William Harvey and the Revolution of Blood Circulation

William Harvey, a pioneering figure in the history of medicine, was born on April 1, 1578, in Folkestone, Kent, to a family of merchants. Educated initially at King's College, Canterbury, he later pursued his studies at Cambridge University before embarking on a transformative journey to the University of Padua to delve deeper into the field of medicine.

Upon his return to England in 1602, Harvey commenced his career as a physician, leveraging his acquired knowledge and skills. His marriage to Elizabeth Browne, daughter of Queen Elizabeth I's physician, in 1604 not only strengthened his personal ties but also facilitated his professional advancement.

In 1607, Harvey was elected as a fellow of the Royal College of Physicians, marking the beginning of a distinguished trajectory in the medical realm. Subsequently, in 1609, he assumed the position of physician at St Bartholomew's Hospital, a role that provided him with ample opportunities for clinical practice and research.

His pivotal role in the medical community was solidified when he became the personal physician to James I in 1618, later extending his services to James' successor, King Charles I. Both monarchs took a keen interest in Harvey's inquiries and provided unwavering support, enabling him to pursue his groundbreaking research endeavors.

Harvey's relentless pursuit of knowledge led him to challenge established theories, particularly those concerning the circulation of blood in the human body. While prevailing wisdom attributed blood movement to the lungs, Harvey embarked on a scientific investigation to unravel the mysteries of circulation.

Through meticulous dissections and physiological experiments on animals, Harvey made groundbreaking discoveries. His observations of the heart's structure revealed the presence of valves, elucidating their role in facilitating unidirectional blood flow. Contrary to Galenic teachings, Harvey demonstrated through live animal experiments that blood was not transferred between ventricles but circulated in a continuous loop.

Furthermore, his meticulous dissections unveiled the absence of perforations in the heart's septum, dispelling misconceptions regarding blood passage. By ingeniously removing a beating heart from a living animal and observing its continued pulsations, Harvey conclusively proved the heart's function as a pump, not a suction mechanism.

In 1616, Harvey presented his revolutionary findings at the College of Physicians, laying the groundwork for his seminal work. Published in 1628 as 'Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus' ('An Anatomical Study of the Motion of the Heart and of the Blood in Animals'), his treatise expounded on the circulatory system's mechanism, detailing how the heart propels blood in a circular course throughout the body.

While met with skepticism on the Continent, Harvey's theories garnered widespread acclaim in England, heralding a paradigm shift in the understanding of human physiology. Moreover, his groundbreaking insights extended beyond circulation, as he was the first to propose the concept of mammalian reproduction through the fertilization of eggs by sperm, a theory ahead of its time.

William Harvey's contributions transcended the boundaries of his era, revolutionizing the field of medicine and laying the foundation for modern cardiovascular science. His relentless pursuit of truth and unwavering commitment to scientific inquiry continue to inspire generations of medical practitioners and researchers, cementing his legacy as a visionary pioneer in the annals of medical history.
William Harvey and the Revolution of Blood Circulation

Biography of William Harvey (1578-1657)

William Harvey was an English doctor who closely observed the bodies of his patients and of animals. He realized that blood flowed round the body. He saw in the action of the heart in small animals and fish what was going on in people.

William Harvey was born in Folkestone, a small fishing village on the English Channel not far from Dover on the first day of April in 1578.

He was a student of medicine in 1600 and mastered the traditional theory of human physiology as well as all the scientific theory and medical practice that depended on it and supported it.

Harvey’s admission to the fellowship of the Royal College of Physician (1607), his appointment as Physician to St Bartholomew’s Hospital (1609), as Lumleian Lecturer in Anatomy (1615) and as Physician Extraordinary to the King are the great landmarks of the Jacobean period in Harvey’s life.

In 1628, Harvey published his revolutionary ‘circulation’ theory of the movement of the blood. He was the first doctor to actually describe the circulation in the body accurately.

Harvey’s discovery, which controverted the ancient theory of Galen, is one of the vital, incontestable breakthroughs in the history of science and medicine.
William Harvey (1578-1657)

Ancient history of blood circulation and blood pressure

The theories regarding blood circulation and blood pressure go far back into historical times. Since the time of the Greeks, blood was known to be the substance that sustained life.

Ancient civilizations also recognized the heart as the mechanics by which the blood was delivered to the tissues of the body.

The meaning of the Greek word arteria was ‘windpipe’. This is because in Greek physiology, the heart was the focus of respiration, as well as the center of the vascular system.

Way back in ancient Greece, Hippocrates and later Galen knew about arteries and veins. 

Aristotle (384-322 BC) a biologist as well as a philosopher considered the heart as the center of system of blood vessels, but he made no distinction between arteries and veins, and showed no sign of any knowledge of the cardiac valves.

Galen was convinced veins and arteries were not connected and blood flowed both backward and forward form the heart. Galen believed that the liver made blood from food. The newly formed blood then proceed through vein to organs.

Galen’s characterization of the blood system carried authority for fifteen hundred years.

At the beginning of the third century BC Praxagoras insisted that the arteries contain no blood but only air.
Ancient history of blood circulation and blood pressure

Circulation Of Blood by William Harvey

Circulation Of Blood by William Harvey
William Harvey (1578-1657), and English physician is credited with discovering the mechanism by which blood circulates in mammals, including human race.

He published his discovery in Anatomical exercise concerning the motion of the Heart and of the Blood in Animals, in 1628.

In that work he did not explicitly compare the heart to a pump, although he did so in his lecture and in one small publication.

Harvey’s method by contrasts to some prior work on related questions, were based on direct observation and on dissection of both human and animal cadavers.

His views overthrew those of Galen, the ancient Greek whose views on the question had become accepted dogma. Galen believed that the liver changed food into blood and that blood flowed through the veins to the body, which consumed it.

Harvey showed that the heart operated as a pump , forcing blood through the arteries to the body and that it returned through the veins to the heart in a closed circulation system.

He also demonstrated the cause of the pulse in the expansion of the arteries following contraction of the heart muscles.

He demonstrated that the pumping chamber or right ventricle of the heart sends blood to the lungs, while the left ventricle supplies blood to the rest of the body through the arteries.

Among his other findings was a measurement of the quantity of blood in the body at a particular moment and studies of the part played by the egg in mammalian reproduction.

He also criticized the concept that illness derived from general changes in humors and instead believed in a more modern notion that it resulted from changes in local tissue.

Harvey’s experiments, while contradicting the assumptions of Galen, confirmed the views of several earlier physicians, including the 13th century Arab Ibn-an-Nafis and the Spaniard Miguel Serveto (Michael Servetus) and the Italian Realdo Colombo and Andrea Cesalpino in the mid 16th century.

Each of these doctors had suspected that blood from the veins passed through the heart and thence to the arteries. None, however had explained the whole system as one of circulation, nor had they traced all the components of the system as clearly as did Harvey.

Harvey at first developed a hypothesis of circulation, which he then later confirmed through experimentation, determining the direction of blood flow. Rather than relying on a nebulous force that moved the blood through the body, Harvey showed that motion as resulting from a specific mechanical action.

Like many other discoveries of the Scientific Revolution, those of Harvey derived from careful and structured observation of facts and restating them with clarity.
Circulation Of Blood by William Harvey