LIVER PULSE. 



H3 



in' 'insufficiency of the tricuspid valve, and the vein may pulsate violently, but if its valves be 

 perfect, the pulse is not propagated along the vein, so that a pulse in the jugular vein is not 

 necessarily a sign of insufficiency of the tricuspid valve, but only of insufficiency of the valve of 

 the jugular vein (Friedreich). 



Liver Pulse. The ventricular systole is propagated into the valveless inferior vena cava, and 

 causes the liver pulse. With each systole blood passes into the hepatic veins, so that the liver 

 undergoes a systolic swelling and injection. 



Fig. 117, 2-8, are curves of the pulse in the common jugular vein. Although at first sight 

 the curves appear to be very different, they all agree in this, that the various events occurring 

 in the heart during a cardiac revolution are indicated more or less completely. In all the 

 curves, a b = auricular contraction. The auricle, when it contracts, excites a positive wave in 

 the veins. The elevation, b c, is caused by the large blood-wave produced in the veins, owing 

 to the emptying of the ventricle. It is always greater, of course, in insufficiency of the tricuspid 

 valves than under normal circumstances (fig. 117, 9 and 10). In the latter case, the closure of the 

 tricuspid valve causes only a slight wave-motion in the auricle. The apex, c, of this wave ma}' 

 be higher or lower, according to the tension in the vein and the pressure exerted by the sphyg- 

 mograph. As a general rule, at least one notch (4, 5, 6, e) follows the apex, due to the 



Fig. 117. 

 Venous pulses (Friedreich). 1-8, from insufficiency of the tricuspid ; 9, 10, pulse of the jugular 

 vein of a healthy person. In all the curves, a b = contraction of the right auricle ; be, of 

 the right ventricle ; d, closure of the aortic valves ; e, closure of the pulmonary valves ; 

 6,/, diastole of the right ventricle. 



prompt closure of the valves of the pulmonary artery. The closure of the closely adjacent 

 aortic valves may cause a small secondary wave near to e (as in 1 and 2, d). The curve falls 

 towards/, corresponding to the diastole of the heart. 



A well-marked venous pulse occurs when .the right auricle is greatly congested, as in cases of 

 insufficiency of the mitral valve or stenosis of the same orifice. In rare cases, in addition to 

 the pulse in the common jugular vein, the external jugular, the facial, thyroid, external 

 thoracic veins, or even the veins of the upper and lower, extremities may pulsate. A similar 

 pulsation must occur in the pulmonary veins in mitral insufficiency, but of course the result is 

 not visible. 



On rare occasions, a pulse occurs in the veins on the back of the hand and foot owing to the 

 arterial pulse being propagated through the capillaries into the veins. This may occur under 

 normal circumstances, when the peripheral ends of the arteries become dilated and relaxed 

 (Quincke), or when the blood-pressure within these vessels rises rapidly and falls as suddenly, 

 as in insufficiency of the aortic valves. 



In progressive effusion into the pericardium, the carotid pulse at first becomes smaller and the 

 venous pulse larger ; beyond a certain stage of pressure the latter ceases (Riegel). 



