Key points related to lung capacities and lung volumes
- • Vital capacity (VC) - Maximum volume of air which can be moved in and out of the lungs. OR
- Maximum amount of air that can be expired from lungs after a maximum inhalation.
- VC = Tidal volume + IRV + ERV
(IRV- Inspiratory Reserve Volume, ERV - Expiratory Reserve Volume)
- Normal vital capacity is 4200 to 4800 ml. It may vary according to the size of a person.
- Vital capacity can be measured by PFT (Pulmonary Function Test) using a Spirometer.
- VC is decreased in COPD, neuromuscular disease, generalized fatigue, atelectasis, obesity, sedentary life style, chronic smokers, old age, chest trauma etc.
- Vital capacity is decreased in restrictive lung disorders and often seen decreased even in obstructive lung disorders.
- Vital capacity can be increased with regular exercise.
- Vital capacity is decreased in all except……..
- Emphysema B) Athletes C) Guillain Barre syndrome D) Rib Fracture Ans: Athletes
Key: Vital capacity generally seems to be decreased in a sick person.