Term
cellular damage:
Reversible cellular injury = cellular degeneration |
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Definition
| Mild cellular injury that the cell is able to recover from. It results in: dysfunction of the cellular membrane Na+/K+ pump which causes the influx of Na+ and Ca+ and the efflux of K+. This results in ECF flowing into the cell down its concentration gradient = cell swelling (hydropic degeneration). Ribosomes may detach from the RER. |
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Term
cellular damage:
Irreversible cell injury: cell death (necrosis) |
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Definition
severe or prolonged injury of the cell leading to cell death that is characterized by the lack of energy production and membrane damage. The changes seen are:
1. mitochondrial vacuolization
2. extensive membrane damage
3. lysosomal swelling
4. mitochondrial calcification
combined this = leakage of lysosomal enzymes |
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Term
| irreversible cell damage: membrane damage |
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Definition
4 mechanisms for membrane damage:
1.progessive loss of phospholipids due to activation of endogenous phospholipases by increasing intra-callular Ca+ influx
2. cytoskeletal abnormalities caused by swelling
3. free radical production (superoxide, hydrogen peroxide, hydroxyl ion)
4. lipid breakdown products from lipases act as detergents |
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Term
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Definition
1. hypoxia = no oxidative phosphorylation = no ATP
2. free radical damage
3.physical agents (trauma, heat, UV light)
4. chemical agents- combine with the membrane or produce free radicals
5. immunologic reactions- hypersensitivity
6.genetic defects- ex. enzyme abnomalities
7.nutrition- nutrient deficiencies
8.aging
9. microbial agents |
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Term
| causes of cell damage: free radical consequences |
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Definition
1. lipid peroxidation of membranes- disrupts the double bonds in PUFA's which results in production of more lipid peroxidases = autocatalytic reactions.
2.formation of cross-links in proteins = enzyme dysfunction
3. DNA strand damage
4. mitochondrial damage = reduced ATP |
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Term
| Morphological appearance of cellular degeneration |
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Definition
1. cell swelling
2.increased cytoplasmic eosinophilia
3.fatty change |
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Term
| Fatty change -(lipidosis, fatty degeneration, fatty infiltration) |
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Definition
abnormal accumulation of Tg's within parenchymal cells. Liver is most commonly affected because of its role in lipid metabolism. Fatty liver is caused by:
1.increased fat mobilization
2.disrupted mitochondrial oxidation
3. reduced transport out of hepatocytes |
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