Resp 6 Flashcards
what 2 variables determine the concentration gradient
O2 reaching alveoli
adequate perfusion of alveoli
define diffusion
random movement of molecules from high to low concentrations
what are the 4 effects that will affect the random movement of gas molecules between the alveoli and capillaries?
concentration gradient
surface area
barrier permeability
diffusion distance
whats the main determinant of diffusion
concentration gradient
what is pulmonary edema
fluid in interstitial space increases diffusion distance
what is emphysema an example of
decreased surface area
what is fibrotic lung disease (pulmonary fibrosis) an example of
decreased barrier permeability
what is pulmonary edema an example of
increased diffusion distance
what is asthma an example of
decreased concentration gradient
the movement of gas molecules from air to liquid is directly proportional to three factors:
the pressure gradient of the gas
solubility of the gas in liquid
temperature which is relatively constant
is CO2 soluble
yes
what is an exception to having hypoxia without hypercapnia, why?
pulmonary edema
CO2 is soluble enough so the increased diffusion difference doesn’t affect PCO2
what does the ficks equation tell
gives an idea of how much oxygen is delivered to your tissues, and how much is used
what is ficks equation
(CO x arteriole O2) - (CO x venous O2) = QO2
how is gas transported in the blood
mass flow or mass balance
what are the 4 protein subunits within hemoglobin
2 alpha globin
2 beta globin
how many o2 can one globin bind
1
how many O2 can hemoglobin bind
4
where is 98% of oxygen in the blood
bound to hemoglobin
what happens to free O2
it will be taken up by hemoglobin until the plasma and HB reach equilibrium
is transfer of O2 fast
yes
what determines the binding and unbinding for hemoglobin and oxygen
the partial pressure gradient of oxygen around hemoglobin
whats the role of oxyhemoglobin
it will go to cells with low levels of O2 then release the O2 so the cells can use it
does oxygen contribute to the partial pressure gradient once bound to hemoglobin
nope
