What is The functional residual capacity is best defined as the sum of : and explain in detail?
The functional residual capacity represents the volume of the air remaining in the lungs after expiration of a normal breath. This is the volume remaining in the lungs after a tidal volume is expired and may be represented as the sum of Expiratory Reserve volume and residual volume (ERV+RV). Lung volumes and capacities (There are 4 primary Lung Volumes and Four Lung capacities: Primary Lung Volumes Lung or Respiratory Capacities The different amounts of air drawn into or out of the lungs by contracting different groups of muscles are called primary lung Volumes Respiratory capacities are when two or more repsiratory volumes are added together Tidal Volume(Vt): (Typically = 500-750 mL) Inspiratory Capacity (2.5 L) (TV+IRV) Tidal volume is the volume inspired or expired with each normal breath. The amount of air that moves into the lungs with each inspiration or the amount that moves out with each expiration during quiet breathing is called the tidal volume (TV) The inspiratory capacity ([?]2.5L) is the maximum amount of air inspired from the end-expiratory level Inspiratory Reserve volume (IRV) (Typically [?]2L) Vital lung capacity ([?]3.5L) (TV+IRV+ERV) Inspiratory Reserve volume is the volume that can be inspired over and above the tidal volume. The air inspired with a maximal inspiratory effo in excess of the TV is the inspiratory reserve volume The vital lung capacity ([?]3.5L) refers to the maximum amount of expired from the fully inflated lung, or maximum inspiratory level Expiratory reserve volume (ERV) (ERV;[?]1L) Functional Residual capacity ([?]2.5L) (RV+ERV) Expiratory reserve volume (ERV) is the volume that can be expired after the expiration of a tidal volume. The volume expelled by an active expiratory effo after passive expiration is the expiratory reserve volume The functional residual capacity represents the volume of the air remaining in the lungs after expiration of a normal breath. The functional residual capacity also includes the RV, so it cannot be measured by spirometry Residual Volume (RV) (RV; [?]1.3L) Total lung capacity ([?]5L) (TV+IRV+ERV+RV) Residual volume (RV) is the volume that remains in the lung after a maximal expiration Residual volume cannot be measured by spirometry Total lung capacity (TLC) is the volume in the lungs after a maximal inspiration and represents the sum of all four lung volumes. Total lung capacities (TLC) includes RV, so it cannot be measured by spirometry Ref: Ganong 24th edition Pgno: 629