Superior medullary velum
Encyclopedia
The superior medullary velum (anterior medullary velum, valve of Vieussens) is a thin, transparent lamina of white substance, which stretches between the 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 fraenulum veli, descends upon its upper part from between the inferior colliculi, and on either side of this the trochlear nerve
emerges.
Blood is supplied by branches from the superior cerebellar artery
.
Superior cerebellar peduncles
The superior cerebellar peduncles , two in number, emerge from the upper and medial part of the white substance of the hemispheres and are placed under cover of the upper part of the cerebellum....
; on the dorsal surface of its lower half the folia
Folium (brain)
A folium is a wrinkle on the surface of the cerebellum. The cortex of a folium consists of three layers of cells - the top molecular layer, the Purkinje layer, and the bottom granular layer - and this cortex covers deeper white matter ....
and lingula
Lingula
Lingula is Latin for "little tongue". It can stand for:* Lingula , a brachiopod genus of the family Lingulidae, which is among the few brachiopods surviving today but also known from fossils over 500 million years old* In anatomy:...
are prolonged.
It forms, together with the superior cerebellar peduncle, the roof of the upper part of the fourth ventricle
Fourth ventricle
The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and 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 fraenulum veli, descends upon its upper part from between the inferior colliculi, and on either side of this the trochlear nerve
Trochlear nerve
The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye....
emerges.
Blood is supplied by branches from the superior cerebellar artery
Superior cerebellar artery
The superior cerebellar artery arises near the termination of the basilar artery.It passes lateralward, immediately below the oculomotor nerve, which separates it from the posterior cerebral artery, winds around the cerebral peduncle, close to the trochlear nerve, and, arriving at the upper...
.