Superior medullary velum

The superior medullary velum (anterior medullary velum) is a thin, transparent lamina of white matter which - together with the inferior medullary velum - forms the roof of the fourth ventricle. It extends between the two superior cerebellar peduncles. The lingula of cerebellum covers - and adheres to - its dorsal surface.

Relations
The superior medullary velum extends between the dorsomedial margins of the two superior cerebellar peduncles. On the dorsal surface of its lower half the folia and lingula are prolonged.

It forms, together with the superior cerebellar peduncle, the roof of the upper part of the fourth ventricle; it is narrow above, where it passes beneath the facial colliculi, and broader below, where it is continuous with the white substance of the superior vermis.

A slightly elevated ridge, the frenulum veli, descends upon its upper part from between the inferior colliculi, and on either side of this the trochlear nerve emerges.

Blood supply
Blood is supplied by branches from the superior cerebellar artery.