INBDE (Integrated National Board Dental Examination) Practice Exam 2026 - Free Practice Questions and Study Guide

The function of the outer circular layer of the pharyngeal muscles is to constrict the pharynx to propel the bolus downward. This muscle contraction helps in the process of swallowing by pushing the food or liquid mass towards the esophagus. This action aids in the movement of the bolus through the digestive system.

Option A (Elevate the pharynx) is incorrect as the action of elevating the pharynx is primarily performed by the superior pharyngeal constrictor muscles.

Option C (Increase tension of the vocal cords) is incorrect as the tension of the vocal cords is controlled by the intrinsic laryngeal muscles such as the thyroarytenoid and cricothyroid muscles.

Option D (Open the airway) is incorrect as the action of opening the airway is primarily controlled by the dilation of the pharynx by the pharyngeal dilator muscles.