The pharynx is tubular structure extending from base of skull superiorly
to esophageal inlet inferiorly, and is composed of three distinct areas: the nasopharynx, the oropharynx, and the hypopharynx, with the pharyngeal walls being composed of the superior, middle, and inferior pharyngeal constrictor muscles. It is part of the digestive system and of the conducting zone of the respiratory system.