Little Shop of Knowledge

On the Motion of the Heart and Blood in Animals by William Harvey

 

For its time, the book was an innovative and a precise approach to a truthful description of the heart and the circulatory system.

 

Harvey explains in the beginning of his work the processes of vivisections (opening live animals) he had to realize in order to uncover many misconceptions on the matter. At the time, there were still many descriptions that were somewhat mystic of the heart and the course of the blood. For example, believing that in the liver the blood got a special “spirit” before it ran through the body. No sir, Harvey wanted precision and he describes through his 17 chapters everything from the heart, arteries, veins, etc., to the motion of the blood through the entire body (he even devotes a section of his book to his motives for writing). In brief, Harvey explains that it is in the state of Systole (counter to Diastole) what truly initiates life and movement in the heart (and animal for that respect). Blood goes through the veins into the heart filling the auricles, making its way down to the ventricles and then being pumped back again to the lungs and the rest of the body through the arteries. The process, of course, is in much more detail and complexity but to express a brief idea of it I’ve written it down above. Something truly fascinating for me were the valves. They are these white membranes that are found in the borders of the arteries, as well as in the ventricles. To make it clear the ventricles are under the atriums, so these valves actually allow blood to pass into the ventricle but were there to be a problem and were blood to be pushed back into the ventricle these valves (due to their shape and texture) would expand with the blood’s pressure, thus blocking the return of blood to the auricles and forcing it to continue its path into the body.

 

I always get nervous when talking about blood. This wasn’t the exception but to realize how the heart works, how its just this moving membrane that allows us to live! Every day it is beating, every second it is something that we take for granted but with every pump there is life running within us. It’s just incomprehensible to me. To have this original work and not some McGraw Hill textbook that condensed the information was an honor. I believe we actually “re-created” moments of discovery regarding this investigation. The amount of detail Harvey provides gave me such a rich perspective on the book