Difference between reversible and irreversible cell injury,Mechanism of cell injury and types of cell injury, Fatty Change and Cellular swelling.pptx

Cell Injury: Any change resulting in loss of the ability to maintain the normal or adapted homeostatic state.
Agents that cause cell injury
• Hypoxia / Ischemia (loss of blood supply)
• Microbial
• Parasitic
• Chemical
• Physical
• Trauma
• Genetic
• Nutritious
• Environmental
Types of Cell injury
Reversible Cell Injury
Pathologic changes that can be reversed in mild cellular injury when the stimulus is removed. Cell injury is reversible only up to a certain point otherwise it will be irreversible.
Changes in reversible cell injury
Cellular Swelling: Due to accumulation of intracellular water and endoplasmic reticulum & mitochondria.
Clumping of chromatin.
Irreversible Cell injury
Pathologic changes that are permanent and cause cell death, they cannot be reversed to normal state.
Changes in irreversible cell injury
Irreversible injury is marked by severe mitochondrial vacuolization, extensive damage to plasma membranes, detachment of ribosomes from the granular endoplasmic reticulum (ER). Injury to lysosomal bodies leads to leakage of lysosomal enzymes into the cytoplasm and condensation, fragmentation and lysis of nuclei.

1. Lecture No 3 Reversible and irreversible cell injury

2. Cell Injury: Any change resulting in loss of the ability to maintain the normal or adapted homeostatic state.

3. Agents that cause cell injury Hypoxia Microbial Nutritious Genetic Chemicals Parasitic

4. Mitochondria is the earliest organelle affected in cell injury Hypoxia Mechanism Of Cell Injury

5. Release of Free (ca++) from intracellular stores with activation of different enzymes

6. Irreversible cell injury Microscopic morphological Changes Once cell death occurs, degradation of the cell begins o Increased eosinophilia o Moth eaten cytoplasm o Loss of cellular detail Nuclear Changes Pyknosis : Nuclear condensation Karyorrhexis: Fragmentation of the nucleus Karyolysis: lysis of the nucleus by endonuclease

7. Irreversible cell injury - N ucle ar Changes

8. Reversible damage – cellular swelling S ynonyms : hydropic change, vacuolar degeneration, cellular edema, cloudy swelling Cellular swelling is an acute reversible change . It is an intracytoplasmic accumulation of water due to the incapacity of the cells to maintain ionic and fluid homeostasis. It is easy to be observed in parenchymal organs: liver kidney , and myocardium. Influx of water along with sodium ion when sodium potassium ion pump fail.

9. Cellular Swelling Gross appearance Organ is often pale Enlarged, swollen Rounded margins Heavy Wet Bulges on cut surface

10. Cellular Swelling Microscopic appearance Swollen renal tubular epithelial cells from a dog in septic shock. Note the bulging of the apical portions of the cells (arrows)

11. Cellular Swelling Microscopic appearance Swollen Hepatocytes

12. Cellular Swelling (Hydropic Change)

13. Reversible damage – fatty change S ynonyms : Steatosis, fatty degeneration, fatty infiltration F atty change ( Steatosis ) is an abnormal retention of fat (Lipids) within a cell or organ. Fatty Change most often affects the liver, the primary organ of  lipid metabolism . Accumulation of neutral fats, ie . Triglycerides (TG) in a cell.

14. Fatty Change Gross appearance Yellow discoloration ( liver) Enlarged (liver) Hepatocytes are chocked full of fat

15. Fatty Change Microscopic appearance Small to large globules Clear Non-membrane bound S mall fatty cytoplasmic droplets or large fat vacuoles which distend the hepatocytes and push the nucleus to the periphery signet ring appearance of cells