Development of the nervous system in humans optical vesicle (which will eventually become the optic nerve, retina and iris) forms at the basal plate of the prosencephalon. In the fifth week, the alar plate of the prosencephalon expands to form the cerebral hemispheres (the telencephalon). The basal plate becomes the diencephalon. The diencephalon, mesencephalon and rhombencephalon constitute the brain stem of the embryo. It continues to flex at the mesencephalon. The rhombencephalon folds posteriorly, which causes its alar plate to flare and form the fourth ventricle of the brain. The pons and the cerebellum form in the upper part of the rhombencephalon, whilst the medulla oblongata forms
Anatomy of the cerebellum association areas linked to the cerebellum by corticopontocerebellar fibres, the cognitive affective syndrome may occur. This results in cognitive defects in the form of diminished reasoning power, inattention, grammatical errors in speech, poor spatial sense, and patchy memory loss. Three arteries supply blood to the cerebellum (Fig. 7): the superior cerebellar artery (SCA), anterior inferior cerebellar artery (AICA), and posterior inferior cerebellar artery (PICA). The SCA branches off the lateral portion of the basilar artery, just inferior to its bifurcation into the posterior cerebral artery. Here, it wraps posteriorly around the pons (to which it also supplies blood) before reaching