Posterior Quadrangular Lobule Of The Brain, Anatomy

Description

Posterior quadrangular lobule (lobulus quadrangularis posterior) occupies the superior surface of the cerebellar hemisphere just posterior to the primary fissure, where it borders the anteriorly placed simplex lobule (lobulus simplex) and continues medially toward the vermian cortex. Broad folia and intervening sulci define the cerebellar cortex in this region, with the superior aspect forming a gently convex contour that sits inferior to the occipital lobes and posterior to the brainstem in standard anatomical position. Laterally, the lobule expands across the cerebellar hemisphere; medially, its folial pattern converges toward the midline vermis. A key landmark. Recognizing this lobule matters when localizing cerebellar signs, because lesions on the superior cerebellar hemisphere often present with ipsilateral limb ataxia, dysmetria, and intention tremor rather than prominent truncal instability. The primary fissure is the practical divider between anterior lobe motor territories and posterior lobe association territories, so a fixed superior view that emphasizes that fissural boundary helps correlate surface anatomy with MRI and operative exposure. In posterior fossa surgery, orientation to the primary fissure and adjacent folia supports safe cortical entry planning and avoids mislabeling a superior hemispheric lesion as vermian or flocculonodular in origin. Neuroanatomy instructors can pair this illustration with sagittal and axial MRI teaching files to reinforce cerebellar lobular nomenclature, and neuroscientists can use it in figures discussing cerebellar functional topography of the hindbrain. It also fits well in neurosurgical and neuroradiology publications describing superior cerebellar artery infarcts, hemispheric metastases, or postoperative mapping of the cerebellar cortex. Anatomical accuracy verified by SciePro's Medical Advisory Board.