physio nov 20

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physio nov 20
2012-12-13 18:43:32

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  1. external respiration vs. internal respiration
    • external respiration is the diffusion of gases in lungs
    • internal respiration is the diffusion of gases at body tissues
  2. what is external and internal respiration dependent on?
    • diffusion of molecules between gas and liquid
    • partial pressure gradients
  3. what is dalton's law?
    total pressure exerted by mixture of gases=sum of pressures exerted by each gas
  4. how does the air composition entering the respiratory structure change in character?
    • decrease in Po2 and increase in Pco2
    • increase in water vapor and temperature
  5. what is Henry's Law
    • amount of gas that dissolves in liquid depends on solubility (Co2 is more soluble than o2) and temperature (solubility decrease with increase in temperature)
    • decrease in volume, increase in pressure, more gas dissolves in liquid
  6. what is the rate of release of O2 determined by?
    • Po2 of tissues, pH and temperature
    • low Po2 and pH, and high temp increases O2 release
  7. how are o2 transported?
    • 1.5% through solution in plasma
    • 98.5% loosely bound to each Fe of hemoglobin (reversible reaction)
  8. what is the Bohr Effect?
    weaking of the Hb-O2 bond
  9. increase in temp, H+ and Pco2 does what?
    • modify the structure of hemoglobin (decrease affinity for o2), enhance unloading
    • occur in systemic capillaries¬†
    • shift O2 hemoglobin dissociation curve to the right¬†
  10. why is it harder to breath at high altitude?
    partial pressure is lower, so there is less of a pressure gradient: not as much O2 gets into blood, so need to breathe more to get the same amount of oxygen
  11. CO2 transported in blood
    • 7-10% dissolved in plasma
    • 20% bound to globin of hemoglobin (amino acid-carbaminohemoglobin)
    • 70% transported as bicarbonate ions in plasma
  12. what is the catalyst of the breakdown of Co2 to HCO3-?
    carbonic anhydrase
  13. where does the Co2 and water combine in? 
    RBC to form carbonic acid which quickly dissociates to bicarbonate ions