All of the following decrease with age except:-

With increasing age, total lung capacity decreases : decrease in lung volumes d/o* Decrease strength of respiratory muscles : decrease TV, decrease TLC* Decrease elasticity of lung : decrease IRC, decrease TLC* Decrease inspiratory capacity : decrease PaO2* Airway remodeling : decrease FEV1 * Increase FRC k/o airway remodeling, more air tends to Increase RV stay trapped in the alveoli. FRC will increase with age, because of loss of elastic tissue and airway remodelling, more amount of air is trapped in alveoli.