Figure 3 - Line drawing of the normal swallow.

a: The bolus is held in the oral cavity by apposition of the soft palate and tongue with the surrounding laryngeal structures and airway at rest. b: The bolus is conveyed into the oropharynx by the tongue and the soft palate has elevated. The airway and surrounding larynx have elevated in preparation for swallow. c: The bolus is descending into the hypopharynx on either side of the cricoid prominence. The epiglottis has tilted down to cover the closed laryngeal aditus. The larynx has reached its maximum elevation. d: The bolus continues through the hypopharynx, through the open cricopharyngeal segment, and into the esophagus, with the peristaltic wave descending behind it. The nasopharynx begins to open and opening progresses in a descending sequence. e: The wave of pharyngeal contraction has obliterated the oropharyngeal cavity and moved into the hypopharynx, with the bolus descending further through the open cricopharyngeal segment into the esophagus. The nasopharyngeal airway continues to open in a cephalocaudal fashion. f: The bolus has disappeared into the esophagus. All structures have returned to the open position: the normal contours of the airway are again visible, although the larynx has not yet completed its descent to its original resting position. Barium is coating the valleculae and piriform sinuses.(Source: Netter images, with permission from Elsevier Science.)