“…At about the time that the bolus reaches the posterior surface of the tongue, the pharyngeal swallow response is triggered. The pharyngeal swallow response is comprised of several closely coordinated functional elements: (1) elevation and retraction of the soft palate with closure of the nasopharynx (levator veli palatini, tensor veli palatini, and palatopharyngeus muscles); (2) anterior superior laryngeal displacement with obliteration of the laryngeal vestibule (mylohyoid, geniohyoid, digastric, stylohyoid, stylopharyngeus, salpingopharyngeus, thyrohyoid muscles) and laryngeal closure at the level of the epiglottis and true vocal folds (thyroarytenoid, aryepiglottic, and oblique arytenoid muscles) [4]; (3) relaxation and opening of the upper esophageal sphincter [5]; and (4) bolus propulsion (tongue) [6,7] and pharyngeal clearance (pharyngeal constrictors, elevators) [8]. Three of these functional elements are discussed in detail below.…”