SPHYGMOGRAPHIC TRACINGS FROM DIFFERENT ARTERIES. 147 



dicrotic pulse. In the remaining portion of the descending limb, down to the 

 base of the curve, two or three lesser elevations are encountered, the first two 

 being elasticity-elevations (e e) and the lowest appreciable only in rare cases 

 and probably indicating a second recoil-wave. The sphygmographic curve of the 

 brachial artery at the bend of the elbow is somewhat larger, but does not differ 

 materially from the radial curve. 



SPHYGMOGRAPHIC TRACING FROM THE FEMORAL ARTERY. 



(Fig. 50, XI, XII.) 



The ascending limb is steep and high; on the apex of the curve, which is quite 

 frequently somewhat flat and broad, there is recorded the closure of the semilunar 

 valves (K) . From that point the curve falls in an abrupt manner to about the 

 lower third. The recoil-elevation (R) appears late after the beginning of the 

 curve, and beyond that point the curve is interrupted in both its ascending 

 and its descending portion by small elasticity-elevations (e e) . 



and Fig. 53.) 



pedis artery the signs indi- 

 apparatus (the heart) are 



SPHYGMOGRAPHIC TRACINGS FROM THE DORSALIS PEDIS ARTERY AND 

 FROM THE POSTERIOR TIBIAL ARTERY. 



(Fig. 50, XIV, XV.) (Fig. 50, XIII, 



In the sphygmographic tracing from the dorsalis 

 eating the great distance from the wave-producing 

 obvious. Thus, the ascending limb of the curve 

 exhibits a gradual ascent and is low, while the re- 

 coil-elevation takes place late. In the descending 

 limb two elasticity-elevations are found so near 

 the apex (Fig. 50, e e x ) that the upper one usually 

 occupies a point close to the latter. The elasticity- 

 elevations in the lower portion of the descending 

 limb are, as a rule, poorly developed. The tracing 

 from the posterior tibial artery in many respects 

 resembles the preceding, especially with regard to 

 the time-relations. 



The tracing shown in Fig. 53 was taken from a 

 medical student, whose height was 180 cm., with the 

 aid of the angiograph, a moderate weight being 

 used and the tracing being recorded on a tablet 

 attached to a vibrating tuning-fork. 



FIG. 53. Tracing from the Pos- 

 terior Tibial Artery, Recorded 

 on the Tablet Attached to a Vi- 

 brating Tuning-fork by means 

 of Landois' Angiograph. 



By measurement 

 it is found that 



1-4 

 1-6 



9-5 



. 20 



3 -5 

 ,61 



One vibration is 

 equivalent to 

 0.01613 second 



= 0.153 second 



= o-3 2 3 

 = 0.492 

 = 0.984 



PHENOMENA OF ANACROTISM. 



As a rule, the ascending limb in the sphygmographic tracing presents the 

 shape of the letter f, with a rather abrupt rise. The pulse-beat throws the arterial 

 wall into elastic vibration, as has been explained, the number of vibrations de- 

 pending largely upon the degree of arterial tension. 



In general the distention of the artery, or the tracing of the ascending limb 

 of the curve, which is the same thing, is completed so rapidly that the time is 

 equivalent to a single elastic vibration. The long-drawn-out f-shaped figure is 

 practically nothing but a long-drawn-out elastic vibration. When, however, the 

 number of elastic vibrations is small, and the evolution of the ascending limb of 

 the curve is relatively prolonged, two long-drawn-out hump-like curves are some- 

 times seen in the ascending limb of the tracing. A condition of this kind, however, 

 is still to be regarded as normal. (See the elevations in Fig. 50, VIII, at i and 2 ; 

 and at X i and 2.) If, however, a number of closely set elastic vibrations are 

 produced toward the upper portion of the ascending limb of the sphygmographic 

 tracing, so that the apex appears cut off obliquely from the ascending limb and 

 indented, there results the phenomena of anacrotism (Fig. 54, a a), which, like 

 the dicrotic pulse, belong in the domain of pathology. 



Anacrotism is observed: i. When the time occupied by the inflow of blood 



