Parietal Lobe

The parietal lobe, posterior to the
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central sulcus, is divided into three parts: (1) the postcentral gyrus, (2) the superior parietal lobule, and (3) the inferior parietal lobule. The postcentral gyrus receives sensory input from the contralateral half of the body. The sequential repre
sentation is the same as in the primary motor area, with sensations from the head being represented in inferior parts of the gyrus and impulses from the lower extremities being represented in superior portions. The superior parietal lobule, located caudal to (that is, below and behind) the postcentral gyrus, lies above the intraparietal sulcus. This lobule is regarded as an association cortex, an area that is not involved in either sensory or motor processing, although part of the superior parietal lobule may be concerned with motor function. The inferior parietal lobule (composed of the angular and supramarginal gyri) is a cortical region involved with the integration of multiple sensory signals.
In both the parietal and frontallobes, each primary sensory or motor area is close to, or surrounded by, a smaller secondary area. The primary sensory area receives input only from the thalamus, while the secondary sensory area receives input from the thalamus, the primary sensory area, or both. The motor areas receive input from the thalamus as well as the sensory areas of the cerebral cortex.

Photograph:Left lateral surface of the brain, showing various lobes of the hemisphere.
Photograph:Left lateral surface of the brain, showing various lobes of the hemisphere.

The parietal lobe is a part of the Brain
positioned above the occipital lobe and behind the frontal lobe. The parietal lobe integrates sensory information from different modalities, particularly determining spatial sense and navigation. For example, it comprises somatosensory cortex and the dorsal stream of the visual system. The parietal lobe is defined by four anatomical boundaries: the central sulcus separates the paretial lobe from the frontal lobe; the parieto-occipital sulcus separates the parietal and occipital lobes; the lateral sulcus is the most lateral boundary separating it from the temporal lobe; and the medial longitudinal fissure divides the two hemispheres.

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brain: human brain

Ch. 14-Parietal lobe