Term
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Definition
| Cell injury that results in premature death of cells in living tissue, caused by external factors |
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Term
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Definition
| Programmed cell death that occurs in multicellular organsisms |
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Term
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Definition
| Irreversible condensation of chromatin in the nucleus of a cell undergoing necrosis or apoptosis |
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Term
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Definition
| An atom, molecule or ion with an unpaired electron or an open shell, which can cause the radical to be highly chemically reactive |
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Term
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Definition
| Restriction in blood supply to tissue, causing a shortage of oxygen and glucose |
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Term
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Definition
| Necrosis caused by an obstruction of the tissue's blood supply, leading to a local lack of oxygen |
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Term
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Definition
| Deprivation of an adequate oxygen supply |
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Term
| List the main types of agent that cause cell injury (there are 7) |
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Definition
1. Metabolic deprivation - hypoxia, ischaemia, infarction
2. Physical agents
3. Chemical agents (including poisons and drugs)
4. Infectious agents (virus, bacteria, fungi, worms)
5. Immunologic
6. Genetic
7. Nutritional imbalance |
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Term
| A cellular response to cell injury depends on |
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Definition
| The type of agent, intensity and duration |
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Term
| Vulnerable areas of injury include |
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Definition
| Cell membrane, mitochondria, protein synthesis, genetic integrity |
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Term
| List the five key mechanisms of injury |
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Definition
1. Mechanical disruption
2. Failure of membrane integrity
3. Mitochondrial damage
4. Free radical formation
5. Loss of calcium homeostasis |
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Term
| Describe how the failure of membrane integrity can occur |
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Definition
| Failure of pumps, lipoprotein alteration, cytoskeleton disruption, ion channel blockage, complement |
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Term
| Mitochondrial damage leads to a depletion in ATP. Mitochondria can be damaged by... |
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Definition
| Phospholipases, oxidative stress (free radicals) and poisons |
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Term
| Damage of the mitochondria leads to.. |
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Definition
1. Pump failure - increased sodium in cells and increased water.
2. Anaerobic respiration leading to acidosis and phosphate accumulation.
3. Mitochondrial permeability transition - a non-selective pore.
4. Leakage of cytochrome C - triggers apoptosis. |
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Term
| Superoxide radicals are produced by |
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Definition
Oxygen and H20 through
1. Redox reactions
2. Macrophage killing
3. Nitric Oxide acting as a free radical |
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Term
| How does the loss of calcium homeostasis lead to cell injury? |
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Definition
When cell is damaged there is an influx of calicum due to the increased non-specific permeability and pump failure. Calcium is released from the mitochondria and ER.
Enzymes are activated. |
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Term
| What enzymes are released due to a loss of calcium homeostasis? |
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Definition
Phospholipases - worsen membrane damage and its breakdown products damage the mitochondria.
Proteases - membrane and cytoskeleton leads to blebbing
Endonucleases - fragment chromatin
ATPase
Bind to phosphates in mitochondria |
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Term
| When is cell injury irreversible? |
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Definition
| When mitochondrial dysfunction cannot be reversed and there is a profound membrane dysfunction |
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Term
| List the types of necrosis |
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Definition
| Coagulative, liquefactive, caseous, fat necrosis, fibroiod necrosis, gangrenous necrosis |
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Term
| After sub-lethal / reversible injury, which occurs first: visible or biochemical changes? |
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Definition
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Term
| List the biochemical changes that occur after reversible / sub-lethal injury. |
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Definition
Ultra-structural changes
Hydropic changes
Fatty changes |
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