is usually true about the cause of diseases?

  They are usually multifactorial
• What are some environmental factors that can cause disease?

  Infective agents, chemicals, nutritional imbalance
• What are infective agents that can cause disease?

  Bacteria, fungi, virus
• How can chemicals contribute to disease?

  Through poison and smoking
• What nutritional imbalance is associated with diabetes type 2?

  Excessive sugar intake
• What is mechanical trauma in the context of disease?

  Injury from radiation or electric shock
• What does hypoxia/anoxia refer to?

  Lack of oxygen in tissues
• What does iatrogenic mean?

  Caused by clinician
• What is cellular adaptation?

  Reversible structural responses to mild stress
• What happens when stress is removed from a cell?

  The cell reverts to normal
• What occurs with severe, persistent stress on a cell?

  Irreversible injury and cell death
• What are the stages in cellular response to stress?

  Adaptive responses, cell injury, cell death
• What is reversible cell injury?

  Cell may recover from mid to moderate stress
• What characterizes irreversible cell injury?

  Persistent or severe stress leads to cell death
• What occurs during reversible cell injury?

  Changes are reversible if damaging stimulus is removed
• What is cellular swelling?

  Cloudy swelling of the cell
• What causes fatty change in cells?

  Abnormal accumulation of triglycerides
• What leads to the appearance of lipid vacuoles in cytoplasm?

  Cells dependent on fat metabolism
• What can cause reversible cellular swelling?

  Membrane disruption and defects
• What happens to the Na/K pump during reversible cellular swelling?

  Decreased efficiency of the pump
• What is hydropic swelling?

  Increased intracellular water in cells
• What are general mechanisms against cell injury?

  Membrane disruption, loss of ATP, oxidative stress
• What does membrane disruption lead to?

  Defects in permeability and failure of pumps
• What causes loss of ATP?

  Ischemia, toxins, mitochondrial damage
• What are consequences of mitochondrial damage?

  Mitochondrial permeability and reactive oxygen species
• What is oxidative stress?

  Generation of free radicals damaging cells
• What is apoptosis?

  Genetically programmed cell death
• How does apoptosis differ from necrosis?

  Apoptosis maintains membrane integrity
• What is necrosis?

  Pathological cell death following injury
• What are nuclear changes in necrosis?

  Pyknosis, karyorrhexis, karyolysis
• What is coagulative necrosis?

  Cells retain outline as proteins coagulate
• What is liquefactive necrosis?

  Brain tissue liquefies due to ischemia
• What is caseous necrosis?

  Structureless collection of lysed cells
• What is pulp necrosis?

  Caused by bacterial infiltration from cavities
• What is the process of apoptosis?

  Cytoskeleton breaks down, forming apoptotic bodies
• What happens to apoptotic bodies?

  They are consumed by phagocytic cells
• What is a key feature of apoptosis?

  No release of cytoplasmic contents
• What are the differences between apoptosis and necrosis?

  • Apoptosis:
  • Physiological/pathological
  • Genetically programmed
  • Maintains membrane integrity
  • Energy dependent
  • No inflammatory response
  • Necrosis:
  • Catastrophic/pathological
  • Loss of membrane integrity
  • Causes inflammation
• What are the types of necrosis and their characteristics?

  • Coagulative necrosis:
  • Cells retain outline, proteins coagulate
  • Liquefactive necrosis:
  • Brain tissue liquefies, forms abscess
  • Caseous necrosis:
  • Structureless collection of lysed cells
  • Pulp necrosis:
  • Caused by bacterial infiltration, reversible or irreversible