AN ANATOMICAL STUDY ON THE 



the lungs and right cavity of the heart. Likewise it 

 sends spiritous blood into the aorta. From this it 

 separates waste-vapors which are released to the 

 lung by the pulmonary artery. From the lung 

 spirits are obtained for the aorta. How is this separa- 

 tion made? How do spirits and waste- vapors pass 

 here and there without mixture or confusion? If 

 the mitral valves* do not stop the passage of waste 

 vapor to the lungs, how do they stop the escape of 

 air? How do the semilunars prevent the return of 

 spirits from the aorta following cardiac diastole? 

 Above all, how can it be said that the pulmonary 

 vein distributes the spiritous blood from the left 

 ventricle to the lungs without hindrance from the 

 mitral valves, having asserted that air enters the 

 left ventricle from the lungs by this same vessel 

 and is prevented from going back to the lungs by 

 these same mitrals? Good God! How do the mitral 

 valves prevent escape of air and not of blood? 



* These are referred to as tricuspides mitrales, and later in this same 

 paragraph simply as tricuspides. The tricuspids and mitral valves are 

 described in Chapter XVII, but not specifically differentiated by name. 

 The specific terminology became established within the next century. 

 Thus William Cheselden (i 688-1 752), in his Anatomy of the Human 

 Body, lyjs, says, "Over the entrance of the auricles in each ventricle, 

 are placed valves to hinder a return of blood when the heart contracts. 

 Those in the right ventricle are named Tricuspides, those in the left 

 Mitrales." Harvey was not the first to use the term "mitral." Ve- 

 salius(i5i4-i564)was apparently the first to compare the left auriculo- 

 ventricular valves to an episcopal miter. The best publication on 

 the heart after Harvey's is Richard Lower's (1631-1690) Tractatus de 

 Corde (1669). In this he specifically and consistently refers to the 

 "mitral valves." 



[18] 



