29 October 2019

Dr William Harvey, a brave scholar on blood circulation Guest blog

Galen, a skilled C2nd AD Greek physician and scholar, taught that there were three main inter-connected systems involved in blood flow: a] brain and nerves; b] heart and arteries; and c] liver and veins. Dark, ven­ous blood formed in the liver and then travelled through the veins through­out the body, to del­iv­er nour­ishment and build tissues. Some blood would come into contact with air in the lungs and go to the heart.

Sometimes the liver produced too much blood, and the body became imbalanced, leading to illness. Blood-letting, drawing off the excess fluid, restored balance.

Galen’s teachings dominated European medicine and schol­ar­ship for centuries, mistakes and all. But one of the main Chinese medicine manuals (Yellow Emperor’s Classic of Medicine c300 BC) stated that all blood in the body was pumped by the heart, completed a circle and kept moving! And in the C13th the Arab Dr Ibn an-Nafis suggested blood circulated only from the heart to the lungs and back, with­out spreading further. Even Italian anat­omist Realdo Colombo (1516-59), who exam­ined the beating hearts of animals during vivisect­ions, couldn’t interpret the heart’s function con­fid­ently.
 
Dr Harvey showing King Charles I his theory of blood circulation ,
painted by R Hanna, dated ?

So in early C17th Europe, most scientific concepts were still based on ancient philosophy & theology. Were contemporary an­at­omical studies limited by doc­t­rinal disapp­rov­al? Or from fear of heresy charges? The dog­matic College of Phys­icians still ch­amp­ioned Galen’s class­icism, even when experiment­at­ion became leg­itim­ate science. 

William Harvey (1578-1657) was born in Folkestone, Kent where his father had been a freeholder-farmer. From King's College in Cant­er­bury, the clever young man got a schol­ar­ship to Cam­bridge Univers­ity.

Then in 1600 he joined other clever C16th Eng­lish al­umni at Padua Univ­ersity, Europe’s best medical school. He did post-grad Medicine under surgeon Girolamo Fab­ric­ius, watching his mentor dissect dead criminals and living animals. Fabricius had discovered valves in the veins and concluded that animal blood moved around in a circle continuously, via the pumping heart!

Back home in 1602, Harvey established himself as a physician & married the daughter of Queen Eliz­abeth's royal physician. In 1607, he took the pos­ition of Surgery Lecturer at the Royal College of Physicians and became physic­ian to St Barth­ol­omew's Hos­pital. In 1618 he became royal physician to King James I (ruled 1603–25) and later Dr Harvey, already a committed royal­ist, served the next King, Charles I.

Harvey was developing a new theory to explain how blood flowed through the body, based on evidence from his dissections. In the hearts in living animals, Harvey could see that systole was the active phase of the heart's move­ment, pumping out the blood by its muscul­ar contraction. The action of the heart mov­ed blood out through the arteries to the body, and then back to the heart via veins, dispelling Galen's theories.

Harvey isolated parts of the heart; he ligated and divided arteries and exerted press­ure on veins on either side of the valves. He utilised cold-blooded animals because their heartbeats were slow, showing that the heart valves allowed blood to flow in only one direction. Harvey revealed his findings at the College of Physic­ians in 1616.

William Harvey published diagram, demonstrating existence of valves in veins. 
Published in De Motu Cordis, 1628

Was Dr Harvey Protestant, Catholic or rationalist?  It has been suggested he was Anglican because although his theories contrasted sharply with the accepted beliefs, Harvey was cautious in his crit­icisms of tradit­ional values. He was a thinking Renaissance man, not a man of the Science Revolution.

In 1628 Dr Harvey produced a shortish, cheap book in Latin called An Anatom­ical Study of the Motion of the Heart and of the Blood in Animals, pub­lished in Frankfurt. Yet it became one of the most influential books in west­ern science history. And since both Stuart kings had so warm­ly encouraged Harvey's research, the au­th­or was described on the title page as the royal phys­ician.

As with many new ideas, his revolutionary circul­ation theory was received with interest in Britain. Many prop­onents agreed with Harvey because of logical experimentation and quantitative methods. Or for religious and philosoph­ical reas­ons.  But there was also controversy among his British colleagues. Some opposed the circulation theory be­cause of their firm commitment to ancient doctrines, the uncertainty of experimentation or because of personal resentments.

In Europe Harvey’s findings were met with some scepticism; while Molière supported Harv­ey’s views, Descar­t­es and others rejected the idea that the heart pumped the blood. So pract­ising physic­ians in Europe continued to use trad­it­ional remed­ies bas­ed on Gal­en’s human physiology eg enemas, purg­atives, blood­letting.

In 1636 Dr Harvey was sent in a diplomatic mission to Holy Roman emperor, Ferdinand II - a year of travel around Europe, meeting famous professors of medicine, philosophy (eg Thom­as Hobbes), literature and art. His connections were impressive. But a great deal of his written work was lost when parliamentary troops ransacked his White­hall home in 1642.

He followed the king on the Scottish campaigns of 1639-41 and in 1642-6 during the English Civil Wars, in Oxford and Newcastle. Harvey returned to London in 1645 and largely retired from public life, becoming the quiet warden of Merton College, Oxford (1645-6) instead.

In 1649 Har­v­ey published Two Anat­omical Exer­cises on the Circul­at­ion of the Blood in response to critic­ism from French anatomists. On the Motion of the Heart and Blood in Animals came out in Eng­lish in 1653. He had calculated the total volume of blood that moved through the body in an hour and showed that it was too high for the body to replenish. The amount of blood in the human body HAD to be constant and in perpetual motion.

An Anatom­ical Study of the Motion of the Heart and of the Blood in Animals,
written by Dr W Harvey, 1628
pub­lished in Latin in Frankfurt.

The Great Fire of London in 1666 engulfed the library that Harvey helped establish at the Royal College of Physicians. His notes on patients, post mortem examinations and animal dissect­ions were lost.

Nonetheless his research continued. Human reprod­uction was poorly understood, so Harvey investigated the role of sperm and menstrual blood in the formation of the embryo. His observations were excellent, but such matters could not be resolved properly without the use of the microscope (which was invented soon after Harvey’s death).

Eventually the poor doctor suffered from kidney stones. He published his final work, Exercises on the Generation of Animals,  n 1651. Harvey attempted suicide but failed and died from stroke at 79 in 1657.

Thomas Wright, Circ­ul­ation: William Harvey's Revolut­ion­ary Idea 2013 was very helpful.

Thanks to the guest blogger, Dr Joe.





12 comments:

Student of History said...

I hope all first year Med students do medical history. History teaches us that we always continue to learn.

Anonymous said...

Quite fascinating. We very much take our blood circulation for granted because it just works so well.

Hels said...

Student,

*nod* every generation believes it is the cleverest generation in history and that so-called knowledge in the past was primitive. As Dr Harvey showed, medical hubris in particular slowed down new learning and sometimes made the lives of the great teachers a misery.

Hels said...

Andrew

that is so true... as long as body parts work properly, we never question our health. I mean who analyses the structure and function of their pancreas over breakfast? But when something goes badly, it is a very clever scientist who can examine, diagnose and resolve a problem that has not been understood before.

A clever scientist like Dr Harvey did not find progress from de novo. Hopefully he learned from previous research (eg the surgeon Girolamo Fab­ric­ius), adding and refining all the time. Goes to show... every single bit of progress had to be carefully published in a timely fashion.

Sue Bursztynski said...

Thanks for the fascinating post! I knew about William Harvey, of course, it’s one of those names you hear in primary school, but not the details of his life.

bazza said...

It seems that the knowledge and learning of classical antiquity had an enormous influence on Western thinking right up to The Enlightenment (at least!). Galen's thinking was not a million miles away from being correct but I have always thought of William Harvey as being such a modern thinker!
CLICK HERE for Bazza’s absentmindedly adroit Blog ‘To Discover Ice’

Hels said...

Sue

If only we did more history in primary school. All I remember is Captain Cook, and Burke and Wills.

Personally speaking, I didn't learn a passion for history until Forms 4,5 and 6, when students could select their own subjects.

Hels said...

bazza

agreed 100%. The Greeks and Romans were wonderful scholars, well supported by their peers and their students. And it didn't matter if they made mistakes.. learning was based on experimentation, mistakes and sharing knowledge. Ditto scholars in Muslim countries.

I felt sorry for European Christian scholars in the Early Modern Era eg "human beings, the object of all Creation, were composed of four humours: black and yellow bile, blood and phlegm". I suspect that at least until the Renaissance, most church teachers believed in occult forces and not in modern science.

Dr Harvey was 17th century.. yet I still think he and his colleagues had to be brave.

Emaraatpk said...

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Architecture in Islamabad

Hels said...

Emaraatpk

welcome aboard "Art and Architecture, mainly".

I love history, but I know very little about science and medicine. So I am delighted to accept guest bloggers, as above. If you have a topic you are passionate about, drop me a line:
helenw@bigpond.net.au

Parnassus said...

Hello Hels, It is kind of understandable why William Harvey had a tough job doing his experiments in a world that still burned witches and in which dark-ages strictures still controlled medical science. But even today, medicine and science, despite their incredible advances, are under attack by the same fundamental forces. In the U.S. stem-cell research for one example has been under assail, and now the president is moving heaven and earth to destroy or undermine the scientific government organizations responsible for ethical and responsible policies.

Still, I am constantly amazed at the geometrically-growing pace of medical and scientific advancement--fascinating discoveries in the fields of bio-medicine, physics, and cosmology especially seem to get into the news feeds.
--Jim

Hels said...

Parnassus

until I studied the Anti-Vaxxer movement by medical professionals, I would have had no idea what you meant by under attack by modern fundamental forces. It might have been centuries ago, but no wonder Tycho Brahe, Nicolas Copernicus and Galileo Galileo felt threatened.