The cerebellum The cerebellum in Latin stands for little brain and it has a fundamental role in motor control and especially important in coordination, precision and timing of movements in addition to motor learning. It is located in the posterior fossa immediately beneath the occipital and temporal lobes; separated from them by the tentorium cerebelli; a tough layer of the dura matter. Anatomical structures and divisions • It consists of two cerebellar hemispheres which are connected by the vermis; a narrow midline structure. And it has a grey matter located on the surface of the cerebellum and it is tightly folded forming cerebellar cortex, together with the white matter that lies underneath the cerebellar cortex embedded with this white matter the four cerebellar nuclei; the dentate, emboliform, globose and fastigi nuclei.. • There are three ways to subdivide the cerebellum, the anatomical lobes,anatomical zones and the functional divisions. Anatomical lobes There are three distinguishable lobes in the cerebellum these are the anterior lobe, posterior lobe and the flocculonodular lobe. These lobes are separated from each other by the primary fissure and posterolateral fissure. Cerebellar zones There are three cerebellar zones: in the midline of the cerebellum is the vermis, on each sides of the vermis is the intermediate zones and lateral to the intermediate zones are the lateral hemispheres Functional divisions There are three functional areas; these are • Cerebro-cerebellar division: is the largest division formed by the lateral hemispheres and involved in plannijg of movements and motor learning. It receives input from the cerebral cortex and pontine nuclei and sends the output through the thalamus and red nucleus. It also regulates coordination of muscle activation and visually guided movements. • Spino-cerebellum division: compposred of the vermis and intermediate zones, it is involved in regulating the bbody movements in response to proprioceptive informations. • Vestibule-cerebellum division: it is equivalent to the fflocculonodular lobe. It is concerned with controlling the balance and ocular reflexex. It receives the input from the vestibular system. Blood supply and venous drainage • Blood supply • There are three paired arterie • Superior cerebellar arteries (SCA) arise from the basilar artery. • Anterior inferior cerebellar arteries that arise from the basilar artery too. • Posterior inferior cerebellar arteries which arises from the vertebral artery. • Venous drainage • Via superior and inferior cerebellar veins that drain into the petrosal, straight and transverse sinuses. Cerebellar pathology • Dysfunction of the cerebellum can be produced by varieties of causes like stroke, tumors, chronic alcoholism, trauma and degenerative diseases and produce symptoms depending on the functional area affected. • Damage to the cerebro-cerebellum and spino-cerebellum presents with defect in carrying out skilled and planned movement and problem in motor learning – DANISH is an acronym to remember the possible manifestations • Dysdiadochokinesia • Ataxia • Nystagmus • Intension tremor • Scaning speech • hypotonia • damage to the vestibule-cerebellum can present with loss of balance with abnormal stance and gait .