Glossopharyngeal nerve 243327 220471775 2008-06-20T00:54:28Z 207.237.111.34 /* Brainstem connections */ {{Infobox Nerve | Name = Glossopharyngeal nerve | Latin = nervus glossopharyngeus | GraySubject = 204 | GrayPage = 906 | Image = Gray791.png | Caption = Plan of upper portions of [[glossopharyngeal]], [[vagus]], and [[accessory nerve]]s. | Image2 = Gray793.png | Caption2 = Course and distribution of the [[glossopharyngeal]], [[vagus]], and [[accessory nerve]]s. (Label for glossopharyngeal is at upper right.) | Innervates = [[stylopharyngeus muscle|stylopharyngeus]] | BranchFrom = | BranchTo = [[tympanic nerve]] | MeshName = Glossopharyngeal+Nerve | MeshNumber = A08.800.800.120.290 | DorlandsPre = n_05 | DorlandsSuf = 12565844 | }} The '''glossopharyngeal nerve''' is the ninth of twelve pairs of [[cranial nerves]]. It exits the brainstem out from the sides of the upper [[Medulla oblongata|medulla]], just rostral (closer to the nose) to the [[vagus nerve]]. ==Functions== There are a number of functions of the glossopharyngeal nerve: * It receives [[sensory fibres]] from the posterior one-third of the [[tongue]], the [[tonsils]], the [[pharynx]], the [[middle ear]] and the [[carotid sinus]]. * It supplies [[parasympathetic]] fibres to the [[parotid gland]] via the [[otic ganglion]]. * It supplies [[motor fibres]] to [[stylopharyngeus muscle]], the only motor component of this cranial nerve. * It contributes to the [[pharyngeal plexus]]. ==Brainstem connections== The glossopharyngeal nerve is mostly sensory. Its superior and inferior (petrous) ganglia contain the cell bodies of pain fibers. It also projects into many different structures in the brainstem: * [[Solitary nucleus]]: Taste from the posterior one-third of the tongue and information from [[baroreceptor|carotid baroreceptors]] and [[chemoreceptor|carotid body chemoreceptors]] * [[Spinal nucleus of the trigeminal nerve]]: Visceral pain as well as somatic sensory fibers from the middle ear. * [[Nucleus ambiguus]]: The [[lower motor neuron]]s for the [[stylopharyngeus]] muscle. * [[Inferior salivatory nucleus]]: [[Parasympathetic nervous system|Parasympathetic]] input to the [[parotid gland|parotid]] and [[mucous gland]]s. The glossopharyngeal nerve also aids in tasting, swallowing and salivary secretions. ==Path== From the [[medulla oblongata]], the glossopharyngeal nerve passes laterally across the [[flocculus]], and leaves the skull through the central part of the [[jugular foramen]], in a separate sheath of the [[dura mater]], lateral to and in front of the vagus and accessory nerves. Within the jugular foramen, the glossopharyngeal nerve forms the superior ganglion (the glossopharyngeal neve is also associated with an inferior ganglion). In its passage through the jugular foramen, it grooves the lower border of the [[petrous part]] of the [[temporal bone]]; and, at its exit from the [[skull]], passes forward between the [[internal jugular vein]] and [[internal carotid artery]]. It descends in front of the latter vessel, and beneath the [[styloid process (temporal)|styloid process]] and the muscles connected with it, to the lower border of the [[stylopharyngeus]]. It then curves forward, forming an arch on the side of the neck and lying upon the [[stylopharyngeus]] and [[middle pharyngeal constrictor]] muscle. From there it passes under cover of the [[hyoglossus]] muscle, and is finally distributed to the [[palatine tonsil]], the [[mucous membrane]] of the [[Fauces (anatomy)|fauces]] and base of the [[tongue]], and the mucous glands of the [[mouth]]. == Branches == * [[Tympanic]] * [[Stylopharyngeal]] * [[Tonsillar]] * [[Nerve to carotid sinus]] * Branches to the [[posterior third of tongue]] * [[Lingual branches]] * A communicating branch to the [[Vagus nerve]] Note: The glossopharyneal nerve contributes in the formation of the [[pharyngeal plexus]] along with the vagus nerve. ==Testing the glossopharyngeal nerve== The [[gag reflex]] is absent in patients with damage to the glossopharyngeal nerve as it is responsible for the afferent limb of the reflex. ==Additional images== <gallery> Image:Gray567.png|Dura mater and its processes exposed by removing part of the right half of the skull, and the brain. Image:Gray719.png|Hind- and mid-brains; postero-lateral view. Image:Gray779.png|Alveolar branches of superior maxillary nerve and sphenopalatine ganglion. Image:Gray792.png|Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ. Image:Gray794.png|Hypoglossal nerve, cervical plexus, and their branches. </gallery> ==External links== * {{BrainInfo|hier|698}} * {{LoyolaMedEd|GrossAnatomy/h_n/cn/cn1/cn9.htm}} * {{MedlinePlusImage|9350}} * {{NormanAnatomy|cranialnerves}} ({{NormanAnatomyFig|IX}}) {{Cranial nerves}} [[Category:Peripheral nervous system]] [[Category:Cranial nerves]] [[de:Nervus glossopharyngeus]] [[fr:Nerf glossopharyngien]] [[lt:Liežuvinis ryklės nervas]] [[nl:Nervus glossopharyngeus]] [[it:Nervo glossofaringeo]] [[ja:舌咽神経]] [[no:Nervus glossopharyngeus]] [[pl:Nerw językowo-gardłowy]] [[pt:Nervo glossofaríngeo]] [[sr:Језично-ждрелни живац]]