Cell Injury Overview Quiz

Cell Injury

Definition

• Cell injury refers to the structural and functional alterations in cells due to harmful stimuli.

Types of Cell Injury

1. Reversible Injury

   • Cells can recover after the removal of the stressor.
   • Characterized by cell swelling and fatty changes.

2. Irreversible Injury

   • Leads to cell death (necrosis or apoptosis).
   • Associated with severe damage to cell membranes, organelles, and genetic material.

Mechanisms of Cell Injury

• Hypoxia: Reduced oxygen supply affects ATP production.
• Chemical Injury: Toxic substances disrupt cellular functions.
• Infections: Pathogens cause cell damage through direct effects or toxins.
• Physical Injury: Trauma, temperature extremes, and radiation impact cell integrity.
• Immunological Injury: Autoimmune responses can harm healthy cells.

Pathophysiological Changes

• Cellular Swelling: Accumulation of water due to failure of ion pumps.
• Fatty Change: Excess fat accumulation in cells, particularly in liver cells.
• Necrosis:
  • Coagulative: Common in hypoxic injury.
  • Liquefactive: Often in bacterial infections.
  • Caseous: Associated with tuberculosis.
  • Apoptosis: Programmed cell death, tidy process, no inflammation.

Indicators of Cell Injury

• Enzymatic Markers: Release of enzymes (e.g., troponin in myocardial injury).
• Morphological Changes: Observed under a microscope (e.g., swelling, membrane blebs).
• Functional Changes: Altered physiological functions of the affected organ/tissue.

Repair Mechanisms

• Regeneration: Replacement of damaged cells with new cells of the same type.
• Fibrosis: Replacement of damaged tissue with scar tissue (collagen).

Conclusion

• Understanding cell injury is crucial for diagnosing and treating various diseases and conditions.

Definition of Cell Injury

• Refers to structural and functional alterations in cells caused by harmful stimuli.

Types of Cell Injury

• Reversible Injury:
  • Cells can recover after removal of the stressor.
  • Characterized by cell swelling and fatty changes.
• Irreversible Injury:
  • Results in cell death, either through necrosis or apoptosis.
  • Involves severe damage to membranes, organelles, and genetic material.

Mechanisms of Cell Injury

• Hypoxia:
  • Reduced oxygen supply leads to decreased ATP production.
• Chemical Injury:
  • Toxic substances disrupt normal cellular functions.
• Infections:
  • Pathogens damage cells directly or via toxins.
• Physical Injury:
  • Trauma, extreme temperatures, and radiation compromise cell integrity.
• Immunological Injury:
  • Autoimmune responses can damage healthy cells.

Pathophysiological Changes

• Cellular Swelling:
  • Occurs due to water accumulation from failed ion pumps.
• Fatty Change:
  • Accumulation of excess fat, particularly in liver cells.
• Necrosis Types:
  • Coagulative: Common in hypoxic conditions.
  • Liquefactive: Typically seen in bacterial infections.
  • Caseous: Associated with tuberculosis.
• Apoptosis:
  • Programmed cell death, a clean process with no inflammation.

Indicators of Cell Injury

• Enzymatic Markers:
  • Release of enzymes such as troponin indicates myocardial injury.
• Morphological Changes:
  • Observable under a microscope, includes swelling and membrane blebs.
• Functional Changes:
  • Alterations in the physiological functions of affected organs or tissues.

Repair Mechanisms

• Regeneration:
  • Process of replacing damaged cells with new cells of the same type.
• Fibrosis:
  • Replacement of damaged tissue with scar tissue, primarily collagen.

Importance of Understanding Cell Injury

• Critical for diagnosing and treating a variety of diseases and conditions.

Test your understanding of cell injury, including its types, mechanisms, and pathophysiological changes. This quiz covers reversible and irreversible injury, along with various factors contributing to cell damage. Perfect for students studying cell biology or related fields.