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Pulmonary
Key definitions and concepts
Question | Answer | |
---|---|---|
PO2 | driving force for diffusion of O2 into tissue | |
SaO2 | percent heme groups occupied by O2 | |
Cyanosis | decreased O2 saturation or 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 |
Perfusion defect | absent blood flow to alveoli | increased alveolar dead space |
RDS is an example of a _____________________ defect. | Ventilation | |
Pulmonary embolism is an example of a _________________ defect. | Perfusion | |
Diffusion defect | O2 cannot cross alveolar-capillary interface | |
Diffusion defect | interstitial lung disease | |
Sarcoidosis is an example of ___________________ defect. | Diffusion | |
Methemoglobin | decreased SaO2 | heme Fe3+; oxidizing agents |
What is the common treatment of Methemoglobin? | IV methylene blue | |
What are some common oxidizing agents? | Sulfur and nitro drugs | |
Clinical Methemoglobinemia | Cyanosis not corrected by O2 | chocolate colored blood |
Carbon monoxide | Decreased SaO2 that causes left-shift O2 binding curve | |
______________ _____________ inhibits cytochrome oxidase. | Carbon monoxide | |
What are some common causes of carbon monoxide intoxication? | Car exhaust, space heaters, smoke inhalation | |
What are signs and symptoms of carbon monoxide poisoning? | headache, cherry red color skin | |
Cyanide | inhibits cytochrome oxidase; systemic asphyxiant | |
What causes LEFT-shift on O2 curve? | DECREASED in: - 2,3-BPG, - carbon monoxide - alkalosis - HbF - methemoglobin - hypothermia | |
What causes a RIGHT-shift on O2 curve? | INCREASED in: - 2,3-BPG, - high altitude, - acidosis - fever | |
High altitude | respiratory alkalosis enhances glycolysis | Increases synthesis of 2, 3-BPG |
Mitochondrial poisons | damages membrane and drain off protons | alcohol , salicylates |
Uncoupling agents in mitochondria | drain off protons | dinitrophenol, thermogenin (brown fat) |
Thermogenin | brown fat | |
Complication mitochondrial poisons/ uncoupling agents | hyperthermia | |
Decreased ATP | impaired Na+/K+ ATPase pump (cellular swelling) | |
Aerobic glycolysis | ATP synthesis in hypoxia | Lactate decreses intracellular pH, and denatures proteins |
Irreverisibly injur hypoxia | Membrane/mitochondrial damage | |
Mitochondrial damage | release of cytochrome c activates apoptosis | |
Free radicals | ||
CO + Cyanide poisoning is seen in _____________________. | house fires |