{{Short description|Space in the brain}} {{Infobox Brain | Name = Cisterna magna | Latin = cisterna magna,<ref name=":0" /><br>cisterna cerebellomedullaris posterior<ref name=":0" /> | Image = Gray768.png | Caption = Diagram showing the positions of the three principal cisterns in the brain. The ''cisterna magna'' is labelled as ''cisterna cerebellomedullaris'' at the lower right. | Image2 = | Caption2 = | System = Ventricular }}
The '''cisterna magna''' ('''posterior cerebellomedullary cistern''',<ref name=":0">{{Cite web |title=Anatonomina |url=http://www.terminologia-anatomica.org/en/Terms/Occurence/5198 |access-date=2023-08-01 |website=www.terminologia-anatomica.org}}</ref> or '''cerebellomedullary cistern<ref name=":022">{{Cite book |last=Sinnatamby |first=Chummy S. |title=Last's Anatomy |publisher= Elsevier Australia|year=2011 |isbn=978-0-7295-3752-0 |edition=12th |pages=440}}</ref><ref name=":224">{{Cite book |last=Standring |first=Susan |title=Gray's Anatomy: The Anatomical Basis of Clinical Practice |year=2020 |isbn=978-0-7020-7707-4 |edition=42th |location=New York |pages=413 |oclc=1201341621}}</ref>''') is the largest of the subarachnoid cisterns. It occupies the space created by the angle between the caudal/inferior surface of the cerebellum, and the dorsal/posterior surface of the medulla oblongata (it is created by the arachnoidea that bridges this angle'''<ref name=":224" />'''). The fourth ventricle communicates with the cistern via the unpaired midline median aperture.'''<ref name=":022" /><ref name=":224" />''' It is continuous inferiorly with the subarachnoid space of the spinal canal.'''<ref name=":224" />'''
The cisterna magna contains the two vertebral arteries, the origins of the two posterior inferior cerebellar arteries, the glossopharyngeal nerve (CN IX), vagus nerve (CN X), accessory nerve (CN XI), hypoglossal nerve (XII), and choroid plexus.'''<ref name=":224" />''' The vertebral artery and posterior inferior cerebellar artery of either side pass traverse either lateral portion of the cistern.'''<ref name=":022" />'''
== Etymology == The ''Terminologia Anatomica'' classifies the terms ''cisterna magna'' and ''posterior cerebellomedullary cistern'' as synonyms.<ref>{{Cite web |title=Anatonomina |url=http://www.terminologia-anatomica.org/en/Search?query=cisterna%20cerebellomedullaris%20posterior |access-date=2023-08-01 |website=www.terminologia-anatomica.org}}</ref> It does not recognise the term "''cerebellomedullary cistern"'' (neither as a synonym or distinct structure)<ref>{{Cite web |title=Anatonomina |url=http://www.terminologia-anatomica.org/en/Search?query=cisterna%20cerebellomedullaris%20posterior |access-date=2023-08-01 |website=www.terminologia-anatomica.org}}</ref> but acknowledges the ''lateral cerebellomedullary cistern'' as a distinct structure.<ref>{{Cite web |title=Anatonomina |url=http://www.terminologia-anatomica.org/en/Terms/Occurence/5199 |access-date=2023-08-01 |website=www.terminologia-anatomica.org}}</ref>
The 42nd edition of ''Gray's Anatomy'' (2020) and 12th edition of ''Last's Anatomy'' (2011) recognise the ''cisterna magna'' and ''cerebellomedullary cistern'' as synonyms, and do not describe a separate ''lateral cerebellomedullary cistern''.'''<ref name=":022" /><ref name=":224" />'''
According to the 8th edition of the ''Clinical Oriented Anatomy'' (2018), the cerebellomedullary cistern is subdivided into the ''posterior cerebellomedullary cistern'' (''cisterna magna''), and the ''lateral cerebellomedullary cistern''.'''<ref>{{Cite book |last1=Moore |first1=Keith L. |title=Clinically Oriented Anatomy |last2=Dalley |first2=Arthur F. |last3=Agur |first3=Anne M. R. |publisher=Wolters Kluwer |year=2018 |isbn=978-1-4963-4721-3 |edition=8th |location= |pages=888–889}}</ref>'''
== Clinical significance == The cisterna magna may be tapped with a needle inserted superior to the posterior arch of atlas.'''<ref name=":022" />'''
==References== {{Reflist}}
{{Meninges}} {{Authority control}}
{{DEFAULTSORT:Cisterna Magna}} Category:Meninges