Forces Driving the Movement of Gases- Part 2 Flashcards
describe the difference between bulk flow and diffusion including whether each changes the concentrations of gas particles in the air or liquid medium
Bulk flow: involves a pressure gradient (requires pressure), all components move, and is fast
diffusion: involved a concentration gradient (does not require pressure); only some particles/gases move if down their concentration gradient, and is slower than bulk flow
bulk flow shouldn’t change concentration of gases since all go together? but diffusion will since only some particles move?
indicate which aspects of gas movement between the airways to tissues and back are driven by bulk flow versus diffusion
all air flow above the level of alveoli is driven by bulk flow; but diffusion drives gas movement into/out of alveoli for gas exchange
describe how humidification with water vapor affects partial pressures of gases of inspired air
humidification is just adding H2O is gas form, so will reduce the partial pressures of all other gases in the mixture because adding another compound
describe how changes in each of the factors included in Fick’s law impact diffusion of gases across membranes
Fick’s law states that the rate of gas transfer is directly proportional to:
1. difference in partial pressures of the gas across the membrane (P1-P2, if larger difference means greater gradient means faster transfer)
2. diffusing capacity of the membrane (DM), which depends on
a. solubility (Sol)
b. membrane area (A)
c. membrane thickness (T)
d. molecular weight of the gas
(MW)
explain what happens to partial pressure for a total gaseous mixture an for individual gases according to Dalton’s law of partial pressure if one gas is added or subtracted
if you add a gas to the mixture, the partial pressure of all other gases in the mixture will decrease
if you subtract a gas from the mixture, the partial pressure of all other gases in the mixture will increase
