In the involuntary pharyngeal phase, the soft palate rises to close the nasopharynx and prevent nasal regurgitations. The hyoid bone rises, bringing the larynx up, while the epiglottis closes the entrance to the larynx. The base of the tongue contacts the pharyngeal wall, at the same time as the hyoid moves forward, coinciding with the relaxation of the cricopharyngeus muscle and the opening of the upper esophageal sphincter.