With increase in age which of the following is true for lungs

Ageing and Lung Changes * Decreased chest wall compliance is counter balanced by a loss of elastic recoil of the lungs (increased lung compliance), which is due to a decrease in the number of parenchymal elastic fibers. * Chest wall and thoracic spine deformities which leads to increase work of breathing. * Dilation of air spaces: "senile emphysema". * Respiratory muscle strength decreases with age and this impairs effective cough, which is impoant for airway clearance. * Clearance of paicles from the lung through the mucociliary elevator is decreased and associated with ciliary dysfunction. * The alveolar dead space increases with age, affecting aerial oxygen without impairing the carbon dioxide elimination. * The airways receptors undergo functional changes with age and are less likely to respond to drugs used in younger counterpas * Decreased sensation of dyspnea and diminished ventilatory response to hypoxia and hypercapnia, making them more vulnerable to ventilatory failure during high demand states (ie, hea failure, pneumonia, etc) * Decreases in the volume of the thoracic cavity and reduced lung volumes. Hence Residual volume increases. Ref:- Relationship between chest wall and pulmonary compliance and age Charles Mittman, Norman H. Edelman, Ahur H. Norris, and Nathan. Pg num:- 202