Answer to Question 1
ANS: D
The ventilation going to lung units with either long or short time constants is less than that re-ceived by units with normal compliance and resistance.
Answer to Question 2
ANS: A
Despite their higher volume, alveoli at the apexes expand less during inspiration than alveoli at the bases or periphery. This is due to their respective positions on the pressure volume curves (Figure 11-14). The apical alveoli are on the flatter or less compliant portion of the curve and thus for any change in pressure there is only a small change in volume. The alveoli in the lung base are on the steep part of the curve, so even small changes in pressure result in comparatively large changes in volume.