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Index
 »Â
Cellular Growth Adaptations, Cellular Injury, Cell Death
 »Â
Chapter 1
 »Â
Cellular Injury
level: Cellular Injury
Questions and Answers List
level questions: Cellular Injury
Question
Answer
Reversible or irreversible damage from stress which exceeds cell's ability to adapt. Injury depends on type of stressor, severity and type of cell
Cellular Injury
Decreased oxygen delivery to tissue -> impaired oxidative phosphorylation -> decreased ATP -> cellular injurt
Hypoxia
Decreased blood flow through organ from: 1. decreased arterial perfusion, 2. decreased venous drainage, 3. shock
Ischemia
Thrombosis of hepatic vain
Budd-Chiari Syndrome
Polycythemia vera
MC cause of Budd Chiari Syndrome
Low partial pressure of oxygen in blood (PaO2 <60, SpO2 <90)
Hypoxemia
FiO2-> PAO2 -> PaO2 -> SpO2
Pathway of oxygen partial pressure
High altitude, Hypoventilation, Diffusion defect, V/Q mismatch
Causes of hypoxemia
Anemia, CO poisoning, Methemoglobinemia
Decreased O2-carrying capacity
Cherry red appearance of skin
Classic finding for CO poisoning
Headache
Earliest sign of CO exposure
Iron in heme is oxidized to Fe3+ which cannot bind O2
Methemoglobinemia
Fe 2+ ("Fe two binds O two")
Normal iron in heme
Cyanosis with chocolate colored blood
Classic finding for methemoglobinemia
IV methylene blue
Treatment for methemoglobinemia
No Na-K pump-> Na and water retention in cell; No Ca++ pump-> inc cytosolic Ca++; Shift to anaerobic glycolysis -> lactic acidosis -> protein denaturation
Effects of low ATP
Cellular swelling
Hallmark of reversible injury
Loss of microvilli; membrane blebbing; dissociation of ribosome from RER -> decreased protein synthesis
Effects of cellular swelling
Membrane damage (plasma membrane, mitochondrial membrane, lysosomal membrane)
Hallmark of irreversible injury
Cytosolic enzyme leakage (eg. cardiac biomarkers), increased intracellular [Ca++]
Plasma membrane damage
Loss of electron transport chain; leakage of cytochrome c -> apoptosis
Mitochondrial membrane damage
Leakage of hydrolytic enzymes into cytosol with activation by calcium
Lysosomal membrane damage
Inner mitochondrial membrane
Location of electron transport chain
Cell death
End result of irreversible injury