In the Middle Ages, the theories of the ancient Greek physician Galen dominated anatomy and physiology. Through actual observation, Galen found that blood is also in arterial blood vessels, so he proposed that there are two different functions of blood in the human body. He believed that blood flowed from the right ventricle through the heart's middiaphragm into the left ventricle, but because the atrial valve was not perfect, a small portion of venous blood flowed backwards from the right ventricle into the vein, and a small portion of arterial blood returned from the artery to the left ventricle. After the mid-sixteenth century, the situation changed, and Savilius proved that Galen's statement that blood passes through the diaphragm was incorrect, because the diaphragm separating the left and right ventricles was a hard muscle that did not allow blood to pass through. However, he was also unable to explain how blood flows from the veins into the arteries, and was the first to propose another explanation by Miguel Servette of Spain, who believed that blood flows from the right ventricle to the left ventricle through the lungs, and that there is only one type of blood in the human body. Servette rejects Galen's theory and discovers the small circulation between the heart and lungs, but before he can further demonstrate the theory of blood circulation, he is burned alive by John Calvin as a heretic. A few decades later, Harvey's teacher, Fabricx, discovered that there were valves in the veins, which was undoubtedly an important discovery, but he did not understand the true meaning of valves, because he also agreed with Galen that blood could flow back and forth in the veins after leaving the heart, and that the role of valves was only to prevent blood from accumulating in the extremities of the body and reduce the flow of blood. The new discoveries of these scholars undoubtedly played a major role in Harvey's later discoveries. If venous blood and arterial blood are considered to be the same, it is found that the path of blood circulation is smooth.
Harvey first developed the concept of blood circulation through a simple mathematical operation. Harvey estimates that the heart makes about two ounces of blood per beat, and since the heart beats 72 times per minute, a simple multiplication can conclude that about 540 pounds of blood are drained from the heart into the aorta every hour. But 540 pounds is far more than a normal entire body weight, and even more so than the weight of the blood itself. As a result, Harvey seemed to clearly recognize that an equal amount of blood was passing through the heart without stopping. After proposing this hypothesis, he spent nine years experimenting and carefully observing, and mastered the details of blood circulation.
William Harvey was born on April 1, 1578, in the town of Folkestone, Kent, England. Harvey's contribution was epoch-making, as his work marked the beginning of a new life sciences and was an important part of the scientific revolution that began in the 16th century. He discovered the law of blood circulation and laid the foundation for the development of modern physiological science. Harvey's brilliant study of the heart and blood system (as well as his research on animal reproduction) made him a giant of the scientific revolution on a par with Copernicus, Galileo, Newton, and others. His book "Theory of the Movement of the Heart" has become an extremely important document in the period of the scientific revolution and in the entire history of science, like "Theory of the Movement of the Heavenly Bodies", "Dialogue on the Two Systems of Ptolemy and Copernicus", and "Mathematical Principles of Natural Philosophy".
Discoverer of blood circulation: William Harvey
William Harvey
The picture comes from the Internet
William Harvey entered the University of Cambridge at the age of 15 and studied a number of subjects related to medicine for two years. In 1602, he studied at the University of Padua in Italy, the most famous scientific institution in Europe at the time, under the tutelage of the famous anatomist Fabricx. During this study, Harvey not only studied hard and practiced actively, and was praised as a "little anatomist" by his classmates, but also became the teacher's right-hand man in Fablix's research on venous vascular anatomy and "venous valves". This period of study and practice laid a solid foundation for Harvey to later establish the theory of cardiovascular exercise. (It is worth mentioning that Galileo was a professor at the University of Pardua when Harvey was a student), and shortly thereafter he received his MD from the University of Cambridge in England at the age of 24.
From 1603 Harvey began practicing medicine in London, and soon he married the daughter of Ronslow Brown, Queen Elizabeth's royal physician. Harvey had no children and no daughters. The marriage was a great help to Harvey's career. In 1607 Harvey was accepted as a member of the Royal Academy of Medicine, and in 1609 on the recommendation of King James I and Dr. Henry Atkins, President of the Royal Academy of Medicine, Harvey was offered the post of Physician Alternate at St. Bartholomew's Hospital; That summer, Dr. Wilkinson died at the hospital, and Harvey filled the void he had left and began to practice on his own. Harvey sits at the desk at least one day a week to receive patients, cares about their suffering, personally visits patients with limited mobility, never pays for it, and often treats the poor free of charge. His motto was that doctors "should do good for the poor." Because of his conscientiousness and hard work, he soon became a famous doctor in London. He has successfully performed breast removal surgery, accumulated rich experience in obstetrics and gynecology, and cured tumors by ligating arteries and blood vessels and cutting off the source of nutrients for tumors. As a result, Harvey was not only a skilled doctor, but also a scientist with a humanitarian mind.
In 1615 he was appointed lecturer at the Lumren Lecture, and in August 1615 Harvey was chosen to be the keynote speaker of the Lemmre Lecture at the Royal Academy of Physicians. In mid-April 1616, Harvey gave a lecture in a school near St. Paul's Church on Knights Street, where he first developed his theory of blood circulation. The manuscript of the lecture was written in Latin and is still in the British Museum. In his lectures, Harvey uses a comparative approach to illustrate human anatomy by dissecting animals. He described the skin, fat, superficial muscles, and abdominal organs of the human body from the surface to the inside, and used vivid metaphors to deepen the impression of the audience. In describing the thoracic cavity and thoracic organs, Harvey devotes a great deal of space to the structure of the heart, the movement of the heart, and the function of valves in the heart and veins. He made it clear that the power of the continuous flow of blood comes from the systolic blood pressure of the heart muscle. In his discussion of the human head and brain, the structure of the nerves and their functions, Harvey made special reference to the writings of the ancients. He pointed out that Galen was not the first to recognize the transmission function of nerves to transmit instructions to the organs of the body, which had been known since Cicero's time. The richness of his lectures shows that the author is well acquainted not only with all contemporary anatomists since Vessarus, but also with the works of ancient Latin poets and essayists. He had read Augustine's writings, was well versed in the Bible, and had a special admiration for Aristotle. Although he did not know much about the works of Shakespeare, the great contemporary literary giant, he knew the pulse of contemporary medicine very well. In order to study the physiological functions of the human and animal bodies, he dissected more than 80 species of various animals. This shows that Harvey's achievements come from his summary of the experience of ancient and modern medical scientists, and also depend on his courageous exploration and active practice. He was a meticulous scientist and a tireless laborer.
Harvey's fame grew, and both Francis Bacon and the Count of Arondell came to see him. After 1618, Harvey was appointed as the royal physician to King James I (r. 1603-1625) and then Charles I (r. 1625-1649), but he continued to attend the Lemmre lectures every year. In 1630, Harvey was ordered by the King to accompany the Duke of Lennox on his visits to the European continent, including Paris, Blois, Somme, Bordeaux and Venice, as well as to Spain. In 1636, he accompanied Count Arondel on his second visit to the European continent on his mission to Germany. At that time, it was the time of the Thirty Years' War, the countryside was sparsely populated, thieves were infested, and birds and beasts were almost extinct. Harvey, however, was still eager to collect information on natural history, which caused the Count to be anxious about his safety. In a letter to a friend, he spoke of the Thirty Years' War, and he said that dogs, crows, kites, etc., were rarely seen, except for a few poor people. He complained that he couldn't find a creature to dissect and was obsessed with his research. During his stay in Germany, Harvey visited Hoffmann of Nuremberg, a famous physician and fierce opponent of the blood circulation theory at the time, several times to discuss problems with him, trying to persuade him, but without success.
After returning from his first trip to Europe at the end of 1636, Harvey accompanied King Charles I to Scotland in 1639. In the same year, he went to Bathrock (Bass Reef) in Edinburgh. The wide variety of seabirds here aroused Harvey's great interest. In his later article, Animal Reproduction, he described in detail the habits of seabirds and criticized the traditional belief that gannets live in trees.
In 1640, when the bourgeois revolution broke out in England, Harvey went into exile with the king because of his special status as royal physician. He fought in the Battle of Mount Edge and was tasked with caring for two princes, later Charles II and James II, in the fortifications. But after the battle began, he took a book out of his pocket and read it carefully. A cannonball exploded near him, and he shifted his position and continued studying.
Harvey spent three years in exile in Oxford with the royal family from 1642 to 1646. Here he was appointed director of Melton College (1645), but he devoted more of his time to the study of physiological anatomy. He often visited George Baselst, a theological scholar, and together they observed the reproduction of hens and the development of chicks, accumulating a large number of experimental notes and observational notes, which became the basis for his later essay "Animal Reproduction".
In 1646, Oxford was captured by the Revolutionary Army, and Harvey returned to London. He resigned from all his positions and went into seclusion with his younger brothers. In 1649, after the end of the English Civil War, Charles I was hanged, and Harvey was fined £200 and banned from the city of London for his loyalty to him. In 1650, Harvey's friend and student, Dr. Ent (1604-1689), met Harvey at the home of Harvey's younger brother Daniel. At the time, Harvey was 72 years old and still engaged in research with great interest. However, he also exudes a sense of unease about the turbulent times, and is even more difficult to conduct in-depth scientific research without conditions. During this meeting, Ente discovered Harvey's manuscript on the observation of animal reproduction, which he approved for publication in 1651.
Harvey may be retiring, but he is obsessed with the Royal College of Medicine, where he has been working in medicine and research for decades. In 1651, he secretly donated money to build a library for the medical school, but the secret soon became known. This magnificent Romanesque building, built in the name of Harvey, was completed and officially handed over in 1654. Downstairs from the library is the examination room, upstairs with a rich collection of books, and a museum with a variety of herbs and animal specimens, as well as a variety of surgical instruments. Because of Harvey's outstanding contributions, the Faculty of Medicine elected him as its Faculty Director in 1654. However, he declined the appointment on the grounds of old age and infirmity, and agreed only to serve as an adviser. Harvey's wife, who had died a few years earlier, had no biological children, and his brother was also wealthy, and in 1656 he decided to donate his hereditary estate in Kent to the Royal College of Physicians as a fund for the librarian's expenses and to encourage scientific research and the "discovery of nature's mysteries". In the same year, he finally resigned from his job at Lemmre Lectures.
Harvey often suffered from gout in his later years, and often soaked his feet in cool water to relieve the pain of the disease. He always maintained a vigorous mental activity. On June 3, 1657, Harvey suffered a sudden stroke, and although he lost the ability to speak, he was able to send his nephews and give them relics. That same evening, Harvey passed away. In Harvey's handwritten will, he donated all the books and documents accumulated over the decades to the medical school library. The entire crew took part in Harvey's funeral procession, taking Harvey's body to the cemetery of Harvey's family in Hampsted, Essex. This great man in the history of medicine lies peacefully in a coffin wrapped in lead. On St. Luke's Day (18 October), Sir Janill, President of the Royal Medical College, personally presided over Harvey's funeral. Medical school colleagues placed the lead coffin in a marble coffin, reburied Harvey's body, and placed it in the Harvey Memorial Hall at Hampsted Cathedral.
Sutton, the founder of the history of contemporary science, once described William Harvey as a "frank hero" and Leonardo da Vinci as a "foolish giant". In Sutton's view, da Vinci's "chains" are prejudices, while Harvey's "golden key" is theory, careful experimentation and careful reasoning. Harvey's brilliance lies in the fact that when he compared the walls of the arteriovenous tubes, he found the venous valves, and the existence of 3 sigmoid colon valves at the bifurcation of the great arteries, and investigated the function of these "organs", that is, to agree on the unidirectional nature of blood flow, to prevent reflux, if the valves are unidirectional, and they are all in the same direction, there can be no other explanation except blood circulation, his "how?" (functional questioning) vs. "Why?" (Purposive questioning) has laid a path and method for the study of modern physiology. Although the microscope had not yet become an observation tool in Harvey's time (Harvey had not been used until several years after his death), and the secrets of capillaries and microcirculation had not been revealed, it did not prevent Harvey from becoming the discoverer of blood circulation. In addition, the preparation and conduct of the anatomy lecture series was a strong impetus for Harvey's great discoveries.
To Sutton's greatest regret, even a man of great wisdom and creativity, Leonardo da Vinci, who had personally dissected many corpses and examined many hearts very closely, was still shackled by Galen's vague doctrine. Leonardo da Vinci's anatomical studies lacked a "classroom" effect, and most of the hundreds of anatomical drawings he drew casually or carefully were hidden in the studio, only to appear as works of art hundreds of years later. There is only one reason why da Vinci failed to discover and publish blood circulation, and that is the obscuration of "prejudice".
In Sutton, he famously wrote in an infinite poetic passage: Whenever I close my eyes and look back on the past, it is as if I see a great discovery locked in a black box, and intelligent observers such as Leonardo, Leonardo da Vinci, Vesari (who comprehensively challenged Galen's anatomical system, pointing out more than 200 errors in Galen's doctrine), Servetus (discoverer of the pulmonary circulation, persecuted by Calvinism in the Church and burned at the stake for pagan charges), Colombo (Harvey's anatomy teacher), If you make up your mind, you can definitely discover this secret. But unfortunately, they all stop at the first step of truth, because "prejudice" is sitting on the black box, and the truth is imprisoned in the black box.
