- Fourth ventricle: tent-like, CSF-filled cavity of the hindbrain, lined by ependyma, in the posterior cranial fossa in front of the cerebellum and behind the pons and upper medulla.
- Triangular in sagittal section, rhomboidal (lozenge-shaped) in horizontal section; continuous above with the cerebral aqueduct of midbrain and below with the central canal of the medulla.
fourth ventricle and related structures, midsagittal section Fourth ventricle and related structures, midsagittal section.