. Human physiology (Volume 1) . immediately rolled in one direction; but oncutting the other, or the one on the opposite side, the movementceased, and the animal lost the power of keeping itself erect, andof walking. From the results of all his experiments, Magendie infers, that ananimal is a kind of automatic machine, wound up for the perform-ance of certain motions,but incapable of producingany other. The marginalfigure of the base of thebrain will explain,more di-rectly, the impulses descri-bed by that corpora striata aresituate in each hemisphere,but their united impulsesm
. Human physiology (Volume 1) . immediately rolled in one direction; but oncutting the other, or the one on the opposite side, the movementceased, and the animal lost the power of keeping itself erect, andof walking. From the results of all his experiments, Magendie infers, that ananimal is a kind of automatic machine, wound up for the perform-ance of certain motions,but incapable of producingany other. The marginalfigure of the base of thebrain will explain,more di-rectly, the impulses descri-bed by that corpora striata aresituate in each hemisphere,but their united impulsesmay be represented by thearrow A ; the impulse seat-ed in the cerebellum, by thearrow B; and those in eachpeduncle of thecerebellum,p,p, by the arrows C andD respectively. When theimpulse backwards is fromany cause destroyed, theanimal is given up to theforward impulse, or to thatrepresented by the arrow to Magendie. 11 Magondies Joum. de Physiol, iv. 405. i> Precis, &c. p. 344. SO*. 354 MUSCULAR MOTION. B, and conversely. In like manner, the destruction of one lateralimpulse leaves the other without an antagonist, and the animalmoves in the direction of the arrow placed over the seat of theimpulsion that remains. In a state of health, all these impulsionsbeing nicely antagonized, they are subjected to the influence ofvolition ; but in disease they may, as we have seen, be so modifiedas to be entirely withdrawn from its control. These four are not the only movements excited by particularinjuries done to the nervous system. Magendiea states, that a cir-cular movement, to the right or left, similar to that of horses in acircus, was caused by the division of the medulla oblongata, to theouter side of the corpora pyramidalia anteriora. When the sectionwas made on the right side, the animal turned, in this fashion, tothe right; and to the left, if it was made on that side. Pathology has, likewise, indicated the brain as the seat of differ-en
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectphysiology, bookyear1
