. The anatomy of the human body. Human anatomy; Anatomy. olivary body; and a deep furrow, directed vertically, separates them on the outer side from the inferior peduncles of the cerebellum or the restiform bodies.* It is of importance to observe, that that portion of the olivary body which projects on the outer side of the p)Tamid is only the external half of the ohvary body, its internal half being imbedded in the substance of the medulla oblongata, so as to reach behind the anterior pyramid.! The Posterior Surface of the Medulla Oblongata. This surface is partly concealed by the cerebellum,
. The anatomy of the human body. Human anatomy; Anatomy. olivary body; and a deep furrow, directed vertically, separates them on the outer side from the inferior peduncles of the cerebellum or the restiform bodies.* It is of importance to observe, that that portion of the olivary body which projects on the outer side of the p)Tamid is only the external half of the ohvary body, its internal half being imbedded in the substance of the medulla oblongata, so as to reach behind the anterior pyramid.! The Posterior Surface of the Medulla Oblongata. This surface is partly concealed by the cerebellum, being received into a groove on Fig. 271. its under surface, and cannot be completely exposed unless the ? medulla oblongata be forcibly bent forward, or the middle part of the cerebellum be divided vertically. It is then seen that the cord appears to open out {t,fig. 271) opposite the upper part of this surface, and to be turned inside out, so that the gray sub- stance is exposed. In consequence of this separation of the posterior columns of the cord, there is left between them a shal- ^?^ low, triangular, or V-shaped depression {p), the bottom of which is smooth, and forms the anterior wall of the fourth ventricle ; Herophilus named this depression, from its appearance, the cal- amus scrijptorius. A vertical median groove corresponds to the shaft of the quill; while its barbs are represented by certain white medullary lines, which vary exceedingly in number, and are not symmetrical; some of these lines are lost upon the walls of the ventricle, and others turn round the lateral surface of the medulla oblongata, and constitute, in part, the origin of the auditory nerves. The point of the pen is represented by the very acute inferior angle formed by the sides of the depression, which terminates below in a cul-de-sac, the/o5- sttte of the fo^irth ?centricle, also called the ventricle of Arantius. According to some au- thors, at the point of the calamus is situated the upper orif
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Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
