Cell Injury and Cellular Adaptations
Definition:
It is change in cell’s morphology and function in response to
stress.
Etiology:
1. Hypoxia and ischemia
2. Physical agents
3. Chemical agents and drugs
4. Microbial agents
5. Immunologic agents
6. Nutritional derangement
7. Aging
8. Idiopathic diseases.
Types of cell injury:
1.Reversible cell injury/ Retrogressive changes
2. Irreversible effects of cell injury/cell death: Necrosis.
3. Programmed cell death/Apoptosis
4.Residual effects of cell injury/ subcellular alteration
5. Deranged cell metabolism/intracellular accumulation of lipid,
protein, carbohydrate
6. After- effects of necrosis: gangrene, pathologic calcification
1.Reversible cell injury:
previously called as degeneration.
a) Hydrophic change/ Cloudy swelling/vacuolar:
Hydrophic change means accumulation of water within the
cytoplasm of the cell.
, It is an entirely reversible change upon removal of the
injurious agent.
Etiology:
Acute and subacute cell injury from various etiologic agents
such as: bacterial toxins, chemicals, poisons, burns, high
fever, intravenous administration of hypertonic glucose or
saline.
Pathogenesis:
Disturbance in the regulation of sodium and potassium at
cell membrane.
This results intracellular accumulation of Na and escape of
K.
This causes increased flow of water into the cell
Leading to cellular swelling.
Morphologic features:
Grossly:
The affected organ such as kidney, liver, pancreas or heart
muscle is enlarged due to swelling.
Microscopically:
The cells are swollen and the microvasculature compressed.
Small clear vacuoles are seen in the cells and hence the term
vacuolar degeneration.
, b) Fatty change/Steatosis:
It is the intracellular accumulation of neutral fat.
It is especially common in the liver but may occur in other
non-fatty tissues like the heart, skeletal muscle, kidneys and
other organs.
Fatty Liver: - Short notes
It is the commonest site of accumulation of fat.
It may be mild & reversible or severe leading to death
depending on cause and amount accumulation
Etiology:
1.Hyperlipidemia:
i)Obesity
ii)Diabetes mellitus
iii)Congenital hyperlipidemia
2.Liver cell damage:
i) Alcoholic liver disease (most common)
ii) Starvation
iii) Hepatotoxins (e.g. chloroform)
iv) Drug-induced liver cell injury (e.g. steroids)
Pathogenesis:
Lipids as free acids enter the liver cell from either of the 2 source:
1.From diet
2.from adipose tissue
Normally:
Definition:
It is change in cell’s morphology and function in response to
stress.
Etiology:
1. Hypoxia and ischemia
2. Physical agents
3. Chemical agents and drugs
4. Microbial agents
5. Immunologic agents
6. Nutritional derangement
7. Aging
8. Idiopathic diseases.
Types of cell injury:
1.Reversible cell injury/ Retrogressive changes
2. Irreversible effects of cell injury/cell death: Necrosis.
3. Programmed cell death/Apoptosis
4.Residual effects of cell injury/ subcellular alteration
5. Deranged cell metabolism/intracellular accumulation of lipid,
protein, carbohydrate
6. After- effects of necrosis: gangrene, pathologic calcification
1.Reversible cell injury:
previously called as degeneration.
a) Hydrophic change/ Cloudy swelling/vacuolar:
Hydrophic change means accumulation of water within the
cytoplasm of the cell.
, It is an entirely reversible change upon removal of the
injurious agent.
Etiology:
Acute and subacute cell injury from various etiologic agents
such as: bacterial toxins, chemicals, poisons, burns, high
fever, intravenous administration of hypertonic glucose or
saline.
Pathogenesis:
Disturbance in the regulation of sodium and potassium at
cell membrane.
This results intracellular accumulation of Na and escape of
K.
This causes increased flow of water into the cell
Leading to cellular swelling.
Morphologic features:
Grossly:
The affected organ such as kidney, liver, pancreas or heart
muscle is enlarged due to swelling.
Microscopically:
The cells are swollen and the microvasculature compressed.
Small clear vacuoles are seen in the cells and hence the term
vacuolar degeneration.
, b) Fatty change/Steatosis:
It is the intracellular accumulation of neutral fat.
It is especially common in the liver but may occur in other
non-fatty tissues like the heart, skeletal muscle, kidneys and
other organs.
Fatty Liver: - Short notes
It is the commonest site of accumulation of fat.
It may be mild & reversible or severe leading to death
depending on cause and amount accumulation
Etiology:
1.Hyperlipidemia:
i)Obesity
ii)Diabetes mellitus
iii)Congenital hyperlipidemia
2.Liver cell damage:
i) Alcoholic liver disease (most common)
ii) Starvation
iii) Hepatotoxins (e.g. chloroform)
iv) Drug-induced liver cell injury (e.g. steroids)
Pathogenesis:
Lipids as free acids enter the liver cell from either of the 2 source:
1.From diet
2.from adipose tissue
Normally:
