The term inferior parietal lobule refers to one of four subdivisions of the parietal lobe identified by dissection in the human ( Carpenter-1983; Ono-1990 ) and the macaque ( Martin-2000 ). It has two components, the more rostral supramarginal gyrus and more caudal angular gyrus. Located on the dorsolateral surface of the cerebral hemisphere, it is, in the human, separated rostrally from the postcentral gyrus by the postcentral sulcus. Dorsally it is separated from the superior parietal lobule by the intraparietal sulcus. Caudally its boundary with the occipital lobe is an oblique plane through the parieto-occipital sulcus on the dorsomedial margin of the hemisphere and the preoccipital notch on the ventromedial margin. For its borders on the ventrolateral surface of the hemisphere see descriptions of its subdivisions, the supramarginal gyrus and the angular gyrus. The other three parts of the parietal lobe are the superior parietal lobule, the postcentral gyrus, and the precuneus. The boundaries in the macaque are the same except that the rostral border with the postcentral gyrus, a vertical line from the rostral tip of the intraparietal sulcus to the lateral fissure, is unmarked by anatomical feature. Its caudal boundary with the occipital lobe is defined by the lunate sulcus of the human. ( Martin-2000 ). Segmented on the basis of internal structure, the lobule includes area 39 of Brodmann and area 40 of Brodmann. in the nomenclature of the Vogts-1919, it includes area Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).