A textbook of human physiology / translated from [the] 6th German edition by W. Stirling.

  • Landois, Leonard
Date:
1888
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Licence: Public Domain Mark

Credit: A textbook of human physiology / translated from [the] 6th German edition by W. Stirling. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    166/980 page 114
    VELOCITY OK THE PULSE-WAVE IN MAN. A. with 18 cm. (Hg.) pressure, the vehjcity per metre = 0-093 second, while with 21 cm. pres- sure (Hg.)=0-09f. second per metre. T„ . ,.,.rj,r„ (C) Th^ specific (iraviln of the liquid influences the velocity of the pulse-wave. In //tc/c«»// the wave is i^ropagated four times more slowly than in water. (D) The velocity in a tube which is more rigid and not so extensile is greater than in a tuut which is easily distended. 78 VELOCITY OF THE PULSE-WAVE IN MAN.—Landois obtained the following results in a student -DiHcrencc between carotid and radial = 0-074 .second (the distance being taken as 62 centimetres) ; carotid and femoral = U-068 second : femoral (inguinal region ancl po.sterior tibial = 0-097 second (distance estimated at 91 centimetres). [Waller obtained betvveen tHe heart and carotid Q-IO second ; heart and femoral, 0-18 sec.; heart and dorsalis peilis, 0 /^.J The velocity of the pulse-wave in the arteries of the upper extremities = metre.s per second, and in those of the lower extremity 9-40 metres per .second, [v.c, about 30 feet per second]. The velocity is greater in the less extensile arteries ol the lower extremities than in those of the upper limb. For the satiie reason it is less in the peripheral arteries and in the yielding arteries of children (Czennak). E. H. Weber estimated the velocitv at 9-24 metres per second; Garrod, 9-10-8 metres ; Orashey, 8-5 metres ; Moens, 8-3 metres, and with diminished pressure during Valsalva s experi- ment 7 -3 metres 60, § 74). i u 4.- i Influencing Conditions.—In animals, luemorrhage, slowing of the heart produced by stnmila- tion of the vagus (J/ooja), section of the si)inal cord, deep morphia-narcosis, and dilatation of the blood-vessels by heat, produce nloiriny of the velocity, while stimulation of the spinal cord accelerates it {Grimmach). The -wave-length of the pulse-wave is ol)tained by multiplying the duration of the inflow of blood into the aorta = 0-0« to 0-09 second 51), by the velocity of the [.)ulse-\vave. Method.—Place the knobs of two tambours (fig. 76) upon the two arteries to be investigated, or i>l:Ke one over the apex-beat and the other u]ion an artery. These receiving tambours^are connected with two registering tambours, as in Brondgeest's pansphygmograpli (§ 67, fig. 76), so that their w riting-levers are directly over each other, and so arranged as to write simultane- ously on one vibrating plate attached to a tuning-fork. [Or they may be made to write upon a revolving cylinder, whose rate of movement is ascertained by causing a tuning-fork of a known rate of vibration to write under them.] The apjparatus is improved by using rigid tubes and filling them with water, in which all impulses are rapidly communicated. In arteries ^^^^^^^^mm^^^^ which are distant from each other, or in the case of the heart A H^IMHjil^fiS^^^I and an artery, the two knobs of the receiving tambours may /XJL e B H P A rx' R P R LP Fig. 96. A, curve of radial artery on a vibrating surface (1 vib.-=0-01613 sec.) ; P, apex of curve ; e, e, elastic vibrations ; E, dicrotic wave. 13. curve of same radial taken along with the heart- beat ; r, H, P, conti'action of the ventricle. be connected by means of a Y-tube with oh*'writing-lever. In fig. 96, B is a curve from the radial artery taken in this way. In it r H P indicates contraction of the ventricle ; H, the apex of the ventricular contraction ; P, the primary apex of the radial curve; v, the beginning of the ventricular contraction ; of the radial pulse. A is the curve of the radial artery alone. From these curves it is evident that in this instance nine vibrations occur between the begin- ning of the ventricular contraction ami the beginning of the pulse in the radial artery = 0-15 .sec. In tig. 97 the difference between the carotid and the posterior tibial pulse = 0'137 sec. Pathological.—In cases of diminished e.rfe>isibilili/ of the arteries, e.g., in atheroma (§ 77, D), the pulse-wave is propagated more rapidly. Local dilatations of the arteries, as in aneurisms, cause a retardation of the wave, and a similar result arises from local constrictions. Relaxation of the walls of the vessels in high fever retards the movement {Hamernjk). 79. OTHER PULSATILE PHENOMENA.—1. In the mouth and nose, when they are tilled with air, and the glottis closed, pulsatile phenomena (due to the arteries in their soft parts).
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