Lung volumes & capacities

Lung volumes & capacities

1. LUNG VOLUMES & CAPACITIES Ms.Anu Sebastian: B.Pharm ; M.Pharm Assistant Professor, Dept. Of Pharmacology Nirmala College Of Pharmacy Muvattupuzha,Ernakulam,Kerala

2. While at rest, a healthy adult averages 12 breaths a minute,with each inhalation & exhalation moving about 500ml of air into and out of the lungs. Spirometer / Respirometer : The apparatus used to measure the volume of air exchanged during breathing & respiratory rate. Spirogram : The record of spirometer.Inhalation is recorded as an upward deflection & exhalation as downward deflection. The Minute Ventillation (MV): the total vol. of air inhaled & exhaled each minute. MV = Respiratory rate * Tidal volume =12 breaths/min* 500ml/breath = 6 litres /min

3. Tidal Volume : The volume of one breath.,i.e 500ml. Inspiratory Reserve Volume : It is the additional volume of air that can be inhaled into the lungs by a forced inspiration after a normal inspiration. For adult male : 3100ml For adult male : 1900 ml Expiratory Reserve Volume : It is the volume of air that can be exhaled from the lungs by forced expiration after a normal expiration. For adult male: 1200 ml For adult female: 700 ml

4. Residual Volume : It is the volume of air that remains in the lungs following a maximal expiration .It can be expelled only by opening the thoracic caviy . For Males: 1200ml For Females: 1100 ml LUNG CAPACITIES Lung capacities are combinations of specific lung volumes. Inspiratory capacity = Sum of tidal volume and Inspiratory reserve volume. For males: 500 ml+ 3100 ml=3600ml For females: 500ml + 1900ml= 2400 ml

5. Functional residual capacity : Sum of residual volume and expiratory reserve volume. For Males: 1200ml + 1200 ml= 2400 ml For Females: 1100ml + 700 ml= 1800ml Vital Capacity : Inspiratory reserve volume + Tidal volume + Expiratory reserve Volume For Males: 4800 ml For Females: 3100 ml Total Lung capacity = Vital capacity + Residual Volume. For Males: 4800 ml + 1200 ml =6000 ml For Females: 3100 ml + 1100 ml =4200 ml

6. THANK YOU