def ines cell injury

1. CELL INJURY

2. TRAUMA
• DEFINATION: Going through very stressful, frightening or distressing
events is sometimes called trauma.
• MEDICAL TRAUMA: Emotional and physical responses to pain, injury,
serious illness, medical procedures and frightening treatment experiences.

3. CELL INJURY
• 2 mechanisms of cell injury:
1. Necrosis
2. Apoptosis

4. APOPTOSIS
• Apoptosis occurs in a cell with intact plasma membrane, and there, DNA
degradation is the result of the activation of specific endonucleases.
• Apoptosis can be triggered by different pathways that are responsible for
caspase activation. These include activation of members of the TNF
superfamily (TNF receptor, Fas, CD40) located on the plasma membrane.
• Withdrawal of growth factors and/or direct insults to the plasma membrane
(starvation, stress, oxidative stress.

5. APOPTOSIS

6. APOPTOSIS

7. NECROSIS
• Necrosis is associated with the disruption of the cell membrane, resulting in
a loss of cytoplasm, and, finally, a random nuclear degradation.

8. NECROSIS

9. REVERSIBLE CELL INJURY
• Decreased supply of oxygen
• Increase in cellular glycolysis to increase ATP stores
• Decrease in cellular glycogen; decrease in intracellular pH
• Decrease in ATP leads to accumulation of sodium and diffusion of
potassium leading to cellular swelling
• Oxygen depletion leads to cellular “blebbing” or malformation of plasma
membrane

10. IRREVERSIBLE CELL INJURY
• Mitochondrial swelling
• Lysosomal swelling
• Damage to plasma membrane and lysosomal membranes that cause enzyme
leakage
• Increased acidosis in the cellular environment

12. HYPOXIC INJURY

13. FREE RADICALS INJURY

14. BIOLOGICAL INJURY
• Prions
• Bacteria
• Viruses
• Parasites
• Fungi

15. CHEMICAL INJURY
• Arsenic, cyanide, mercury
• Alcohol
• Acids
• Metabolites

16. PHYSICAL INJURY
• Burns
• Deep cold
• Radiation
• Electric shock
• Mechanical trauma

17. NUTRITIONAL DEFICIENCIES
• Protein and vitamin deficiency
• Malabsorption syndromes (Diarrhea)
• Starvation
• Diabetes mellitus
• Excess fats and vitamins (Atherosclerosis, Obesity)

18. GENETIC ABNORMALITIES
• Down syndrome
• Sickle cell anemia

19. TYPES OF NECROSIS
1. Coagulative necrosis
2. Caseous necrosis
3. Liquefactive necrosis
4. Fat necrosis
5. Fibrinoid necrosis
6. Gangrenous necrosis
7. Avascular necrosis
8. Osteonecrosis

20. SIGNIFICANCE OF APOPTOSIS
• Crucial for development (Tadpole tail, Finger webs) Maintenance of normal
tissue during development
• Maintenance of hemoestasis (Infectious and harmful agents)
• Removal of injured, damaged or cancerous cells (Prevent tumor formation)
• Avoid autoimmunity by removing self reacting T lymphocytes
• Elimination of viral infected cells
• Balance between cell division and cell death