Functional residual capacity (FRC)

Definition

Functional Residual Capacity is the volume of air remaining in the lungs after a normal, passive exhalation. It represents the balance point between the forces of the chest wall pushing outwards and the lungs recoiling inwards.

Related terms

Tidal Volume: The amount of air inhaled or exhaled during a normal breathing cycle.

Vital Capacity: The maximum amount of air a person can exhale after maximum inhalation, demonstrating lung capacity.

Residual Volume: The volume of air left in the lungs after maximal exhalation, ensuring they do not collapse