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Dysphagia

, Volume 24, Issue 3, pp 333–348 | Cite as

Brain Stem Control of the Phases of Swallowing

  • Ivan M. Lang
Review Article

Abstract

The phases of swallowing are controlled by central pattern-generating circuitry of the brain stem and peripheral reflexes. The oral, pharyngeal, and esophageal phases of swallowing are independent of each other. Although central pattern generators of the brain stem control the timing of these phases, the peripheral manifestation of these phases depends on sensory feedback through reflexes of the pharynx and esophagus. The dependence of the esophageal phase of swallowing on peripheral feedback explains its absence during failed swallows. Reflexes that initiate the pharyngeal phase of swallowing also inhibit the esophageal phase which ensures the appropriate timing of its occurrence to provide efficient bolus transport and which prevents the occurrence of multiple esophageal peristaltic events. These inhibitory reflexes are probably partly responsible for deglutitive inhibition. Three separate sets of brain stem nuclei mediate the oral, pharyngeal, and esophageal phases of swallowing. The trigeminal nucleus and reticular formation probably contain the oral phase pattern-generating neural circuitry. The nucleus tractus solitarius (NTS) probably contains the second-order sensory neurons as well as the pattern-generating circuitry of both the pharyngeal and esophageal phases of swallowing, whereas the nucleus ambiguus and dorsal motor nucleus contain the motor neurons of the pharyngeal and esophageal phases of swallowing. The ventromedial nucleus of the NTS may govern the coupling of the pharyngeal phase to the esophageal phase of swallowing.

Keywords

Swallowing Oral phase Pharyngeal phase Esophageal phase Reflexive swallow Deglutitive inhibition Failed swallows Central pattern generator Deglutition Deglutition disorders 

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© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Dysphagia Institute Animal Research Laboratory, Department of Medicine, Division of Gastroenterology and HepatologyMedical College of WisconsinMilwaukeeUSA

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