ACTION OF THE VALVES OF THE MAMMALIAN HEART. 



191 



anatomique, physiologique et pathologique des mouvements du coeur de l'homme," pub- 

 lished in 1848, M. Parchappe, Professeur de Physiologie a l'ficole de Medecine et de 

 Pharmacie de Rouen, after describing most fully the structure of the various cavities and 

 valves of the heart, describes the auriculo-ventricular valves as closing the orifices by 

 being applied face to face. 



M. Berard, in his Cours de Physiologie, puts this theory of Parchappe's even 

 more clearly. 



Professor Ktiss of Strasbourg (Manual of Physiology, being a course of Lectures 

 delivered by Professor Kilss at the Medical School of the University of Strasbourg, edited 

 by M. Duval, and translated by Robert Amory, M.D., 1875, pp. 134, et seq.) elaborates 

 this theory at great length. 



He considers that the auriculo-ventricular valves, with the space between them, are 



" only movable continuations of the auricle acted on by certain muscular powers 



The first result of the contraction of the papillary muscles is the lengthening of the 

 auricular cone, the edges of which are afterwards brought near each other. While this 

 hollow cone descends into the ventricles, the sides of the latter contract, and approach 

 the cone in such a manner that the auriculo-ventricular apparatus acts as a sort of hollow 

 piston, which penetrates the ventricle and comes into close contact with its wall ; and 

 thus the ventricle empties itself completely, the 

 contact becoming perfect between its sides and the 

 auricular prolongation." 



As already mentioned, he distinctly states that 

 by the finger inserted into the auriculo-ventricular 

 opening, we can detect that the space is not oc- 

 cluded as described by Chaxjveau and Faivre. 



To a certain extent he is right ; but it is impos- 

 sible that the small auricular pressure could main- 

 tain the valves in the condition shown in his figure, 



convex towards the ventricular cavity, against the enormously greater ventricular 

 pressure. What really occurs is, that the valves are pressed face to face throughout 

 the greater part of their extent ; and that only between their upper parts is auricular 

 blood to be found — the space for it being maintained by the tension of the valves. In 

 the mitral valve, when the large anterior cusp forms what Onimus described as the 

 central septum of the ventricular cavity, this space is specially well marked. 



In a long and exhaustive paper (Archives de Physiologie, 2nd series, t. i., 1874, pp. 

 552 and 848), M. Marc See, after giving a very full historical account of the work already 

 accomplished on the subject, from a careful consideration of this work and of the anato- 

 matical relationship of the valves, comes to the following conclusions in regard to their 

 mode of action : — 



"3°. Les muscles papillaires des valvules se contractent en meme temps que l'ensemble 

 des parois ventriculaires. 



Fi«. 38.— Showing the 

 auriculo - ventricular 

 system during the re- 

 pose of the ventricle. 



Fig. 39.— Showing the auri- 

 culo-ventricular apparatus 

 during the contraction of 

 the ventricle. 



