(a) Inspiratory Reserve volume- it is the additional volume of air a person can inspire by a forcible inspiration. It ranges between 2500ml to 3000ml.

         Expiratory Reserve volume- it is the additional volume of air a person can expire by a forcible expiration. It ranges between 1000ml to 1100ml.

(b) Vital capacity -   vital capacity is the maximum volume of air that  a person can breathe in after a forced expiration. This includes ERV,TV and IRV or the maximum         volume of air a person can breathe out after a forced inspiration. i.e, Vc=ERV +IRV + TV

         Total lungs capacity – total using capacity is the total volume of air accommodated in the lungs at the end of a forced inspiration. This include RV,ERV,TV and IRV         or vital capacity + residal volume. I,e, TLC =RV +(ERV +IRV +TV) or VC +RV

(c) Emphysema -  emphysema is a chronic disorder of respiratory system. In which alveolar cells are damaged due to which regulatory respiratory surface is decreased .   Caused by emphysema is cigarette smoking.

           Occupational respiratory disorder -  it is caused due to the long exposure of dust produced by stone grinding or breaking and give rise to inflammation leading to            fibrosis and thus causing serious lung damage. Protective masks are provided for the workers in such industries