A text-book of human physiology : designed for the use of practitioners and students of medicine / by Austin Flint.

  • Flint, Austin, 1836-1915.
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of human physiology : designed for the use of practitioners and students of medicine / by Austin Flint. Source: Wellcome Collection.

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

    64/1010 (page 42)
    diroctioii and consequently project the entire organ against tlie walls of the chest. This movement is aided by the recoil of the ventricles as they discharge their contents. The displacement of the heart during its systole has long been observed in vivisections and may be demonstrated in any of the mammals. The most interesting observations on this point are those of Ghauveaii and Faivre, which were made upon a monkey. In this animal, in which the position of the heart is very much the same as in the human sub- ject, the locomotion of the organ was fully established. Twisting of the Heart.—Tho spiral course of the superficial fibres would lead ns to look for another phenomenon accompanying its contraction ; namely, twisting. If we attentively watch the apex of the heart, especially when its action has become a httle retarded, there is a palpable twisting of the point upon itself from left to right with the systole, and an untwisting with the diastole. hardening of the Heart.—If the heart of a living animal be grasped by the hand, it will be observed that at each systole it becomes hardened. The fact that it is composed almost exclusively of fibres, resembling very closely those of the voluntary muscles, . explains this phenomenon. Like any other muscle, it is sensibly hardened during con- traction. Shortening and Elongation of the ^.ari.-The phenomena which we have just de- scribed are admitted by all writers on physiology and can easily be observed; but the change in length of the heart during its systole has been a matter of discussion. AH who have st^idied the heart in action have observed changes in length during contraction and ^elaxa on • but the contemporaries of Harvey were divided as to the periods m the heai^ . acSn whl^h are attended with elongation and shortening, ^arvey him^^^^^^^ elongation during the systole ; but HaUer l^^^^^''that the heart is com^s shortened. The view generally entertained a ^^^J^^^^l ^^^^^^^ truded shortened during its systole. There as no doubt *^^^^^^^^^ the Ventricles, during the ventricular systole, but this p^^^^^^ By suddenly cutting the heart out ot a waim dioou« en'a which Lcompany the few regular cont-tions which f U^^^^^^ ;Vi;;eciated by the tricles invariably shorten during the systole. T^!^ ;'^; ^^^J.^ , J4,t with a plane eye, but more readily if the point of -S^n .^rufm^ observed to recede, surface at right angles, when, at each - tion t nnm^t y ^^^^ ^^^^^^^^ The following experiments we have frequently r^ea ed beto Hospital Medical College, and have satisfied o^y^^^^^.^ artificial respiration foumlland pup, about nine months o d, ^^J^-^f,^Zusion of the point and was kept up, and the heart exposed. After showing 1 rapidly removed, the apparent elongation of the heai-t while ^^^J^^^^^^^fj the base, pinning placed upon the table, and confined by two ^^^Sf ^fjf ^^f^f J^^^ ,^3tole the ventricles t to the wood. It contracted for one or t- ^J^^f^'^^^^^ an upright, and it re- were manifestly shortened^ The point .^^^^ this ph— -s 'apparent to ceded with each systole about an eighth of ^n >^o^.. i V ^^^^.^^^ all present. In another experiment. P-f-ned ^ ^ Ty pinning t ^vith two needles to