186 CIRCULATION. 



closure of the tricuspid and mitral valves. This act accom- 

 plished, the heart has a period of repose, the blood flowing 

 into the auricles, and from them into the ventricles, until the 

 auricles are filled, and another contraction takes place. 



Locomotion of the Heart. The position of the heart after 

 death, or during the repose of the organ, is with its base di- 

 rected slightly to the right, and its apex to the left side of 

 the body ; but with each ventricular systole, it raises itself 

 up, the apex is sent forward, and moved a little from left to 

 right. The movement from left to right is a necessary con- 

 sequence of the course of the superficial fibres. The fibres 

 on the anterior surface of the organ are longer than those on 

 the posterior surface, and pass from the base, which is com- 

 paratively fixed, to the apex, which is movable. From this 

 anatomical arrangement the heart is moved upwards and 

 forwards. Their course, from the base to the apex, is from 

 right to left ; and as they shorten, the apex is of necessity 

 slightly moved from left to right. 



The locomotion of the entire heart forwards was observed 

 by Harvey in the case of the son of the Yiscount Montgom- 

 ery. The young man, aged about nineteen years, suffered a 

 severe injury to the chest, resulting in an abscess, which on 

 cicatrization left an opening into which Harvey could intro- 

 duce three fingers and the thumb. This opening was directly 

 over the apex of the heart. The action of the portion of the 

 heart thus exposed is described by Harvey in the following 

 words : 



"We also particularly observed the movements of the 

 heart, viz. : that in the diastole it was retracted and with- 

 drawn; whilst in the systole it emerged and protruded; 

 and the systole of the heart took place at the moment the 

 diastole or pulse in the wrist was perceived. To conclude, the 

 heart struck the walls of the chest, and became prominent at 

 the time it bounded upward and underwent contraction on 

 itself." 1 



1 HARVEY, op. cit., p. 384. 



