564 HANDBOOK OF PHYSIOLOGY -^ CIRCULATION I 



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ao 



FIG. 9. Analysis of the relation between systolic ejection and the arterial pressure pulse. The 

 uptake of successive parts of the arterial tree, as the pulse wave of distention passes down, is sum- 

 mated to produce the arterial uptake curve, U. To this is added the arteriolar outflow resulting 

 from systolic increase in pressure D. iV + D gives the toted ejection, E. Diagram .-1 is derived from 

 a pulse in the presence of high resistance, B from one with intermediate resistance, and C from one 

 with low resistance. [From Remington & Hamilton (ill).] 



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FIG. 10. Ballistocardiographic forces calculated from the 

 forces needed to accelerate the blood that is ejected into the 

 aorta and the pulmonary artery. A: solid line, forces attendant 

 upon ejection of blood from the left ventricle; broken line, 

 forces attendant upon movement of blood in the ascending 

 aorta; dotted line, forces involved in moving blood down the 

 descending aorta. B: solid line, summation of forces in the 

 left diagram with, in addition, the forces attendant in moving 

 blood from the right ventricle and through the pulmonary 

 artery; broken line, the ballistocardiogram given by a high 

 frequency ballistocardiograph, and dotted line by a low 

 frequency ballistocardiograph. [From Hamilton et at. (59).] 



transient pressure changes it seems more reasonable 

 to accept a figure between 1.75 and 7.5 ml and closer 

 to the smaller figure. This is acceptable on other 

 grounds. Systolic air movements are barely percepti- 



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FIG. 1 1 . Cardiopneumogram with simultaneous recording 

 of brachial pulse, a) period of isometric contraction; h) end of 

 systole; c) beginning of active systole; d) beginning of rapid 

 venous return to atria. [From Hamilton (56).] 



ble sensorially. As indicated by movements of a film 

 of saliva covering the open lips or by movements of 

 tobacco smoke through the open lips when the in- 

 ternal nares are closed, the glottis open, and the 

 respiration at rest, the air movement is very small. 



The fact that the intrathoracic pressure indicates 

 that there is small net change in intrathoracic blood 

 volume has relevance to ballistocardiography in 

 that it implies that the stream back to the heart 

 through the great veins pulsates as does the stream 

 out from the heart through the arteries. Forces s;en- 



