Fourth ventricle

Fourth ventricle
Animation showing the fourth ventricle (in red) in relation to the ventricular system.
Drawing of a cast of the ventricular cavities, viewed from above. (Fourth ventricle visible at bottom center.)
Details
Identifiers
Latinventriculus quartus
MeSHD020546
NeuroNames621
NeuroLex IDbirnlex_1256
TA98A14.1.05.701
TA25966
FMA78469
Anatomical terms of neuroanatomy

The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct (aqueduct of Sylvius) to the obex, and is filled with cerebrospinal 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 oblongata. CSF entering the fourth ventricle through the cerebral aqueduct can exit to the subarachnoid space of the spinal cord through two lateral apertures and a single, midline median aperture.