stages of swallowing

Stages of Swallowing
I-Oral Stage:
· The oral stage is voluntary and requires control of oral structures, including the
anterior position of the soft palate.
· Following mastication, the food is pulled together into a cohesive mass.
· Next, in a second or less, the tongue propels the bolus posteriorly.
· The oral stage ends once the material passes the anterior faucial arches at the back of
the throat.
· This posterior tongue movement and the material passing along the anterior faucial
arches help activate the involuntary or reflexive swallow that constitutes the
pharyngeal stage.
· The reflex is believed to originate in the fauces, soft palate, base of the tongue, and posterior
pharyngeal wall.
· Innervation is primarily from the vagus in the brain stem, but involves cranial nerves IX
through XI.
II-Pharyngeal Stage
· This is a reflexive stage that begins with the raising of the hyoid and larynx, and
closing of the thyroarytenoid and ventricular cords to create a velopharyngeal seal.
· Next, the epiglottis tilts and the cricopharyngeus muscle, or superior esophageal
sphincter, is relaxed, opening the esophagus.
· With the help of accessory muscles, a peristaltic wave moves the bolus through
the hypopharynx and into the esophagus in approximately one second..
III-Esophageal Stage:
· This phase begins as the superior esophageal sphincter opens and, propelled by the
peristaltic wave contractions that were started in the pharyngeal phase, the bolus
passes through the esophagus and inferior esophageal sphincter into the stomach.
· This stage takes from 8 to 20 seconds.