Morphology Of Cell Injury Question And Answers

Morphology Of Cell Injury Important Notes

1. Types of necrosis

Morphology Of Cell Injury Types of necrosis

2. Types of degeneration

  • Cloudy swelling – a most common type
  • Hydropic
  • Hyaline
  • Mucoid degeneration

3. Morphological forms of cell injury

  • Reversible
    • Cellular Swelling
    • Fatty change
    • Hyaline change
    • Mucoid change
  • Irreversible
    • Apoptosis
    • Autolysis
    • Necrosis

4. Apoptosis

  • Apoptosis is physiological or programmed cell death
  • It eliminates cells that are genetically altered or injured beyond repair without eliciting a severe host reaction
  • It prevents the development of epithelial dysplasia by programmed cell death
  • It is usually single-cell death and undergoes coagulative necrosis.

Morphology of Cell Injury

Morphology Of Cell Injury Long Essays

Question 1. Classify necrosis. Discuss its nuclear changes.

Necrosis Classification:

Necrosis is classified into the following types:

1. Coagulative necrosis

  • Caused by irreversible focal injury

2. Liquefaction necrosis

  • Occurs due to ischaemic injury and bacterial or fungal infections

3. Caseous necrosis

  • Found in the center of foci of tuberculous infections

4. Fat necrosis

  • Occurs at two anatomically different locations

5. Fibrinoid necrosis

  • Deposition of fibrin-like material occurs

Morphology Of Cell Injury Fibrinoid necrosis

Nuclear Changes In Necrosis:

1. Pyknosis

  • It is a condensation of nuclear chromatin

2. Karyolysis

  • Undergo dissolution

3. Karyorrhexis

  • Fragmentation

Question 2. Define necrosis. Classify and discuss different types of necrosis.
Define necrosis. Discuss etiopathogenesis and morphology of various types of necrosis.


Necrosis is defined as a localized area of death of tissue followed by degradation of tissue by hydrolytic enzymes liberated from dead cells, it is invariably accompanied by an inflammatory reaction

Necrosis Types:

There are five types of necrosis

1. Coagulative necrosis

  • Causes:
    • Ischaemia
    • Bacterial infection
    • Chemical agents like mercuric chloride
  • Pathogenesis
    • Irreversible cell injury
    • Results in sudden cessation of blood flow

2. Liquefaction necrosis

  • Causes:
    • Ischaemia
    • Bacterial infections
  • Pathogenesis
    • Bacterial and fungal infections produce hydro-lytic enzymes
    • This causes the degradation of tissue

3. Caseous necrosis

  • Occurs in the center of foci of Tuberculous infections

4. Fat necrosis

  • Occurs at two anatomically different locations
  • Types
    • Acute pancreatic necrosis
    • Traumatic fat necrosis

5. Fibrinoid necrosis

  • Deposition of fibrin-like material occurs

Morphology of types of Necrosis:

Morphology Of Cell Injury Morphology of types of Necrosis

Question 3. Define and classify gangrene. Write the differences between dry and wet gangrene


  • Gangrene is a form of necrosis of tissue with superadded putrefaction

Gangrene Classification:

  • Gangrene is classified into two main types
  1. Dry gangrene
  2. Wet gangrene

Read And Learn More: Pathology Question And Answers

Difference Between Dry and Wet Gangrene:

Morphology Of Cell Injury Differences between Dry and Wet Gangrene

Question 4. Write about wet gangrene.

Wet Gangrene:

Wet gangrene usually occurs in moist tissues and organs

Site Involved:

  • Mouth
  • Bowel
  • Lung
  • Cervix
  • Vulva

Wet Gangrene Cause:

  • Venous blockage

Wet Gangrene Pathogenesis:

  • The affected part is filled with blood
  • It favors the rapid growth of Putrefaction bacteria
  • Formation of toxic products by bacteria
  • Absorption of toxic products
  • Causes septicemia
  • Finally causes death

Wet Gangrene Features:

1. Gross features

  • The affected part appears soft, swollen, putrid, rotten, and dark
  • Part is stained dark

2. Microscopic features

  • Coagulative necrosis is seen
  • There is ulceration of the mucosa and intense inflammatory infiltration
  • Lumen shows mucus and blood
  • There is no line of demarcation present.

Morphology Of Cell Injury Short Essays

Question 1. Types of necrosis with examples

Types of Necrosis:

Morphology Of Cell Injury Types of necrosis and Examples

Question 2. Dry gangrene


  • Gangrene is a form of necrosis of tissue with super-added putrefaction

Dry Gangrene:

  • It is a form of gangrene occurring due to Ischaemia

Dry Gangrene Causes:

  • Ischaemia
  • Atherosclerosis
  • Buerger’s disease
  • Raynaud’s disease
  • Trauma
  • Ergot poisoning

Dry Gangrene Features:

  • Begins in the distal part of a limb
  • Occurs in one of the toes which is farthest from the blood supply
  • Here bacteria fail to grow in the necrosed tissue
  • Gangrene spreads slowly upwards until it reaches an area with a good blood supply
  • The line of demarcation is seen between the gangrenous part and the viable part

Dry Gangrene Gross Appearance:

  • The affected part is dry, shrunken, and dark black
  • It appears black due to the liberation of hemoglobin from hemolysed red blood cells which is acted upon by hydrogen disulfide produced by bacteria
  • The line of demarcation is seen

Dry Gangrene Microscopic Appearance:

  • Necrosis with smudging of the tissue is seen
  • The line of demarcation contains inflammatory granulation tissue

Question 3. What is dystrophic calcification? Give two examples.

Dystrophic calcification is the deposition of calcium salts in dead and degenerated tissues with normal calcium metabolism and normal serum calcium levels

Dystrophic Types:

1. Calcification in dead tissue: Examples

  • Caseous necrosis in tuberculosis
  • Liquefaction necrosis in chronic abscess
  • Fat necrosis
  • Gamma Gandy bodies in chronic venous congestion
  • Infarcts
  • Thrombi in veins
  • Haematomas in bones
  • Dead parasites
  • Calcification in breast cancer
  • Congenital toxoplasmosis

2. Calcification in degenerated tissues

  • Stroma of tumors
  • Atheromas
  • Dense old scars
  • Cysts
  • Calcinosis cutis
  • Senile degeneration

Dystrophic Pathogenesis:

1. Initiation

  • Precipitates of calcium and phosphate begin to accumulate both intracellularly and extracellularly

2. Propagation

  • Mineral deposits propagate to form mineral crystals

Question 4. Differences between Necrosis and Apoptosis.

Morphology Of Cell Injury Differences between Necrosis and Apoptosis

Morphology Of Cell Injury Short Question And Answers

Question 1. Irreversible cell injury

  • Cell injury is defined as a variety of stresses a cell en-. counters as a result of changes in its internal and external environment
  • When such an injury is severe and persistent, cell death occurs
  • Such an injury is called irreversible cell injury

Irreversible cell injury Features:

  • The inability of the cell to reverse mitochondrial dysfunction
  • Disturbance in cell membrane functions
  • Reduction in ATP
  • Continued depletion of proteins
  • Reduced intracellular pH
  • Leakage of lysosomal enzymes

Question 2. Etiology of cell injury

Cell injury occurs due to the following causes:

1. Genetic causes

2. Acquired causes

  • Hypoxia and ischemia
  • Physical agents
  • Chemical agents
  • Microbial agents
  • Nutritional derangements
  • Immunologic agents
  • Aging
  • Iatrogenic factors
  • Idiopathic

Question 3. Free radical injury

  • The free radical injury occurs in situations like ionizing radiation
  • Oxygen free radicals are produced within the mitochondrial matrix
  • They are:
    • Superoxide
    • Hydrogen peroxide
    • Hydroxyl radical

Free radical injury Effects:

  • Lipid peroxidation
  • Oxidation of proteins
  • DNA damage
  • Cytoskeletal damage

Question 4. Reversible cell injury

  • Cell injury is defined as a variety of stresses a cell encounters as a result of changes in its internal and external environment
  • When the stress is mild to moderate, the injured cell may recover, it is called reversible cell injury

Morphology Of Cell Injury Reversible cell injury

Question 5. Hyaline calcification

  • It describes the glassy, homogeneous, eosinophilic appearance of a material
  • It is associated with pathological conditions that may be intracellular or extracellular

Morphology Of Cell Injury Hyaline calcification conditions and Examples

Question 6. Dystrophic and metastatic calcification.

Morphology Of Cell Injury Differences between Dystrophic calcification and Metastatic calcification

Question 7. Apoptosis

Apoptosis is a form of coordinated and internally programmed cell death that has significance in a variety of physiologic and pathological conditions

1. Apoptosis in biological processes

  • Organized cell destruction during the development of the embryo
  • Physiologic involution of cells in hormone-dependent tissues
  • Normal cell destruction

2. Pathologic process

  • Cell death in tumors
  • Cell death by cytotoxic T cells
  • Cell death in viral infections
  • Pathologic atrophy of organs

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