226 



HUMAN PHYSIOLOGY 



rise in the intra-auricular pressure. When the auricular 

 systole stops, the pressure falls rapidly, reaching its lowest 



A S. V. S. 



AS. 



PRESSUHE IN 



Artery. 



t 



Auricle. 

 Great Veins 

 Ventricle. * 



FLOW of BLOOD 

 from 



1. Great Veins to Auricles. 



2. Auricles to Ventricles- 



S. Ventricles to Arteries. 



CLOSURE o^ 



1. Aunculo-Ventricular Valve. 



2. Semilunar Valves. 

 SOUNDS of HEART. 



CARDIAC IMPULSE. 



FIG. 114. Diagram to show the relationship of the events in the Cardiac Cycle to 

 one another. A.S., Auricular Systole ; V.S., Ventricular Systole ; P., Pause. 



level when the ventricles are throwing their blood into the 

 arteries. Sometimes there is an interruption to this descent, 



