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

From its origin, it passes anteroinferiorly and laterally. It passes anterior to the palatine tonsil.

Origin

The palatoglossus arises (the oral aspect of) the palatine aponeurosis of the

soft palate The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft biological tissue, tissue constituting the back of the roof of the mouth. The soft palate is part of the palate of the mouth; the other part is ...

, where it is continuous with its contralateral partner (i.e. the same muscle of the opposite side).

Insertion

It inserts onto the side of the

tongue The tongue is a Muscle, muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper s ...

; 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 The pharyngeal plexus is a nerve plexus located upon the outer surface of the pharynx. It contains a motor component (derived from the vagus nerve (cranial nerve X)), a sensory component (derived from the glossopharyngeal nerve (cranial nerve ...

. It is the only muscle of the tongue ''not'' innervated by the

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated b ...

(CN XII).

Controversy

Some sources state that the palatoglossus is innervated by fibers from the cranial part of the

accessory nerve The accessory nerve, also known as the eleventh cranial nerve, cranial nerve XI, or simply CN XI, is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles. It is classified as the eleventh of twelve pairs of cranial nerv ...

(CN XI) 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.Chapter 8 Head and Neck. In: Drake RL, Vogl W, Mitchell AWM, editors. Gray's Anatomy for Students. London: Elsevier; 2005. p991

Actions/movements

The palatoglossus elevates the root of the tongue (i.e. the posterior attached portion of the tongue). It approximates the ipsilateral (same side) palatoglossal arch to the contralateral (opposite side) one, thus separating the

oral cavity A mouth also referred to as the oral is the body orifice through which many animals ingest food and vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alime ...

and the

oropharynx The pharynx (: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates, though its ...

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.

References

External links

* {{Authority control Muscles of the head and neck Tongue Innervation of the tongue.