Happy Valentine's Day - De Motu Cordis

Happy Valentine’s Day from the Poor Historians Podcast. Here’s a heart-related milestone in honor of the holiday.

De Motu Cordis

Thought to be one of the first scientists to sort out the correct pathways of human circulation, William Harvey (1578 – 1657) wrote on the subject in his text, De Motu Cordis (The Motion of the Heart).

There was much debate in the times of the ancient Greek physicians as to what the role of the heart was and how blood seemed to circulate about the body. Names such as Aristotle, Plato, Hippocrates and Galen all had interesting theories on the exact function of the circulatory system. One school of thought was that the heart not only circulated blood but created it in the first place. Noting that blood seemed to change from blue (oxygen poor) to bright red (oxygen rich), Galen, for instance, thought blood passed between the right ventricle to the left ventricle through small ‘pores’ between the two chambers.

Fast forward from the 2nd century CE to the year 1628 when the first edition of De Motu Cordis was published. In this work, Harvey applied empirical research and scientific methodology to describe how circulation occurred. Through experimentation Harvey was able to show that blood in the veins flowed towards the heart, not away from it. He described the ideas of systole (heart contraction) and diastole (heart relaxation) which work to create the flow of blood and indeed the pulse one can feel in an artery.

Not only did Harvey’s work modernize the understanding of the circulatory system, but it was also seen as a re-thinking of the principles of ancient Greek medicine. In other words, maybe the four humors approach was wrong after all.

Image from De Motu Cordis and information sourced from the Glasgow University Library Special Collections Department. Check it out: https://www.gla.ac.uk/myglasgow/library/files/special/exhibns/month/june2007.html

Max

[Doctor with a mustache]