When is the rate of gaseous diffusion across a biological membrane decreased?
a. The diffusion distance is small.
b. The gas diffusion constant increases.
c. The partial pressure gradient is low.
d. The surface area is large.
Q. 2 What is the primary determinant of the PAO2?
a. Body's CO2
b. Metabolic rate of the body tissues
c. PaO2
d. PO2 in the inspired gas
Q. 3 Calculate the approximate PAO2 given the following conditions (assume R = 0.8): FiO2 = .40, PB = 770 mm Hg, PACO2 = 31 mm Hg
a. 100 mm Hg
b. 135 mm Hg
c. 250 mm Hg
d. 723 mm Hg
Q. 4 The PAO2 depends on which of the following factors?
1. Ambient (atmospheric) pressure
2. Fractional concentration of inspired O2
3. Level of VA
4. Types of fuels burned (fat, protein, and carbohydrate)
a. 1, 2, and 3 only
b. 1 and 2 only
c. 3 only
d. 1, 2, 3, and 4
Q. 5 In a person breathing room air (and with all else being normal), if the alveolar PCO2 rises from 40 to 70 mm Hg, what would you expect?
a. PAO2 to fall by approximately 30 mm Hg
b. PAO2 to fall by approximately 40 mm Hg
c. PAO2 to rise by approximately30 mm Hg
d. PAO2 to rise by approximately 40 mm Hg