<prompt> In comparison to the apex of the lung, the base of the lung hasHigh pulmonary arterial pressure O2High pulmonary arterial pressure CO2High ventilation perfusion ratioSame ventilation perfusion ratio  <response>: 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. 