Role of distention in swallow phase transition

Abstract

The effect of pharyngeal and esophageal distention on swallow phase transition has not been fully elucidated. In quadrupeds we hypothesize pharyngeal to esophageal (P:E) ratio is dependent on distention of the pharynx and/or esophagus to trigger a phase transition. To this effect videofluoroscopy was performed on 8 cats using liquid and puree consistencies laced with 40% barium. Awake cats were given 30 seconds after food/liquid presentation to initiate eating/drinking. Using MicroDicom viewer software (MicroDICOM; Sofia, Bulgaria) diameter was calibrated using an object placed in the viewing field (i.e. dime). The diameter of the pharynx, upper esophageal sphincter opening, and bolus size in the esophagus were measured. There was a significant difference between the tolerated pharyngeal distention between liquid (9.5 ± 1.9 mm) and puree (12.6 ± 2.5 mm) boluses (p=0.01), as well as esophageal distention between liquid (6.5 ± 1.9 mm) and puree (8.3 ± 2.2) boluses (p<0.05). The average distention of the UES was not significantly different (p> 0.05) with a diameter of 7.8 ± 2.0 mm for liquid versus 9.0 ± 2.0 mm for puree. The ratio of pharyngeal to esophageal phase swallows range from 2–6 in liquid boluses and 1–3 in puree boluses. The variable pharyngeal to esophageal phase ratio supports the hypothesis that transition through each phase of swallow is driven by distention of the pharyngeal and esophageal walls and not by a set P:E ratio.Support or Funding InformationSupported by R00‐ HL 111215 and The Kentucky Spinal Cord and Head injury Trust.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.