Final answer:
The upper esophageal sphincter relaxes to allow the bolus to pass into the esophagus, and peristalsis propels it towards the stomach. The epiglottis folds to prevent the bolus from entering the respiratory pathways. Mucus secreted by esophageal glands lubricates the esophagus for easier bolus passage.
Step-by-step explanation:
The process that allows the bolus to move from the laryngopharynx to the esophagus is facilitated by the relaxation of the upper esophageal sphincter. When food is swallowed, the epiglottis folds to cover the glottis, which prevents the bolus from entering the respiratory pathways like the trachea, and allows it to pass on both sides of the epiglottis into the esophagus. Once the bolus enters the esophagus, coordinated muscular contractions known as peristalsis propel it through the esophagus toward the stomach. The lower esophageal sphincter then relaxes to allow the bolus to move from the esophagus into the stomach, and subsequently contracts to prevent chyme from re-entering the esophagus. Additionally, to aid in this process, esophageal glands secrete mucus that lubricates the esophagus, allowing easier passage of the bolus.