Palatoglossus muscle

Overview
The palatoglossus (glossopalatinus) is a small fleshy fasciculus, narrower in the middle than at either end, forming, with the mucous membrane covering its surface, the glossopalatine arch.

It arises from the anterior surface of the soft palate, where it is continuous with the muscle of the opposite side, and passing downward, forward, and lateralward in front of the palatine tonsil, is inserted into the side of the tongue, some of its fibers spreading over the dorsum, and others passing deeply into the substance of the organ to intermingle with the Transversus linguæ.

Action
Elevates posterior tongue, closes the oropharyngeal isthmus, and aids initiation of swallowing.

Innervation
The palatoglossus is the only muscle of the tongue that is not innervated by the hypoglossal nerve (CN XII). Rather, the palatoglossus is innervated by the vagus nerve (CN X) via the pharyngeal plexus.