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There are four phases involved in swallowing. The oral preparatory phase, the oral propulsive phase and the pharyngeal and esophageal phases. This illustrates the steps involved in the pharyngeal phase (these actions are overlapping and rapid). These steps are described in order from left to right.1. Principal anatomy involved in sagittal section2. Bolus moved to rear of oropharynx, and soft palate begins to elevate. The epiglottis moves to protect airway, while the vocal folds close at the midline. Hyoid bone elevates.3. Epiglottis has closed off larynx, and the soft palate has blocked food entry into the nasopharynx. Tongue elevates.4. Tongue pushes towards back of oropharynx, and inferiorly toward the esophagus. Upper esophageal sphincter relaxes to.
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