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22 Cards in this Set
- Front
- Back
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What is this?
-Shrinkage in the size of the cell by loss of cell substance |
Atrophy
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What is this?
Increase in cell size resulting in an increase in organ size DOES NOT imply an increase in the number of cells |
Hypertrophy
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What is this?
Increase in the number of cells in an organ or tissue typically resulting in an increased size of the organ or tissue |
Hyperplasia
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What is this?
-Incomplete development of an organ so that it fails to attain adult size |
Hypoplasia
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What is this?
-Literally means “disordered growth” -The cells have undergone deranged development with atypical proliferative changes |
Dysplasia
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What is this?
-Complete lack of development of an organ |
Aplasia
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What is this?
A reversible change in which one adult cell type is replaced by another adult cell type |
Metaplasia
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Cellular adaptations:
Pathologic/Physiologic ... - e.g. after unilateral nephrectomy ... - e.g. uterus in pregancy |
Compensatory
Hormonal Hyperplasia |
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Causes of Cell injury:
... - decreased oxygen delivery to tissue -Decreased blood flow -Decreased oxygen content of the blood ... agents -Trauma -Thermal ... Agents -Hypertonic glucose or salt -Poisons -Insecticides -Alcohol -Oxygen in high concentrations Drugs ... agents -viruses, bacteria, fungi, parasites ... reactions -anaphylaxis, autoimmune disease ... derangements -chromosomal abnormalities -enzyme defects Nutritional imbalances |
Hypoxia
Physical Chemical Infectious Immunologic Genetic |
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Response of cells to injury:
... - Cell undergoes changes that enable it to cope with excess stress; thus it escapes injury Injury - Occurs if the cell is unable to adapt to stress - two types -... injury - If injurious agent is removed, cell reverts back to normal state, both morphologically (appearance) and functionally -... injury - Cell will not revert to normal, even when agent of injury is removed, occurs in persistent or severe injury, death of cell is inevitable |
Adaptation
Reversible Irreversible |
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Response of cells to injury:
The response of the cell to injury depends, in part, on -... of exposure to the injurious agent- E.g. brief exposure may induce only reversible injury, while prolonged exposure may cause irreversible injury -... of injurious agent -> Small dose = minimal changes, Large dose = cell death -... of cell and its ability to ... - e.g. Neuron less able to adapt to hypoxia than cardiac muscle cell |
Length of time
Dose Type adapt |
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Mechanisms of cell injury:
Role of oxygen** -.../... -> Lack of oxygen within cell causes decrease in ATP production with resultant biochemical mayhem -Other injurious agents -> are capable of converting intracellular oxygen into oxygen-derived ..., very toxic ATP depletion -Due either to activation of ... or decreased ATP ... - Leads to loss of integrity of cell ... |
Ischemia/hypoxia
free radicals ATPases synthesis membrane |
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Mechanisms of cell injury:
Intracellular calcium and loss of calcium ...** -Injurious agents can interfere with membrane-bound calcium ATP-ases ("calcium pumps") -This allows calcium that is normally sequestered within organelles (mitochondria and endoplasmic reticulum), as well as calcium that is outside the cell, to enter the .... -This increases ... calcium concentration -Results in activation of calcium dependent enzymes that can injure cell |
homeostasis
cytosol cytosolic |
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Mechanisms of cell injury:
Activation of calcium dependent enzymes -Activated ... - Destroy membrane phospholipids -Activated ... - Destroy proteins of cell membrane and cytoskeleton -Activated ... - DNA / chromatin fragmentation -Activated ... - ATP depletion |
phospholipases
proteases endonucleases ATPases |
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Mechanisms of cell injury:
Defects in membrane permeability -Due to direct damage by ... -Indirectly through activation of ... enzymes -Can involve cell's plasma membrane, as well as organellar membranes (e.g. mitochondria) |
toxin
calcium-dependent |
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Ischemic/Hypoxic injury:
Reversible injury- Some biochemical features Decrease, or loss, of ... within cell due to decrease in oxidative phosphorylation by mitochondria Decrease in aerobic ATP production has consequences -Leads to increase in anaerobic glycolysis --> will generate ... within the cell --> lowers intracellular pH --> results in decreased activity / inactivation of ... -Causes failure of sodium (Na+) pumps of cell's membranes--> results in influx of sodium and water into cytosol and organelles--> impairs function These are all early biochemical events--> if blood flow (and thus oxygen supply) is restored to the cell at this point in time, the cell would recover and return to normal |
ATP
lactic acid intracellular enzymes |
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Ischemic/hypoxic injury:
Irreversible Injury -Critical biochemical events -Inability to reverse ... dysfunction even upon reoxygenation--> ability to generate ATP is permanently lost -Profound disturbances in plasma membrane function due to serious membrane damage -Damage is caused by * progressive loss of ... from membrane *due to phospholipid degradation by calcium-activated ... -decrease in phospholipid synthesis due to lack of ATP |
mitochondrial
phospholipids phospholipases |
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Ischemic/hypoxic injury:
Irreversible Injury -Critical biochemical events -Cytoskeletal abnormalities *Calcium-activated ... degrade cytoskeletal proteins which causes deformation of overlying membrane -... injury *When blood flow (and therefore oxygen) is restored to irreversibly injured cells, large numbers of oxygen-derived free radicals may be generated--> can cause major membrane damage to injured cells as well as to other, even healthy, cells within the area of tissue (thus extending the amount of tissue damage) |
proteases
Reperfusion |
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Ischemic/hypoxic injury
Irreversible Injury -Critical biochemical events -Lipid breakdown products that result from phospholipid degradation have detergent effect on membranes -Loss of intracellular amino acids - certain amino acids (principally...) protect membrane from hypoxic damage--> loss of these leads to membrane injury -All of this profound membrane damage results in cell ... |
glycine
death |
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Toxic/free radical injury:
... -chemicals with an unpaired electron -extremely reactive and unstable -will react with variety of intracellular molecules Oxygen-derived free radicals -generated from the oxygen within a cell -important ones include ...(O2- ), hydrogen peroxide (H2O2), and hydroxyl ion (OH - ) -normally present within cells |
Free radicals
superoxide |
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Toxic/free radical injury:
Oxygen-derived free radicals --> kept in low concentrations by various biochemical mechanisms -Spontaneous decay into non-reactive elements. -Termination of free radical reactions by several mechanisms: *..., e.g. vitamins A, C and E; glutathione (can block initiation of free radical formation, or directly inactivate free radicals) *... and ... proteins, e.g. ceruloplasmin and transferrin (they bind iron and copper, essential elements for the formation of oxygen-derived radicals) *... enzymes like superoxide dismutase, catalase, and glutathione peroxidase (convert radicals into inert substances, e.g. H2O and O2) |
Antioxidants
Storage and transport Intracellular |
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Toxic/free radical injury:
Certain injurious agents can increase production of these free radicals --> large numbers of free radicals within the cell will lead to serious injury Mechanisms of cell injury by O2-derived free radicals -Lipid ... of membranes --> direct disruption of membrane lipids, with generation of peroxides, which further attack membrane lipids (chain reaction) -... modification of proteins --> degrades critical cytoplasmic enzymes -DNA damage (nuclear and mitochondrial) |
peroxidation
Oxidative |
