APPLICATIONS TO PHYSIOLOGY 



283 



Fig. 198. 



On observing the series from above 

 downwards, the following phenomena 

 are observed : — 



1. The ventricle, v, has completed 

 its systole, and has diminished in 

 volume. The auricle, a, is full, en- 

 larged, and shiny. 



2. The auricle has commenced to 

 empty itself and change its form ; 

 its external surface is flattened, and 

 exhibits two irregular borders and a 

 roundedextremity,givingit a tongue- 

 like appearance. The ventricle is 

 beginning to enlarge. 



3. The auricle has diminished in 

 size, and the extremity is approach- 

 ing the ventricle; the latter is be- 

 coming still larger. 



4. The auricle is still contracting, 

 and the ventricle is approaching its 

 maximum of repletion. 



5. The auricle has completely 

 emptied itself, and the ventricle is 

 diminished in volume ; its systole 

 is commencing (at this moment the 

 blood is being poured into the re- 

 servoir). 



6. The ventricular systole con- 

 tinues, and the relaxed auricle com- 

 mences to fill. 



7. The ventricular systole is com- 

 pleted, the auricle is distended and 

 shiny, and the phase represented in 

 the first of the series is repeated. 



ft 



