Physiology and biochemistry in modern medicine . llow for the time lost in propa-gation of the pulse from the heart to the radial artery. This line 3 (corrected in case of radial pulse) corresponds to the be-ginning of the sphygmic period of ventricular systole—i. c., to the open-ing of the semilunar valves. Measure the distance from it to the near-est vertical line that was made to indicate the relative position of thewriting points. Then measure off the same distance in the venous trac-ing from the corresponding indicator line. This will fall at the begin-ning of the small wave (c), which is
Physiology and biochemistry in modern medicine . llow for the time lost in propa-gation of the pulse from the heart to the radial artery. This line 3 (corrected in case of radial pulse) corresponds to the be-ginning of the sphygmic period of ventricular systole—i. c., to the open-ing of the semilunar valves. Measure the distance from it to the near-est vertical line that was made to indicate the relative position of thewriting points. Then measure off the same distance in the venous trac-ing from the corresponding indicator line. This will fall at the begin-ning of the small wave (c), which is due to the bulging into the auriclesof the closed auriculoventricular valves. (Pig. 96.) 273 274 THE CIRCULATION OF THE BLOOD The auricular wave (a) occurs one-fifth of a second in front of c, andmay now be ascertained by measuring off this distance in front of is line 1. Now measure the distance on the radial pulse tracing from the begin-ning of the upstroke to the dicrotic notch. The distance between these isthe sphygmic period (E).. Fig. 95.—Polysphygmograph. This instrument records in ink on glazed paper two simul-taneous tracings, i. e., radial pulse and one other, such as carotid, jugular, apex beat, etc., in addi-tion to the time tracing. The ink tracings are both more convenient and permanent than smokedpaper tracings. The clockwork operates at variable speeds, permitting the taking of protractedrecords at different speeds. Measure off the same distance on the venous tracing from c. Line5 will be found to fall just before a small wave (v), which is due to thesudden opening of the tricuspid valves. This practically coincides withthe dicrotic notch on the radial pulse tracing. Sometimes a little wave
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