Hypoglossal nerve

Hypoglossal nerve

Infobox Nerve
Name = Hypoglossal nerve
Latin = nervus hypoglossus
GraySubject = 207
GrayPage = 914


Caption = Hypoglossal nerve, cervical plexus, and their branches.


Caption2 =
Innervates = genioglossus, hyoglossus, styloglossus
BranchFrom =
BranchTo = ansa cervicalis
MeshName = Hypoglossal+Nerve
MeshNumber = A08.800.800.120.330
The hypoglossal nerve is the twelfth cranial nerve (XII), leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the "olive" and the "pyramid". It then passes through the hypoglossal canal. On emerging from the hypoglossal canal, it gives off a small meningeal branch and picks up a branch from the anterior ramus of C1. It spirals behind the vagus nerve and passes between the internal carotid artery and internal jugular vein lying on the carotid sheath. After passing deep to the posterior belly of the digastric muscle, it passes to the submandibular region to enter the tongue.

It supplies motor fibres to all of the muscles of the tongue, except the palatoglossus muscle which is innervated by the accessory nerve, which runs in part with the vagus nerve (Cranial nerve X).

Testing the hypoglossal nerve

To test the function of the nerve, a person is asked to poke out their tongue. If there is a loss of function on one side ( [http://www.answers.com/topic/unilateral-paralysis unilateral paralysis] ) the tongue will point towards the affected side.

The strength of the tongue can be tested by getting the person to poke the inside of their cheek, and feeling how strongly they can push a finger pushed against their cheek - a more elegant way of testing than directly touching the tongue.

The tongue can also be looked at for signs of lower motor neuron disease, such as fasciculation and atrophy.

Ipsilateral paralysis/paresis of the tongue results in contralateral curvature of the tongue (apex toward the unimpaired side of the mouth) i.e., the tongue will point away from the affected side.


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External links

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* (NormanAnatomyFig|XII)


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Look at other dictionaries:

  • Hypoglossal nerve — The hypoglossal nerve is the twelfth cranial nerve. The twelve cranial nerves, the hypoglossal nerve included, emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. The hypoglossal… …   Medical dictionary

  • hypoglossal nerve — noun supplies intrinsic muscles of the tongue and other tongue muscles • Syn: ↑hypoglossal, ↑nervus hypoglosus, ↑twelfth cranial nerve • Hypernyms: ↑cranial nerve …   Useful english dictionary

  • hypoglossal nerve — noun Date: 1831 either of the 12th and final pair of cranial nerves which are motor nerves arising from the medulla oblongata and supplying muscles of the tongue in higher vertebrates called also hypoglossal …   New Collegiate Dictionary

  • hypoglossal nerve — the twelfth cranial nerve (XII), which supplies the muscles of the tongue and is therefore responsible for the movements of talking and swallowing …   The new mediacal dictionary

  • hypoglossal nerve — hy′poglos′sal nerve′ n. anat. either one of the twelfth pair of cranial nerves, consisting of motor fibers that innervate the muscles of the tongue • Etymology: 1840–50 …   From formal English to slang

  • hypoglossal nerve — /haɪpəˌglɒsəl ˈnɜv/ (say huypuh.glosuhl nerv) noun either of the last pair of cranial nerves which gives rise to the movements of the tongue; twelfth cranial nerve …  

  • hypoglossal nerve — Anat. either one of the twelfth pair of cranial nerves, consisting of motor fibers that innervate the muscles of the tongue. [1840 50] * * * …   Universalium

  • Lingual branches of hypoglossal nerve — Infobox Nerve Name = PAGENAME Latin = rami linguales nervi hypoglossi GraySubject = GrayPage = Caption = Hypoglossal nerve, cervical plexus, and their branches. Caption2 = Plan of hypoglossal nerve. Innervates = BranchFrom = hypoglossal nerve… …   Wikipedia

  • hypoglossal nerve descending — radix superior ansae cervicalis …   Medical dictionary

  • hypoglossal nucleus — n a nucleus in the floor of the fourth ventricle of the brain that is the origin of the hypoglossal nerve * * * nucleus of hypoglossal nerve n. nervi hypoglossi …   Medical dictionary

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