Fig. 4.

Relative timing of swallow related events time correlated to cricopharyngeal deactivation (CP off) for different bolus volumes (mean values). Interestingly, peak submental activation (◇) occurs prior to maximal UES opening (○) for 2 and 5 ml volume swallows, while peak SM activity occurs following maximal opening at 10 and 20ml. The inference is that the bolus itself plays an important role in initiating sphincter opening, including CP deactivation, at larger volumes