Cerebral aqueduct Cn3nucleus.png Section through superior colliculus showing path of oculomotor nerve. Gray736.png Drawing of a cast of the ventricular cavities, viewed from the side. Details Identifiers Latin aqueductus mesencephali (cerebri). aqueductus Sylvii MeSH D002535 NeuroNames 509 NeuroLex ID birnlex_1261 FMA 78467 Anatomical terms of neuroanatomy [edit on Wikidata] The cerebral aqueduct, also known as the aqueductus mesencephali, mesencephalic duct, sylvian aqueduct or the aqueduct of Sylvius is within the mesencephalon (or midbrain), contains cerebrospinal fluid (CSF), and connects the third ventricle in the diencephalon to the fourth ventricle within the region of the mesencephalon and metencephalon, located dorsal to the pons and ventral to the cerebellum.