Demonstrations of anatomy : being a guide to the dissection of the human body / by G.V. Ellis.

  • George Viner Ellis
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: Demonstrations of anatomy : being a guide to the dissection of the human body / by G.V. Ellis. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    Sulcus of Iiolando is behind corona] suture. Parieto- occipital fissure; situation. Lobes of hemisphere. Frontal lol e is largest: orbital lobule. Parietal lobe: boundaries are in great part artificial. Occipital lobe. Temporn- splienoidal lobe. Central lobe, or island of Refl, The furrow of Rolando (central sulcus ; fig. 60, r) crosses the outer surface of the hemisphere near the middle. Beginning above close to the margin of the great longitudinal fissure, the furrow runs downwards and somewhat forwards, with a serpentine course, to end about one inch behind the place of division of the Sylvian fissure, and very near to its posterior limb. This sulcus is used to separate the frontal from the parietal lobe. The upper end of the furrow of Rolando is placed from an inch- and-a-half to two inches, the lower end about one inch behind the coronal suture. The parieto-occipital fissure (fig. 61, po) is a deep sulcus at the hinder part of the inner surface of the hemisphere. Its upper end appears on the superior surface of the cerebrum about midway between the preceding sulcus and the posterior extremity of the hemisphere, and extends outwards for nearly an inch from the margin of the longitudinal fissure (fig. 60, po). It ■ indicates the anterior limit of the occipital lobe. The parieto-occipital fissure is placed opposite the summit of the lambdoid suture. Lobes. The outer surface of the hemisphere is divided into five lobes (excluding the olfactory) which haA'e the following names and limits :— The frontal hie forms the anterior half of the hemisphere. It is limited below by the posterior branch of the fissure of Sylvius (fig. 60, s), and behind by the furrow of Rolando (?•). Its under part, which rests on the roof of the orbit, is named the orbital lobule. The parietal lobe is little more than half the size of the frontal. Its anterior limit is the luridw of Rolando (r), and its posterior a line drawn transversely over the hemisphere from the parieto-occipital fissure. Below, it is bounded in its fore part by the posterior branch of the fissure of Sylvius (*'), and in its hinder part by a line extending from the spot where this sulcus turns upwards to the posterior extremity of the hemisphere. Its convolutions are con- tinuous with those of the occipital lobe behind, and of the temporo- sphenoidal lobe below. The occipital lobe is small, and triangular in shape. It is separated from the parietal lobe for a short distance above by the parieto- occipital fissure (po); but its anterior boundary is for the most part artificial, being constituted by a line continuing the direction of that fissure, across the outer surface of the hemisphere. Its convolutions join those of the parietal and temporo-sphenoidal lobes. The temporo-sphenoidal lobe projects into the middle fossa of the base of the skull. Its fore part is separated from the frontal and \ parietal lobes by the fissure of Sylvius, but its hinder part is only limited by the lines above mentioned, across which its con- volutions pass into those of the parietal and occipital lobes. The central lobe, insula, or island of Reil (fig. 61, c), is placed at I the bottom of the fissure of Sylvius, and is concealed by the over- lapping of the temporo-sphenoidal, parietal and frontal lobes. If the