Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus, (An Anatomical Exercise on the Motion of the Heart and Blood in Living Beings) is the best-known work of the physician William Harvey

William Harvey

William Harvey was an English physician who was the first person to describe completely and in detail the systemic circulation and properties of blood being pumped to the body by the heart...

. The book was first published in 1628 and established the circulation of the blood. It is a landmark in the history of physiology

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

. Just as important as its substance was its method. Harvey combined observations, experiments, measurements and hypotheses in extraordinary fashion to arrive at his doctrine. His work is a model of its kind. It had an immediate and far-reaching influence on Harvey's contemporaries; Thomas Hobbes

Thomas Hobbes

Thomas Hobbes of Malmesbury , in some older texts Thomas Hobbs of Malmsbury, was an English philosopher, best known today for his work on political philosophy...

 said that Harvey was the only modern author whose doctrines were taught in his lifetime.

In the De motu cordis, Harvey investigated the effect of ligatures

Ligature (medicine)

In surgery or medical procedure, a ligature consists of a piece of thread tied around an anatomical structure, usually a blood vessel or another hollow structure to shut it off. With a blood vessel the surgeon will clamp the vessel perpendicular to the axis of the artery or vein with a hemostat,...

 on blood flow. The book also argued that blood was pumped around the body in a "double circulation", where after being returned to the heart, it is recirculated in a closed system to the lungs and back to the heart, where it is returned to the main circulation.

Synopsis

This work is one of the greatest and most famous contributions to physiology, for it introduces into biology the doctrine of the complete circulation of the blood. Partial anticipations of Harvey's great discovery go back to the thirteenth century, when the pulmonary or lesser circulation was proposed by Al-Nafis

Al-Nafis

Ala-al-din abu Al-Hassan Ali ibn Abi-Hazm al-Qarshi al-Dimashqi , known as Ibn al-Nafis , was an Arab physician who is mostly famous for being the first to describe the pulmonary circulation of the blood.He was born in 1213 in Damascus...

. In 1553, Michael Servetus

Michael Servetus

Michael Servetus was a Spanish theologian, physician, cartographer, and humanist. He was the first European to correctly describe the function of pulmonary circulation...

 said that blood flows from the heart to the lungs, and that it there mixes with air to form the arterial blood which flows back to the heart. Between 1570 and 1590, Cesalpino suggested, in a controversy with Galenists, that the movement of blood was more like a circulation than an oscillation; but this view lacks clarity. In 1603, Hieronymus Fabricius

Hieronymus Fabricius

Hieronymus Fabricius or Girolamo Fabrizio or by his Latin name Fabricus ab Aquapendende also Girolamo Fabrizi d'Acquapendente was a pioneering anatomist and surgeon known in medical science as "The Father of Embryology."...

 ab Acquapendente

Acquapendente

Acquapendente is a city and comune in the province of Viterbo, in Lazio . Acquapendente is an important centre for the agricultural production of vegetables and wine, and has a tradition of pottery craftmanship.-History:...

 published a work clearly describing the valves in the veins and showing that they hinder the flow of blood away from the heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

. From 1597 to 1602, Harvey studied arts and medicine at Padua

Padua

Padua is a city and comune in the Veneto, northern Italy. It is the capital of the province of Padua and the economic and communications hub of the area. Padua's population is 212,500 . The city is sometimes included, with Venice and Treviso, in the Padua-Treviso-Venice Metropolitan Area, having...

, and made a careful study of the heart and the movement of blood. By 1616, he was presenting in lectures his case for the circulation of the blood, but it was not until 1628 that he published it in his classic work, De Motu Cordis et Sanguinis. This book is important both for the discovery of the complete circulation and for the experimental, quantitive and mechanistic methodology which Harvey introduced. He looked upon the heart, not as a mystical seat of the spirit and faculties, but as a pump

Pump

A pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...

 analyzable along mechanical lines. He also measured the amount of blood which it sent out to the body. He observed that with each beat two ounces of blood leave the heart; so that with 72 heart beats per minute, the heart throws into the system 540 pounds of blood every hour. Where could all this blood come from? The answer seems to be that it is the same blood that is always returning. Moreover, the one-way valves in the heart, like those in the veins, indicate that, following the pulmonary circulation

Pulmonary circulation

Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen-depleted Blood away from the heart, to the Lungs, and returns oxygenated blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn...

, the blood goes out to all parts of the body through the arteries and returns by way of the veins. The blood thus makes a complete closed circuit. As Harvey expressed it, "There must be a motion, as it were, in a circle." There was, however, one stage in the circulation which Harvey was not able to see - that in which the veins and arteries lose themselves by subdivision into the tiny capillary vessels. It was in 1660, three years after Harvey's death, that Marcello Malpighi

Marcello Malpighi

Marcello Malpighi was an Italian doctor, who gave his name to several physiological features, like the Malpighian tubule system.-Early years:...

 saw the blood moving in the capilaries

Capillary

Capillaries are the smallest of a body's blood vessels and are parts of the microcirculation. They are only 1 cell thick. These microvessels, measuring 5-10 μm in diameter, connect arterioles and venules, and enable the exchange of water, oxygen, carbon dioxide, and many other nutrient and waste...

 of the frog

Frog

Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

's lung, and thus supplied the missing link in Harvey's proof of the circulation of the blood.

External links

• English translation of the book at Fordham University
  Fordham University
  Fordham University is a private, nonprofit, coeducational research university in the United States, with three campuses in and around New York City. It was founded by the Roman Catholic Diocese of New York in 1841 as St...
  
  
• Exercitatio Anatomica de Motu Cordis et Sanguinis 1628. From Rare Book Room
  Rare Book Room
  Rare Book Room is an educational website for the repository of digitally scanned rare books made freely available to the public.Starting around 1996 the California based company Octavo began scanning rare and important books from libraries around the world. These scans were done at extremely high...
  
  . Scanned first edition.