William Harvey was an English medical doctor, who has the esteemed acknowledgment of being the first doctor to properly describe, in exact detail, the human body’s systemic circulation and properties of blood being pumped around the body by the heart. This was discovered before Harvey’s era but had been lost over time with the exception of three copies of Michael Servetus. Therefore, the secrets of circulation were lost until Harvey rediscovered it approximately a century later.
William Harvey was born on April 1st, 1578 in Folkestone, Kent, England, to Thomas Harvey, an affluent yeoman, and his wife Joan Halke. He was educated at The King’s School, Canterbury, Gonville and Caius College, Cambridge and the University of Padua which was also attended by Copernicus and studied under Hieronymus Fabricius and Cesare Cremonini an Aristotelian philosopher from which William graduated in 1602. He also received a Bachelor of Arts in 1597 from the Gonville and Caius College.
After graduation Harvey returned to England where he married Elizabeth Browne who was the daughter of an important London physician, Lancelot Browne. They didn’t have any children. He then started his career as a doctor at St. Bartholomew’s Hospital in London and stayed there from 1609 to 1643. He also became a Fellow of the Royal college of Physicians. He returned to Oxford and became head warden at Merton College after his time was spent in the St. Bartholomew’s Hospital. In 1651 Harvey donated money to the college for building and furbishing the library that was dedicated in 1654. He gave a donation to hire a Liberian and to present a yearly lecture which goes on to this day in his honor. In William Harvey’s will, he left money for the founding of a boy’s school in his home town of Folkestone which opened in 1674 and the Harvey Grammar School has had a permanent history to the current day.
Harvey’s teacher at Padua, Hieronymus Fabricius, had already claimed discovery of valves in the veins but had not come close to discovering how they worked. The rationalization that was given by Hieronymus did not persuade the mind of William, so he took it upon himself to investigate and find out the truth about how these veins worked in the body. Eventually the research told him that there was a larger question to be answered to the explanation of the motion of blood.
It was 1616 when William Harvey announced his discovery of the circulatory system and by 1628 he published his work in a book of sorts which held the title of An Anatomical Exercise on the Motion of the Heart and Blood in Animals. This was based on scientific methodology. He argued the idea that blood was pumped around the body by the heart returning to the heart while being re-circulated by a closed system. This clashed with the conventional method at the time which stemmed from Galen who identified dark red blood and brighter blood and each had a different function. Galen thought that the dark red blood originated in the liver and arterial blood in the lung. It was the consensus that the blood flowed from these organs to all parts of the body where it was consumed after it was used. These were the very reasons that findings of Ibn-al-Nafis, another prominent physician, had been ignored in Europe.
When William Harvey did his research he made careful observations, by recording during his experiments with animals, during controlled experiments. He was the first person to do this in this manner. During his research he did experiments on how much blood would flow through the heart in a day. He estimated the hearts capacity, how much blood was expelled each time the heart pumped and the amount of times the heart beat in an hour. This was all recorded carefully and placed at amounts at the lower end of the scale so that people would understand just how much blood the liver would be required to produce.
His findings were estimated that the capacity of the heart was 1.5 ounces and every time the heart pumped one eight of the blood was expelled. This led him to the conclusion that one sixth of an ounce of the blood went through the heart every time it pumped which left him with a heart that beat 1000 times in an half an hour, which gave ten pounds, six ounces, of blood in an half an hour. He then multiplied by forty eight half hours in a day and proved that the liver would have to produce five hundred and forty pounds of blood in a day. The common theory was that the blood was recycled and not continuously produced.
William Harvey projected that blood flowed through the heart in two separate closed loops. One loop which he called the Pulmonary Circulation, which connected the circulate system to the lungs and the second loop the Systematic Circulation caused blood to flow to the vital organs of the body and tissues. He also discovered that while veins would let blood flow freely to the heart, the veins would not allow the blood to flow in the opposite direction.
He also used another technique to prove his point. He tied off a human arm and observed as the arm became red and swollen above where he had tied and pale and cool below the tie off. He released the pressure slowly which allowed the blood to flow freely again in the deep arteries. He watched as the arteries filled with blood. When this was done he could see the arteries but the opposite effect had taken place in the lower arm, warm and swollen.
The veins were now more visible as they were full of blood, at the same time he noticed bumps in the veins which he realized were the valves. He tried to push the blood back down the arm physically but couldn’t do it but when he pushed it up it ran easily. This same effect was noticed in other parts of the body, except the neck. He surmised at the time these were different veins than the rest not allowing the blood to flow up but only down.
Harvey came to the conclusion that veins permitted blood to flow to the heart and the valves maintained the one way flow. It was Harvey’s discovery that the heart pumped blood and forced it to move through the body instead of the theory of the day that blood flow was caused by a sucking motion of the heart and liver combined. These were two major contributions to the world of medicine in the understanding of the mechanisms of the circulation of the human body.
William Harvey also conducted experiments on embryology but this came later in his career. In 1651 he wrote On Generation of Animals. He supported Aristotelian’s theory of epigenesist which stated that embryos formed gradually and did not possess the characteristics of an adult in the early stages.
William Harvey’s ideas were not always accepted in the physician society at the time and there were times he had to defend his theories but did so successfully. During his life he was personal physician to James I but when James took with a fatal illness and succumbed to it Harvey took the blame for wanting James dead. He was saved from this by Charles I to which he became his personal physician.
William Harvey was Lumleian Lecturer to the Royal College of Physicians but his biggest contribution was the questions he raised while doing his experiments which led others to take up his ideas and continue looking for more information. Arthur Schlesinger Jr. who was a Pulitzer Prize winner included William Harvey in his Ten Most Influential People of the Second Millennium in the World Almanac & Book of Facts. William Harvey died at the age of 79 in 1657 from a stroke.
