Diseases of the nervous system / edited by Archibald Church.

Date:
1908
Catalogue details

Licence: In copyright

Credit: Diseases of the nervous system / edited by Archibald Church. Source: Wellcome Collection.

    38/1256 (page 10)
    sphere. Anterior to this is a secondary fossa of this sulcus extending verti- cally ; above it is the sulcus paracentrails. Among the anterior convolutions on the median surface of the hemisphere we find the gyrus frontalis superior and a few of its subdivisions, then the one mentioned above, the lobulus paracentralis, which corresponds to the cen- tral convolutions between the sulcus paracentralis and the ascending portion of the sulcus calloso-marginalis behind the precuneus, it is of a square form, and reaches posteriorly to the parieto-occipital fissure. This is joined dorsally by the triangular cuneus between the last mentioned furrow and the fissura calcarina, the anterior point of which runs as the pedicle of the cuneus to the isthmus gyri fornicati; finally we observe the gyrus descendens which passes downward behind the fissura calcarina to the gyrus lingualis, which was de- scribed when outlining the temporal lobe. A brief description of the island must be given. The island of Reil is covered by the surrounding portions of the brain, and externally immediately Fig. 6.—Longitudinal Section through the Middle of the Human Brain. (After Edinger.) adjoins the ganglia of the cerebrum. Around this structure runs the sulcus circularis Reilii; anteriorly and ventrally the island passes into the free structure at the base of the brain, and at the limen insulae directly into the lamina perforata anterior. A permanent sulcus, the sulcus centralis insulae, divides the island into two lobes; the larger anterior (pars frontalis) pos- sesses three to four gyri breves, the smaller posterior (pars parieto-occipitalis) has one to two gyri longi which pass to the temporal pole. The region of the island, which is especially developed in man as the association region of human speech, shows in animals a gradually ascending development. Waldeyer found in his investigations of the brain of anthropomorphic apes that the construction of the island in the monkey is fundamentally the same as in man; there is first an arching convolution with strongly linked frontal and weaker temporal arches; an increased development is apparent as we pass