Inclusive Anatomy
Anatomy
Structure
The pharyngotympanic tube is a narrow canal that connects the middle ear (tympanic cavity) to the nasopharynx.[1] It lies within the parapharyngeal region of the skull base, extending from the anterior wall of the tympanic cavity to the lateral wall of the nasopharynx.[1]
The tube measures approximately 36 mm in total length.[1] The posterolateral one-third (approximately 12 mm), adjacent to the tympanic cavity, is bony and lies within the petrous part of the temporal bone.[1] The remaining anteromedial two-thirds (approximately 24 mm) consists of elastic fibrocartilage, which opens into the nasopharynx.[1]
The pharyngotympanic tube is lined by respiratory mucosa that is continuous posteriorly with the mucosa of the tympanic cavity and anteriorly with the mucosa of the nasopharynx.[1] This continuity facilitates pressure regulation and mucociliary clearance between the middle ear and upper respiratory tract.[1]
Function
The primary function of the pharyngotympanic tube is to equalize air pressure between the middle ear and the external atmosphere.[1] By intermittently opening—most commonly during swallowing, yawning, or chewing—the tube allows air to pass between the nasopharynx and the tympanic cavity.[1]
Pressure equalization enables the tympanic membrane to vibrate freely, maintaining optimal tension for efficient transmission of sound waves through the ossicular chain.[1,2] Dysfunction of the tube may result in impaired ventilation of the middle ear, contributing to conditions such as otitis media, barotrauma, or conductive hearing loss.[2]
References
Moore KL, Dalley II AF, Agur AMR. Clinically Oriented Anatomy. 8th ed. Wolters Kluwer; 2018.
Peterson DC, Sutton AE. Anatomy, Head and Neck: Middle Ear. In: StatPearls. StatPearls Publishing; 2026.