Precentral Sulcus Of The Human Brain

Description

Precentral sulcus (sulcus precentralis) is identified on the lateral surface of the human cerebrum as a vertically oriented groove in the frontal lobe that runs roughly parallel to the central sulcus. Anteriorly it borders the posterior frontal gyri, while posteriorly it abuts the precentral gyrus (gyrus precentralis), which contains the primary motor cortex along its crown. Superiorly, the sulcus approaches the superomedial margin of the hemisphere near the superior frontal gyrus, and inferiorly it typically terminates above the Sylvian fissure region without reaching the lateral sulcus. Orientation is unambiguous. The sulcal walls and adjacent gyral ridges are modeled to support landmark-based navigation in a single lateral perspective. Separating precentral gyrus from the posterior frontal gyri matters because the precentral gyrus is the surface correlate most often targeted during motor mapping, and the precentral sulcus provides a reliable anterior boundary when the central sulcus is ambiguous from surface landmarks alone. In ischemic stroke affecting the middle cerebral artery territory, cortical infarction posterior to this sulcus produces contralateral weakness most prominent in face and upper limb representations, whereas lesions anterior to it more often impact premotor planning and motor initiation. The fixed lateral view helps learners internalize how motor cortex relates spatially to the frontal lobe and to common operative corridors used in craniotomy for perirolandic tumors and seizure foci. Neuroanatomy and neuroscience courses can use this illustration to teach gyral and sulcal identification on the lateral cerebrum, and neuroradiology texts can pair it with axial or sagittal MRI to reinforce surface localization of the motor strip. Neurology and neurosurgery materials will also find it suited for explaining bedside cortical localization, planning transcranial magnetic stimulation targets, and communicating perirolandic risk during informed consent. Anatomical accuracy verified by SciePro's Medical Advisory Board.