Palatoglossus muscle


The palatoglossal muscle is a muscle of the soft palate and an extrinsic muscle of the tongue. Its surface is covered by oral mucosa and forms the visible palatoglossal arch.

Structure

Origin

The palatoglossus arises the palatine aponeurosis of the soft palate, where it is continuous with its contralateral partner.

Insertion

From its origin, it passes anteroinferiorly and laterally. It passes anterior to the palatine tonsil. It inserts onto the side of the tongue; some of its fibers extend over the dorsum of the tongue, and some pass into the substance of the tongue to intermingle with the transverse muscle of tongue.

Innervation

The palatoglossus muscle receives motor innervation from the pharyngeal plexus of vagus nerve.
It is the only muscle of the tongue not innervated by the hypoglossal nerve.

Controversy

Some sources state that the palatoglossus is innervated by fibers from the cranial part of the accessory nerve that travel via the pharyngeal plexus.
Other sources state that the palatoglossus is not innervated by XI hitchhiking on X, but rather it is innervated by IX via the pharyngeal plexus formed from IX and X.

Actions/movements

The palatoglossus elevates the root of the tongue. It approximates the ipsilateral palatoglossal arch to the contralateral one, thus separating the oral cavity and the oropharynx.

Function

It closes the oropharyngeal isthmus, and aids initiation of swallowing. This muscle also prevents the spill of saliva from vestibule into the oropharynx by maintaining the palatoglossal arch.