Median aperture

The median aperture (median aperture of fourth ventricle or foramen of Magendie) is an opening at the caudal portion of the roof of the fourth ventricle.<ref name="Waxman-2009">Template:Cite book</ref> It allows the flow of cerebrospinal fluid (CSF) from the fourth ventricle into the cisterna magna.<ref name="Johns 2014 pp. 19–26">Template:Cite book</ref><ref name="Singhal Prabhakar 2016 pp. 21–27">Template:Cite book</ref> The other openings of the fourth ventricle are the lateral apertures - one on either side.<ref name="Ciolkowski" /> The median aperture varies in size but accounts for most of the outflow of CSF from the fourth ventricle. <ref name="Waxman-2009" />

Structure

Relations

The median foramen on axial images is posterior to the pons and anterior to the caudal cerebellum. It is surrounded by the obex and gracile tubercles of the medulla, tela choroidea of the fourth ventricle and its choroid plexus, which is attached to the cerebellar vermis.<ref name="Ciolkowski">Template:Cite journal</ref><ref name="Spierer-2023">Template:Cite journal</ref>

Eponym

The foramen of Magendie is named for François Magendie, who first described it.<ref name="WhoNamedIt">Template:WhoNamedIt</ref> The term "foramen of Magendie" is commonly used, and this opening is frequently described and illustrated as a foramen in the inferior roof of the fourth ventricle. However, the opening is an aperture, rather than a foramen.<ref name="Spierer-2023" />

File:CSF circulation.png

CSF circulation

Additional images

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  Median aperture