Types of Necrosis Quiz

Types of Necrosis

• Coagulative necrosis: most common type of necrosis, dead tissue architectures are preserved for at least a couple of days, caused by hypoxia, burns, and viral hepatitis.
• Liquefactive necrosis: necrotic cells undergo complete digestion and liquefaction, high level of enzymatic activity on dead cells, commonly seen in tissue rich in lysosomal enzymes (brain) and suppurative inflammation (Pyogenic bacterial infections).
• Caseous necrosis: unique form of cell death, tissue maintains a cheese-like appearance, grayish white, soft and friable, accompanied by granulomatous inflammation, seen in Mycobacterium tuberculosis infection.
• Fat necrosis: necrosis of fatty tissue, two types: enzymatic fat necrosis and traumatic fat necrosis, seen in conditions like acute fatty liver in pregnancy and hepatotoxins.

Mechanism of Necrosis

• Hypoxia leads to increased anaerobic glycolysis, accumulation of lactic acid, and denaturation of intracellular proteins (lysosomal enzymes).
• Digestion of necrotic cells occurs through autolysis (digestion by its own enzymes) or heterolysis (digestion by enzymes secreted by other cells like neutrophils and macrophages).

Characteristics of Necrosis

• Always accompanied by inflammatory reaction.
• Result of a pathological condition.
• Causes: hypoxia, pathogens, chemical and physical agents, immunological injury.
• Morphological changes include nuclear changes (pyknosis, karyorrhexis) and cytoplasmic changes (protein denaturation, eosinophilic karyolysis).

Removal of Necrotic Tissue

• Two mechanisms: autolysis and heterolysis.
• Autolysis: digestion of necrotic tissue by its own enzymes (lysosomes).
• Heterolysis: digestion by enzymes secreted by other cells (neutrophils, macrophages).

Test your knowledge on different types of necrosis including coagulative and liquefactive necrosis. Learn about the causes, mechanisms, and characteristics of each type of necrosis.