How the most important discovery in history about the functioning of the body was made – BBC News



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2018/09/02

In the mid-seventeenth century there was a kind of sui generis competition between France and England, which revolved around blood transfusions.

In Oxford, a group of young researchers who wanted to discover each other and the idea of ​​injecting blood directly from one animal to another, first met them, Dick Lower, in 1664.

In 1666, Lower made his first transfusion experiment, letting the blood pass from an artery of two large mastiffs (one after the other) to the vein of a small dog.

At the end of the experiment, the Mastiffs were dead and the ground was flooded with blood, but the little dog "jumped off the table and, apparently unaware of his injuries, began to caress his master and rolled over the grass to purify blood. . "

The highlight of the experiments came in November 1667: Lower performed the first blood transfusion in a human at the newly established Royal Society in London.

The English physiologist Richard Lower (1631-1691) transfused blood from a lamb to the arm of a man in 1667.

There were reports that the experiment it had already been successfully tested in Parisbut they were not confirmed, so speed was essential.

And a man named Arthur Coga, described as an "eccentric scholar", was persuaded to allow a blood transfusion of lamb, which was done successfully.

One of the objectives of the experiment was to see what qualitiescan be transmitted through the blood transfusion.

Can the blood of a Quaker, for example, calm a violent man?

The discovery of Harvey

However, the transfusion experiments had to be abandoned when one of the volunteers died in Paris.

And the blood transfusion as a treatment it would not be revived until the 20th centurywhen a lot of progress was made in the knowledge of blood and its properties.

It would take centuries before blood transfusions were made again. Here an article from 1922 entitled "The heroism of a doctor".

The question, however, is why this interest in transfusion in the 1660s?

Almost 2000 years in the West there were doctors taking blood your patients to heal them.

Why was someone thinking about giving him blood?

The reason is that the idea was only unthinkable until the discovery of the circulatory system, made by the doctor William Harvey at the beginning of the 17th century in London.

The familiar and indisputable

Blood circulation is the most important discovery that has been made about how the body works, because it underlies our current understanding and all investigations into its functioning.

Until the discovery of Harvey, everyone (doctors, skilled people, Shakespeare, anybody) They knew the blood was moving, but not that it was circulating.

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Galen was brilliant, but the attitude of the doctors to religiously hold his words centuries later was not true.

They believed that, as the ancient Greek physician Galen said, there were two blood systems in humans.

The first consisted of the arteries that arose from the heart, and in them it was blood the vehicle of the spirits: the spirits breathed in the lungs and in the arteries they served to keep the body vitalized.

The veins, on their side, came from the liver and in them was the blood just those things of nutritionit was the fluid that produced the liver from the food we ate, and it was slowly spread throughout the body to the whole body to feed all parts.

According to this model, all blood in both systems, arteries and veins went out and was used to keep the body alive.

There was nothing that required explanation.

And all learned drugs (diagnosis, prognosis and treatment) it was based on this concept about the two different types of blood, each with its specific role.

Frontal challenge for the established

In his book from 1628, however, Harvey showed for the first time that everything anatomists thought about the heart and veins was contradictory and confusing.

"therefore"Said Harvey,"it would be useful to explore deeper the caseand consider the movements of the arteries and the heart, not only in man, but also in all other beings who have a heart; So so also do frequent dissections of living beings, and with a lot of eye testimony, differentiate and search the truth".

The title of the book was "Anatomical exercises on the movement of the heart and blood in animals".

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The title of the book was "Anatomical exercises on the movement of the heart and blood in animals".

His task was extremely complicated, because the movements of the heart are very fast, especially under the stress of vivisection.

"I immediately noticed that it was something difficult to achieve (…) I almost believed that the movement of the heart was known only by God(…) because of the speed of movement, that in some beings he appeared in an instant, like the passing of lightning", is in" Anatomical Exercises … ".

But what was crucial in Harvey's research was the fact that he studied all animals, not only creatures such as man – with heart and lungs – but also those with hearts, but not with lungs.

That is what has allowed him to decipher what the heart does … any heart, all the hearts: pass the blood from the veins to the arteries and then pump it to the whole body.

The only explanation: circulation

"It was after a long thought and reflection How much it is abundant donate blood (for the body), and in How much short period of time,Which I finally saw that or the veins they were completely empty and the arteries about to explode with too much blood burglary, or the blood I came back to go from the veins to the arteries and I came back to the right ventricle of the heart", Harvey describes.

"I started thinking if it would not be the movement was completesomething that I later discovered was true".

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Before William Harvey discovered that the blood circulated, it was inconceivable to bring blood to the body; the only thing that was believed that could be done was the removal.

Thanks to this and other observations, Harvey could confidently describe the movement of the heart.

"PThe atrium contracts that with its contraction the blood it contains in the ventricle throws. With this the heart that stands up is full, tensions all his fibers pulls his ventricles together and carries out his battle; by of the pulsation continuously releases the blood that it received from the atrium through the arteries".

But Harvey hesitated to publish his findings. He had solved the questions about the movement of the heart and the blood in the animals, but the last answer (that circulates the blood) was totally unexpected for him.

"Esas things (…) they are so new and unknown that I am not only afraid that hurt me because of the bad will of other people, but I'm also afraid that every man is my enemy, in front of custom and doctrine have received the upper hand once and deeply rooted"he wrote.

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That is why he took precautions before he published. He repeatedly showed his findings to his colleagues at the London College of Physicians for assessment. And how personal doctor of the kingCharles I assumed a flowery devotion in the hope that the prince would place his book under royal protection.

"Very gracious king, andThe heart of creatures is the basis of life, the Prince of all, the Sun of his Microcosm, () from which all power and strength flow. In the same way, the king is the foundation of his kingdoms () where all strength and grace comes from"says the dedication.

It is all a disaster

Unfortunately, the protection of the king was not very useful. His announcement of the discovery turned out to be a disaster. Your private patients, as well as the general public, they thought I was "crazy" and they have left it; and most of the anatomists and doctors turned against him.

It was only after two decades that the tide changed in his favor.

In his enthusiasm to reject his theory with evidence, some of his colleagues felt he was right and he had to admit his mistake and the validity of Harvey's finding.

Around the time of Harvey's death, in 1657, the idea of ​​blood circulation was so accepted that these young people at Oxford, led by Dick Lower, might think of a transfusion.

And the blood transfusion undoubtedly confirmed that the heart was the driving force of the body.


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