General angiology. History of the discovery of blood circulation. Development and structure of arteries. Distribution of arteries in organs. Opening of blood circulation

History of the development of the doctrine of blood circulation

St. Petersburg, 2010.

1. Introduction
2. Pre-Harvey circulatory studies
   1. Claudius Galen
   2. Miguel Servet
   3. Realdo Colombo
   4. Andrea Caesalpin
3. Harvey's discovery
   1. Biography
   2. Opening of blood circulation
4. Opponents of Harvey's discovery
   1. Jean Riolan
   2. Guy Paten
5. Circulation studies after Harvey
   1. I.P. Pavlov

Conclusion

1. Introduction

It is difficult to name a discovery whose significance for biology and medicine would be equal to the discovery of blood circulation. It radically changed doctors’ ideas about the origin of many diseases and prompted them to change their treatment methods.

Today it is well known that in vertebrates blood circulation occurs in a closed vascular system, which includes the central circulatory organ - the heart. In mammals, blood vessels form two closed circles of blood circulation, communicating only through the heart - large and small. Through the systemic circulation, blood flows from the left ventricle of the heart to all organs of the body, with the exception of the lungs, and, passing through the capillaries, enters the right atrium. Having passed from the right atrium to the right ventricle, blood is expelled by its contractions into the pulmonary circulation. In a pulmonary circle, blood flows from the right ventricle through the pulmonary artery to the lungs. After passing through the capillaries of the lungs, the blood flows through the four pulmonary veins into left atrium. Having passed from it to the left ventricle, it again enters the systemic circulation. The pulmonary artery is the only artery that carries venous blood, and the pulmonary veins are the only veins that contain arterial blood.

The heart is a hollow muscular organ divided by longitudinal and transverse septa into four chambers. The longitudinal septum divides the heart into right and left sections, the transverse septum divides each of these sections into the atrium and ventricle.

The aorta, which begins the systemic circulation, departs from the left ventricle, and the pulmonary artery, which is the beginning of the pulmonary or pulmonary circulation, departs from the right ventricle.

Arteries are vessels through which blood flows from the heart to the capillaries. Starting from the aorta, each artery gives off arterial trunks of smaller diameter, which in turn branch into smaller and smaller arteries. Capillaries are the smallest vessels connecting the arterial and venous system. In the systemic circulation, the exchange of substances between blood and tissues takes place through the walls of the capillaries, and in the small circle, the exchange of gases takes place between blood and air. Veins are vessels through which blood returns to the heart through a network of capillaries. From the capillaries of the systemic circulation, blood flows into the smallest veins - venules; merging, they form small veins, which then flow into veins of larger diameter. Ultimately, all venous blood is collected in two large venous trunks - the superior and inferior vena cava, which flow into the right atrium. In the pulmonary circulation, the pulmonary capillaries become small veins, from the fusion of which ultimately four pulmonary veins are formed, flowing into the left atrium.

All these are now well-known provisions about the movement of blood. Historically, the issue of blood circulation was very difficult to clarify. It was solved by many scientists, and a lot of time passed before it was solved. Previously, during autopsies of corpses, they talked about those tubes that we now know as arteries circulatory system that these are tubes of the air system. And this is partly understandable, because these vessels on a corpse are filled with air, not blood. Gradually, the doctrine of blood circulation came to the state in which it is now.

1. Pre-Harvey circulatory studies

It can be considered generally accepted that the doctrine of blood circulation is a product of European natural science of the New Age and that we owe the creation of this harmonious system of physiological ideas to W. Harvey. Harvey's discovery of blood circulation (1628) is understood by most historians, physiologists, and clinicians as a milestone with which scientific physiology in general and the physiology of blood circulation in particular began. Arguments in favor of this point of view can be built as follows. The subject of Harvey's research was precisely blood circulation, that is, the movement of blood through a closed system, including two isolated circulatory circles. Each conclusion was based on experimental observations and mathematical calculations, the most important tools of new, experimental knowledge. The system of evidence as a whole, the very style of scientific thinking testified to the similarity of the methodological attitudes of the author and his contemporary Francis Bacon. What we have here is not a guess of a brilliant mind and not a harmonious hypothesis that needs fundamental proof. We have before us a consistently and carefully developed research program, which later became the basis for the study of physiology and then pathology of the heart. vascular system. Both the research methodology and the facts themselves, ascertained and clarified by Harvey, are included without any reservations in the modern doctrine of blood circulation. In this sense, the entire previous period can be considered as the pre-Harvey era of the initial accumulation of knowledge about the movement of blood through the vessels.

Borelli taught that muscle contraction depends on the swelling of cells due to the penetration of blood and spirits; the latter travel along the nerves voluntarily or involuntarily; as soon as the spirits meet the blood, an explosion occurs and a contraction appears. The blood restores the organs, and the nervous spirit maintains their vital properties.

According to Hoffmann, life consists of blood circulation and the movement of other fluids; it is supported by blood and spirits, and through separations and secretions it balances the functions and protects the body from putrefaction and deterioration. Blood circulation is the cause of heat, all strength, muscle tension, inclinations, qualities, character, intelligence and madness; The cause of blood circulation should be considered the narrowing and expansion of solid particles, which occurs as a result of very complex composition blood. Heart contractions are caused by the influence of nerve fluid developing in the brain.

1. Claudius Galen

Claudius Galen was quite close to the discovery of blood circulation. He examined in detail the mechanism of breathing, and the work of muscles, lungs and nerves was sequentially analyzed; He considered the purpose of breathing to weaken the warmth of the heart. The main place where blood is located was recognized as the liver. Nutrition according to Galen consists of borrowing the necessary particles from the blood and removing unnecessary ones; Each organ secretes a special fluid.

Claudius Galen and all his followers believed that the bulk of the blood is contained in the veins and communicates through the ventricles of the heart, as well as through openings (“anastomoses”) in the vessels passing nearby. Despite the fact that all attempts by anatomists to find the holes in the septum of the heart indicated by Galen were in vain, Galen's authority was so great that his statement was usually not questioned. The Arab physician Ibn al-Nafiz (1210-1288) from Damascus, the Spanish physician M. Servetus, A. Vesalius, R. Colombo and others only partially corrected the shortcomings of Galen’s scheme, but the true meaning of the pulmonary circulation remained unclear until Harvey.

1. Miguel Servet

The first person to have such a thought was Miguel Servet, a Spanish doctor who was burned for Arianism in Geneva about 140 years ago. He gave a description of the pulmonary circulation, thus refuting Galen's theory about the passage of blood from the left half of the heart to the right through small holes in the atrial septum.

Miguel Servetus was born in 1511 in Spain. He studied law and geography, first in Zaragoza, then in France, in Toulouse. For some time after graduating from university, Servetus served as secretary to the confessor of Emperor Charles V. While at the imperial court, for a long time lived in Germany, where he met Martin Luther. This acquaintance aroused Servetus' interest in theology. Although Servetus was self-taught in this area, he nevertheless studied theology deeply enough that he did not agree with the teachings of the church fathers in everything.

Yielding to the persuasion of his friend, the court physician of the Prince of Lorraine, Servet thoroughly studied medicine in Paris. His teachers were, like Vesalius, Silvius and Gunther. Contemporaries said that it is hardly possible to find an equal to Servetus in knowledge of the teachings of Galen. Even among learned anatomists, Servetus was known as an excellent expert in anatomy. Servetus became the house physician of the Archbishop of Vienna, in whose palace he spent twelve quiet years, working on solving certain issues of medicine and faith.

In a book entitled The Restoration of Christianity, published in 1553, he clearly states that blood passes through the lungs from the left to the right ventricle of the heart, and not through the septum separating the two ventricles, as was believed at that time. So, chronologically, the first description of the pulmonary circulation in Europe appears in a work devoted not to medical, but to theological problems. “The Restoration of Christianity” is the most complete expression of the anti-trinitarian views of Servetus, very inaccurately defined by W. Wotton as “Arianism”. At first glance, the question of blood movement seems " foreign body", artificially placed in a theological treatise. But upon careful examination, one gets the impression that the idea of ​​blood circulation in Servetus’ text is natural and organic.

Chapter 5 of “The Restoration of Christianity” talks about the Holy Spirit, which, according to Servetus, is not a hypostasis of the Trinity, but a form of manifestation of God, a connecting link between God and man. From the concept of the Spirit, Servetus moves on to the concept of the soul, relying on those provisions in Old Testament, which says that the soul is in the blood. For him, there is a logical need to give some idea of ​​the blood, its purpose as the abode of the soul and its movement in the body. Here we meet the formulation of the thesis about pulmonary circulation. Servetus tries to fit this thesis into the general picture of the world, which includes the idea of ​​God and man.

The version about the unconditional priority of Servetus in the discovery of pulmonary circulation lasted for more than 200 years. But in 1924, a manuscript by the Arab physician Ibn al-Nafis, “Commentary to the Treatise of Ibn Sina,” dating back to the 2nd half of the 13th century, was discovered in Damascus, and this manuscript contained a clearly formulated statement about the movement of blood from the right half of the heart through lungs to his left half. Servetus did not know about the existence of the text of Ibn al-Nafis and came to the discovery of the pulmonary circulation on his own.

1. Realdo Colombo

A few years after Servetus, Vesalius's student Realdo Colombo, coming up with a similar hypothesis, based it on more rigorous scientific evidence. The pulmonary circulation was opened a second time. At the same time, the works of Colombo and other researchers of that time organically fit into the foundation of physiological knowledge created by Harvey.

Colombo was born in 1516 in Cremona and studied in Venice and Padua. In 1540, he was appointed professor of surgery in Padua, but then this department was transferred to Vesalius, and Colombo was appointed his assistant. He was then invited to be a professor of anatomy in Pisa, and two years later Pope Paul IV appointed him a professor of anatomy in Rome, where he worked until the end of his life. Colombo's work "On Anatomy", where thoughts about the pulmonary circulation were expressed, was published in the year of his death.

William Harvey was familiar with Colombo's idea of ​​the pulmonary circulation, absolutely identical to Servetus's; he himself writes about it in his work on the movement of the heart and blood. No one can say whether Harvey knew about Servetus’ work. Almost all copies of the book Restoring Christianity were burned.

1. Andrea Caesalpin

Another predecessor of Harvey is the Italian Andrea Caesalpina (1519-1603), professor of anatomy and botany in Pisa, physician to Pope Clement VIII. In his books “Questions on the Doctrine of the Peripatetics” and “ Medical issues“Caesalpinus, like Servetus and Colombo, described the passage of blood from the right half of the heart to the left through the lungs, but did not abandon Galen’s teaching about the leakage of blood through the septum of the heart. Caesalpinus was the first to use the expression “blood circulation,” but did not put into it the concept that was later given by Harvey.

1. Harvey's discovery

The Englishman Harvey clarified the question of the movement of blood in the body. This was a huge task for his time. But his predecessors had already moved away from the classical misconception that blood vessels are air tubes. All that remained was to trace the entire path of the blood and establish that the entire body was permeated with tubes that did not end anywhere, passing into one another, representing a completely closed system. To do this, it was necessary to trace a particle of blood along its entire path.

Harvey did it and did it this way. He bandaged in various parts blood vessels and looked at what happened to the contents of the vessels above and below the ligation site. So gradually he determined the movement of blood.

1. Biography

William Harvey, the founder of modern physiology and embryology, was born on April 1, 1578 in the city of Folkestone, located on the southeast coast of England in Kent. His grandfather, John Harvey, was a sheep farmer. Father - Thomas Harvey - maintained a postal station for communication with the county center - the city of Canterbury. By his second marriage, he and his wife, Joanna Hoke, had nine children—seven sons and two daughters. In 1605, after the death of his second wife, Thomas Harvey left Folkestone and settled in London.

At less than eleven years old, William graduated from private primary school Johnson. Seeing good progress son in his studies, the father takes the boy to Canterbury Royal School to continue his education. The preparation at school was thorough. In high school they wrote essays in Latin prose and verse. Schoolchildren were only allowed to speak to each other in Latin and Greek.

At the age of 15, William entered Cambridge University, where he began his medical education. The University of Cambridge, founded in the 13th century, consisted of a number of colleges, as did Oxford. On May 31, 1593, Harvey was accepted to study at Goville Cayuse College. Medical studies here were planned for six years. He did not finish his college education, the reason was his illness.

William decided to complete his education abroad. The University of Padua, which arose in early XIII centuries. The teaching of medicine began there in 1250, and in the 14th century the medical faculty was already well organized. For three centuries, this university was considered one of the best, if not the best, in Europe. Harvey went there at the end of 1599 - beginning of 1600.

In Padua, Harvey listened to lectures by Hieronymus Fabricius of Acquapendente, a student of Gabriel Fallopius, who headed the department of anatomy after his teacher, and Galileo Galilei. It will soon be five years since the famous anatomist Fabricius lectured in the new anatomical theater built for him by order of the Venetian Senate. Fabricius spent twenty-five years studying the valves of veins in different parts of the body. Having studied in detail the structure of organs human body, he did not take up their function, did not have time to do this. Under the threat of persecution by the inquisitors, he was forced to abandon scientific research forever in the prime of his strength and talent.

From the first days of his studies, Harvey became Fabrice's most diligent student. He did not miss a single one of his lectures, and during the lectures he caught every word. The whole atmosphere of Padua aroused interest in anatomy. Just half a century ago, the great Vesalius lived here and created his world-famous work.

In the spring of 1602, Harvey brilliantly conducted a doctoral disputation. He showed excellent knowledge on all the questions asked at the debate. After the debate, a vote took place. All the professors voted unanimously to award Harvey the degree of Doctor of Medicine.

At the very beginning of 1603, Harvey returned to England. His first concern was to obtain a doctorate in medicine in his homeland, from an English university. After receiving a second doctorate from Cambridge University, he decided to practice medicine in London. But this required a license, which was issued only after passing the exams. The exam was scheduled for May 4, 1603. Harvey answered all questions brilliantly and received a license giving him the right to practice in London and other cities of England.

But this was not enough for his irrepressible nature; he strives to become a permanent member of the College. On 7 August 1604, after passing three oral examinations and a fourth before the entire College, he was elected a candidate member of the Royal College of Physicians. His election as a member of the College of Physicians took place on June 5, 1607. Subsequently, he occupied the Department of Anatomy and Surgery at the College and worked there until his death.

At the age of 26, William achieved his initial goal. Now William could think about marriage. His bride was a modest, serious girl, Elizabeth Brown. Her father, Dr. Lancelot Brown, was physician to Queen Elizabeth and, after her death, to James I. Brown intercedes for his son-in-law to obtain a position as physician in the Tower. Despite authoritative support, Harvey's appointment to the Tower was denied.

From February 1609, Harvey served as junior and then chief physician at St. Bartholomew's Hospital in London. Harvey worked at this hospital for over thirty years. It was founded in 1123 under Henry I. Previously, it was administered by the Catholic Augustinian order. Under Henry VIII, when he broke with the Vatican and liquidated all Catholic orders and monasteries in England, it was removed from the subordination of the church.

Harvey had many private patients, in whose treatment he used his own special techniques. Unlike most doctors of that time, he did not like complex multi-layered recipes, medicines consisting of a dozen or more components, although precisely such recipes were in the eyes of the public special price. Practitioners bought prescriptions from pharmacists for their famous colleagues.

Harvey, like Hippocrates, placed his main hopes on the forces of nature, sought to create hygienic conditions for the patient, provide proper nutrition, and prescribed baths. His recipes were simple and contained only the basic active remedies. Nowadays, this approach is recognized as correct. But then colleagues criticized Harvey for violating the principles of treatment. They did not approve of the fact that, relying on the forces of nature, he often adhered to wait-and-see tactics and expectation. Such doctors were called “wait-and-see doctors.”

Among Harvey's patients was the famous philosopher Francis Bacon, a man of irritable, melancholic and hysterical character. Not without reason, he reproached the doctors of his time for their penchant for scholastic reasoning and for neglecting the study and generalization of observations from their practice. Bacon recommended that doctors start compiling a collection of medical observations, descriptions of medical histories, discussing and classifying them. He owns the aphorism “All medical art consists of observations.” Bacon died of pneumonia. He caught a cold while filling tanks with snow while studying the effects of cold as a means of preserving meat.

In February 1618, William Harvey was invited to be his physician by James I, then Charles I, with whom he moved to Oxford for a short time. Upon returning to London, Harvey withdraws from public life in order to devote himself entirely to his research. The result was a description of the systemic and pulmonary circulation.

1. Opening of blood circulation

William Harvey came to the conclusion that a snake bite is dangerous only because the venom spreads through the vein from the site of the bite throughout the body. For English doctors, this guess became the starting point for reflection that led to the development intravenous injections. It is possible, the doctors reasoned, to inject this or that medicine into a vein and thereby introduce it into the entire body. But next step German doctors did this in this direction by using a new surgical enema on humans (as intravenous injection was then called). The first injection experience was carried out by one of the most prominent surgeons, the second half XVII century Mateus Gottfried Purman from Silesia. Czech scientist Pravac proposed an injection syringe. Before this, syringes were primitive, made from pig bladders, with wooden or copper spouts embedded in them. The first injection was performed in 1853 by English doctors.

After arriving from Padua, simultaneously with his practical medical activities, Harvey conducted systematic experimental studies of the structure and function of the heart and blood flow in animals. He first presented his thoughts in another Lumley lecture, which he gave in London on April 16, 1618, when he already had a large amount of observational and experimental material. Harvey briefly formulated his views by saying that blood moves in a circle. More precisely, in two circles: small - through the lungs and large - through the whole body. His theory was incomprehensible to listeners, it was so revolutionary, unusual and alien to traditional ideas. Harvey's Anatomical Inquiry into the Movement of the Heart and Blood in Animals appeared in 1628 and was published in Frankfurt am Main. In this study, Harvey refuted Galen's teaching about the movement of blood in the body, which had prevailed for 1500 years, and formulated new ideas about blood circulation.

Of great importance for Harvey's research was detailed description venous valves that direct the movement of blood to the heart, first given by his teacher Fabricius in 1574. The simplest and at the same time the most convincing proof of the existence of blood circulation, proposed by Harvey, was to calculate the amount of blood passing through the heart. Harvey showed that in half an hour the heart ejects an amount of blood equal to the weight of the animal. This a large number of moving blood can only be explained based on the concept of a closed circulatory system. Obviously, Galen's assumption about the continuous destruction of blood flowing to the periphery of the body could not be reconciled with this fact. Harvey received another proof of the fallacy of his views on the destruction of blood on the periphery of the body in experiments on applying a bandage to upper limbs person. These experiments showed that blood flows from arteries to veins. Harvey's research revealed the importance of the pulmonary circulation and established that the heart is a muscular sac equipped with valves, the contractions of which act as a pump forcing blood into the circulatory system.

1. Opponents of Harvey's discovery

Having refuted Galen's ideas, Harvey was criticized by contemporary scientists and the church. Opponents of the theory of blood circulation in England called its author the name “circulator”, which was offensive to a doctor. This Latin word translates as “wandering medicine man”, “charlatan”. They also called all supporters of the doctrine of blood circulation circulators. It is noteworthy that the Paris Medical Faculty also refused to recognize the fact of blood circulation in the human body. And this is 20 years after the discovery of blood circulation.

1. Jean Riolan

The fight against Harvey was led by Jean Riolan son. In 1648, Riolan published the work “Manual of Anatomy and Pathology,” in which he criticized the doctrine of blood circulation. He did not reject it as a whole, but expressed so many objections that, in essence, he crossed out Harvey's discovery. Riolan personally sent his book to Harvey. Main feature Riolan as a scientist was conservatist. He knew Harvey personally. As physician to Marie de' Medici, the French dowager queen, mother of Henrietta Maria, wife of Charles I, Riolan came to London and lived there for some time. Harvey, as the king's personal physician, when visiting the palace, met with Riolan, demonstrated his experiments to him, but could not convince his Parisian colleague of anything.

Riolan's father was the head of all anatomists of his time. He, like his son, bore the name Jean. Father Riolan was born in 1539, in the village of Montdidier near Amiens, and studied in Paris. In 1574 he received the degree of doctor of medicine and in the same year the title of professor of anatomy. Then he was dean of the Paris Faculty of Medicine (in 1586-1587). Riolan's father was a famous scientist: in addition to medicine, he taught philosophy and foreign languages, left many works on metaphysics and on the works of Hippocrates and Fernel; outlined the doctrine of fevers in “Tractatus de febribus” (1640). He died in 1605.

Jean Riolan son was born, studied and received his doctorate in medicine in Paris. Since 1613, he headed the department of anatomy and botany at the University of Paris, and was physician to Henry IV and Louis XIII. The fact that, as the first physician to Henry IV's wife Marie de' Medici, he followed the disgraced queen into exile and treated her for varicose veins veins and remained with her until her death, enduring countless hardships, speaks of his spiritual qualities.

Riolan the son was an excellent anatomist. His main work, “Anthropographie” (1618), wonderfully describes human anatomy. He founded the Royal Garden medical herbs", relating to scientific institutions, conceived in 1594 by Henry IV. Under the pseudonym Antarretus he wrote whole line polemical articles against Harvey. Through the efforts of this magnificent scientist, the outstanding physician Harvey was slandered at the faculty: “He who allows blood to circulate in the body has a weak mind.”

1. Guy Paten

Devoted student of Riolan the son of Guy Paten, one of the luminaries of the then medicine, physician Louis XIV, wrote about Harvey’s discovery: “We are living through an era of incredible inventions, and I don’t even know whether our descendants will believe in the possibility of such madness.” He called Harvey's discovery "paradoxical, useless, false, impossible, incomprehensible, absurd, harmful to human life" and so on.

Patan's parents prepared him to become a lawyer, and at worst they agreed to become a priest, but he chose literature, philosophy and medicine. In his immense zeal as an orthodox follower of Galen and Avicenna, he was very distrustful of the new means used in medicine in his time. Paten's reactionary attitude may not seem so wild if we remember how many victims the craze for antimonial drugs brought about. On the other hand, he welcomed bloodletting. Even infancy didn't save me from this dangerous procedure. “Not a day passes in Paris,” writes Patin, “when we do not prescribe bleeding from infants.”

“If medicines do not cure, then death comes to the rescue.” This is a typical reflection of the era when the satire of Molière and Boileau ridiculed the scholastic doctors, who, as they aptly put it, stood with their backs to the patient and their faces to the “holy scriptures.” For his conservatism that knows no bounds, Moliere ridiculed Guy Patin in “Malade imaginoire” (“The Imaginary Invalid”), showing him in the person of Doctor Diafuarus.

For a long time, the Paris Faculty of Medicine was a hotbed of conservatism; it consolidated the authority of Galen and Avicenna by parliamentary decree, and doctors adhering to new therapy, deprived of practice. The Faculty in 1667 banned blood transfusions from one person to another. When the king supported this saving innovation, the faculty went to court and won the case.

Harvey found defenders. The first among them was Descartes, who spoke out in favor of blood circulation, and thereby greatly contributed to the triumph of Harvey’s ideas.

In 1654, Harvey was unanimously elected president of the London College of Medicine, but declined the position for health reasons.

If Vesalius laid the foundations of modern human anatomy, Harvey created a new science - physiology, a science that studies the function of human and animal organs. I.P. Pavlov called Harvey the father of physiology. He said that the doctor William Harvey spied one of essential functions body - blood circulation and thereby laid the foundation for a new department of exact knowledge - animal physiology.

1. Studies of blood circulation after Harvey.

Harvey did not know about the existence of capillaries, which he designated as “tissue pores.” He could not see them without a microscope, and the assumption of their existence was a brilliant guess based on correct premises. In 1661, after Harvey's death, capillaries were discovered by Malpighi. After Malpighi's discovery there could no longer be any doubt about the correctness of Harvey's views, which had previously been disputed.

Malpighi, using a microscope, studies the development of the chicken, blood circulation in the smallest vessels, the structure of the tongue, glands, liver, kidneys, and skin. Ruysch became famous for his excellent fillings (injections) of vessels, which made it possible to see vessels where they were previously unsuspected. Over the course of 50 years, Leeuwenhoek found many new facts in the study of all tissues and parts of the human body; discovered blood cells and seminal filaments (spermatozoa).

Next important event in the study of blood circulation was the determination of the value of arterial blood pressure. This was done by measuring the height to which blood rises in a vertically mounted glass tube connected to the lumen carotid artery horses (Gels experiment, 1732).

Intensive development of the physiology of blood circulation began only in the 40s of the last century. Since that time, graphic recording of processes occurring in the circulatory system began to be used; the amount of blood in the body was measured, the question of the significance of various physical factors involved in blood movement. At the same time, the study of the regulation of blood circulation began.

An important study that established the existence of nervous influences on the activity of the circulatory system was the work carried out in 1842 in Kyiv by N. I. Pirogov’s student, Walter. He proved that stimulation of the “sympathetic threads” contained in the sciatic nerve of the frog leads to a narrowing blood vessels paws. Then the inhibitory effect of the anticipatory nerve on the heart was established (Weber brothers, 1845): an increase in heart rate was shown when sympathetic nerve fibers were excited (Pezold, Zion); the influence of various nerves on blood vessels was studied in detail (Claude Bernard); reflex changes in blood circulation were discovered. naturally occurring in response to irritation of afferent fibers coming from the aortic receptors (I. F. Iipn and K. Ludwig). V. Ovsyannikov accurately established that certain areas of the medulla oblongata contain nerve formations, the destruction of which disrupts the reflex regulation of the sogus. At about the same time, N. O. Kovalevsky, M. Traube and others proved that blood circulation changes when carbon dioxide accumulates in the blood.

Thus, for the period 1840-1880. a number of important individual facts characterizing the physical processes occurring in the circulatory system were described in detail, the influence exerted on the heart and blood vessels by nerve fibers approaching them, and changes in blood circulation that reflexively occur during “painful” irritation, bloodletting, asphyxia (suffocation) and other effects on the body. These works revealed some processes that play an important role in the regulation of blood circulation, but could not give clear ideas about the mechanisms that determine normal functioning circulatory system in normal conditions life activity.

1. I.P. Pavlov

For the first time I.P. Pavlov in 1880-1890. with his systematically conducted experiments, he indicated ways to study the normal regulation of blood circulation, showing that the regulation of blood circulation can be studied under conditions of chronic experiment on healthy, non-anesthetized animals. It was in these animals that he established a significant constancy of arterial blood pressure and found that it was maintained due to the constantly ongoing regulatory influence of the central nervous system leading to blood redistribution.

By introducing the technique of “cold cutting” (reversible shutdown by cooling) vagus nerve, Pavlov showed the importance of nervous influences in maintaining a relatively constant level of blood pressure.

I.P. Pavlov did not at all belittle the importance of vivisection experiments - his study of the amplifying nerve of the heart is an example of research of this kind. He saw, however, in acute experiments only a means for isolating (analyzing) the role of various factors involved in this or that complex phenomenon, and never forgot that the vivisection technique as such is associated with a disruption of the animal’s normal connections with the environment.

Back in 1882, Pavlov raised in all its breadth the question of the importance of the regulation of blood circulation in maintaining the relative constancy of blood pressure. He wrote about this: “The enormous importance of an accurate study of the devices that guard this desire for constancy is immeasurable.”

After Ludwig, Zion and Pavlov, the physiological mechanisms that ensure the constancy of blood pressure began to be studied in detail again only in the 20s of our century. At the same time, however, foreign researchers focused only on reflexes from two groups of receptors of the vascular system, namely from the endings of the aortic nerve discovered by Zion and Ludwig and from the receptors of the branching region of the common carotid artery discovered about 30 years ago. Meanwhile, Pavlov emphasized back in the 80s that the regulation of blood circulation is carried out due to the action of various stimuli “... on the peripheral endings of the centripetal nerves,” i.e., receptors contained in all organs and all tissues. The irritation of these receptors constitutes, as Pavlov wrote, “the starting point of the reflex,” which “... in life complex organism... is the most significant and most common nervous phenomenon.” In particular, all normal regulation of blood circulation is based on reflexes. Thus, I.P. Pavlov 60-70 years ago indicated ways to study the normal regulation of blood circulation as reflex acts arising from various receptors.

Clinical studies have been and are of significant importance in the study of blood circulation. The clinic allows you to study in humans changes in blood circulation caused by one or another damage to the heart, blood vessels, nervous system, etc. The needs of the clinic led to the development of methods for determining blood pressure in the arteries and veins of a person, the amount of blood ejected by the heart. Many works have been carried out to study fluctuations in blood pressure and pulse rate, as well as venous pressure, blood flow speed and the amount of blood ejected by the heart per minute in various diseases and different conditions of the body. Much research has been devoted to the so-called functional diagnostics cardiovascular system, studying the causes and consequences of long-term increased blood pressure (hypertension) and its sharp fall(for shock, collapse, blood loss), studying the mechanism of occurrence of vascular spasms and blockage of blood vessels, analyzing changes in the activity of the heart by studying electrical phenomena in it, etc.

Conclusion

Both experimental and clinical studies of blood circulation still often reflect a narrowly analytical, metaphysical approach to physiological phenomena. This approach led, for example, to the idea that blood circulation is independent of the activity of the higher parts of the brain and is subordinate only to special autonomic centers that influence the heart and blood vessels through the sympathetic and parasympathetic parts of the “autonomic” nervous system. The relatively slow development of circulatory physiology was largely due to these incorrect attitudes, which led away from the study of the normal regulation of blood circulation in the whole organism.

Even researchers from ancient times assumed that in living organisms all organs are functionally connected and influence each other. A variety of assumptions have been made. Hippocrates, the father of medicine, and Aristotle, the greatest Greek thinker, who lived almost 2500 years ago, were interested in issues of blood circulation and studied it. However, their ideas were not perfect and in many cases erroneous. They represented venous and arterial blood vessels as two independent systems not connected to each other. It was believed that blood moves only through the veins, while the arteries contain air. This was justified by the fact that during autopsies of human and animal corpses, there was blood in the veins, but the arteries were empty, without blood.

This belief was refuted by the work of the Roman explorer and physician Claudius Galen (130-200). He experimentally proved that blood moves through the heart through both arteries and veins.

After Galen, until the 17th century, it was believed that blood from the right atrium somehow entered the left atrium through the septum.

In 1628, the English physiologist, anatomist and physician William Harvey (1578-1657) published his work “An Anatomical Study of the Movement of the Heart and Blood in Animals,” in which for the first time in the history of medicine he experimentally showed that blood moves from the ventricles of the heart through the arteries and returns to the atria through the veins. Undoubtedly, the circumstance that more than any other led William Harvey to the realization that blood circulates was the presence of valves in the veins, the functioning of which is a passive hydrodynamic process. He realized that this could only make sense if the blood in the veins flows towards the heart, and not away from it, as Galen suggested and as European medicine believed before Harvey's time. Harvey was also the first to quantify cardiac output in humans, and mainly due to this, despite the huge underestimation (1020.6 g, that is, about 1 l/min instead of 5 l/min), skeptics were convinced that arterial blood cannot be continuously created in the liver, and therefore it must circulate. Thus, he constructed a modern diagram of the blood circulation of humans and other mammals, which includes two circles (see below). The question of how blood gets from arteries to veins remained unclear.

It is interesting that it was in the year of publication of Harvey's revolutionary work (1628) that Marcello Malpighi was born, who 50 years later discovered capillaries - a link of blood vessels that connects arteries and veins - and thus completed the description of a closed vascular system.

The earliest quantitative measurements of mechanical phenomena in the circulation were made by Stephen Hales (1677-1761), who measured arterial and venous blood pressure, the volume of individual chambers of the heart, and the rate of blood flow from several veins and arteries, thus demonstrating that most resistance blood flow occurs in the area of ​​microcirculation. He believed that, due to the elasticity of the arteries, the flow of blood in the veins is more or less steady, and not pulsating, as in the arteries.

Later, in the 18th and 19th centuries. a number of famous hydromechanics became interested in the issues of blood circulation and made significant contributions to the understanding of this process. Among them were Euler, Daniel Bernoulli (who was in fact a professor of anatomy) and Poiseuille (also a doctor; his example especially shows how an attempt to solve a particular applied problem can lead to the development of fundamental science). One of the greatest universal scientists was Thomas Young (1773-1829), also a physician, whose research in optics led to the adoption wave theory light and understanding color perception. Another important area of ​​research concerns the nature of elasticity, in particular the properties and function of elastic arteries; his theory of wave propagation in elastic tubes is still considered a fundamentally correct description pulse pressure in the arteries. It is in his lecture on this subject to the Royal Society in London that the explicit statement is made that "the question of how and to what extent the circulation of the blood depends on the muscular and elastic forces of the heart and arteries, on the assumption that the nature of these forces is known, must become simply a question of the most advanced branches of theoretical hydraulics.”

In the 20th century it has been shown that for venous return (see below) contractions also play a significant role skeletal muscles and the suction action of the chest.

Human blood circulation. Structure, properties and regulation of the heart

In the 3rd century BC. e. Erasistratus believed that arteries carry air to tissues. Hence the name “artery” (Greek aer - air, tereo - contain, store).

This position was developed by the founder of experimental medicine Galen (2nd century AD): he believed that blood is formed in the liver from food, which, after processing in the stomach and intestines, passes to the liver through the ducts. Next, the blood from the liver is carried through the veins to all parts of the body, where it is consumed. According to Galen, part of the blood enters the right ventricle, then through the openings of the septum into the left ventricle (he proved the presence of blood in it using a puncture). In the left ventricle, blood is mixed with air coming from the lungs, and then distributed through the arteries to all organs of the body and the brain. In the brain, blood is converted into the “animal spirit” necessary for the movement of every part of the body.

Ibn al-Nafiz (13th century) first came to the conclusion that all the blood from the right ventricle passes through the vessels of the lungs and returns to the left heart.

M. Servetus (16th century) described the pulmonary circulation. He established that blood flows to the lung through the pulmonary artery, the diameter of which is equal to the diameter of the aorta, and venous blood flows through the arteries, which is freed from “soot” in the lungs.

W. Harvey (17th century) discovered blood circulation in the body. In his work “Anatomical Study of the Movement of the Heart and Blood in Animals,” he with impeccable logic refuted the Galenic doctrine that had prevailed for more than 1,500 years. Having measured the sheep's systolic blood volume, heart rate per minute and total blood, Harvey claimed: “There is no more than 4 pounds of blood in the whole body, as I was convinced of this on a sheep.”

He calculated that in 1.5-2 minutes all the blood should pass through the heart, and within 30 minutes an amount of blood equal to the animal’s body weight should pass through the heart. Such rapid and continuous production of blood in the body is impossible.

Harvey allowed the same blood to return to the heart through a closed cycle. He explained the closed circle of blood circulation by the direct connection of arteries and veins through the smallest tubes (capillaries), which were discovered by M. Malpighi 4 years after Harvey’s death. The closed system according to Harvey has 2 circles - large and small (pulmonary), which are connected to each other through the heart. The pulmonary circulation makes direct contact with the external environment, and the large circulation – with the organs and tissues of the body.

In our body, blood continuously moves through a closed system of blood vessels in a strictly defined direction. This continuous movement of blood is called blood circulation .

Blood circulation ensures basic metabolic processes, determining the transport of blood to all organs and tissues and the removal of metabolic products from them. It is determined by the activity of the heart, which performs the function of a pump, and the tone peripheral vessels. The work of the heart serves as the main engine of blood. The heart, like a dynamic pump, pushes blood into an impressively complex network of blood vessels that could encircle the Earth 2.5 times. Driving force comes from the ventricles with their thick muscular walls contracting so that blood is pumped into the arteries. The pumping action of the heart is repeated automatically with the rhythm of the pulse, and the amount of blood pumped depends on the degree of tension of the person and the actions he performs. Blood ejected from the heart enters large arteries, then into the microcirculation system (arterioles, capillaries, venules), veins and returns to the heart.

Circulatory functions:

Trophic - involves the transfer of oxygen and nutrients, coming from environment;

Excretory - promotes the removal of cellular metabolic products through the excretory organs;

Regulatory - ensures the transfer of hormones and biologically active substances, redistribution of fluid and maintaining temperature balance in the body.

Blood circulation in a closed system consists of two circles:

1. Big circle – the path of blood from the left ventricle to the right atrium. From the left ventricle, oxygenated blood (arterial blood, scarlet, bright) is pumped into the widest vessel - the aorta. From there, the blood flows through the arteries to various parts of the body: the brain, organs abdominal cavity, torso, limbs. Flowing through the capillaries of the systemic circulation, the blood gives off oxygen and adds carbon dioxide. The veins receive blood that is poor in oxygen (venous, dark). Deoxygenated blood from the trunk, abdominal organs, lower limbs through a large vessel - the inferior vena cava - enters the right atrium. Venous blood from the head, neck, and arms enters here through the superior vena cava.

2. Small (pulmonary) circle - the path of blood from the right ventricle to the left atrium. This path is much shorter. From the right ventricle, venous blood enters a large vessel - the pulmonary artery. In the lungs pulmonary artery branches into a dense network of capillaries intertwining the respiratory vesicles. Venous blood, passing through the capillaries of the lungs, is saturated with oxygen and turns into arterial blood. Arterial blood now flows through the pulmonary veins into the left atrium. The small circle is an exception; venous blood flows in the remaining veins of the body, and arterial blood flows in the arteries.

The right and left ventricles pump blood simultaneously, and it moves simultaneously through both circulation circles. The division into large and small circles of blood circulation is conditional: they are connected to each other, one is a continuation of the other, that is, two circles are connected in series - this is closed system . The two parts of the cardiovascular system are named because each of them begins in the heart and returns to the heart, but individually they do not form closed systems. In fact, there is one common closed circle of blood circulation.

“He is firm in argument, unshakable in his views, never changes his judgments... he blindly believes our ancient teachers and does not even want to hear about the so-called discoveries of our century regarding blood circulation and the like.” This is how the hero of the comedy praised the virtues of the doctor Moliere"The Imaginary Sick" Doctor Diafuarus. This is precisely the position that the outstanding researcher of the human body had to face. William Harvey(1578-1657), when he first published his essay on the movement of the heart and blood.

The scientist had to fight against the then dominant traditional view, based on the teachings of the great doctor Antiquity Galena. The passionate and heated discussion about blood circulation went far beyond the circle of specialists. The Paris Faculty of Medicine, whose professors unwaveringly adhered to the teachings of Galen, declared real war on Harvey.

Blood swirls

Followers of the “ancient teacher” Galen believed that the arteries contain little blood and a lot of air, while the veins are filled with blood. It would seem, where did this belief come from? After all, with any injury that affects an artery, blood flows! This has been known since ancient times, and was also observed during ancient sacrifices. But doctors had a different picture. They relied on data obtained from autopsies. And in a dead body, the arteries are bloodless, while the veins are full. And this picture got in the way correct understanding Problems. Therefore, nothing was known about blood circulation. It was believed that blood was formed in the liver and from there through the greater vena cava it entered the heart.

William Harvey. Photo: Commons.wikimedia.org

Known for his skepticism even in his student years, Harvey wrote: “When I first turned all my thoughts and desires to observations based on vivisections (to the extent that I had to do them), so that through my own contemplations, and not from books and manuscripts, to recognize the meaning and benefits of cardiac movements in living beings, I discovered that this question is very complex and full of mysteries at every step.” The scientist came to his conclusion through numerous experiments, when he studied the still beating hearts and lungs of dissected animals.

Harvey made this great discovery in 1616, when he said in one of his lectures that “the blood circles in the body.” However long years he continued to search and accumulate evidence. And only twelve years later he finally published the results of his work: “Anatomical studies on the movement of the heart and blood of animals.”

Accusations of vivisection - experiments involving the dissection of living animals - continue to haunt his reputation to this day. However, everything he did, he did for the sake of science. The burning candle on William Harvey's coat of arms symbolized "life consumed by flame, yet luminous."

Marcello, you're wrong!

According to Harvey, when the heart ventricles contract, blood is pushed into the aorta, through it and its branches it penetrates into the legs, arms, head, any part of the body, delivering vital oxygen there, then collects again and flows through the veins back to the heart. True, Harvey's system lacked some links, for example, the connecting part between the arterial system and the venous system. Capillary system- a complex of the thinnest vessels that are the end of arteries and the beginning of veins - was discovered after the death of the scientist. This important part The circulatory system was described by Marcello Malpighi.

Malpighi also had a hard time. One day, two faculty professors came to his country house incognito and disagreed with his discovery. The venerable anatomists were accompanied by masked people. Malpighi, who was 61 at the time, was beaten and his household belongings were destroyed. Moreover, this method of conducting scientific disputes was not something unusual in Italy at that time. For example, outstanding figure Renaissance professor at the University of Bologna Berengario da Carpi also once destroyed the apartment of his scientific opponent. Such was the degree of scientific discussions then.

Pre-Harvey circulatory studies

It can be considered generally accepted that the doctrine of blood circulation is a product of European natural science of the New Age and that we owe the creation of this harmonious system of physiological ideas to W. Harvey. Harvey's discovery of blood circulation (1628) is understood by most historians, physiologists, and clinicians as a milestone with which scientific physiology in general and the physiology of blood circulation in particular began. Arguments in favor of this point of view can be built as follows. The subject of Harvey's research was precisely blood circulation, that is, the movement of blood through a closed system, including two isolated circulatory circles. Each conclusion was based on experimental observations and mathematical calculations, the most important tools of new, experimental knowledge. The system of evidence as a whole, the very style of scientific thinking testified to the similarity of the methodological attitudes of the author and his contemporary Francis Bacon. What we have here is not a guess of a brilliant mind and not a harmonious hypothesis that needs fundamental proof. We have before us a consistently and carefully developed research program, which later became the basis for the study of physiology and then the pathology of the cardiovascular system. Both the research methodology and the facts themselves, ascertained and clarified by Harvey, are included without any reservations in the modern doctrine of blood circulation. In this sense, the entire previous period can be considered as the pre-Harvey era of the initial accumulation of knowledge about the movement of blood through the vessels.

Borelli taught that muscle contraction depends on the swelling of cells due to the penetration of blood and spirits; the latter travel along the nerves voluntarily or involuntarily; as soon as the spirits meet the blood, an explosion occurs and a contraction appears. The blood restores the organs, and the nervous spirit maintains their vital properties.

According to Hoffmann, life consists of blood circulation and the movement of other fluids; it is supported by blood and spirits, and through separations and secretions it balances the functions and protects the body from putrefaction and deterioration. Blood circulation is the cause of heat, all strength, muscle tension, inclinations, qualities, character, intelligence and madness; The cause of blood circulation should be considered the narrowing and expansion of solid particles, which occurs due to the very complex composition of the blood. Heart contractions are caused by the influence of nerve fluid developing in the brain.

Claudius Galen

Claudius Galen was quite close to the discovery of blood circulation. He examined in detail the mechanism of breathing, and the work of muscles, lungs and nerves was sequentially analyzed; He considered the purpose of breathing to weaken the warmth of the heart. The main place where blood is located was recognized as the liver. Nutrition according to Galen consists of borrowing the necessary particles from the blood and removing unnecessary ones; Each organ secretes a special fluid.

Claudius Galen and all his followers believed that the bulk of the blood is contained in the veins and communicates through the ventricles of the heart, as well as through openings (“anastomoses”) in the vessels passing nearby. Despite the fact that all attempts by anatomists to find the holes in the septum of the heart indicated by Galen were in vain, Galen's authority was so great that his statement was usually not questioned. The Arab physician Ibn al-Nafiz (1210-1288) from Damascus, the Spanish physician M. Servetus, A. Vesalius, R. Colombo and others only partially corrected the shortcomings of Galen’s scheme, but the true meaning of the pulmonary circulation remained unclear until Harvey.

Miguel Servet

The first person to have such a thought was Miguel Servet, a Spanish doctor who was burned for Arianism in Geneva about 140 years ago. He gave a description of the pulmonary circulation, thus refuting Galen's theory about the passage of blood from the left half of the heart to the right through small holes in the atrial septum.

Miguel Servetus was born in 1511 in Spain. He studied law and geography, first in Zaragoza, then in France, in Toulouse. For some time after graduating from university, Servetus served as secretary to the confessor of Emperor Charles V. While at the imperial court, he lived for a long time in Germany, where he met Martin Luther. This acquaintance aroused Servetus' interest in theology. Although Servetus was self-taught in this area, he nevertheless studied theology deeply enough that he did not agree with the teachings of the church fathers in everything.

Yielding to the persuasion of his friend, the court physician of the Prince of Lorraine, Servet thoroughly studied medicine in Paris. His teachers were, like Vesalius, Silvius and Gunther. Contemporaries said that it is hardly possible to find an equal to Servetus in knowledge of the teachings of Galen. Even among learned anatomists, Servetus was known as an excellent expert in anatomy. Servetus became the house physician of the Archbishop of Vienna, in whose palace he spent twelve quiet years, working on solving certain issues of medicine and faith.

In a book entitled The Restoration of Christianity, published in 1553, he clearly states that blood passes through the lungs from the left to the right ventricle of the heart, and not through the septum separating the two ventricles, as was believed at that time. So, chronologically, the first description of the pulmonary circulation in Europe appears in a work devoted not to medical, but to theological problems. “The Restoration of Christianity” is the most complete expression of the anti-trinitarian views of Servetus, very inaccurately defined by W. Wotton as “Arianism.” At first glance, the question of the movement of blood seems to be a “foreign body” artificially placed in a theological treatise. But upon careful examination, one gets the impression that the idea of ​​blood circulation in Servetus’ text is natural and organic.

Chapter 5 of “The Restoration of Christianity” talks about the Holy Spirit, which, according to Servetus, is not a hypostasis of the Trinity, but a form of manifestation of God, a connecting link between God and man. From the concept of the Spirit, Servetus moves on to the concept of the soul, relying on those provisions in the Old Testament where it is said that the soul is in the blood. For him, there is a logical need to give some idea of ​​the blood, its purpose as the abode of the soul and its movement in the body. Here we meet the formulation of the thesis about pulmonary circulation. Servetus tries to fit this thesis into the general picture of the world, which includes the idea of ​​God and man.

The version about the unconditional priority of Servetus in the discovery of pulmonary circulation lasted for more than 200 years. But in 1924, a manuscript by the Arab physician Ibn al-Nafis, “Commentary to the Treatise of Ibn Sina,” dating back to the 2nd half of the 13th century, was discovered in Damascus, and this manuscript contained a clearly formulated statement about the movement of blood from the right half of the heart through lungs to his left half. Servetus did not know about the existence of the text of Ibn al-Nafis and came to the discovery of the pulmonary circulation on his own.

Realdo Colombo

A few years after Servetus, Vesalius's student Realdo Colombo, coming up with a similar hypothesis, based it on more rigorous scientific evidence. The pulmonary circulation was opened a second time. At the same time, the works of Colombo and other researchers of that time organically fit into the foundation of physiological knowledge created by Harvey.

Colombo was born in 1516 in Cremona and studied in Venice and Padua. In 1540, he was appointed professor of surgery in Padua, but then this department was transferred to Vesalius, and Colombo was appointed his assistant. He was then invited to be a professor of anatomy in Pisa, and two years later Pope Paul IV appointed him a professor of anatomy in Rome, where he worked until the end of his life. Colombo's work "On Anatomy", where thoughts about the pulmonary circulation were expressed, was published in the year of his death.

William Harvey was familiar with Colombo's idea of ​​the pulmonary circulation, absolutely identical to Servetus's; he himself writes about it in his work on the movement of the heart and blood. No one can say whether Harvey knew about Servetus’ work. Almost all copies of the book Restoring Christianity were burned.

Andrea Caesalpin

Another predecessor of Harvey is the Italian Andrea Caesalpina (1519-1603), professor of anatomy and botany in Pisa, physician to Pope Clement VIII. In his books “Questions of the Doctrine of the Peripatetics” and “Medical Questions,” Caesalpinus, like Servetus and Colombo, described the transition of blood from the right half of the heart to the left through the lungs, but did not abandon Galen’s teaching about the leakage of blood through the septum of the heart. Caesalpinus was the first to use the expression “blood circulation,” but did not put into it the concept that was later given by Harvey.

Harvey's discovery

The Englishman Harvey clarified the question of the movement of blood in the body. This was a huge task for his time. But his predecessors had already moved away from the classical misconception that blood vessels are air tubes. All that remained was to trace the entire path of the blood and establish that the entire body was permeated with tubes that did not end anywhere, passing into one another, representing a completely closed system. To do this, it was necessary to trace a particle of blood along its entire path.

Harvey did it and did it this way. He ligated blood vessels in various parts and looked at what happened to the contents of the vessels above and below the ligation site. So gradually he determined the movement of blood.

Opening of blood circulation

William Harvey came to the conclusion that a snake bite is dangerous only because the venom spreads through the vein from the site of the bite throughout the body. For English doctors, this insight became the starting point for reflection that led to the development of intravenous injections. It is possible, the doctors reasoned, to inject this or that medicine into a vein and thereby introduce it into the entire body. But German doctors took the next step in this direction by using a new surgical enema on humans (as intravenous injection was then called). The first injection experience was made by one of the most prominent surgeons of the second half of the 17th century, Mateus Gottfried Purman from Silesia. Czech scientist Pravac proposed an injection syringe. Before this, syringes were primitive, made from pig bladders, with wooden or copper spouts embedded in them. The first injection was performed in 1853 by English doctors.

After arriving from Padua, simultaneously with his practical medical activities, Harvey conducted systematic experimental studies of the structure and function of the heart and blood flow in animals. He first presented his thoughts in another Lumley lecture, which he gave in London on April 16, 1618, when he already had a large amount of observational and experimental material. Harvey briefly formulated his views by saying that blood moves in a circle. More precisely, in two circles: small - through the lungs and large - through the whole body. His theory was incomprehensible to listeners, it was so revolutionary, unusual and alien to traditional ideas. Harvey's Anatomical Inquiry into the Movement of the Heart and Blood in Animals appeared in 1628 and was published in Frankfurt am Main. In this study, Harvey refuted Galen's teaching about the movement of blood in the body, which had prevailed for 1500 years, and formulated new ideas about blood circulation.

Of great importance for Harvey's research was the detailed description of the venous valves that direct the movement of blood to the heart, first given by his teacher Fabricius in 1574. The simplest and at the same time the most convincing proof of the existence of blood circulation, proposed by Harvey, was to calculate the amount of blood passing through the heart. Harvey showed that in half an hour the heart ejects an amount of blood equal to the weight of the animal. Such a large amount of moving blood can only be explained based on the concept of a closed circulatory system. Obviously, Galen's assumption about the continuous destruction of blood flowing to the periphery of the body could not be reconciled with this fact. Harvey received another proof of the fallacy of his views about the destruction of blood on the periphery of the body in his experiments of applying a bandage to the upper limbs of a person. These experiments showed that blood flows from arteries to veins. Harvey's research revealed the importance of the pulmonary circulation and established that the heart is a muscular sac equipped with valves, the contractions of which act as a pump forcing blood into the circulatory system.

Opponents of Harvey's discovery

Having refuted Galen's ideas, Harvey was criticized by contemporary scientists and the church. Opponents of the theory of blood circulation in England called its author the name “circulator”, which was offensive to a doctor. This Latin word translates as “wandering medicine man”, “charlatan”. They also called all supporters of the doctrine of blood circulation circulators. It is noteworthy that the Paris Medical Faculty also refused to recognize the fact of blood circulation in the human body. And this is 20 years after the discovery of blood circulation.

Jean Riolan

The fight against Harvey was led by Jean Riolan son. In 1648, Riolan published the work “Manual of Anatomy and Pathology,” in which he criticized the doctrine of blood circulation. He did not reject it as a whole, but expressed so many objections that, in essence, he crossed out Harvey's discovery. Riolan personally sent his book to Harvey. The main feature of Riolan as a scientist was conservatism. He knew Harvey personally. As physician to Marie de' Medici, the French dowager queen, mother of Henrietta Maria, wife of Charles I, Riolan came to London and lived there for some time. Harvey, as the king's personal physician, when visiting the palace, met with Riolan, demonstrated his experiments to him, but could not convince his Parisian colleague of anything.

Riolan's father was the head of all anatomists of his time. He, like his son, bore the name Jean. Father Riolan was born in 1539, in the village of Montdidier near Amiens, and studied in Paris. In 1574 he received the degree of doctor of medicine and in the same year the title of professor of anatomy. Then he was dean of the Paris Faculty of Medicine (in 1586-1587). Riolan the father was a famous scientist: in addition to medicine, he taught philosophy and foreign languages, left many works on metaphysics and the works of Hippocrates and Fernel; outlined the doctrine of fevers in “Tractatus de febribus” (1640). He died in 1605.

Jean Riolan son was born, studied and received his doctorate in medicine in Paris. Since 1613, he headed the department of anatomy and botany at the University of Paris, and was physician to Henry IV and Louis XIII. The fact that, as the first physician to Henry IV's wife Marie de' Medici, he followed the disgraced queen into exile, treated her for varicose veins and remained with her until her death, enduring countless hardships, speaks volumes about his spiritual qualities.

Riolan the son was an excellent anatomist. His main work, “Anthropographie” (1618), wonderfully describes human anatomy. He founded the "Royal Garden of Medicinal Herbs", a scientific institution, conceived in 1594 by Henry IV. Under the pseudonym Antarretus he wrote a number of polemical articles against Harvey. Through the efforts of this magnificent scientist, the outstanding physician Harvey was slandered at the faculty: “He who allows blood to circulate in the body has a weak mind.”

Guy Paten

A devoted student of Riolan the son of Guy Patin, one of the luminaries of the then medicine, the physician of Louis XIV, wrote about Harvey’s discovery: “We are living through an era of incredible inventions, and I don’t even know whether our descendants will believe in the possibility of such madness.” He called Harvey's discovery “paradoxical, useless, false, impossible, incomprehensible, absurd, harmful to human life,” etc.

Patan's parents prepared him to become a lawyer, and at worst they agreed to become a priest, but he chose literature, philosophy and medicine. In his immense zeal as an orthodox follower of Galen and Avicenna, he was very distrustful of the new means used in medicine in his time. Paten's reactionary attitude may not seem so wild if we remember how many victims the craze for antimonial drugs brought about. On the other hand, he welcomed bloodletting. Even infancy did not save from this dangerous procedure. “Not a day passes in Paris,” writes Patin, “when we do not prescribe bleeding from infants.”

“If medicines do not cure, then death comes to the rescue.” This is a typical reflection of the era when the satire of Molière and Boileau ridiculed the scholastic doctors, who, as they aptly put it, stood with their backs to the patient and their faces to the “holy scriptures.” For his conservatism that knows no bounds, Moliere ridiculed Guy Patin in “Malade imaginoire” (“The Imaginary Invalid”), showing him in the person of Doctor Diafuarus.

For a long time, the Paris Faculty of Medicine was a hotbed of conservatism; it consolidated the authority of Galen and Avicenna by parliamentary decree, and deprived doctors who adhered to the new therapy of practice. The Faculty in 1667 banned blood transfusions from one person to another. When the king supported this saving innovation, the faculty went to court and won the case.

Harvey found defenders. The first among them was Descartes, who spoke out in favor of blood circulation, and thereby greatly contributed to the triumph of Harvey’s ideas.

In 1654, Harvey was unanimously elected president of the London College of Medicine, but declined the position for health reasons.

If Vesalius laid the foundations of modern human anatomy, Harvey created a new science - physiology, a science that studies the function of human and animal organs. I. P. Pavlov called Harvey the father of physiology. He said that the doctor William Harvey spied on one of the most important functions of the body - blood circulation and thereby laid the foundation for a new department of precise knowledge - animal physiology.

Circulation studies after Harvey

Harvey did not know about the existence of capillaries, which he designated as “tissue pores.” He could not see them without a microscope, and the assumption of their existence was a brilliant guess based on correct premises. In 1661, after Harvey's death, capillaries were discovered by Malpighi. After Malpighi's discovery there could no longer be any doubt about the correctness of Harvey's views, which had previously been disputed.

Malpighi, using a microscope, studies the development of the chicken, blood circulation in the smallest vessels, the structure of the tongue, glands, liver, kidneys, and skin. Ruysch became famous for his excellent fillings (injections) of vessels, which made it possible to see vessels where they were previously unsuspected. Over the course of 50 years, Leeuwenhoek found many new facts in the study of all tissues and parts of the human body; discovered blood cells and seminal filaments (spermatozoa).

The next important event in the study of blood circulation was the determination of arterial blood pressure. This was done by measuring the height to which the blood rises in a vertically reinforced glass tube connected to the lumen of the horse's carotid artery (Gels experiment, 1732).

Intensive development of the physiology of blood circulation began only in the 40s of the last century. Since that time, graphic recording of processes occurring in the circulatory system began to be used; The amount of blood in the body was measured, and the importance of various physical factors involved in the movement of blood was studied. At the same time, the study of the regulation of blood circulation began.

An important study that established the existence of nervous influences on the activity of the circulatory system was the work carried out in 1842 in Kyiv by N. I. Pirogov’s student, Walter. He proved that stimulation of the “sympathetic threads” contained in the sciatic nerve of the frog leads to a narrowing of the blood vessels of the leg. Then the inhibitory effect of the anticipatory nerve on the heart was established (Weber brothers, 1845): an increase in heart rate was shown when sympathetic nerve fibers were excited (Pezold, Zion); the influence of various nerves on blood vessels was studied in detail (Claude Bernard); reflex changes in blood circulation were discovered. naturally occurring in response to irritation of afferent fibers coming from the aortic receptors (I. F. Iipn and K. Ludwig). V. Ovsyannikov accurately established that certain areas of the medulla oblongata contain nerve formations, the destruction of which disrupts the reflex regulation of the sogus. At about the same time, N. O. Kovalevsky, M. Traube and others proved that blood circulation changes when carbon dioxide accumulates in the blood.

Thus, for the period 1840-1880. a number of important individual facts characterizing the physical processes occurring in the circulatory system were described in detail, the influence exerted on the heart and blood vessels by nerve fibers approaching them, and changes in blood circulation that reflexively occur during “painful” irritation, bloodletting, asphyxia (suffocation) and other effects on the body. These works revealed some processes that play an important role in the regulation of blood circulation, but could not provide clear ideas about the mechanisms that determine the normal functioning of the circulatory system under normal living conditions.

I. P. Pavlov

For the first time I.P. Pavlov in 1880-1890. with his systematically conducted experiments, he indicated ways to study the normal regulation of blood circulation, showing that the regulation of blood circulation can be studied under conditions of chronic experiment on healthy, non-anesthetized animals. It was in these animals that he established a significant constancy of arterial blood pressure and found that it was maintained due to the constantly ongoing regulatory influence of the central nervous system, leading to the redistribution of blood.

By introducing the technique of “cold cutting” (reversible shutdown by cooling) of the vagus nerve, Pavlov showed the importance of nervous influences in maintaining a relatively constant level of blood pressure.

I.P. Pavlov did not at all belittle the importance of vivisection experiments - his study of the amplifying nerve of the heart is an example of research of this kind. He saw, however, in acute experiments only a means for isolating (analyzing) the role of various factors involved in this or that complex phenomenon, and never forgot that the vivisection technique as such is associated with a disruption of the animal’s normal connections with the environment.

Back in 1882, Pavlov raised in all its breadth the question of the importance of the regulation of blood circulation in maintaining the relative constancy of blood pressure. He wrote about this: “The enormous importance of an accurate study of the devices that guard this desire for constancy is immeasurable.”

After Ludwig, Zion and Pavlov, the physiological mechanisms that ensure the constancy of blood pressure began to be studied in detail again only in the 20s of our century. At the same time, however, foreign researchers focused only on reflexes from two groups of receptors of the vascular system, namely from the endings of the aortic nerve discovered by Zion and Ludwig and from the receptors of the branching region of the common carotid artery discovered about 30 years ago. Meanwhile, Pavlov emphasized back in the 80s that the regulation of blood circulation is carried out due to the action of various stimuli “... on the peripheral endings of the centripetal nerves,” i.e., receptors contained in all organs and all tissues. The irritation of these receptors constitutes, as Pavlov wrote, “the starting point of the reflex,” which “... in the life of a complex organism... is the most significant and most frequent nervous phenomenon.” In particular, all normal regulation of blood circulation is based on reflexes. Thus, I.P. Pavlov 60-70 years ago indicated ways to study the normal regulation of blood circulation as reflex acts arising from various receptors.

Clinical studies have been and are of significant importance in the study of blood circulation. The clinic allows you to study in humans changes in blood circulation caused by one or another damage to the heart, blood vessels, nervous system, etc. The needs of the clinic led to the development of methods for determining blood pressure in the arteries and veins of a person, the amount of blood ejected by the heart. Many works have been carried out to study fluctuations in blood pressure and pulse rate, as well as venous pressure, blood flow speed and the amount of blood ejected by the heart per minute in various diseases and different conditions of the body. Many studies are devoted to the so-called functional diagnostics of the cardiovascular system, the study of the causes and consequences of a long-term increase in blood pressure (hypertension) and its sharp drop (with shock, collapse, blood loss), the study of the mechanism of vascular spasms and blockage of blood vessels, the analysis of changes in heart activity by studying electrical phenomena in it, etc.