The physiology of the circulation in plants, in the lower animals, and in man : being a course of lectures delivered at the Surgeons' Hall to the president, fellows, etc. of the Royal College of Surgeons of Edinburgh, in the summer of 1872 / by J. Bell Pettigrew.

  • Pettigrew, James Bell, 1834-1908.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: The physiology of the circulation in plants, in the lower animals, and in man : being a course of lectures delivered at the Surgeons' Hall to the president, fellows, etc. of the Royal College of Surgeons of Edinburgh, in the summer of 1872 / by J. Bell Pettigrew. Source: Wellcome Collection.

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    the segments, from their being more or less in contact at the end of the systole, being closed by the slightest reflux, and with almost no noise. By transfixing by hooks two of the six segments composing the aortic and pulmonic semi- lunar valves, an abnormal element is introduced which renders the experiment of little value. The substitution of one sound for another proves nothing, and if the second sound is de- stroyed there is some fallacy, as only two of the six segments which were supposed to produce it were restrained. I am therefore disposed to put a different construction on the results obtained by Dr. Williams, and to attribute the second sound partly to the closure and susurrus of the auricles, but mainly to the rush of blood into the ventricular cavities, and against the auriculo-ventricular valves, chordae tendineae, carneae columnae, and musculi papillares. To this is to be added the flapping together of the semilunar valves, a slight degree of regurgitation, and the susurrus produced by the dilatation of the ventricles, venae cavae, and pulmonic veins. As an illustration of the extreme difficulty experienced by investigators in determining the precise nature of the move- ments and sounds of the heart, I may cite the case of M. Groux, who exhibited in his person an almost unique example of congenital fissure of the sternum. Here we had the parts in the vicinity of the heart opened up as it were for inspection. M. Groux visited the principal schools on the Continent, in America, Russia, and Britain, and was examined by upwards of 2000 physicians, many of them eminently distinguished. The discrepancy of opinion is quite remarkable. In M. Groux's case, the fissure extended the whole length of the sternum, and presented a V-shaped appearance. In natural respiration, the fissure was depressed to variable depths, and had a transverse measurement at its upper boundary of one inch and a quarter; this increasing at the central part on a level with the third and fourth ribs to an inch and a half, and decreasing at the lower boundary of the fissure to a quarter of an inch. Through the action of the pectoral muscles, the hands being joined and pulling upon each other, the fissure could be dilated to the width of about two and a half inches. The fissure could be increased by forced ■ expiration and decreased by forced inspiration.