Fabio Zampieri
Alberto Zanatta
Padua, Italy

Born in Brussels in 1514, Andreas Vesalius studied Latin, Greek, and Hebrew in Leuven, and medicine in Paris. Arriving in Padua, at that time “the most famous gymnasium in the world,” he graduated in medicine in 1537 and was professor of anatomy from 1538 to 1543.¹

In Padua, Vesalius would have been able to read Galen and other classic works in the original Greek texts obtained from nearby Venice. Already the Venetian humanist Aldo Manuzio had published Aristotle’s work between 1495 and 1498 and Galen’s Opera Omnia in 1525. Vesalius could also improve his skills in dissection, practiced in Padua from the fourteenth century. Pietro d’Abano (1257-1316) reported in De venenis, composed around 1303 and published in 1472, the first autopsy, done in Padua on an apothecary who died from the accidental ingestion of mercury.² Anatomy had been taught there at the university for some time, as indicated by a statute ordaining that each year the cadavers of two executed criminals were to given to the university for dissection. Also in Padua practiced many of the most important pre-Vesalian anatomists, such as Gabriele de Zerbi (†1505), Alessandro Benedetti (1450-1512), and Nicolò Massa (1485-1569).

In this favorable environment Vesalius was able to change the culture from medieval speculative learning to modern natural philosophy.³ He demonstrated that the human body was an extraordinarily complex “fabric,” to be studied and shown to be work of God, whereas during the Middle Ages it was not considered a noble object of investigation. Vesalius stressed this in the Preface of the Fabrica: “[. . .] the wonderful knowledge of the human body attests the wisdom of the immense Creator.”⁴ Vesalius also emphasized that no theory could be sustained unless supported by empirical observations. In the preface of the Fabrica, Vesalius decried the practice of physicians relegating “the use of the work of hands” to inexperienced and ignorant surgeons and barbers, strongly affirming the notion that surgery was an ancient and useful part of medicine, based on the “investigation of nature.” Thus his revolutionary founding of modern human anatomy consisted of three main points: 1) anatomical teaching; 2) anatomical divulgation; and 3) anatomical emancipation from Galen.

In the Middle Ages the “quodlibetarian” model of teaching anatomy required three “actors”: 1) “Lector”, the anatomy professor, who read from the classic textbooks without touching the cadaver; 2) “Ostensor”, the assistant, who pointed to the parts of the cadaver described by the professor; and the 3) “Sector”, the vulgar “barber,” practically performing the dissection with his hands. Vesalius described this model with sarcastic words: “[. . .] the hateful method by which one dissects the body and another describes its parts: this latter, perched on a pulpit like a crow, haughtily repeats ideas that he didn’t learn directly from the cadaver, but that he read in other’s books.”⁴ Both in the hardcover of the Fabrica and in Vesalius’ portraits inside the book, his innovation can immediately be appreciated. In the first image, Vesalius is depicted dissecting the cadaver of a woman, touching the body with his right hand, pointing with the finger of his left hand, and thus personifying all the three actors of the previous method.

These illustrations introduce the second point of Vesalius’ revolution. Before him, anatomy was taught without images. In Vesalius’ book there are more than 250 illustrations, some of the whole body, some of specific organs and parts of organs, some of anatomical instruments and techniques. Many of them show cadavers in allegorical poses and imaginary landscapes. These art pieces were attributed to Jan Steven van Calcar (1499–1546), a German-born Italian painter working at the Titian (about 1490-1576) school of painting in Venice, which was focused on the vivid representation of nature, an approach consonant with that of Vesalius. As described by Vesalius, the Fabrica “[. . .] contains illustrations of all the parts, as the scholars of medicine can keep an eye on the whole of nature’s works, such as there should be a body dissected in front of them.” Moreover, Vesalius stressed the value of anatomical illustration with this significant comparison: “Everybody has experienced in geometry and mathematics how figures are useful and how they results clearer than a discourse even much detailed.”⁴

Thanks to his descriptions and illustrations Vesalius demonstrated that Galen’s anatomy was erroneous – the third point of his revolution. It was heresy to be against Galen at that time, because he was considered to be the preeminent authority in medicine, especially as his original texts had only recently been translated. Vesalius was well aware “[. . .] how physicians [. . .] are upset when they ascertain that Galen, in the course of just one anatomical demonstration, gets wrong more than 200 times in the description of the parts, the harmony, the use and the function of human body.”⁴ Vesalius also showed why Galen was wrong: “Indeed, those who are now dedicated to the ancient study of medicine [. . .] are beginning to learn to their satisfaction how little and how feebly men have laboured in the field of anatomy to this day from the times of Galen, who [. . .] did not dissect the human body; and the fact is now evident that he described the fabric of the ape’s body, although the latter differs from the former in many aspects.”⁴

Vesalius’ new anatomy gave rise to a new morphological knowledge as well as also to a new physiology, which fully developed in the following century. In the Tabulae anatomicae sex, six anatomical tables published by Vesalius in 1538,⁵ at the beginning of his academic carrier, he presented some of the fundamental anatomical errors underlying Galen’s physiology.⁶ Probably the most significant among these was the idea that interventricular septum of the heart was pervious, so that blood could pass from the right to the left ventricle, where “vital spirit” was created by the mixing of the blood and the air coming to the heart from the pulmonary vein. In the first edition of the Fabrica, Vesalius expressed doubts about the patency of interventricular septum: “Thus we are compelled to astonishment at the industry of the Creator who causes the blood to sweat from the right ventricle into the left through passages which escapes our sight.”⁴ In the second edition of 1555, Vesalius clearly denied the existence of these structures: “However much the pits may be apparent, yet none, as far as can be comprehended by sense, passes through the septum of the heart from the right ventricle into the left. I have not seen even the most obscure passages by which the septum of the ventricles is pervious, although they are mentioned by professors of anatomy since they are convinced that blood is carried from the right ventricle to the left. As a result – as I shall declare more openly elsewhere – I am in no little doubt regarding the function of the heart in this part.”⁷

The last part of this quotation is extremely significant, because from it emerged a new physiology of the heart. In another passage of the Fabrica this idea became explicit: “In presenting reasons for the construction of the heart and the use of the parts I have in large degree fitted my discourse to the teachings of Galen, not because I believe them to be in entire agreement with the truth, but because I am yet hesitant to present a completely new use and function for those parts.”⁷ If the blood could not pass from the right to the left ventricle through interventricular septum, it was necessary to think an alternative way. This passage remained mandatory, otherwise the fact that arteries were filled up by blood would have been inexplicable.

It is not fortuitous that the pulmonary circulation was first described by Realdo Colombo (1516-1559) in his 1559 De re anatomica. Colombo was student of Vesalius and his successor at the chair of Surgery and Anatomy in Padua. It is probable that the doubts and suggestions of his master influenced Colombo to find the solution. The pulmonary circulation was the starting point to think about systemic circulation and again related to Padua, because of William Harvey (1578-1657) who was a student in Padua, from where he graduated in 1602 and declared his debt to its medical school.

This extraordinary sequence of discoveries, which brought to a complete rethinking not only of human anatomy, but also of human physiology, started with Vesalius and his revolution in anatomy. His innovations affected all medical sciences, based as they were on a new method of research in medicine and a new approach to nature.

References

1. O’Malley C. Andreas Vesalius of Brussels 1514-1564. Berkeley and Los Angeles: University of California Press, 1964.
2. D’Abano P. Conciliator differentiarum philosophorum et praecipue medicorum, cum tractatu de venenis. Mantuae: per Thomam Septem Castrensem et Johannem Burster, 1473.
3. Cassirer E. The Place of Vesalius in the Culture of the Renaissance. Yale J Biol Med 1943;16(2):109-120.
4. Vesalius A. De humani corporis fabrica libri septem. Basileae: ex officina Ioannis Oporini, 1543.
5. Vesalius A. Tabulae anatomicae sex. Venetiis: sumptibus Ioannis Stephani Calcarensis, 1538.
6. Zampieri F, Basso C, Thiene G. Andreas Vesalius’ Tabulae anatomicae sex (1538) and the seal of the American College of Cardiology. J Am Coll Cardiol 2014;63(7):694-695.
7. Vesalius A. De humani corporis fabrica libri septem. Basileae: Per Iannem Oporinum, 1555.