Coordination of deglutition and respiration

Abstract

Respiratory-swallowing coordination is vital for airway protection and other aspects of swallowing function. Perturbations in coordinative mechanisms have been linked to disordered swallowing in susceptible patients. We provide a general overview of respiratory-swallowing interactions in adults discussing neural control systems, reconfigurations of shared muscle systems, timing of the initiation of swallowing processes within the respiratory cycle, disorders of coordination and potential mechanisms, and directions of future clinical and basic research. Importance is given to the normal timing of the initiation of swallowing during the expiratory phase of the breathing cycle at mid to low lung volumes. The airway protection and potential mechanical advantages of this coordinative relationship are highlighted. Potential differences in coordinative synchrony related to task and subject factors are reviewed and set the stage for additional experimental inquiry. Future directions related to re-training of appropriate respiratory-swallowing mechanisms to improve swallowing function disrupted by various clinical pathologies are introduced.