The palatoglossus or palatoglossal muscle is a muscle of the soft palate and extrinsic muscle of the tongue. Its surface is covered by oral mucosa and forms the visible
palatoglossal arch
The palatoglossal arch (glossopalatine arch, anterior pillar of fauces) on either side runs downward, lateral (to the side), and forward to the side of the base of the tongue, and is formed by the projection of the glossopalatine muscle with its c ...
.
Structure
Palatoglossus arises from the
palatine aponeurosis
Attached to the posterior border of the hard palate is a thin, firm, fibrous lamella called the palatine aponeurosis, which supports the muscles and gives strength to the soft palate.
It is thicker above and narrows on the way down where it becom ...
of the
soft palate
The soft palate (also known as the velum, palatal velum, or muscular palate) is, in mammals, the soft 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 the hard 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
The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...
, some of its fibers spreading over the dorsum, and others passing deeply into the substance of the organ to intermingle with the
transverse muscle of tongue
The transverse muscle of tongue (transversus linguae) is an intrinsic muscle of the tongue. It consists of fibers which arise from the median fibrous septum. It passes laterally to insert into the submucous fibrous tissue at the sides of the ton ...
.
Innervation
Palatoglossus is the only muscle of the tongue that is ''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 by ...
(CN XII). It is innervated by the pharyngeal branch of the vagus nerve (CN X).
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]
Function
Elevates posterior tongue, closes the
oropharyngeal isthmus
The fauces, isthmus of fauces, or the oropharyngeal isthmus, is the opening at the back of the mouth into the throat. It is a narrow passage between the velum and the base of the tongue.
The fauces is a part of the oropharynx directly behind th ...
, 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
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{{Authority control
Muscles of the head and neck
Tongue
Innervation of the tongue.