- Fourth ventricle
Infobox Brain
Name = PAGENAME
Latin = ventriculus quartus
GraySubject = 187
GrayPage = 797
Caption = Scheme showing relations of the ventricles to the surface of the brain. (Fourth ventricle labeled at bottom center.)
Caption2 = Drawing of a cast of the ventricular cavities, viewed from above. (Fourth ventricle visible at bottom center.)
IsPartOf =
Components =
Artery =
Vein =
BrainInfoType = hier
BrainInfoNumber = 617
MeshName = Fourth+Ventricle
MeshNumber = A08.186.211.276.500
The fourth ventricle is one of the four connected fluid-filled cavities within the humanbrain . These cavities, known collectively as theventricular system , consist of the left and right lateral ventricles, thethird ventricle , and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct ("aqueduct of Sylvius") to theobex , and is filled withcerebrospinal fluid (CSF).The fourth ventricle has a characteristic diamond shape in cross-sections of the human brain. It is located within the
pons or in the upper part of the medulla. CSF entering the fourth ventricle through the cerebral aqueduct can exit to thesubarachnoid space of thespinal cord through two lateralforamina of Luschka (singular: "foramen of Luschka") and a single, midline foramen of Magendie (seeList of human anatomical parts named after people ).Roof and floor
The fourth ventricle has a "roof" dorsally and a "floor" ventrally. The roof of the fourth ventricle is formed by the
cerebellum (superior and inferior medullary velums), the floor by therhomboid fossa , and the side "walls" formed by the cerebellar peduncles. Among the prominent features of the floor of the fourth ventricle are the:*
facial colliculus : formed by the internal part of thefacial nerve as it loops around theabducens nucleus in the lowerpons ;
*sulcus limitans : which represents the border between thealar plate and thebasal plate of the developingneural tube ;
*obex : represents the caudal tip of the fourth ventricle; the obex is also a marker for the level of theforamen magnum of theskull and therefore is a marker for the imaginary dividing line between the medulla andspinal cord .
=AdditionalExternal links
* - "Fourth Ventricle, Sagittal Section, Medial View"
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