Two clinical lectures / by Alexander Morison.

  • Blackhall-Morison, Alexander, 1850-1927.
Date:
1901
Catalogue details

Licence: In copyright

Credit: Two clinical lectures / by Alexander Morison. 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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    rate valvular support of the vibrating blood-columns is necessary. The study of some congenital cardiac malformations especially appears to support this conclusion, because with considerable parietal defects and bruits caused by such the sounds of the heart may be well heard so long as the division of the blood is fairly maintained by the valves. This conclusion from clinical observations and argument is essentially the same as that reached by the late Dr. Arthur Leared, formerly one of the physicians to the Great Northern Hospital. I cannot, however, agree with him when he writes that the events which occur in the ventricles and at the arterial orifices have no more to do with the generation of the sounds than the vibration of a door [has] with the sound produced by air [passing] through its key- hole.1 There is a difference in the noise made by a door slammed to and one pushed open. The former represents the second, the latter the first sound of the heart, and in both the character and distribution of the vibrations differ. The conclusion I have drawn differs somewhat likewise from that arrived at by my late friend Sir Richard Ouain, in that I cannot attribute so much importance as he did to the impact of the ventricular blood against the close semilunar valves only and the superincumbent blood-columns, although I think there can be little doubt that it is at this point that the most impor- tant portion of the vibrations arise which result in the produc- tion of the first sound of the heart. Dr. Leared appears to me to have attributed too much and Sir Richard Quain too little impor- tance to the sound-producing qualities of the blood itself. The truth appears to lie between the views of these two observers and may include as a very subsidiary factor a note derived from the muscular contraction of the organ. The estimation of the last point, however, by the clinician is a very difficult matter. 1 ' lissav on the Sounds caused by the Circulation of the Blood,' London, 1S61.