Answer to Question 1
ANS: D
At the bottom of the lung, blood flow is greater than ventilation, resulting in a low / (approxi-mately 0.66), low PO2 (89 mm Hg), and slightly higher PCO2 (42 mm Hg).
Answer to Question 2
ANS: C
A decrease in pulmonary capillary blood flow will cause a fall in alveolar PCO2 and a rise in al-veolar PO2 assuming minute ventilation remains the same. This will result in an area of high .