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Monday, October 1, 2012

Andreas Vesalius



The Belgian anatomist Andreas Vesalius (1514-1564) was the founder of modern anatomy. His major work, "De humani corporis fabrica," is a milestone in scientific progress.
Andreas Vesalius was born on Dec. 31, 1514, in Brussels, the son of Andries van Wesele and his wife, Isabel Crabbe. Vesalius's paternal ancestors, who hailed from the German town of Wesel, came to Brussels in the early 15th century and became prominent as physicians and pharmacists. His father served as pharmacist to Margaret of Austria and later to Emperor Charles V. His great-grandfather, Johannes Wesalia, was the head of the medical school at the University of Louvain, where Vesalius started his medical studies in 1530. He matriculated as Andres van Wesel de Bruxella.
In 1533 Vesalius transferred to the medical school of the University of Paris. One of his two teachers of anatomy there was Johann Guenther von Andernach, a personable man but a poor anatomist. The other was Jacobus Sylvius, who departed from tradition by giving some role to dissecting in anatomical instructions. Both teachers gave in their own ways a telling testimony of their student's anatomical expertise. Guenther, in a book published in 1536, recorded in glowing terms Vesalius's discovery of the spermatic vessels. Sylvius, however, decried violently Vesalius's daring claim that Galen, the great authority in physiology since classical times, wrote on the inner organs of the body without ever seeing them.
Because of the outbreak of war between France and Charles V, Vesalius, a citizen of the Low Countries, which were a part of the Holy Roman Empire, had to leave Paris in 1536. He returned to Louvain, where, at the recommendation of Guenther, Vesalius, still a student, was permitted to conduct public dissections. He also published a Paraphrase of the Ninth Book of Rhazes (Rhazes, also known as al-Rasi, was a Moslem physician of the early 10th century), in which he made a considerable effort to substitute Latin terms for the still heavily Arabic medical terminology.
But Vesalius soon became embroiled in disputes with faculty members, evidencing both his genius and his quarrelsome character. He was practically compelled to go the next year to the University of Padua. There Vesalius passed his doctoral examination with such honors in December 1537 that he was immediately appointed professor of surgery and anatomy. In 1538 he published six sheets of his anatomical drawings under the title Tabulae anatomicae sex. The publication was a signal success. Because of the great demand the sheets soon were reprinted, without Vesalius's authorization, in Cologne, Paris, Strasbourg, and elsewhere. In 1539 there followed his essay on bloodletting in which he first described the veins that draw blood from the side of the torso. This opened the way to the study of the venous values and led ultimately to the discovery of the circulation of blood by William Harvey.
Major Work
Vesalius's commitment to actual observing was much in evidence in his edition of some of Galen's works in 1540 but especially in his epoch-making De humani corporis fabrica libri septem (Seven Books on the Construction of the Human Body), published in 1543 in Basel. Book 1 on the bones was generally correct but represented no major advance. Book 2 on the muscles was a masterpiece. Book 3 on blood vessels was exactly the opposite. Somewhat better was book 4 on the nerves, a great advance on everything written on the topic before, but it was largely outmoded a century later. Excellent was his treatment in book 5 of the abdominal organs. Book 6 dealt with the chest and neck, while book 7 was devoted to the brain. Some of the woodcut illustrations of the Fabrica are among the best of 16th-century drawings and probably were executed by Jan Stephan van Calcar. Vesalius's own drawings were of moderate value. The revolutionary aspect of the work was the dominating role of observation as the very foundation of progress in anatomy. The importance of the large folio was immediately recognized by the fact that almost simultaneously with the original an epitome of it was published.
Vesalius was, like some other geniuses of his age, such as Copernicus and Thomas More, a daring innovator and a strong traditionalist at the same time. Thus Vesalius, the meticulous observer, did not part with Galen as far as theory was concerned. He was also a child of his age in carefully paving his way into the imperial court. No sooner was his Fabrica published than he sought service on the medical staff of Charles V and was immediately accepted.
In 1544 Vesalius married Anne von Hamme and also increased his holdings by a substantial inheritance from his father. In 1546 came his Letter on the Chinese Root, on a worthless but very popular medicine. The letter's true significance derived from the fact that in it Vesalius replied to the detractors of his Fabrica and corrected some of its erroneous statements. From 1553 on Vesalius had private practice as a physician in Brussels, and in 1556 his official ties with the court of Charles V came to an end.
The second edition of the Fabrica, in 1555, contained many improvements on the first, but in retrospect it was also a disappointment. One wonders about the new course medicine might have taken, had Vesalius dedicated himself completely to the cause of anatomical research. Some time after the accession of Philip II to the imperial throne, Vesalius became again one of the imperial physicians. Vesalius's absence from medical schools showed itself in his Examination of Gabriele Fallopio's Anatomic Observations (1561), in which he had to avoid passing judgment on a number of points in Fallopio's book because he had no way of verifying them.
It is a moot question whether Vesalius used a pilgrimage to the Holy Land in 1564 as a pretext to leave Spain and the imperial court. Some claimed that he went to the Holy Land to study medicinal plants on the plains of Jericho, a topic on which he is known to have discoursed on his way there. Vesalius might have very well made the pilgrimage out of devotion, as did many millions before and after him. Upon his return from Jerusalem he was to take the chair of the suddenly deceased Fallopio in Padua, but he died on the island of Zenta off the Greek coast.