William Harvey and the Mechanics of the Heart

This sturdy, hardcover book is 140 pages long, and generously illustrated with some 37 black and white pictures, quarter page, half page, and full page. This is not a kid's book. It is suitable for the older teenager and for adults. We learn about the social milieu existing at the time of William Harvey. We learn about Harvey's education, his teachers, the works of other physiologists, and we learn about his detractors. While the book does disclose elements of the physiology and anatomy of the circulatory system, if your goal is to learn these things, it is best to look elsewhere. I recommend the following: If you want to learn about the physiology of the heart, you should use the internet, and go to the National Heart, Lung, and Blood Institute (part of the National Institutes of Health (NIH)), and view their narrated motion pictures of the pulmonary circulation, and of the electrical impulses from the SA node and AV node. Once you have consulted this cartoon at the NIH web site, you should have an easier time with Jole Shackelford's book. Most interesting, is the book's disclosure of earlier (incorrect and largely speculative) thoughts about heart physiology, which were replaced by William Harvey's correct thoughts. Here are some examples: CIRCULATORY SYSTEM. Galen of Pergamon thought that venous blood and arterial blood were totally separate and never mixed. Harvey discovered that they were the same blood, and that there was only one circulatory system. Ancient Greeks thought that the heart provided heat to the blood. Ancient Greeks thought that the liver provided blood with nutrients, and the purpose of veins was to come out of the liver, and deliver nutrients throughout the body. They also thought that the purpose of the lungs was to cool down the blood, in case the heart made it too hot (p. 46). Harvey based his argument on the circulatory system on this type of calculation: The amount of blood coming out the heart in one hour is ten times the volume of the entire body (p. 62), and that no amount of metabolism could possibly be consuming this amount of blood. Therefore, there must be a means to re-circulate the blood. WHY DOES BLOOD FLOW TO THE HEART. Galen thought that blood was naturally attracted to the heart, just like objects naturally fall because of gravity. But Harvey showed that blood flowed to the heart, because the heart pumped it around in a circuit. THE HEART HEATS THE BLOOD. Descartes, a contemporary of Harvey, thought that the heart heated the blood to the point that it vaporized, and that in coming back to the heart through the veins, the blood condensed in the veins (p. 108). The book points out that Descartes' view was a hybrid of William Harvey's view and the view of the ancient Greeks. PULMONARY CIRCULATION. Michael Servetus discovered pulmonary circulation, but there were only 3 copies of his manuscript, and so William Harvey re-discovered the pulmonary circulation, and thus Harvey receiv