What does FRC stand for in respiratory mechanics?

• A. Functional Residual Capacity
• B. Forced Respiratory Capacity
• C. Functional Response Cycle
• D. Forced Residual Capacity

Answer: (A)

Functional Residual Capacity (FRC) refers to the volume of air that remains in the lungs after a normal, passive expiration. It is a critical measurement in respiratory mechanics as it helps to assess the lung's ability to maintain adequate gas exchange and oxygenation even between breaths. FRC is made up of two components: the expiratory reserve volume (ERV) and the residual volume (RV). This capacity is significant because it represents the air that is constantly available for gas exchange, thus preventing alveolar collapse and ensuring that oxygen and carbon dioxide levels can be effectively maintained in the blood.

The measurement of FRC can provide valuable insights into various respiratory diseases and conditions, such as obstructive and restrictive lung diseases, as abnormalities in FRC might indicate impairments in lung function. Understanding FRC is essential for clinicians when assessing lung health and determining appropriate interventions for respiratory disorders.