BMS314 Lecture Notes - Lecture 22: Neutrophil, Gas Gangrene, Digestion
• What can cause a healthy cell to become injured and what can cause an injured cell to become
healthy again
• There are 4 basic things that can go wrong (1 or more could go wrong)
o These all involve the critical cell functions
• Cell membranes
• Aerobic respiration (generation of ATP)
• Protein synthesis
• Genetic function
o These are not mutually exclusive events
o Often all become involved in cell injury and then potentially cell death
• Severity, type and duration will influence whether a cell becomes in injured or note
• Cell specific factors include
o How adaptable is the cell (stable, labile or permanent)
o Tissue type
• When thinking about cell injury
o Think about the 4 critical functions
o Features about the injurious agent and how it's coming in contact with the cell
o Features of the cell
• Example - hypoxia and the result on the tissues and how long it takes
• If the cell is irreversibly injured it dies
Major categories of cell injury (consider making a pneumonic) (PHIIIGNAC?)
Hypoxia -> aerobic respiration
Ischemia -> aerobic respiration
Nutritional -> protein synthesis/aerobic respiration
Biological (or infectious) -> Cell membranes
Immunological -> Cell membrane/Genetic Function
Chemical -> Cell membranes/Aerobic Respiration
Physical -> Cell membranes
Genetic -> Genetic Function
Ageing -> Cell membranes, Aerobic Respiration, Protein Synthesis, Genetic Function
• Lots of injury affect the cell via interrupting the production of ATP
o All metabolic function of the cell needs ATP
• Consequences
o Without oxidative phosphorylation, there is a lack of energy, the Na/K pump doesn’t
work effectively and a lot a K+ flows out of the cell and Na+ (and water) inside the cell
(cell swelling)
o Anaerobic pathways are activated instead of aerobic pathways
• Chromatin clumping can be seen histologically
• Consequence is a fatty change resulting in damage and loss of cell specialisation
features
• These are indicators of reversible cell injury
