palatopharyngeus

Palatopharyngeus is a slender longitudinal muscle of the soft palate and pharynx that forms the posterior faucial pillar, part of the palatopharyngeal arch opposite the palatoglossal arch. It acts in concert with other pharyngeal muscles to influence the dimensions of the pharynx during swallowing and speech.

Origin and insertion: The muscle arises from the palatine aponeurosis of the soft palate and from the posterior border of the hard palate and adjacent palatine bone. Its fibers descend and pass laterally to join with the fibers of the pharyngeal constrictors, inserting into the lateral wall of the pharynx and blending with the fibers near the posterior border of the thyroid cartilage.

Innervation and vascular supply: Palatopharyngeus is supplied by the pharyngeal plexus, predominantly from the vagus nerve (cranial nerve X). Blood supply comes from branches of the ascending pharyngeal artery, as well as from facial and maxillary arteries via their pharyngeal and tonsillar branches.

Function: The muscle elevates the pharynx and larynx during swallowing, contributing to shortening and widening of the pharynx to facilitate bolus transit. It also helps guide the pharyngeal walls medially, aiding in the closure of the nasopharynx during swallowing and forming part of the muscular action of the soft palate and pharynx.

Clinical significance: The palatopharyngeal arch marks the boundary of the tonsillar fossa, with the palatopharyngeus forming the posterior pillar. Injury or dysfunction can affect swallowing or velopharyngeal coordination, and the muscle serves as an important anatomic landmark in head and neck surgery, including tonsillectomy.