How significant were the contributions of William Harvey to the study of anatomy and physiology?Going Further – Alia Abd RahimThe Scientific Revolution was one of the greatest turning points for humanity because of the advancement that developed the profundity of understanding the world around us. William Harvey wrote in one of his most successful researches, “All we know is still infinitely less than all that remains unknown” to encourage surrounding researchers (O’Malley 1961). However, little did he know, his discoveries were driven by that same thinking, and it constantly fuelled his motivation to find out about the truth.
His thinking led him to discover the mysteries of the human body because he wanted to learn more and more to the best of his ability. Essentially, Harvey’s contribution were no less than significant compared to any other scientists of the Scientific Revolution. He spent most of his life trying to understand the blood flow and its circulation, and his contributions to the Scientific Revolution was remarkable. William Harvey’s contributions to the ?areas of embryology and hematology? ?were necessary for the progression of contemporary scientists.William Harvey was born on the 1st of April, 1578 during the end of the Renaissance and was the eldest son of Thomas Harvey, a merchant that became the Mayor of Folkestone (Schlager and Lauer 2001). Harvey grew up in Folkestone where he learned Latin and attended the King’s School in Canterbury at the age of 10 (Gribbins 2007, 90). William Harvey was en route to becoming a medical student when he enrolled himself in the University of Cambridge at the age of 15 (Grendler and Sons 2000).
He managed to obtain a scholarship to finance his living expenses for the next 6 years of his life (Stewart 2015). By the age of 21, he attended the University of Padua that is located in Italy in the year 1599; there, he met one of his biggest mentors, Hieronymus Fabricius (Grendler 2000). Eventually, he became a fellow at the Royal College of Physicians in 1607 but was appointed as a Lumleian lecturer in 1615 (Gregory 2009). Around 20 years before his death, he published one of his greatest masterpieces, De Motu Cordis – The Motion of the Heart (Stewart 2015). He accurately explained the functions of the heart as well as the circulation of blood throughout the body.
William Harvey died at the age of 73, but he left a storm before departing (Schlager and Lauer 2001).Both Galen and Harvey were physicians who spoke about their ideas regarding the way the blood flowed around the body. Although Galen is known as the “Father of Medicine,” it was William Harvey who properly explained the circulation of the blood (Trueman 2013). Galen thought that “…blood is formed in the liver and is then carried by the veins to all parts of the body… ” because he believed that the liver was the fundamental organ for the creation of blood (Encyclopedia Britannica 2017). His ideas are flawed because he hypothesized that the liver created blood, but had no physical evidence. Galen introduced an idea that brought an answer to a question that longed for an answer, but unfortunately, he was incorrect.
Primarily because as we know today, the liver “…functions as a filter for the blood from the digestive tract, before passing it to the rest of the body…” (Hoffman). Galen was known to be the starting point of the discovery of the circulation of blood, and he influenced contemporary scientists of the same area, which included William Harvey (BBC 2014). Another physician was Andrea Cesalpino. Although he was mostly known as a botanist, “…his work on the anatomy and physiology of the cardiovascular system anticipated the work of William Harvey…” (Encyclopedia Britannica 2007). His ideas about the circulation system were new, but unfortunately, Harvey had no memory of Cesalpino’s ideas.
Of course, Cesalpino’s ideas were important, but his ideas were never proven until Harvey brought it to life.The many contributions by William Harvey would not have happened without the influence of Hieronymus Fabricius, one of Harvey’s greatest mentors. Fabricius is known as the “Father of Embryology,” and discovered that the valves existed in the veins (Ribatti 2009). As stated above, Harvey first encountered Fabricius in the University of Padua and was able to study on anatomy and medicine and further his knowledge. Since Harvey was living during the Enlightenment era, the discoveries of the valves could have sparked new ideas. For example, he might have wondered ‘what the valves were doing there, and why?’ However, eventually, Fabricius had figured out that the valves were there so it would stop the backflow of the blood (Grendler and Sons 2000).
Fabricius is one of his mentors because this finding helped solidify Harvey’s knowledge on the circulation of the blood. Since Harvey knew that the valves were there to prevent backflow, he explained that the movement of blood is a continuous cycle and that it flows in one direction. But, “it was not until 1628 that their function was fully understood, with the discovery of the blood circulation by William Harvey” (Schultetus 2001). Unlike what Fabricius believed, Harvey came to the realization that venous blood was directed toward the heart and not away from it as Fabricius had assumed (Grendler and Sons 2000). Since Harvey was one of Fabricius’ students, he was richly exposed to Fabricius’ ideas and findings.
By knowing the basis of the function of the valve, Harvey was able to use his knowledge to reinforce his statements about his knowledge of the circulation of the heart. Fabricius ideas were one of the biggest influence that affected Harvey’s train of thought. Harvey’s contributions addressed multiple concerns to the subject of embryology and initiated the starting point of modern embryology. William Harvey had published multiple books within his time, and Exercitationes de Generatione Animalium was published in 1651(Ribatti 2009). Through this book, he was able to create the starting point for modern embryology. He “addresses many embryological issues including conception, embryogenesis, and spontaneous generation” (Lopez 2010).
His studies of embryology are currently used in hospitals to this day and have helped us understand the basics of the reproductive system. Furthermore, it helps with the knowledge to understand the overall organization of the human body. Embryology is evidence for the understanding of the growth or development of a species. Because of this, we know that they are similar species, like humans and apes. Furthermore, “eventually a theory of epigenesis modified from that of Harvey was adopted and is currently accepted” (Neil Schlager and Josh Lauer). Epigenesis is a theory “that an individual animal or plant develops by the gradual differentiation and elaboration of a fertilized egg cell” (Collins Dictionary). Epigenesis leads to the study of epigenetics, which are the study of the changes in the genetic mutations (Collin Dictionary).
Epigenetics is very important because it leads to understanding the genetic mutations that could be passed along the generations further down. Because of Harvey’s findings, the hospitals around us are able to identify the normal factors of our bodily functions and help the doctors distinguish the abnormalities that could be harmful to the human bodies. Thus, Harvey’s contribution to embryology helped the scientific world understand the growth of a species.William Harvey’s most known book was Motion of the Heart because it contained information about how the heart moved the blood in one direction throughout the body. In one of his excerpts, he wrote, “I began to think whether there might not be A MOTION, AS IT WERE, IN A CIRCLE” (Halsall 1998).
The circulation system is one of the most important bodily functions in the body. It brings oxygen to the other parts of the body, most importantly, the brain. The nutritional supply it carries to the rest of the body makes our body function, without the circulatory system working the way it does, life is not conceivable. Thus, William Harvey made an important statement when he said it moved in a circular motion.
It describes how the blood moves around our body to transport nutrients to the organs in order for it to function. Moreover, “afterward both Harvey and his contemporaries continued to regard his views on the motion of the heart and arteries as quite significant in themselves” (Sons 2008). Arteries and veins are different because they have different functions. Arteries are important to the blood system because they bring the blood away from the heart in order to transfer the nutrients around the body, unlike the veins, that bring oxygen-less blood cells towards the heart. Harvey was able to identify that the arteries and the heart are in relation to one another because he was able to link the pulse in the arteries from the contraction of the left ventricles (BBC 2014). He was able to identify organs that helped with the circulation of the blood and link them to one another.
By learning and explaining the nature of blood in the human body, William Harvey was able to emphasize and strengthen his thinking and ideas of his researches. Harvey observed heartbeats of living animals, both cold-blooded and warm-blooded alike. Harvey would closely observe the heartbeats by counting the number of beats at a constant rate.
Because of this, he “…
established the existence of the pulmonary circulation…” to further emphasize that blood flows in one direction only (Medical Discoveries, 2006). When he discovered that the heartbeat pumped in order to circulate the blood and move it around the body, he must have realized that there was a constant flow of blood through the heart. Thus, he focused on the heart for a period of time, especially the amount of blood flowing in and out of the heart at a constant rate. In his experiments, Harvey’s results “.
.. indicated the heart pumped 0.
5 – 1 liter of blood per minute” revealed that he put a lot of time aside to figure out a specific range with a tenacious attitude of observation (Gregory 2017). By connecting the dots with the valves from Fabricius’ findings, he figured out that blood wasn’t produced as rapidly as those results. The answer only strengthened his idea of the circulation of blood because blood was not consumed by the body, but it was circulated around the body. Unfortunately, modern science learned that instead of the amount Harvey suggested, the true amount of blood circulating through the heart is “..
. 4 liter per minute at rest and 25 liters per minute during exercise” which is much more than what Harvey implied (Gregory 2017). Harvey’s observations helped the advancement of the knowledge of the human body with his discoveries. Just like any other scientist, William Harvey conducted experiments to prove his theories to his colleagues. One of his most recognized experiments was for his On the Circulation of the Blood. In figure 1, Harvey replicated what Fabricius had done and tied the ligature around the upper part of a man’s arm. He noticed that the blood flowed into the bottom part of the arm that was cut off, but when it loosened, it was hard for the blood to travel back up the upper part of the arm. The veins become more noticeable as they are engorged with blood, and the more closely he looked, the could see the valves that Fabricius has discovered, however, it took a slight push of a finger to let the blood flow (Indiana University 2009).
The experiments Harvey conducted helped him understand that if it took a finger to push away the blood, it must have meant that the blood does not flow that way. The experiment bolstered his theory about the blood flowing in one direction. Though this experiment was used similarly when Fabricius discovered the valves, it was this experiment that helped Harvey to understand that blood only moves in one direction.
Other experiments that Harvey conducted was to back his theory of the relation between the heart and the arteries. In chapter 13 of his book, he wrote, “… it must, therefore, be concluded that the blood in the animal body moves around in a circle continuously and that the action or function of the heart is to accomplish this by pumping” (Ribatto 2009). Harvey summarized that the heart was a pump and it worked by muscular force. Harvey was able to identify the importance of that arteries and the heart are in relation to one another because he connected the pulse in the arteries from the contraction of the left ventricles (BBC 2014). Harvey kept observing and writing about his experiments when he observed something strange, from this, he was able to understand that it wasn’t only the heart that made the blood flow, but the force from the contraction of the heart and the force produced.Rene Descartes was one of the contemporary scientists around William Harvey who was deeply influenced affected by the ideas that Harvey introduced.
Rene Descartes had an early response to William Harvey’s theory of the circulation of the blood, but he dismissed Harvey’s notion that the heart pumps the blood to the rest of the body because did not want to believe that involuntary muscular actions could occur within the human body (Bruce 2003). Unlike Harvey, Descartes embraced physics, mathematics, and psychology into what he was trying to understand (Bruce 2003). Thus, Descartes had a harder time to understand why involuntary muscular actions happened in the human body because he believed everything had a reason. To him, an involuntary action that happened in the body defies his logic when he implements physics and psychology into his thinking. Although Descartes was in constant disagreement with Harvey’s ideas, he was highly affected by what Harvey brought up. On the other hand, Descartes and Harvey had a difference in their opinions, they both rejected Galen’s idea. However, like Harvey, he wanted to know and understand more about the human body.
Harvey created a train of thought for Descartes. Another contemporary scientist around William Harvey was Marcello Malpighi. “Malpighi solidified Harvey’s concepts and was the first man ever to describe the pulmonary capillaries and alveoli,” since Harvey only had a theory with no physical evidence (Ribatti 2009). Although Harvey contributed significantly to the scientific knowledge, he did not discover the capillaries and alveoli before his death. On the other hand, Malpighi took what Harvey brought to the table and started to prove it with what Harvey provided as a foundation for his theory. William Harvey became an influence, not only to these two scientists but also to the other scientists in the next centuries.
William Harvey became one of the most important physicians in the scientific revolution because of his ideas and influences to later physicians. His ideas about the circulation of the blood, embryology and his methods to prove ideas were important, not only to the contemporary scientist but to the world now. It was obvious that Harvey was motivated by his curiosity of the human anatomy, but he didn’t falter after he faced multiple walls during his researches. It’s impossible to measure the amount of research Harvey has contributed because of the foundation of information he has laid out for us. Our knowledge in science has advanced by tenfold since the scientific revolution.