Superior Medullary Velum, Posterior View

Description

Superior medullary velum forms the thin rostral segment of the roof of the fourth ventricle, stretched between the right and left superior cerebellar peduncles. From this posterior perspective, the paired peduncles appear as stout longitudinal columns converging toward the midbrain, with the velum spanning their medial borders like a translucent sheet. Superiorly, the velum continues toward the region of the inferior colliculi and the frenulum veli, where the trochlear nerves (CN IV) classically emerge dorsal to the brainstem. Boundaries matter. Neurosurgeons and neuroanatomy faculty often need a reliable view of this membrane because it defines the superior limit of the fourth ventricle and sits directly along routes used to access lesions of the ventricular roof and dorsal brainstem. The fixed posterior viewpoint emphasizes the relationship between the superior cerebellar peduncles and the ventricular roof, a relationship that can be hard to conceptualize when learners only see mid-sagittal schematics. Clinical correlations include tumors arising in or distorting the fourth ventricular roof, such as medulloblastoma and ependymoma, and postoperative discussions of approach-related injury to nearby structures, including the superior cerebellar peduncle decussation and dorsal midbrain landmarks. Neuroanatomy courses, neuroradiology teaching files, and operative anatomy chapters can pair this illustration with axial or sagittal MR images to orient readers to the fourth ventricle’s superior roof and the dorsal midbrain-cerebellar junction. It also fits well in board-review materials covering cerebellar peduncle pathways and CN IV emergence, where a posterior brainstem-cerebellar relationship is the point. Anatomical accuracy verified by SciePro's Medical Advisory Board.