Evaluate the characteristics of gas exchange in the alveoli.
a. Alveoli are the primary sites of gas exchange.
b. Exchange of gases also occurs between blood and the conducting parts of the respiratory tract.
c. O2 and CO2 are exchanged in these sites by active transport.
d. The rate of diffusion is affected by the solubility of gases and the thickness of the membranes.
e. Partial pressure is the pressure contributed by an individual gas in a mixture of gases.
f. There is a concentration gradient for oxygen from alveoli to blood and from blood to tissues.
g. There is a concentration gradient for CO2 from alveoli to blood and from blood to tissues.
h. The solubility of O2 is 20-25 times higher than that of CO2.
