What is Vestibulo-ocular reflex is concerned with - and explain in detail?
Ans. B. Flocculonodular lobeFUNCTIONAL DIVISIONS OF CEREBELLUM: -a. From a functional point of view, the cerebellum is divided into three parts. The nodulus in the vermis and the flanking flocculus in the hemisphere on each side form the vestibulo cerebellum (or flocculonodular lobe).b. This lobe, which is phylogenetically the oldest part of the cerebellum, has vestibular connections and is concerned with equilibrium and eye movements. The rest of the vermis and the adjacent medial portions of the hemispheres form the spino cerebellum, the region that receives proprioceptive input from the body as well as a copy of the "motor plan" from the motor cortex. By comparing plan with performance, it smooths and coordinates movements that are ongoing.c. The vermis projects to the brainstem area concerned with control of axial and proximal limb muscles (medial brainstem pathways), whereas the hemispheres of the spino cerebellum project to the brainstem areas concerned with control of distal limb muscles (lateral brainstem pathways). The lateral portions of the cerebellar hemispheres are called the cerebro cerebellum. They are the newest from a phylogenetic point of view, reaching their greatest development in humans. They interact with the motor cortex in planning and programming movements.d. Most of the vestibulocerebellar output passes directly to the brainstem; but the rest of the cerebellar cortex projects to the deep nuclei, which in turn project to the brainstem. The deep nuclei provide the only output for the spino cerebellum and the cerebro cerebellum. The medial portion of the spino cerebellum projects to the fastigial nuclei and from there to the brainstem. The adjacent hemispheric portions of the spino cerebellum project to the emboliform and globose nuclei and from there to the brainstem.e. The cerebro cerebellum projects to the dentate nucleus and from there either directly or indirectly to the ventrolateral nucleus of the thalamus.