The Dynamics of Swallowing. I. Normal Pharyngeal Mechanisms

Swallowing is a complex mechanism in which the functions of the central and autonomic nervous systems are integrated to produce a smooth and speedy transference of the bolus from the mouth to the stomach. The pharyngeal phase of deglu-tition is the most rapid, being usually of less than a second's duration, and for this reason has been difficult to analyze fully. The forces involved in the propulsion of the bolus through the pharynx have been a source of controversy. Some have maintained that the bolus is advanced under positive pressure by the action of the muscles of the tongue and pharynx (1, 2); yet others have postulated negative intra-pharyngeal pressures (3), in particular Barclay