Faculty Collaboration Database

Characterization and mechanisms of the pharyngeal swallow activated by stimulation of the esophagus. Am J Physiol Gastrointest Liver Physiol 2016 Nov 01;311(5):G827-G837

Date

11/03/2016

Pubmed ID

27634013

Pubmed Central ID

PMC5130554

DOI

10.1152/ajpgi.00291.2016

Scopus ID

2-s2.0-84994607928 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

Stimulation of the esophagus activates the pharyngeal swallow response (EPSR) in human infants and animals. The aims of this study were to characterize the stimulus and response of the EPSR and to determine the function and mechanisms generating the EPSR. Studies were conducted in 46 decerebrate cats in which pharyngeal, laryngeal, and esophageal motility was monitored using EMG, strain gauges, or manometry. The esophagus was stimulated by balloon distension or luminal fluid infusion. We found that esophageal distension increased the chance of occurrence of the EPSR, but the delay was variable. The chance of occurrence of the EPSR was related to the position, magnitude, and length of the stimulus in the esophagus. The most effective stimulus was long, strong, and situated in the cervical esophagus. Acidification of the esophagus activated pharyngeal swallows and sensitized the receptors that activate the EPSR. The EPSR was blocked by local anesthesia applied to the esophageal lumen, and electrical stimulation of the recurrent laryngeal nerve caudal to the cricoid cartilage (RLNc) activated the pharyngeal swallow response. We conclude that the EPSR is activated in a probabilistic manner. The receptors mediating the EPSR are probably mucosal slowly adapting tension receptors. The sensory neural pathway includes the RLNc and superior laryngeal nerve. We hypothesize that, because the EPSR is observed in human infants and animals, but not human adults, activation of EPSR is related to the elevated position of the larynx. In this situation, the EPSR occurs rather than secondary peristalsis to prevent supraesophageal reflux when the esophageal bolus is in the proximal esophagus.

Author List

Lang IM, Medda BK, Jadcherla SR, Shaker R

Authors

Ivan M. Lang DVM, PhD Adjunct Professor in the Medicine department at Medical College of Wisconsin
Bidyut K. Medda PhD Associate Professor in the Medicine department at Medical College of Wisconsin
Reza Shaker MD Assoc Provost, Sr Assoc Dean, Ctr Dir, Chief, Prof in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Cats
Deglutition
Electric Stimulation
Electromyography
Esophagus
Female
Larynx
Male
Muscle Contraction
Peristalsis
Pharynx