4 Answers
Vital capacity is the maximum volume of air that can be exhaled after a maximum inspiration. It is about 3.5 – 4.5 litres in the human body. It promotes the act of supplying fresh air and getting rid of foul air, thereby increasing the gaseous exchange between the tissues and the environment
Functional Residual Capacity (FRC): The volume of air which remains in the lungs after a normal expiration is called Functional Residual Capacity. FRC = ERV + RV.
ERV =1000 to 1100 ml
RV = 1100 to 1200 ml
So, FRC = 2100 to 2300 ml.
Vital capacity is the maximum volume of air a person can breathe in after a forced expiration. It is the sum of Inspiratory reserve volume (IRV), Expiratory reserve volume (ERV) and the Tidal volume (TV).
The vital capacity is different for different person. Its higher in athletes than in non-athletes, in mountain dwellers than in people living on plains and in youth than in old age. Cigarette smoking reduces the vital capacity.
Vital capacity (VC):
The maximum volume of air a person can breathe in after a forced expiration. This includes ERV (Expiratory Reserve Volume), TV (Tidal volume) and IRV (Inspiratory Reserve volume) of the maximum volume of air a person can breathe out after a forced inspiration.