Ventilation and Gas Exchange Flashcards
There are two types of ventilation, what are they?
Minute Ventilation: (volume of breath exhaled in 1 min)
[ V* = F (breath/min) * Vt (mL/breath) ]
Alveolar Ventilation: (useful vol. of breath exhaled in 1 min)
[ V* = F (breaths/min) * (Vt -Vd) (∆ mL/breath) ]
When calculating anatomic dead space, what value can you use to estimate Vd?
individuals weight in lbs –> mL (NOT LITERS) *keep units constant
There are two types of dead space, what are they?
Anatomic Dead Space: volume of air in conductive zone
Physiological Dead Space: conductive ds + alveolar ds
Total dead space can be calculated using the Bohr equation. What is the Bohr equation, and what are the important relationships?
Vd/Vt = (Pa,COz - Pe,COz) / (Pa, COz)
What is the difference between minute ventilation rate, and alveolar ventilation rate? What is the formula for each? What happens to A-ventilation in diseased lung?
Remember quick breaths decrease your tidal volume
MV: [ V* = F (breaths/min) * (Vt) ]
AV: [ V* = F (breaths/min) * (Vt -Vd) ]
Diseased: increased dead space
Decreasing breathing frequency does what to Vt?
At low Freq. work against what force is higher?
At high Freq. work against what force is higher?
Name the three forces that the body works against
Increases
Elastic Recoil
Resistance
What is the def. of partial pressure?
P(partial) = Ptotal * fractional concentration
at equilibrium, Pgas (liquid) = Pgas (air)
The amount of gas dissolved in a solvent can be determined by Henry’s Law. What is Henry’s law?
Cgas (in liq) = Ppressue-gas * (solubility constant)
What factors determine Alveolar gas constant? What are normal partial pressure?
Ventilation, Metabolism PA, Oz = 100 mmHg, PACOz = 40 mmHg
Diffusing Capacity (D-(lungs) What is the equation?
Measure how well diffusion occurs between alveolar air and the blood.
D-L,CO = V* CO / PA,CO - is an intrinsic property, specific to a driving force.
