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Cell bio is altered by

adaptation, injury, neoplasia, aging, disease


decrease in cell size


increase in cell size


increase in number of cells


reversible replacement of one type of mature cell by another


abnormal cell changes, size, shape, organization; "atypical hyperplasia"

cell adaptation if...

atrophy, hypertrophy, hyperplasia, metaplasia

Reversible cell injury

loss of ATP, cell swelling, ribosome detachment

active injury to cell

immediate response of "entire" cell

irreversible cell injury

structural "pint of no return", vacuolization, mitochondrial damage, Ca2+ movement into cell


common, severe cell swelling/ organelle breakdown


programmed cell death


lack of sufficient oxygen


total starvation of oxygen/ block of oxygen


reduction of o2 in whole body


reduction of blood supple to certain tissue

common cell injuries

ATP depletion, oxygen-deprived free radicals, intracellular Ca2+ increases, changes in membrane permeability

Free radicals

uncharged atoms of molecules with an unpaired electron

examples of free radicals

reactive oxygen species, superoxide, hydrogen peroxide, hydroxyl radicals, nitric oxide

problems linked to free radicals

atherosclerosis, strokes, ischemia brain injury, alzheimer disease, cancer, diabetes, reperfusion


vitamins C and E, cysteine, glutathione, albumin, and transferin

enzymes that fight antioxidants

superoxide dismutase, catalase, glutathione peroxidase

symptoms of cell injury

fatigue, malaise, pain loss of sense of well-being and altered appetite, fever and increased heart rate, leukocytosis


kidneys, heart and adrenals. protein denaturation; tissue firm and swollen


ischemic injury to neurons and glial cells; cells digested by own enzymes; tissue soft and become liquid- produces pus

caseous necrosis

TB in the lungs; combined coagulative and liquefaction; looks like clumped cheese

fat necrosis

breast, pancreas and abdominal structures; caused by lipases; tissue opaque and chalk white


usually from severe hypoxia; dry, wet and gas


active process of cell destruction. programmed cell death

mechanisms of apoptosis

mitochonrial (intrinsic) pathway, death (extrinsic) pathway

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