Sulcus Postcentralis, Lateral View

Description

Seen from the left lateral aspect, the cerebral hemisphere is dominated by the long, vertical central sulcus separating the frontal lobe anteriorly from the parietal lobe posteriorly, with the postcentral gyrus immediately posterior to it. The sulcus postcentralis is traced as a furrow running roughly parallel to the central sulcus, demarcating the posterior border of the postcentral gyrus and separating it from the superior and inferior parietal lobules more posteriorly. Superiorly it approaches the superomedial margin near the interhemispheric fissure, while inferiorly it becomes more discontinuous as it trends toward the lateral sulcus (Sylvian fissure). Cerebellum and brainstem sit posteroinferiorly for orientation. Clear landmarks. For teaching cortical topography, the postcentral sulcus matters because it brackets primary somatosensory cortex (S1, Brodmann areas 3, 1, and 2) on the postcentral gyrus, a region you localize routinely when correlating contralateral sensory deficits with parietal lobe lesions. On MRI and in operative navigation the postcentral sulcus can be the more reliable posterior boundary of S1 when the central sulcus has atypical branching, and it helps distinguish lesions of the postcentral gyrus from those extending into the superior parietal lobule, where deficits shift from elementary sensation to impaired stereognosis and other cortical sensory functions. This relationship also underlies functional mapping during awake craniotomy for tumors abutting the sensorimotor strip. Use this lateral view in neuroanatomy and neuroscience coursework to anchor sulcal anatomy, in neuroradiology primers to support landmark-based localization on sagittal and axial sequences, and in neurosurgical education when describing approaches to perirolandic masses and cortical stimulation mapping reports. Anatomical accuracy verified by SciePro's Medical Advisory Board.