Gas exchange Flashcards
What portion of the respiratory tract does dry air go through?
the conducting portion
What happens to dry air in the conducting portion of the respiratory tract?
it is warmed and humidified
Where does the exchange of O2 and CO2 occur?
at the alveolar respiratory membrane
How do gas molecules move?
by diffusion via kinetic motion
Does the kinetic motion by which gas molecules move change?
yes, at -273 degrees celcius
In what direction does gas movement go?
from higher concentration to lower concentration
What is partial pressure determined by?
concentration and solubility
Explain Dalton’s law of partial pressures?
the pressure of a mixture of gases is the sum of the pressures of individual components
How is pressure affected at higher altitudes?
it is lower
What pressure reduces PO2?
vapor pressure
CO2 is __ times more soluble than O2
24
What is Ficks law of diffusion of gases?
Vgas = (A x D(P1-P2))/ T
What is P1 in Ficks law of diffusion of gases?
O2 on the alveolar side (altitude)
What is P2 in Ficks law of diffusion of gases?
O2 on the capillary side
What is D in Ficks law of diffusion of gases?
diffusion co-efficient
What is T in Ficks law of diffusion of gases?
thickness of the membrane
In emphysema, the area is reduced, why is this bad?
because there is a smaller area for oxygenation
Does thickness affect CO2’s diffusion?
no, because it diffuses 20 times faster than O2
Explain Henry’s law of gas diffusion.
the basis of getting N2 dissolved into the blood under higher pressure
What is the equation for Henry’s law of gas diffusion?
Cx=Px X Beta x
What is the clinical application of Henry’s law of gas diffusion?
scuba diving and N2 narcosis
Why is hyperbaric oxygen therapy beneficial?
the atm is higher to allow for more O2 absorption
Why is air humidified?
for saturation
What happens to PH20 and P1O2 when temperature increases?
PH2O increases and P1O2 decreases
Where does O2 diffuse from and to?
alveolus to the red blood cell
Where does CO2 diffuse from and to?
red blood cell to the alveolus
