The Esophageal Stage

This is another involuntary swallowing stage. It length of time changes depending on the consistency of the bolus. Peristaltic waves move the bolus through the esophagus.

Esophageal Opening

The cricophayngeus muscle which is inverted by CN X controls the upper esophageal sphincter. While the bolus moves through the pharynx it opens and relaxes 

Esophageal Constriction

Esophagus is a collapsed tube behind the trachea.The esophagus is made up of 3 regions Cervical region, Thoracic region, and Abdominal region. Peristaltic waves move bolus through esophagus to the stomach.