The ventilatory response (change in minute ventilation) in the healthy aged patient (70-year-old) to either a hypercapnic or hypoxic stimulus is half that seen in the 25-year-old.

• 70岁的健康老人通气反应（分钟通气量的变化）对高碳酸血证和低氧的刺激仅是25岁年轻人的一半。