Editing Andreas Vesalius (section)

== Medical career and accomplishments ==
On the day of his graduation he was immediately offered the chair of surgery and anatomy (''explicator chirurgiae'') at the [[University of Padua]]. He also guest-lectured at the [[University of Bologna]] and the [[University of Pisa]]. Prior to taking up his position in Padua, Vesalius traveled through Italy and assisted the future [[Pope Paul IV]] and [[Ignatius of Loyola]] to heal those afflicted by [[leprosy]]. In Venice he met the illustrator [[Jan van Calcar|Johan van Calcar]], a student of Titian. It was with van Calcar that Vesalius published his first anatomical text, ''Tabulae Anatomicae Sex'', in 1538.<ref>{{cite web|url=http://thephysicianspalette.com/2014/12/01/vesalius-at-500/|title=Vesalius at 500|work=The Physician's Palette|archive-url=https://web.archive.org/web/20141210143700/http://thephysicianspalette.com/2014/12/01/vesalius-at-500/|archive-date=10 December 2014}}</ref> Previously these topics had been taught primarily from reading classical texts, mainly [[Galen]], followed by an animal dissection by a barber–surgeon whose work was directed by the lecturer.<ref name=":4">{{Cite journal |last=Gumpert |first=Martin |date=1948 |title=Vesalius: Discoverer of the Human Body |url=http://www.jstor.org/stable/24945814 |journal=Scientific American |volume=178 |issue=5 |pages=24–31 |doi=10.1038/scientificamerican0548-24 |jstor=24945814 }}</ref> No attempt was made to confirm Galen's claims, which were considered unassailable. Vesalius, in contrast, performed dissection as the primary teaching tool, handling the actual work himself and urging students to perform dissection themselves. He considered hands-on direct observation to be the only reliable resource.

Vesalius created detailed illustrations of anatomy for students in the form of six large woodcut posters. When he found that some of them were being widely copied, he published them all in 1538 under the title ''Tabulae anatomicae sex''. He followed this in 1539 with an updated version of Winter's anatomical handbook, ''Institutiones anatomicae.''

In 1539 he also published his ''Venesection Epistle'' on [[bloodletting]]. This was a popular treatment for almost any illness, but there was some debate about where to take the blood from. The classical Greek procedure, advocated by Galen, was to collect blood from a site near the location of the illness. However the Muslim and medieval practice was to draw a smaller amount of blood from a distant location. Vesalius' pamphlet generally supported Galen's view but with qualifications that rejected the infiltration of Galen.

In Bologna, Vesalius discovered that all of Galen's research was restricted to animals, since the tradition of Rome did not allow dissection of the human body.<ref name=":1">{{Cite web |date=27 April 2021 |title=Comparative Anatomy: Andreas Vesalius – Understanding Evolution |url=https://evolution.berkeley.edu/the-history-of-evolutionary-thought/pre-1800/comparative-anatomy-andreas-vesalius/ |access-date=7 January 2023 |language=en-US}}</ref> Galen had dissected [[Barbary macaque]]s instead, which he considered structurally closest to man. Even though Galen was a qualified examiner, his research produced many errors owing to the limited anatomical material available to him.<ref>{{Cite book|title=Andreas Vesalius of Brussels, 1514–1564|last=O'Malley|first=Charles Donald|publisher=Berkeley : University of California Press|year=1964}}</ref> Vesalius contributed to the new Giunta edition of Galen's collected works and began to write his own anatomical text based on his own research. Until Vesalius pointed out Galen's substitution of animal for human anatomy, it had gone unnoticed and had long been the basis of studying human anatomy.<ref name=":4" />

Unlike Galen, Vesalius was able to procure a steady supply of human cadavers for dissection. In 1539, a judge at the Padua criminal court had been interested by Vesalius' work and had agreed to regularly supply him the cadavers of executed criminals.<ref name=":1" /><ref name=":2" />

Galen had assumed that arteries carried the purest blood to higher organs such as the brain and lungs from the left ventricle of the heart, while veins carried blood to the lesser organs such as the stomach from the right ventricle. In order for this theory to be correct, some kind of opening was needed to interconnect the ventricles, and Galen claimed to have found them. So paramount was Galen's authority that for 1400 years a succession of anatomists had claimed to find these holes, until Vesalius admitted he could not find them. Nonetheless, he did not venture to dispute Galen on the distribution of blood, being unable to offer any other solution, and so supposed that it diffused through the unbroken partition between the ventricles.<ref name="Corporation1872">{{cite journal|author=Bonnier Corporation|title=Popular Science|journal=The Popular Science Monthly|url=https://archive.org/details/bub_gb_qR8DAAAAMBAJ|date=May 1872|publisher=Bonnier Corporation|pages=[https://archive.org/details/bub_gb_qR8DAAAAMBAJ/page/n99 95]–100|issn=0161-7370}}</ref>

Other famous examples of Vesalius disproving Galen's assertions were his discoveries that the lower jaw ([[mandible]]) was composed of only one bone, not two (which Galen had assumed based on animal dissection) and that humans lack the [[rete mirabile]], a network of blood vessels at the base of the brain that is found in sheep and other [[ungulates]].

[[File:Skelett im Anatomischen Museum Basel - 4675.jpg|thumb|upright|The skeleton of Jakob Karrer, articulated by Vesalius in 1543]]
In 1543, Vesalius conducted a public dissection of the body of Jakob Karrer von Gebweiler, a notorious felon from the city of [[Basel]], [[Switzerland]]. He assembled and articulated the bones, finally donating the [[skeleton]] to the [[University of Basel]]. This preparation ("The Basel Skeleton") is Vesalius' only well-preserved skeletal preparation, and also the world's oldest surviving anatomical preparation. It is still displayed at the Anatomical Museum of the [[University of Basel]].<ref>{{cite web|url=http://www.vhsbb.ch/asp/pdf/senuni_07021213_zf_kurz.pdf |title=Archived copy |access-date=10 October 2009 |url-status=dead |archive-url=https://web.archive.org/web/20070927043755/http://www.vhsbb.ch/asp/pdf/senuni_07021213_zf_kurz.pdf |archive-date=27 September 2007 }}</ref>

In the same year Vesalius took residence in Basel to help [[Johannes Oporinus]] publish the seven-volume ''[[De humani corporis fabrica]]'' (''On the fabric of the human body''), a groundbreaking work of [[human anatomy]] that he dedicated to Charles V. Many believe it was illustrated by [[Titian]]'s pupil [[Jan Van Calcar|Jan Stephen van Calcar]], but evidence is lacking, and it is unlikely that a single artist created all 273 illustrations in a period of time so short. At about the same time he published an abridged edition for students, ''Andrea Vesalii suorum de humani corporis fabrica librorum epitome'', and dedicated it to [[Philip II of Spain]], the son of the Emperor. That work, now collectively referred to as the [[De humani corporis fabrica|Fabrica of Vesalius]], was groundbreaking in the history of medical publishing and is considered to be a major step in the development of scientific medicine. Because of this, it marks the establishment of anatomy as a modern descriptive science.<ref name=":0">{{Cite journal|last=Harcourt|first=Glenn|date=1 January 1987|title=Andreas Vesalius and the Anatomy of Antique Sculpture|journal=Representations|language=en|volume=17|issue=17|pages=28–61|doi=10.2307/3043792|issn=0734-6018|jstor=3043792|pmid=11618035}}</ref>

Though Vesalius' work was not the first such work based on actual dissection, nor even the first work of this era, the production quality, highly detailed and intricate plates, and the likelihood that the artists who produced it were clearly present in person at the dissections made it an instant classic. Pirated editions were available almost immediately, an event Vesalius acknowledged in a printer's note would happen. Vesalius was 28 years old when the first edition of ''Fabrica'' was published.