476 CIRCULATION OF BLOOD AND LYMPH. 



before entering the capillary regions, but as a result of dilatation in 

 the arteries of an organ the pulse may carry through and appear in 

 the veins, in which it may be shown, for instance, by the rhythmical 

 flow of blood from an opened vein. The term venous pulse, how- 

 ever, as generally used applies to an entirely different phenomenon, 

 namely, to a pulse seen especially in the external jugular vein. 

 When this vein is prominent or is made prominent by some com- 

 pression a pulse may be seen and recorded which is synchronous 

 with the heart beat. It is not a wave that has come through the 

 capillary circulation in the head, since if the vein be completely 

 blocked by the finger the wave disappears on the upper side. It is 

 due to the heart beat; and is usually attributed to the auricular 

 contraction. At each contraction of the auricle the venous flow 

 is partially blocked; at each relaxation the flow is suddenly aug- 

 mented. Under pathological conditions a marked venous pulse 

 of a different origin maybe seen in the jugular or may be felt over the 

 liver (liver pulse). This wave is usually described in connection 

 with an insufficiency of the auriculo- ventricular valves. Under such 

 a condition it is evident that the contraction of the ventricles will 

 be accompanied by a regurgitation toward the auricles and the 

 production of a positive wave in the venae cavse and their branches.* 



* For a discussion of the venous pulse consult works on clinical methods, 

 e. g., Sahli, " Lehrbuch der klinischen Untersuchungs-Methoden," 1902. 



