Define age related changes in Respiratory system

During ageing, alveoli (present in the lungs) become flatter and shallower, alveolar ducts enlarge, walls become thinner, contains less capillaries, respiratory surface area decreases, elastic recoil response is lost, pulmonary diffusing capacity gets reduced. The respiratory response to hypoxia and hypercapnia is sluggish in the elderly. There is an overall impairment in ventilation, diffusion, regulation etc. that leads to slowing down of the respiratory responses.