Palatopharyngeus muscle

The palatopharyngeus is a longitudinal muscle of the pharynx and an important component of the soft palate. It forms the posterior pillar of the fauces (palatopharyngeal arch) and functions as a dynamic link between the palate and the pharyngeal wall.

Anatomical details

1. Origin

• Superior surface of the palatine aponeurosis and posterior margin of the hard palate.

• The muscle is attached to the palatine aponeurosis by two distinct lamellae (a.k.a. the anterior and posterior fascicles) that embrace the levator veli palatini muscle between them as they descend.

2. Course and insertion

From its origin, the lamellae of the palatopharyngeus muscle descends vertically, crossing the margin of the soft palate to become a single muscular sheet. The muscle passes posterior to the palatine tonsil, forming the palatopharyngeal arch (posterior tonsillar pillar).

Inferiorly, the fibres spread and insert into:

• The posterior border of the thyroid cartilage, and

• The pharyngeal wall, where they blend with fibres of the salpingopharyngeus and stylopharyngeus muscles.

Innervation

• Pharyngeal branch of the vagus nerve (cranial nerve X) via the pharyngeal plexus, which receives cranial part contributions from the accessory nerve (CN XI).

Actions

• Depresses the soft palate, helping close the oropharyngeal isthmus.

• Draws the palatopharyngeal arches toward the midline, like curtains closing — narrowing the oropharyngeal isthmus.

• Elevates the pharynx and larynx during swallowing and speech.

Relations

• Lies deep and posterior to the palatine tonsil within the palatopharyngeal arch (posterior tonsillar pillar).

• Positioned posterior and medial to the palatoglossus muscle (and palatoglossal arch).

Functional note

• Together with the stylopharyngeus (CN IX) and salpingopharyngeus (CN X), the palatopharyngeus forms the internal longitudinal layer of the pharyngeal musculature. All three cooperate to shorten and elevate the pharynx during swallowing, ensuring efficient propulsion of the bolus and proper airway protection.