In comparison to the apex of the lung, the base of the lung has: (A) High pulmonary arterial pressure O2, (B) High pulmonary arterial pressure CO2, (C) High ventilation / perfusion ratio, (D) Same ventilation / perfusion ratio
Answer is B. Apical alveoli have low ventilation and perfusion per unit volume of the lung, whereas the basal alveoli have high ventilation and perfusion.
Ventilation-perfusion ratio and the PaO2 is maximum at the apex. PCO2 is maximum at the base.