Which physiological process is facilitated by hyolaryngeal excursion during swallowing?

Which physiological process is facilitated by hyolaryngeal excursion during swallowing?

• A. Opening of the Lower Esophageal Sphincter
• B. Opening of the Upper Esophageal Sphincter
• C. Velar Elevation
• D. Vocal Fold Abduction

Answer: (B)

Hyolaryngeal excursion—the upward and forward movement of the hyoid bone and larynx during swallow—primarily opens the upper esophageal sphincter. The cricopharyngeus muscle at the UES stays tonically contracted and then relaxes as the hyoid and larynx rise and move forward, pulling the sphincter open so the bolus can pass from the pharynx into the esophagus. This motion is essential for bolus transit through the pharyngoesophageal segment, even though it also aids airway protection through other coordinated actions. Velar elevation, by contrast, relates to closing the velopharyngeal port (important for preventing nasal regurgitation and for certain speech sounds) and does not govern UES opening. Vocal fold abduction is about widening the airway for airflow and protection, not about facilitating passage into the esophagus.

Hyolaryngeal excursion—the upward and forward movement of the hyoid bone and larynx during swallow—primarily opens the upper esophageal sphincter. The cricopharyngeus muscle at the UES stays tonically contracted and then relaxes as the hyoid and larynx rise and move forward, pulling the sphincter open so the bolus can pass from the pharynx into the esophagus. This motion is essential for bolus transit through the pharyngoesophageal segment, even though it also aids airway protection through other coordinated actions.

Velar elevation, by contrast, relates to closing the velopharyngeal port (important for preventing nasal regurgitation and for certain speech sounds) and does not govern UES opening. Vocal fold abduction is about widening the airway for airflow and protection, not about facilitating passage into the esophagus.