PULSE 



53 



Pulse. If a finger be placed on any artery in the body 

 there will be transmitted to it a perceptible impulse. This 

 impulse is what is called the pulse. It is caused by the force 

 of the heart's action against the elastic arterial wall, 'and the 



FIG. 28. Interior of right auricle and ventricle exposed by the 

 removal of a part of their walls. (From Yeo after Allen- 

 Thompson.} 



i, superior vena cava; 2, inferior vena cava; 2', hepatic veins; 3, 3', 3", inner 

 wall of right auricle; 4, 4, cavity of right ventricle; 4', papillary muscle; 5, 

 5', 5", flaps of tricuspid valve; 6, pulmonary artery in the wall of which_ a 

 window has been cut; 7, on aorta near the ductu's arteriosus; 8, 9, aorta and its 

 branches; 10, u, left auricle and ventricle. 



subsequent contraction of this wall against the current it 

 contains. 



