Sunday, June 14, 2015

Deglutation Reflex

The deglutition or swallowing reflex is centered in the medulla oblongata and pons, acting through the hypoglossal nerve (CN XII), which innervates three of the four muscles involved in deglutition (geniohyoid, genioglossus, hyoglossus), and the mylohyoid nerve which supplies the fourth muscle that participates in deglutition, the mylohyoid muscle. The swallowing center also initiates the peristalsic movement of the esophagus.

Swallowing is the process by which the bolus (chewed food) passes from the mouth to the pharynx and into the esophagus as the epiglottis swings down to block the entrance of the trachia, avoiding the food getting into the air passage. Pharyngeal contraction drives bolus into esophagus.