Respiratory Volumes Types and Definitions
The contraction of the diaphragm and the inter coastal muscles produces expansion of the chest cavity, so air enters into the lungs during inspiration. A forced inspiration can produce additional expansion, so more air can enter the lungs . Similarly, a forced expiration can expel an extra volume of air.
The various respiratory volumes are:
1. Vital Capacity:
Vital capacity is defined as the volume of the air that can be expelled by a forced expiration after a forced inspiration.
2. Tidal air:
Tidal air is the volume of the air passing in and out of the lungs with ordinary quiet breathing.
3. Inspiratory reserve:
Inspiratory reserve is the additional volume of air that can be taken in by forced inspiration.
4. Expiratory reserve:
Expiratory reserve is the volume of air that can be expelled by forced expiration after normal inspiration.
5. Residual Volume:
Residual volume is the volume of the air which remains in the lungs on forced expiration after normal inspiration.
6. Total Lung Capacity:
It is the sum of vital capacity and residual volume.