There is a decline in the efficiency of the respiratory system with ageing. There is a gradual loss of elastic tissue & the chest wall becomes less capable of expansion. These changes show up as a reduction in vital capacity (The maximum volume of air that can be expired after a maximum inspiration). This may decrease by as much as 35% by the age of 70. All other aspects of function decline in performance notably, the action of cilia & protective activity of white blood cells. This leaves the system more prone to disease like pneumonia, bronchitis & emphysema.
