Diffusion Flashcards
1
Q
Diffusion of gas
A
In gas: O2 diffuses faster
In liquid: CO2 diffuses faster
2
Q
Ficks Law of Diffusion
A
Vgas = (DxAxP)/X
X is thickness of membrane
3
Q
Diffusion limited
A
PA > Pa
Diffusion rate must be increased by increasing driving pressure
Ex CO
Fibrosis, strenuous exercise at high alt
4
Q
Perfusion limited
A
Pa equilibriates rapidly with Pa
Transfer depends only on amount of blood flow
Ex N2O
Increase blood flow to increase rate
Oxygen under normal conditions is perfusion limited
5
Q
Diffusion capacity
A
DL = Vgas/Pgas
6
Q
Single Breath CO Method for DL Determination
A
When DLCO increases, diffusion of all resp gases increases
And vise versa
Increases with inc body size, recumbent position, exercise, Hb conc
Fibrosis and emphysema dec DLCO
7
Q
Resistance to diffusion
A
R = 1/DLgas
