Walsh & Hoyt: Tumors Involving the Parietal Lobe

Each parietal lobe is situated posterior to the rolandic (central) fissure and above the sylvian fissure but has no sharp boundaries inferiorly and posteriorly, where it merges with the temporal and occipital lobes, respectively. The parietal lobe contains, in addition to Wernickes speech area (areas 39 and 40), the primary somatosensory areas (areas 1, 2, 3) and the more posteriorly located secondary somatosensory cortex. All these areas have extensive afferent and efferent communications with the thalamus, cerebellum, brain stem, and spinal cord, as well as with the frontal, temporal, and occipital lobes of the same hemisphere and, through the middle part of the corpus callosum, with corresponding parts of the contralateral hemisphere.