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GHY1
Hi Yield goljan
Question | Answer |
---|---|
PO2 | driving force for diffusion of O2 into tissue |
SaO2 | percent heme groups occupied by O2 |
Cyanosis | decreased O2 saturation (SaO2); O2 content |
Oxygen | electron acceptor in oxidative pathway |
Hypoxia | inadequate O2 leads to ATP depletion |
Ischemia | decreased arterial (or venous) blood flow |
Respiratory acidosis | retention of CO, always decreases PaO2 |
Ventilation defect | impaired delivery of O2 to alveoli; intrapulmonary shunting of blood (e.g., RDS) |
Perfusion defect | absent blood flow to alveoli; increased alveolar dead space (e.g., pulmonary embolus) |
Diffusion defect | O2 cannot cross alveolar-capillary interface; interstitial lung disease (e.g., sarcoidosis) |
Methemoglobin | ↓ SaO2; heme Fe+3; oxidizing agents (sulfur/nitro drugs); Rx with IV methylene blue |
Clinical methemoglobinemia | cyanosis not corrected by O2; chocolate colored blood |
Carbon monoxide | ↓ SaO2; left-shift O2 binding curve; inhibits cytochrome oxidase |
Causes carbon monoxide poisoning | car exhaust, space heaters, smoke inhalation |
S/S carbon monoxide poisoning | headache; cherry red color skin |
Cyanide | inhibits cytochrome oxidase; systemic asphyxiant |
Carbon monoxide + cyanide poisoning | house fires |
Left-shifted O2 curve | ↓ 2, 3 BPG, carbon monoxide, alkalosis, HbF, methemoglobin, hypothermia |
Right-shifted O2 curve | ↑ 2, 3 BPG, high altitude, acidosis, fever |
High altitude | respiratory alkalosis enhances glycolysis; ↑ synthesis 2,3 BPG |
Mitochondrial poisons | damages membrane and drains off protons; alcohol, salicylates |
Uncoupling agents in mitochondria | drain off protons; dinitrophenol, thermogenin (brown fat) |
Complication mitochondrial poisons/uncoupling agents | hyperthermia |
Decreased ATP | impaired Na+/K+ ATPase pump (cellular swelling); reversible |
Anaerobic glycolysis | ATP synthesis in hypoxia; lactate ↓ intracellular pH, denatures proteins |
Irreversible injury hypoxia | membrane/mitochondrial damage |
Mitochondrial damage | release cytochrome c activates apoptosis |
Irreversible injury hypoxia | ↑ cytosolic Ca2+ activates phospholipase, proteases, endonuclease |
Free radicals | unpaired electron in outer orbit; damage cell membranes and DNA |
Free radicals | superoxide, hydroxyl, peroxide, drugs (acetaminophen) |
Superoxide dismutase | neutralizes superoxide |
Glutathione | neutralizes peroxide, drug FRs |
Catalase | neutralizes peroxide |
Lipofuscin | indigestible lipid of lipid peroxidation; brown pigment increased in atrophy and FR damage |
Reperfusion injury in heart | superoxide FRs + calcium |
Mitochondrial injury | cytochrome c in cytosol initiates apoptosis |
SER hyperplasia | alcohol, barbiturates, phenytoin |
Complications SER hyperplasia | increases drug metabolism (e.g., oral contraceptives); low vitamin D |
Chediak-Higashi | membrane protein defect in transferring lysosomal enzymes to phagocytic vacuoles |
Chediak-Higashi | AR; giant lysosomes |
I cell disease | absent enzyme marker in Golgi apparatus (mannose 6-phosphate); empty lysosomes |
Rigor mortis | stiff muscles after death due to ATP depletion |
Fatty change in liver | MCC alcohol (increase in NADH); DHAP → G3P → TG |
Fatty change in liver | VLDL pushes nucleus to side |
Causes fatty change | ↑ synthesis TG/FAs, beta-oxidation of FAs, synthesis apoproteins/release VLDL |
Fatty change in kwashiorkor | ↓ synthesis of apoproteins |
Ferritin | primary iron storage protein; soluble in blood; serum level reflects marrow storage iron |
Hemosiderin | insoluble ferritin degradation product visible with Prussian blue stain |
Atrophy | reduction in cell/tissue mass by either loss or cell shrinkage |