Gas Exchange 1 Flashcards
What is in the air
78% Nitrogen
21% Oxygen
0.9% Argon
0.037% CO2
What is an important variable in respiratory gas exchange
Rate of diffusion
Diffusion of gas is influenced by: (5 items)
Solubility of the gas in the medium (water, air) Partial pressure gradient Temperature Distance for diffusion Surface area for diffusion
What is the Fick equation?
Rate of diffusion = Diffusion coefficient * SArea * Pressure gradient
Rate of diffusion is smallest when ___
The distance is at its smallest
What is the diffusion coefficient
Index of ease of diffusion of a particular substance through a given medium
The diffusion coefficient depends on what
Temperature and solubility
The pressure of the gas is a measure of ____
the thermodynamic activity of the gas molecules
Dalton’s Law of Pressures
Each gas exerts its own partial pressure. The sum of the partial pressures = total pressure and is proportional to the total number of gas molecules
What is the Ideal gas law?
PV=nRT
What is P equivalent to in the Ideal gas law?
P=(nRT)/V
Partial pressure depends on ___
Temperature of the gas
If the temperature increases and volume is not constant, what will happen?
The volume will increase & pressure stays constant & concentration of gas decreases
If temperature increases and volume is constant, what will happen?
Pressure increases & concentration of gas stays the same
What does a gas need to do before it diffuses into a cell?
Dissolve into the liquid
The amount of gas that will dissolve in a liquid is dependent on ___
Partial pressure in air & solubility in the liquid
What is Henry’s Law
Concentration of gas dissolved in liquid = Partial pressure of gas in atmosphere * Solubility of gas in liquid
What has a large effect on solubility of gases in liquids?
Temperature & salinity
What is Graham’s Law
Diffusion of a gas in a liquid is proportional to its solubility & inversely proportional to the square root of its molecular weight
Which diffuses faster in air: O2 or CO2
O2 is 1.2 faster to diffuse than CO2
Which is more soluble in water: O2 or CO2
CO2 is 24 times more soluble in water than O2
Which is more soluble in air: O2 or CO2
Same
Which has higher molecular weight: O2 or CO2
CO2
What is the diffusion rate for oxygen in water vs. air
Diffusion rate for O2 in water is 300,000 times more slower than air