The parietal lobe of the brain

Behind the central sulcus is the parietal lobe (lobus parietalis). The posterior border of this lobe is the parieto-occipital sulcus (sulcus parietooccipitalis). This sulcus is located on the medial surface of the cerebral hemisphere, deeply dissects the upper edge of the hemisphere and passes to its upper lateral surface. The border between the parietal and occipital lobes on the dorsolateral surface of the cerebral hemisphere is an imaginary line - a downward continuation of the parieto-occipital sulcus. The lower border of the parietal lobe is the lateral sulcus (its posterior branch), separating this lobe (its anterior sections) from the temporal lobe.

Within the parietal lobe, there is a postcentral sulcus (sulcus postcentralis). It begins at the lateral sulcus below and ends at the top, not reaching the upper edge of the hemisphere. The postcentral sulcus lies behind the central sulcus, almost parallel to it. Between the central and postcentral sulci is the postcentral gyrus (gyrus postcentralis). Above, it passes onto the medial surface of the cerebral hemisphere, where it connects with the precentral gyrus of the frontal lobe, forming together with it the paracentral lobule (lobulus paracentralis). On the upper lateral surface of the hemisphere, below, the postcentral gyrus also passes into the precentral gyrus, embracing the central sulcus from below. From the postcentral sulcus, the intraparietal sulcus (sulcus intraparietalis) extends posteriorly. It is parallel to the upper edge of the hemisphere. Above the intraparietal sulcus is a group of small convolutions called the superior parietal lobule (lobulus parietalis superior). Below this sulcus is the inferior parietal lobule (lobulus parietalis inferior), within which two convolutions are distinguished: the supramarginal (gyrus supramarginalis) and the angular (gyrus angularis). The supramarginal gyrus encompasses the end of the lateral sulcus, and the angular gyrus encompasses the end of the superior temporal sulcus. The lower part of the inferior parietal lobule and the adjacent lower sections of the postcentral gyrus, together with the lower part of the precentral gyrus, overhanging the insular lobe, form the frontoparietal operculum of the insula (operculum frontoparietale).

The parietal lobe includes the posterior central gyrus (primary sensory or projection sensory cortex) and the association parietal cortex. Situated between the tactile and visual cortex, the parietal lobe is important in the perception of three-dimensional space. The superior parietal lobe integrates sensory input from the primary somatosensory cortex with the influences of higher mental functions (attention, motivation, etc.), especially during voluntary, purposeful limb movements.

The inferior parietal lobule, consisting of an anterior part (gyrus supramarginalis) and a posterior part (gyrus angularis), has even more complex functions. Here, multimodal sensory information (somatic sensations, vision, and hearing) is integrated with the processes of perception of internal and external space, language and symbolic thinking, and attention directed to external objects and to one's own body.