Anatomical Presentation Of The Supramarginal Gyrus Of The Brain

Description

Supramarginal gyrus curves over the posterior termination of the lateral sulcus (Sylvian fissure) on the lateral surface of the cerebral hemisphere, forming the anterior component of the inferior parietal lobule. Its cortical ribbon sits posterior to the postcentral gyrus and superior to the superior temporal gyrus, with the gyrus arching around the end of the fissure before blending posteriorly toward the angular gyrus. Bounding sulci typically include the postcentral sulcus anteriorly and segments of the intraparietal sulcus superiorly, placing the supramarginal gyrus at a junction where parietal, temporal, and perisylvian cortices meet. Spatial relationships are presented in a fixed lateral perspective to keep the perisylvian contour legible. Lesions involving the supramarginal gyrus, most often from middle cerebral artery territory infarction or perisylvian mass effect, are a classic substrate for language network disconnection, including conduction aphasia with impaired repetition when dominant-hemisphere association cortex and adjacent arcuate fasciculus pathways are affected. Apraxia and impaired phonological processing also localize well to this region, and right-hemisphere involvement can contribute to attentional deficits and aspects of hemispatial neglect. Topographic clarity matters here: a small shift in localization from postcentral gyrus to supramarginal gyrus changes the clinical story, and this illustration keeps that transition crisp along the posterior bank of the lateral sulcus. A surgical corridor landmark. Use this illustration in neuroanatomy and neuroscience teaching on the inferior parietal lobule, in stroke and aphasia chapters that need a perisylvian cortical reference, or in preoperative planning materials discussing cortical mapping near the posterior Sylvian region and inferior parietal tumors. Anatomical accuracy verified by SciePro's Medical Advisory Board.