Flashcards in Cellular Injury and Adaptation Deck (174)
balance of physiologic and biochemical functions within the body
Alteration of homeostasis results in
stress to cell, cellular injury or adaptive changes to survive altered environment
injury is corrected prior to destruction of cellular repair mechanisms; severity of injury does not exceed the cells ability to repair itself
repair mechanisms are destroyed (removal from altered environment will be insufficient) cell cannot repair itself --> DEATH; injury exceeds the cell's ability for self-repair, resulting in cell death
Hypoxia, Physical agents, chemicals, infectious agents, immune reactions, genetic derangements, nutritional imbalance
Decreased supply of O2 to cell or inability to use O2
Complete absence of O2
Causes of Hypoxia
Ischemia (decreased BF), decreased oxygenation of blood, decreased O2 carrying capacity, inability to utilize O2
Examples of Physical injury to cell
mechanical trauma, temperature extremes, atmospheric pressure variation, radiation, electrical injury
Examples of Chemical Injury to cell
Simple agents (electrolytes, glucose), Poisons, Pollutants, Insecticides, herbicides, industrial products, drugs (therapeutic or recreational), alcohol
Infectious Causes of cell injury
bacteria, rickettsia, fungi, virus, parasite
Immune Response Causes of cell injury
4 Key Signs of REVERSIBLE cell injury
Decreased aerobic respiration, cellular edema, ribosome detachment from RER, ultrastructural morphological changes
Reversible Injury - Decreased Aerobic Respiration Results in
Decreased ATP production, increased AMP and anaerobic glycolysis, Increased lactate (decreased pH), decreased cellular glycogen, clumping of nuclear chromatin, decreased protein synthesis
Examples of nutritional variations that cause cellular injury
deficits, excess, malabsorption, altered use
Sites that are altered in cellular injury
cell membrane integrity, aerobic respiration, enzyme/protein synthesis, genetic apparatus
What causes cellular edema in reversible cell injury?
Suppression of Na+ pump with increased [Na+] retention; increased intracellular Na+
Ultrastructural Morphological Changes in reversible cellular injury
Phospholipid membrane alteration, loss of microvilli, myelin figure formation, mitochondrial swelling, RER swelling
Key Signs of IRREVERSIBLE cellular injury
ATP Depletion, Cell Membrane Damage
Cell Membrane Damage as a result of irreversible damage
Phospholipid Depletion, Cytoskeletal breakdown, toxic ROS, Lipid breakdown products, amino acid loss
Structural changes in IRREVERSIBLE cell injury include
vacuolization of mitochondria, PM damage, Lysosomal swelling, Loss of proteins, enzymes, and RNA
What characterizes cell injure as irreversible?
ATP depletion, cellular edema -> PM tears and damage, mitochondrial dysfunction (high [Ca2+] intracellularly), Membrane phospholipid depletion, cytoskeleton changes, ROS, lipid breakdown products, and amino acid loss
Irreversible Cellular Damage - What is the determining/most important factor?
Cellular Membrane Dysfunction
Irreversible Cellular Damage - What results from mitochondrial dysfunction?
ATP depletion -> increased cytosolic [Ca2+] -> mitochondrial phospholipase activation -> phospholipid breakdown + accumulation of FFA -> altered permeability of PM
Myelin figures are characteristic of
cellular edema is characteristic of
Irreversible Cellular Damage - What causes membrane phospholipid depletion?
increase [Ca2+] intracellular activation of phospholipase AND ATP-dependent maintenance and production of phospholipids
Irreversible Cellular Damage - What causes cytoskeletal abnormalities?
Hypoxia AND activation of proteases by high intracellular levels of [Ca2+]
Irreversible Cellular Damage - What causes Toxic oxygen radical production?
sudden repercussion of hypoxic tissue