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A TEXTBOOK OF PHYSIOLOGY 



The examination of the pulse is of great importance to the physician. 

 It yields him information as to the state of the heart, the state of the 

 arteries, the amount and variations of the arterial pressure. 



The pulse may be investigated either directly by the finger or by 

 the aid of instruments known as sphygmographs (Fig. 113). The pulse 

 is generally felt in the radial at the wrist, preferably on both sides. 

 With the finger the points noted may be grouped into (a) those which 

 give information concerning the heart e.g., the frequency, generally 

 seventy to seventy-five per minute in man, regularity or irregularity, 

 equality or inequality of the beats; (6) those which yield knowledge 



FIG. 114. MACKENZIE'S POLVGKAIMI. 



The parts of the polygraph may be described as follows: The body A, containing the 

 paper- rolling and time-marker movements; the writing tambours BB, with 

 supporting bar, B\ ; wrist tambour, C, with attachment, Cl, for strapping on 

 to wrist; paper roll bracket, D; paper roll, Dl ; cup receiver, E; pens, FFF. 



about the vessel e.g., its size and the condition of its wall; (c) those 

 which yield combined information of the two the volume, force, and 

 tension of the pulse. 



By volume is meant the amount of movement in the pulse during 

 the passage of the pulse-wave; by force is understood the maximum 

 pressure as felt by the finger in the vessel during the beat ; by tension 

 the pressure between the beats. 



These last data can only be accurately measured by means of the 

 sphygmometers already described, for the finger begins to flatten the 

 artery and stop the passage of the pulse-wave when exerting a pressure 

 much less than that within the artery. 



In a normal healthy pulse the beats are regular and of equal 

 strength. The vessel is soft and pliant, not tortuous, rigid, or thick- 

 ened. The force and tension are moderate that is, they are best 

 felt when a moderate degree of pressure is applied. 



