Abstract

Nature, Key Functions, Neural Control & Clinical Impact.

The airway is a dynamic conduit, extending from the nose to the air sacs. Its key functions include protection, volume maintenance and ventilation, which are coordinated with other motor acts. Neural control of motor output provides airway defense as a first priority, with rapid protection of the lower airway being afforded by laryngeal closure and central apnea. During breathing, stability of airway volume (patency) and gas flow with ensuing gas exchange are also controlled centrally via coordination of motor activities that interact with physiochemical (structural) mechanisms. Sensors rapidly relay information about all key motor functions and, if required, this monitoring results in within-breath pattern adaptations. Neural control of the airway is not only dynamic but varied, with many motor output patterns noted during development and in different physiological (e.g. sleep) and pathological states. The clinician uses this knowledge to interpret breathing patterns as normal or abnormal, and uses this synthesis to direct both investigation of the airway and/or its central control and therapy.