ventricular system of brain, 3d

anatomical anatomy anterior aqueduct arachnoid brain cerebellum cerebral cerebrospinal cerebrum choroid cortex csf diagram dura flow foramen fourth horn human body hypothalamus illustration inter ventricular interventicular interventricular lateral luschka magendie mater monro nervous neurology noone nobody organ structure subarachnoid sylvius system ventricle ventricles 3d biology stem canal fluid