Term
| how does gas move across the bloo dgas barrier |
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Definition
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Term
| all gases move across the alveolar wall via |
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Definition
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Term
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Definition
| the rate of transfer of gas across the cell wall is proportional to the area and to teh difference in pressure across the wall and inversley proportional to the thickness of the wall |
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Term
| CO2 diffuses ____ times as ______ as O2 |
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Definition
| 20 times as rapidly as 02 |
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Term
| co2 diffuses more rapidly because it has a higher -________ and same molecular weight |
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Definition
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Term
| the diffusion constant is proportional to the _____ of the gas and inversly proportional to the _______ |
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Definition
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Term
| CO is the classic example of _____ limited |
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Definition
diffusion
it does not increase the partial pressure in the rbc significantly because the CO binds to the heme |
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Term
| N2O is the classic example of ____ limited gas |
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Definition
perfusion
it increases rbc pressure fully and would continue to do so as long as there were rbcs |
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Term
| under normal respiratory conditions, o2 is ______ limited like ______ |
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Definition
| perfusion limited like N2O |
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Term
| whether a gas is diffusion limited or not depensds on |
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Definition
its solubility in the blood gas interface vs the soluility in the blood
co is diffusion limited small gate and big field
n2o is perfusion limited big gate and big field |
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Term
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Definition
pulmonary blood flow is greatl increased and the time spent by the red blood ell int he cap is abreduced.
if blood gas barrier is thicked by disease the rate of o2 rise slow and may not get to 100 percent |
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Term
| another way to stress the rbc PO2 |
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Definition
| is to decrease the alveolar po2 |
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Term
| diffusion impairment can be seen |
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Definition
excercise in the himalayas
thickened lung tissue and excercise |
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Term
| oxygen tranfer into the pulmonary capillary is normally limited by |
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Definition
| the amount of blood flow available |
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Term
| measurment of diffusing capacity |
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Definition
carbon monoxide is used because the upatke of gas is diffusion limited
noram l diffusing capacity is 25 ml per min per mm HG
diffusing capacity increases on excercise. |
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Term
| diffusing cpaacity of ling for CO is the |
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Definition
| volume of CO tranferred in ml per minute mer mm Hg of alveolar partial pressure |
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Term
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Definition
| single inspiration of dilute carbon monoxide is mad eand the rate of disappearance fromt he alveolar gas during a 10 second breathold is calculated. |
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Term
| the reaction between Hg and o2 is fast on the order of |
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Definition
| .2 seconds. Yet oxygenation of capillaries by the alveoli occurs so quiickly that htis .2 seconds slows it down. |
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Term
| 2 stages of 02 or co2 uptake |
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Definition
diffusion of o2 through the blood gas barrier
2) reaction of the o2 with hemoglobin |
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Term
| diffusing capacity in words |
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Definition
| volume of gas (flow)/pressure difference |
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Term
| Inverse of the diffusing capacity |
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Definition
pressure/flow
analogous to electrical resistance |
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Term
| resistance of the blood gas barrier |
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Definition
1/Dm
1/ the diffusion capacity of the membrane |
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Term
| The resistance of the reaction with hemoglobine is same as |
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Definition
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Term
| The resistance of the reaction with hemoglobine is same as |
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Definition
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Term
| The resistance of the reaction with hemoglobine is same as |
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Definition
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Term
| The resistance of the reaction with hemoglobine is same as |
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Definition
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Term
| measuring diffusing capacity of the lung for CO depends not only on the area and thickness of the blood gas barrier but also on the |
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Definition
| volume of blood in the pulmonary capapillaries |
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Term
| it is possible to get diffusion problem with co2 though very rare |
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Definition
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