General Medical Information

Modification of Inspired Air

Thomas V. Mccaffrey

The upper airways provide an important protective function by heating ambient air to a temperature of 37°C and saturating it with water vapor. This is a suitable environment for alveolar gas exchange. The demands placed on the upper airway vary with the ambient conditions of temperature and humidity. The heat for warming and the water for humidification of the ambient air are provided by the moist, highly vascular mucosa of the upper airway, particularly the nose. Conditions that reduce the effective surface area of the nasal mucosa available for exchange, such as atrophic rhinitis, impair this essential function of the nasal airway.