isothermic saturation boundary

isothermic saturation boundary

(ī″sō-thĕr′mĭk) [″ + Gr. therme, heat],

ISB

The location in the airways where inhaled gases become as warm as body temperature and maximally humidified for that temperature. In a healthy person the ISB typically occurs about 5 to 6 cm below the carina.
Mentioned in ?