On the order of succession in which the vital actions are arrested in asphyxia / by John Reid.

  • Reid, John, 1809-1849.
Date:
[©1841?]
Catalogue details

Licence: Public Domain Mark

Credit: On the order of succession in which the vital actions are arrested in asphyxia / by John Reid. Source: Wellcome Collection.

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

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    mcroiis experiments he fomul, that when an animal is aspliyxiutcd, bUick blood at first traverses tlie lungs to reach the left side of the heart, and may for a short time be projected from a cut artery, with very considerable force ; and he further satisfied himself, that the contractions of the heart could be renewed even after they had become quiescent in different kinds of violent deaths, by in- jecting venous blood along one of the pulmonary veins towards the left side of the heart.* Bichat especially dwelt upon the im- portance of discriminating between the effects of asphyxia upon the functions of animal and those of organic life ; of ascertaining the priority of the suspension of those two great sets of functions, and the influence which they exerted upon each other. He main- tained that the heart's action does not cease because the dark blood transmitted to the left side of the heart cannot excite it to con- tract, but because the dark blood, by being circulated through the coronary arteries in the muscular tissue of the heart, arrests its con- tractility. This effect of the dark blood upon the contractility of the heart was, however, regarded by Bichat as only an isolated phenomenon in asphyxia; for he believed that the vitality of all the tissues of the body was equally affected by the circulation of this dark blood, and that the functions of the brain or the animal functions were always arrested before those of organic life.f He maintained that the accumulation of the blood in the right side of the heart did not depend upon any mechanical obstruction in the blood-vessels of the lungs, but from various other causes, among which he enumerates the obstacles opposed to the force of the al- ready enfeebled right side of the heart, by the effects of the cir- culation of dark blood in the bronchial arteries, and the cessation of the excitation of the lungs by the atmospheric air,| aided by the circumstance, that the systemic ventricle can more easily over- come the resistance presented by the capillaries of the body ge- nerally, than the veins and pulmonic \cntriclc can overcome that arising from the capillaries of the lungs. Bichat appears to have entertained doubts whether the circulation of the venous blood through the capillaries of the systemic circulation arrested the vi- tality of the tissues simply by default of excitation, or by exerting some deleterious influence upon it; for, while discussing its effects upon the brain, he thus expresses himself— Je ne puis dire si c'est negativement ou positivement que s'cxerce son influence; tout ce que je sais, c'est que les fonctions du cerveau sontsuspen- dues par elle. Although Bichat failed in giving the correct ex- planation of the manner in which the vital actions are arrested in • Sur La Vie et La Mort, article sixieme, § ii. t Car, d'apres ce que nous dirons, I'afriiibHssemeiit qu' eprouve alors le coeui n'est qu'un symptome particulier de cette nialadie dans Icqutlle tous les autres organes sont le siege d'une seiiiblab^e dcbilite. J '• Le defaut de son excitation par j'air vital.