MOTION OF THE HEART AND BLOOD 



No one denies that all the ingested nourishment 

 may pass through the liver to the vena cava in man 

 and all large animals. If nutrition is to proceed, 

 nutriment must reach the veins, and there appears to 

 be no other way. Why not hold the same reasoning 

 for the passage of blood through the lungs of adults, 

 and believe it to be true, with Columbus, that great 

 anatomist, from the size and structure of the pul- 

 monary vessels, and because the pulmonary vein 

 and corresponding ventricle are always filled with 

 blood, which must come from the veins and by no 

 other route except through the lungs? He and I 

 consider it evident from dissections and other reasons 

 given previously. 



Those who will agree to nothing unless supported 

 by authority, may learn that this truth may be con- 

 firmed by the words of Galen himself, that not only 

 may blood be transmitted from the pulmonary artery 

 to the pulmonary vein, then into the left ventricle, 

 and from there to the arteries, but that this is ac- 

 complished by the continual beat of the heart and 

 the motion of the lungs in breathing. 



There are three sigmoid or semilunar valves at 

 the opening of the pulmonary artery, which prevent 

 blood forced into this pulmonary artery from flowing 

 back into the heart. Galen clearly explains the func- 

 tions of these valves in these words {De Usu Part,, 

 Lib. 6, cap. jo) : ''There is generally a mutual anastomo- 



Burton-Opitz' Physiology, Phila., 1920, p. 390-393. and W.H. Howell's 

 Physiology, Phila., 1927, 10th Ed., p. 670-673. 



I63I 



