Division of air in lungs. Measured by spirometer.
1. Tidal Air (T.A.): Quantity of air taken in or given out in a breath 500 cc.
2. Inspiratory Reserve Volume (I.R.V.): Air taken in by extra effort 2500 cc.
3. Expiratory Reserve Volume (E.R.V): Air given out by extra effort 1500 cc.
4. Vital Capacity (V.C.): TA + IRV + ERV = 4500 cc
5. Residual Volume (R.V.): Remaining air after ERV = 1000 cc.
6. Total lung capacity : V.C. + R.C. = 5500 cc.
7. Dead space: Air present in Respiratory system except alveoli = 150 cc.