Lateral sulcus Lateral sulcus The lateral sulcus (also called Sylvian fissure or lateral fissure) is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe. The insular cortex lies deep within the lateral sulcus. The lateral sulcus divides both the frontal lobe and parietal lobe above from the temporal lobe below. It is in both hemispheres of the brain. The lateral sulcus is one of the earliest-developing sulci of the human brain. It first appears around the fourteenth gestational week. The
Longitudinal fissure cortex, thus requiring any tracts to pass through the corpus callosum. The vasculature of falx cerebri supplies blood to the innermost surfaces of the cortex, neighboring the midsagittal plane. The two hemispheres of the human cortex are not perfectly symmetrical, both in structure and in function. For example, the planum temporale, roughly corresponding to the Wernicke’s area, was found to be 10 times larger in the left than the right hemisphere. In contrast, the caudate nucleus, within the basal ganglia, was found to be larger in the right hemisphere. The longitudinal fissure plays a key role in corpus callosotomy, a