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etiology
cause of disease
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cellular adaptation is physiologic and pathologic
Atrophy•Hypertrophy•Hyperplasia•Metaplasia•Dysplasi
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atrophy
reversible; cell decrease in size because demand decreases
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causes of call atrophy
disuse, ischemia, Endocrine dysfunction, Persistent cell injury, Aging
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hypertrophy
cells increase in size because increased demand
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hypertrophy can be either physiologic or pathologic
- physiologic: normal, weight lifting
- pathologic: abnormal, enlarged organs
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hyperplasia
increase in number of cells
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hyperplasia can be physiologic or pathologic
- physiologic: great and uterine enlargement
- pathologic: enlargement of the prostate gland
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metaplasia
- 1. Replacement of one differentiated cell type with another
- 2. Cells retains same basic tissue type
- 3. Usually occurs in response to chronic irritation and inflammation
- 4. Reversible
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dysplasia
- 1. Cells mutate with abnormal variations in size, shape and arrangement
- 2. abnormal
- 3. may be reversible
- 4. strongly implicated as a precursor to cancer
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cellular injury mechanisms
hypoxic injury, free radical and reactive oxygen species injury, chemical injury, infectious injury, immunologic/ inflammatory injury
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hypoxic injury
single most common cause of cellular injury
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hypoxic injury results from
- *Reduced amount of oxygen in the air•Loss of hemoglobin or decreased efficacy of hemoglobin
- *Decreased production of red blood cells, *Diseases of the respiratory and cardiovascular systems
- *Poisoning of the oxidative enzymes within the cells
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most common cause of hypoxia is
ischemia. Can be progressive or acute
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ischemia
an inadequate blood supply to an organ or part of the body, especially the heart muscles.
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Ischemia is often caused by
Arteriosclerosis (gradual narrowing of arteries) Thrombosis (complete blockage by blood clot)
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Arteriosclerosis
gradual narrowing of arteries
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Thrombosis
complete blockage by blood clot
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Free radicals and reactive oxygen species
Electrically uncharged atom or group of atoms having an unpaired electron that damage:•Lipid peroxidation•Alteration of proteins•Alteration of DNA•Mitochondria
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Chemically injury
Carbon tetrachloride• lead •Carbon monoxide•Ethanol•Mercury•Social or street drugs •Over the counter or prescribed drugs
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blunt force injuries
confusions, abrasions, lacerations, fractures
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sharp force injuries
puncture wounds, stab wounds, incised wounds, chop wounds
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other two types of unintentional and intentional wounds
gunshot wounds and Asphyxial injuries
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