{{Short description|Collection of facial nerve neurons}} {{Distinguish|Medial geniculate nucleus|Lateral geniculate nucleus}} {{Infobox nerve | Name = Geniculate ganglion | Latin = ganglion geniculi nervi facialis | Image = Gray789.png | Caption = The course and connections of the facial nerve in the temporal bone. | Image2 = Ear internal anatomy numbered.svg | Caption2 = Cranial nerves VII and VIII and selected structures of the inner and middle ear. 1 Nervus vestibularis, 2 Nervus cochlearis, 3 Nervus intermediofacialis, 4 '''Ganglion geniculi''', 5 Chorda tympani, 6 Cochlea, 7 Ductus semicirculares, 8 Malleus, 9 Membrana tympani, 10 Tuba auditiva | Innervates =Lacrimal glands, submandibular glands, sublingual glands, tongue, palate, pharynx, external auditory meatus, stapedius muscle, posterior belly of the digastric muscle, stylohyoid muscle, muscles of facial expression | BranchFrom = | BranchTo = }} The '''geniculate ganglion''' (from Latin ''genu'', for "knee"<ref name="latin-knee">{{cite web |url=http://www.wordinfo.info/words/index/info/view_unit/897 |title=genu-, geni-, gen- + (Latin: knee). |work=WordInfo |access-date=2008-10-03}}</ref>) is a bilaterally paired special sense ganglion<ref name=":1">{{Cite book |last1=Fitzgerald |first1=Maurice J. T. |title=Clinical Neuroanatomy and Neuroscience |last2=Gruener |first2=Gregory |last3=Mtui |first3=Estomih |publisher=Saunders |year=2011 |isbn=978-0-7020-3738-2 |edition=6th |location=Edinburgh |pages=241–243}}</ref> of the intermediate nerve component of the facial nerve (CN VII).<ref name=":2">{{Cite web |title=ganglion géniculé l.m. - Dictionnaire médical de l'Académie de Médecine |url=https://www.academie-medecine.fr/le-dictionnaire/index.php?q=ganglion+g%C3%A9nicul%C3%A9+l.m. |access-date=2024-05-24 |website=www.academie-medecine.fr}}</ref> It is situated within facial canal of the head.{{Citation needed|date=May 2024}}
It contains cell bodies of first-order unipolar sensory neurons which convey gustatory (taste) afferents from taste receptors of the anterior two-thirds of the tongue by way of the chorda tympani, and of the palate by way of the greater petrosal nerve, From the ganglion, the proximal fibres proceed to the gustatory (i.e. superior/rostral<ref name=":2" />) part of the solitary nucleus where they synapse with second-order neurons.<ref name=":1" />
== Anatomy ==
=== Structure === The geniculate ganglion is conical in shape. The greater petrosal nerve diverges from CNVII and the lesser petrosal nerve diverges from CN IX at the geniculate ganglion.<ref name=":2" />
=== Relations === It is located close to the internal auditory meatus.<ref name=":0">{{Cite journal|last1=Hall|first1=George M.|last2=Pulec|first2=Jack L.|last3=Rhoton|first3=Albert L. Jr.|date=1 November 1969|title=Geniculate Ganglion Anatomy for the Otologist|journal=Archives of Otolaryngology|volume=90|issue=5|pages=568–571|doi=10.1001/archotol.1969.00770030570007|pmid=5347117 |issn=0003-9977}}</ref> It is covered superiorly by the petrous part of the temporal bone (which is sometimes absent over the ganglion).<ref>{{Cite journal|last1=Rhoton|first1=Albert L.|last2=Pulec|first2=Jack L.|last3=Hall|first3=George M.|last4=Boyd|first4=Allen S.|date=1 January 1968|title=Absence of Bone over the Geniculate Ganglion|url=https://thejns.org/view/journals/j-neurosurg/28/1/article-p48.xml|journal=Journal of Neurosurgery|language=en-US|volume=28|issue=1|pages=48–53|doi=10.3171/jns.1968.28.1.0048|pmid=5639739 |url-access=subscription}}</ref>
== Clinical significance == The geniculate ganglion is an important surgical landmark near the internal auditory meatus.<ref name=":0" />
=== Herpes zoster oticus === The geniculate ganglion may become inflamed due herpes zoster virus virus infection. Swelling of the ganglion may result in facial palsy (Ramsay Hunt syndrome). The syndrome presents with intense pain in one ear that is followed by a vesicular rash around the ear canal.<ref name=":1" />
== Additional images == <gallery> File:Gray788.png | Plan of the facial and intermediate nerves and their communication with other nerves. </gallery>
== See also == *Ramsay Hunt syndrome type II
== References == <references/>
== External links == * {{NormanAnatomy|cranialnerves}} ({{NormanAnatomyFig|VII}}) * {{NormanAnatomy|lesson3}} ({{NormanAnatomyFig|midearcavity}})
{{Cranial nerves}} {{Authority control}}
Category:Nervous ganglia of the head and neck Category:Gustatory system Category:Sensory ganglia Category:Otorhinolaryngology Category:Cranial nerves Category:Facial nerve