A text-book of physiology, for medical students and physicians . ^ a microphonewere transmitted to a capillary electrometer and the movementsof the latter were photographed. As one result of their work theygive the schema shown in Fig. 226. It will be seen from this figurethat the first sound begins about sec. before the cardiogramshows the commencement of systole, and that for the first sound is heard only over the apex of the heart (a-b). Over the. oisee. Fig. 226.—Schematic representation of the relation of the heart sounds to the ventric-ular beat: C, The cardiogram; 1, t
A text-book of physiology, for medical students and physicians . ^ a microphonewere transmitted to a capillary electrometer and the movementsof the latter were photographed. As one result of their work theygive the schema shown in Fig. 226. It will be seen from this figurethat the first sound begins about sec. before the cardiogramshows the commencement of systole, and that for the first sound is heard only over the apex of the heart (a-b). Over the. oisee. Fig. 226.—Schematic representation of the relation of the heart sounds to the ventric-ular beat: C, The cardiogram; 1, to show the duration of the first heart sound; 2, theduration of the second heart sound; S, the time record, each division corresponding sec. In 1, a-a marks the instant that the first heart sound is heard over the apex,and b-b the moment that it is heard at the second intercostal space.—(Einthoven andGeluk.) base of the heart (second intercostal space) the first sound is heard(b to c-d) just at the time when the semilunar valves are opened(&),—that is, at the beginning of the period of emptying accordingto the classification given on p. 527. The first sound ceases longbefore the ventricular contraction itself is over,—a fact whichwould seem to indicate that the muscular element in the first soundis not a muscular sound, such as is given out by a contractingskeletal muscle. The beginning of the second sound seems to markexactly the time of cl
Size: 2636px × 948px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookautho, bookcentury1900, bookdecade1900, booksubjectphysiology
