Nasopharynx

The nasopharynx (from the Latin pars nasalis pharyngis) is the upper, exclusively respiratory part of the pharynx. It is a cavity located posterior to the nasal cavity and superior to the soft palate. Superiorly, its vault borders the cranial base (the sphenoid and occipital bones). Unlike the oral and laryngeal parts of the pharynx, the nasopharynx is not involved in swallowing.

The walls of the nasopharynx do not collapse, as they are rigid and fixed to the bones of the skull. Its primary function is to conduct inhaled air from the choanae (internal nasal apertures) to the lower respiratory tract, while also warming, humidifying, and filtering it.

Anatomy

The cavity of the nasopharynx has several important communications. Anteriorly, through the choanae, it communicates with the nasal cavity. Inferiorly, it continues into the oropharynx. On its lateral walls, the pharyngeal openings of the auditory (Eustachian) tubes are located, connecting the nasopharynx with the middle ear. This connection ensures pressure balance on both sides of the tympanic membrane.

The mucosa of the vault and posterior wall of the nasopharynx contains an accumulation of lymphoid tissue known as the pharyngeal tonsil (the “third tonsil”). Pathological enlargement of this tonsil, especially in childhood, is known as adenoids. The entire nasopharynx is lined with pseudostratified ciliated epithelium, characteristic of the respiratory tract.

Clinical significance

The nasopharynx is a common site for several pathological processes, particularly in childhood. Its condition directly affects nasal breathing and middle ear function.

Major pathologies of the nasopharynx include:

• Adenoid hypertrophy (adenoid vegetations): Enlargement of the pharyngeal tonsil, which may obstruct the choanae and auditory tubes. This condition leads to impaired nasal breathing, snoring, sleep disturbances, and recurrent otitis media.
• Adenoiditis: Acute or chronic inflammation of the pharyngeal tonsil.
• Nasopharyngitis: Inflammation of the mucosa of the nasopharynx, often as a manifestation of acute respiratory viral infections.
• Tubootitis (Eustachitis): Inflammation of the auditory tube caused by infection spreading from the nasopharynx; may lead to hearing loss and a sensation of ear fullness.
• Neoplasms: Both benign (e.g., juvenile angiofibroma) and malignant (e.g., nasopharyngeal carcinoma) tumors may develop in the nasopharynx.

Inspection of the nasopharynx is performed during endoscopic evaluation, which allows detailed assessment of the mucosa, adenoids, and openings of the auditory tubes.

Differential Diagnosis

The symptoms of nasopharyngeal diseases, particularly nasal obstruction, often resemble those of rhinitis or sinusitis. A key distinctive features indicating pathology in the nasopharynx is ear involvement — hearing loss, recurrent otitis media, and a sensation of ear fullness. Endoscopy enables precise identification of the cause of obstruction and helps distinguish adenoid hypertrophy from mucosal edema in nasopharyngitis or from a mass lesion requiring biopsy.