Pathology chapter 01
Terms
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- Define hyperplasia
- Increased cell number
- Define hypertrophy
- Increased cell mass
- Define atrophy
- Decreased cell mass
- Define metaplasia
- Change from one mature cell type to another
- Define reversible injury
- Denotes pathologic cell changes that can be restored to normalcy if the stimulus is removed or if the cause of injury is mild
- Define irreversible injury
- Occurs when stressors exceed the capacity of the cell to adapt (beyond a point of no return) and denotes permanent pathologic changes that cause cell death
- Define necrosis
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The more common type of cell death, involving severe cell swelling, denaturation and coagulation of proteins, breakdown of cellular organelles, and cell rupture. Usually, a large number of cells in the adjoining tissue are affected
Necrosis always represents a pathologic process - Define apoptosis
- Occurs when a cell dies by activation of an internal suicide program, involving and orchestrated disassembly of cellular components; there is minimal disruption of the surrounding tissue.
- What causes oxygen deprivation?
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1. Ischemia (loss of blood supply).
2. Inadequate oxygenation (eg cardiorespiratory failure).
3. Loss of oxygen-carrying capacity of the blood (eg anemia, carbon monoxide poisoning) - Responses to injurious stimuli depend on:
- Type of injury, its duration, and its severity
- Consequences of injury depend on:
- Type, State, and Adaptability of the injured cell
- Cell injury results from abnormalities in one or more of these five cellular components:
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1. Aerobic respiration, involving mitochondrial oxidative phosphorylation and ATP production
2.Integrity of the genetic apparatus
3. Protein synthesis
4.Intracellular cytoskeleton
5.Maintenace of cell membrane integrity - The intracellular mechanisms of cell injury fall into one of these five general pathways:
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1. ATP depletion
2. Mitochondrial damage
3. Influx of intracellular calcium and loss of calcium homeostasis
4. Accumulation of Oxygen-derived radicals
5. Defects in membrane permeability - Damaged mitochondria form a high-conductance channel called:
- Mitochondrial permeability transition (MPT)
- What two phenomena consistenty characterize irreversible injury?
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1. Inability to reverse mitochondrial dysfunction.
2. Development of profound disturbances in membrane function - Name two morphological characteristics of reversible injury
- Cell swelling and Fatty change
- What two processes underlie the basic morphologic changes in necrosis
- Denaturation of proteins and enzymatic digestion of organelles and other cytosolic components
- Define coagulative necrosis
- Most common pattern, predominated by protein denaturation with presevation of the cell and tissue framework. Characteristic of hypoxic death
- Define liquefactive necrosis
- Occurs when autolysis or heterolysis predominates over protein denaturation. Necrotic area is soft and filled with fluid
- Define caseous necrosis
- Characteristic of tuberculous lesions. Apperas forssly as soft, friable,cheesy material and microscopically as amorphous eosinophilic material with cell debris
- Define fat necrosis
- Seen in adipose tissue. Lipase activation releases fatty acids from triglycerides, which then complex with calcium to create soaps.