Cell Injury and Necrosis Quiz

Cell Injury: Necrosis

• Necrosis is a type of cell death characterized by the premature disintegration of cells.
• Necrotic cells stain eosinophilic and display a glassy, homogenous appearance.
• Calcification, a process where calcium deposits within the cells, can occur in necrotic cells. This is called dystrophic calcification.

Types of Cell Death

• Cell death includes necrosis, apoptosis, pyroptosis, necroptosis, and ferroptosis.

Necrosis: Detailed Characteristics

• RNA, which typically stains basophilic (darker), is lost in necrotic cells.
• Denatured (changed) proteins, generally, increase in necrotic cells.
• Glycogen is often lost in necrotic cells.

DNA Damage in Necrosis

• Karyopicnosis is a nuclear shrinkage and increased basophilia; often seen in apoptosis, also occurs in necrosis.
• A picnotic nucleus results from fragmentation of the nucleus.
• Karyolysis involves a pale nucleus due to loss of basophilia, caused by endonuclease-induced DNA loss.

Types of Necrosis

• Coagulation Necrosis:

  • Occurs after ischemia (restricted blood flow)
  • The most prevalent type of necrosis.
  • Ischemic conditions cause a drop in pH
  • Enzymes and proteins denature (lose their structure)
  • No enzymatic degradation happens.

• Other Types of Necrosis:

  • Enzymatic destruction of cells is involved.
  • Liquefactive Necrosis: Cell breakdown into liquid viscous substance, often observed in brains and abscesses.
  • Gangrenous Necrosis: Typically, found in extremities, it has a two-part categorization, dry and wet gangrene. Dry gangrene demonstrates coagulation necrosis while wet gangrene also includes liquefaction necrosis.
  • Caseous Necrosis: Shows a cheese-like appearance and is commonly associated with tuberculosis.
  • Fat Necrosis (Saponification Necrosis):
  • Is characterized by the breakdown of fat tissues due to trauma and pancreatitis.
  • Fibrinoid Necrosis: Immunity complex vasculitis (PAN), and other similar conditions often lead to this type of necrosis.

Additional Notes

• Coagulation necrosis maintains cellular integrity, whereas in other forms necrosis, cells are degraded.
• Eosinophilic dead cells devoid of nuclei (ghost cells) are a feature of coagulation necrosis.

Test your knowledge on cell injury and necrosis in this quiz. Explore the characteristics of necrosis, different types of cell death, and DNA damage associated with necrotic cells. Understand key terms and mechanisms involved in cell disintegration.