The Circulation And Sleep Experimental Investigations Accompanied By An Atlas

Author : John F. Shepard
Publisher : Forgotten Books
ISBN 13 : 9780267145515
Total Pages : 106 pages
Book Rating : 4.1/5 (455 download)

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Download or read book The Circulation and Sleep written by John F. Shepard and published by Forgotten Books. This book was released on 2018-01-29 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from The Circulation and Sleep: Experimental Investigations Accompanied by an Atlas There have been innumerable speculations as to' the nature of sleep, and there are several types of theories which may claim a more or less scientific basis. At present, however, I shall be concerned with the circulatory theories only. I shall begin with a discussion of several important investigations of the relations between sleep and changes in the circulation. Mosso published his great work, Kreislauf des Blutes im Menschlichen Gehirn, in 1881. It is based upon a study of three cases, although only a few curves were obtained from each. One was a woman, a considerable portion of whose skull had been removed as a result of syphilitic infection. The second was an epileptic child who had been injured and trephined when eighteen months old. The third was a farmer, trephined on account of injury from a falling brick. Mosso concludes that in sleep there is relaxation of the vessels of the limbs, shown by plethysmographic tracings from the arm, and decrease of the blood supply to the brain. The heart rate is in general lowered, though subject to great irregularities. A stimulus that does not waken the subject causes a constriction of the vessels of the arm, and consequent increase of flow through the brain. Abdominal breathing is decreased, chest breathing increased. In both waking and sleeping there are undulations in the brain curve, and these are of three types: passive, caused by alterations in general blood pressure, in which there is no change in pulse form; active, due to contraction and relaxation of the brain vessels themselves, in which there is change of pulse form; and another type of passive wave, due to change in venous outflow, in which the pulse at the crest of the wave is restricted, being in this regard the reverse of the first two types. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.