Deglutition Reflex
The deglutition (swallowing) reflex is a coordinated sensorimotor brainstem and cranial nerve–mediated reflex that transfers a bolus from the oral cavity to the esophagus while protecting the airway.
It is triggered by sensory input from oropharyngeal structures and is executed through sequential phases involving tongue, pharynx, and laryngeal musculature.
Reflex Afferent Input
Sensory (afferent) limb is mediated by glossopharyngeal (CN IX) and vagus (CN X) pathways from the oropharynx and laryngeal inlet.
Triggering sensation is conveyed to swallowing centers in the medulla.
Central Pattern Generator
Swallowing is orchestrated by brainstem swallowing pattern generator networks in the medulla that coordinate timing across cranial motor nuclei.
Deglutition reflex integrity depends on intact brainstem circuitry and input from the upper aerodigestive tract.
Reflex Efferent Output
Motor (efferent) output is mediated by cranial nerves that control oral, pharyngeal, and laryngeal phases, including trigeminal (CN V), facial (CN VII), hypoglossal (CN XII), glossopharyngeal (CN IX), and vagus (CN X).
Laryngeal closure and airway protection during swallowing depend on coordinated activity of laryngeal adductor and related muscles driven by vagal motor pathways.
Swallowing Sequence
Swallowing is functionally described as oral, pharyngeal, and esophageal phases.
The pharyngeal phase is the core reflex phase and rapidly coordinates pharyngeal contraction with airway protection.
Clinical Significance
Impaired deglutition reflex or impaired pharyngeal motor execution can contribute to oropharyngeal dysphagia and aspiration risk.
Disruption of sensory input from the oropharynx or disruption of brainstem swallowing circuitry can impair triggering or execution of the reflex.
Related Terms
The deglutition reflex is closely related to the swallow reflex used clinically to assess sensory-triggered swallowing and aspiration risk.
Oropharyngeal sensation and laryngeal protective reflexes are commonly evaluated together when swallowing dysfunction is suspected.
Key Points
The deglutition reflex is a brainstem-based protective reflex that coordinates bolus transit and airway protection.
The afferent limb is primarily CN IX and CN X input from the oropharynx.
The efferent limb coordinates cranial nerve–driven oral, pharyngeal, and laryngeal motor activity to complete swallowing.