The palatoglossus is a relatively small muscle of the soft palate that is also associated with the tongue. It is one of the four paired extrinsic tongue muscles, meaning it extends outside the tongue but inserts within it. The palatoglossus anchors the tongue to the surrounding structures. 

In the lateral pharyngeal walls, both palatoglossus muscles form the palatoglossal arch that separates the oral cavity from the oropharynx. From the origin site, the palatoglossus arches anteriorly, inferiorly and laterally to reach the sides of the tongue. It goes anterior to the palatine tonsils.

Origin: inferior surface of the palatine aponeurosis (Read more!), where the palatoglossus fuses together with its contralateral muscle (muscle of the opposite side). 

Insertion: lateral side of the root of the tongue; some of its fibers also distribute within the dorsal surface of the tongue, others extend deeply into the soft tissue of the tongue and mix with the fibers of the transverse muscle of the tongue (one of the intrinsic tongue muscles).

Action: elevates the root of the tongue and pulls the soft palate inferiorly towards the tongue. It narrows the oropharyngeal isthmus and closes off the oral cavity from the oropharynx. The palatoglossus shortens the palatoglossal arch.

Innervation: pharyngeal branch of the vagus nerve (CN X) via the pharyngeal plexus.

Blood supply: lingual artery of the external carotid artery and tonsillar artery of the facial artery.