Researches on the action of the heart / by George Paton.

  • G. P. (George Paton)
Date:
1866
Catalogue details

Licence: Public Domain Mark

Credit: Researches on the action of the heart / by George Paton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    systole, and not to precede it,a because tbe first stage of the dilatation and the pause is completed before the auricles contract, and shoot down to the foramen of the ventricle to complete the second stage of the diastole, on which the ventricle immediately contracts. Haller, who seems to have viewed the action of the heart when it was slow, and who strongly maintained the doctrine of the relaxation of the ventricles, enquires the reason of the particular order or occurrence of the movements—that is, why the auricles contract, whilst the ventricles dilate, and dilate whilst the ventricles contract; and then the ventricles repose dilated, and the auricles smartly contract? And Dr. Hope, considers the reason to be that the auricles, which have been refilling during the contraction of the ventricles, are brought to a state of distention, by which they contract at the moment of repose, in order that the ventricles by the additional quantity of blood which they receive from the auricles, may then be distended and stimulated to contract. But according to the views which we have advanced, these movements arise as a necessary consequence from, or are intimately connected with the action of the heart when it is slow; and the movements are performed in a different manner when the action is accelerated; the reason of which movements will become more obvious as we proceed. This subject, however, will be better understood if we describe a few of the experiments we have performed in our researches on the action of the heart. If we expose the heart of a living fish, whose gills are well protected by tbe operculum, enabling them to retain a due degree of moisture, sufficient to sustain the function of respiration for a considerable time, after the animal has been removed from the water—and it is surprising to what extent this power is possessed by some fishes—it will be found that when the effect of the operation has subsided, the circulation will be carried on with energy, and the animal will survive for a time, affording ample opportunity to study the movements of the heart. July 8.—Denuded the heart of a living fishb, and carefully observed the action of the heart. The heart beat at thirty-six pulsations per minute, and the auricle, on contracting, projected the blood into the cavity of the a Dr. Hope on the Heart, p 19. b Commonly termed the Mud Cat Fish.
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