Description
A great deal is already known about the physiology of swallowing. We understand the distinction between upper sphincter opening1-3 and relaxation or distension. We understand pharyngeal motor phenomena too. We are aware of pharyngeal asymmetry and that the pharyngeal wave is a clearing wave not a propulsive wave.4 We know that the retrolingual bolus chamber is where the bolus sits and waits ready to be ejected, that ejection is very efficient and that 80% of a bolus collected there will eject within the first 130 msec of a swallow.
