Nasopharynx

The nasopharynx forms the superior-most part of the pharynx, in continuity with the inferior oropharynx, and the posterior continuation of the anterior nasal cavity.

Gross anatomy

Boundaries

• anteriorly: posterior nares and posterior margin of nasal septum ^1,2
• inferiorly: soft palate ²
• superiorly: basisphenoid and basiocciput ^1,2
  • roof of the nasopharynx is called the vault (or fornix) of the pharynx, where the mucosa firmly attaches to the sphenoid and pharyngobasilar fascia
• posteriorly: C1 and C2 ¹
• laterally
  • the pharyngeal opening of the Eustachian tube is located in the center of the lateral wall ^1,2
  • lymphoid tissue aggregates, also known as the tubal tonsil occur around the opening of the Eustachian tube ^1,3
  • the fossa of Rosenmüller lies between the posterior margin of the Eustachian tube and the posterior wall of the nasopharynx ^1,2

Blood supply

• arteries
  • ascending pharyngeal artery ²
  • ascending palatine branch of facial artery ²
  • ascending cervical artery ²
  • maxillary artery ²
• veins: occur as plexi which drain into the internal jugular vein
  • pterygoid plexus ²
  • pharyngeal plexus ²

Lymphatic drainage

Lymphatic drainage in the nasopharynx occurs laterally and medially:

• lateral drainage pathway: lymph vessels traverse the superior constrictor muscle and drain into the lateral retropharyngeal, deep cervical and posterior triangle lymph nodes ⁴
• medial drainage pathway: lymph vessels from the roof and posterior wall drain into the median retropharyngeal lymph nodes ⁴

Innervation

• sensory
  • pharyngeal nerve of the maxillary division of the trigeminal nerve (CN Vb) ²
  • glossopharyngeal nerve (CN IX) ²
• motor
  • pharyngeal plexus: contains branches of cranial nerves IX and X together with sympathetic fibers ²