An Overview of Functional Residual Capacity (FRC)
Tests that measure FRC include alung plethysmographor a helium dilution method. Even though you exhale, air is still left in the lungs. The volume of remaining air after a normal breath is called the FRC. BSIP / UIG / Getty Images As you breathe, youralveoli(tiny air sacs) always stay open. This is due to a number of factors. Surfactant, a sticky substance that lines the inside of your alveoli, helps keep them open....