physio nov 20
Card Set Information
physio nov 20
external respiration vs. internal respiration
external respiration is the diffusion of gases in lungs
internal respiration is the diffusion of gases at body tissues
what is external and internal respiration dependent on?
diffusion of molecules between gas and liquid
partial pressure gradients
what is dalton's law?
total pressure exerted by mixture of gases=sum of pressures exerted by each gas
how does the air composition entering the respiratory structure change in character?
decrease in P
and increase in P
increase in water vapor and temperature
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
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
how are o2 transported?
1.5% through solution in plasma
98.5% loosely bound to each Fe of hemoglobin (reversible reaction)
what is the Bohr Effect?
weaking of the Hb-O2 bond
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
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
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
what is the catalyst of the breakdown of Co2 to HCO3-?
where does the Co2 and water combine in?
RBC to form carbonic acid which quickly dissociates to bicarbonate ions