Editing Andreas Vesalius (section)

== Scientific findings ==

=== Skeletal system ===
[[File:Andreas Vesalius-Pierre Poncet.jpg|thumb|Andreas Vesalius by Pierre Poncet (1574–1640)]]
* Vesalius believed the [[skeletal system]] to be the framework of the human body.  It was in this opening chapter or book of [[De humani corporis fabrica|''De fabrica'']] that Vesalius made several of his strongest claims against [[Galen|Galen's]] theories and writings which he had put in his anatomy books. In his extensive study of the skull, Vesalius claimed that the [[Human mandible|mandible]] consisted of one bone, whereas Galen had thought it to be two separate bones. He accurately described the [[Vestibule of the ear|vestibule]] in the interior of the [[temporal bone]] of the skull.
* In [[Galen|Galen's]] observation of the ape, he had discovered that their [[sternum]] consisted of seven parts which he assumed also held true for humans.  Vesalius discovered that the [[human sternum]] consisted of only three parts.
* He also disproved the common belief that men had one rib fewer than women and noted that the [[fibula]] and [[tibia]] bones of the leg were indeed larger than the [[humerus]] bone of the arm, unlike [[Galen]]'s original findings.

=== Muscular system ===

* One of Vesalius' contributions to the study of the [[muscular system]] is the illustrations that accompany the text in ''De fabrica'', which would become known as the "muscle men".  He describes the source and position of each muscle of the body and provides information on their respective operation.

=== Vascular and circulatory systems ===

* Vesalius' work on the [[Blood vessel|vascular]] and [[circulatory system]]s was his greatest contribution to modern medicine. In his dissections of the heart, Vesalius became convinced that Galen's claims of a porous [[interventricular septum]] were false. This fact was previously described by [[Michael Servetus]], a fellow of Vesalius, but never reached the public, for it was written down in the "Manuscript of Paris",<ref>[http://www.michaelservetusresearch.com/ENGLISH/works.html Michael Servetus Research] {{Webarchive|url=https://web.archive.org/web/20121113223851/http://www.michaelservetusresearch.com/ENGLISH/works.html |date=13 November 2012 }} Website with graphical study on the Manuscript of Paris by Servetus</ref> in 1546, and published later in his ''Christianismi Restitutio'' (1553), a book regarded as heretical by the [[Inquisition]]. Only three copies survived, but these remained hidden for decades, the rest having been burned shortly after publication. In the second edition Vesalius published that the septum was indeed waterproof, discovering (and naming), the [[mitral valve]] to explain the blood flow.
* Vesalius believed that [[systole (medicine)|cardiac systole]] is synchronous with the [[Pulse (anatomy)|arterial pulse]].
* He not only verified [[Charles Estienne|Estienne's]] findings on the valves of the [[hepatic veins]], but also described the [[azygos vein]], and discovered the canal which passes into the fetus between the [[umbilical vein]] and [[vena cava]].

=== Nervous system ===

* Vesalius defined a nerve as the mode of transmitting sensation and motion and thus refuted his contemporaries' claims that [[ligament]]s, [[tendon]]s and [[aponeuroses]] were three types of nerve units.  
* He believed that the brain and the nervous system are the center of the mind and emotion in contrast to the common [[Aristotelianism|Aristotelian]] belief that the heart was the center of the body. He correspondingly believed that nerves themselves do not originate from the heart, but from the brain—facts already experimentally proved by [[Herophilus]] and [[Erasistratus]] in the classical era, but suppressed after the adoption of Aristotelianism by the Catholic Church in the Middle Ages.
* Upon studying the [[optic nerve]], Vesalius came to the conclusion that nerves were not hollow.

=== Abdominal organs ===

* In ''De fabrica'', he corrected an earlier claim he made in ''Tabulae'' about the right kidney being set higher than the left.  Vesalius claimed that the kidneys were not a filter device for urine to pass through, but rather that the kidneys serve to filter blood as well, and that excretions from the kidneys travelled through the [[ureters]] to the bladder.
* He described the [[Greater omentum|omentum]], and its connections with the stomach, the spleen and the colon gave the first correct views of the structure of the [[pylorus]].
* He also observed the small size of the [[Appendix (human)|caecal appendix]] in man and gave the first good account of the [[mediastinum]] and [[pleura]].
* Vesalius admitted that due to a lack of pregnant cadavers he was unable to come to a significant understanding of the reproductive organs.  However, he did find that the uterus had been falsely identified as having two distinct sections.

=== Heart ===

* Through his work with muscles, Vesalius believed that a criterion for muscles was their voluntary motion.  On this claim, he deduced that the heart was not a true muscle due to the obvious involuntary nature of its motion.
* He identified two chambers and two atria. The [[right atrium]] was considered a continuation of the [[Inferior vena cava|inferior]] and [[Superior vena cava|superior]] [[venae cavae]], and the [[left atrium]] was considered a continuation of the [[pulmonary vein]].
* He also addressed the controversial issue of the heart being the centre of the soul.  He wished to avoid drawing any conclusions due to possible conflict with contemporary religious beliefs.[[File:1543, Andreas Vesalius' Fabrica, Base Of The Brain.jpg|thumb|Base of the [[Human brain|brain]], showing the [[optic chiasm]]a, [[cerebellum]], [[olfactory bulb]]s, etc.]]
* Against Galen's theory and many beliefs he also discovered that there was no hole in the [[septum]] or [[heart]].

=== Other achievements ===
* Vesalius disproved Galen's assertion that men have more teeth than women.<ref name=NPO>{{cite web|title=Vesalius was belangrijker dan Copernicus|url=http://nos.nl/artikel/2011283-vesalius-was-belangrijker-dan-copernicus.html|author=Lambert Teuwissen|publisher=[[Nederlandse Publieke Omroep (organization)|Nederlandse Publieke Omroep]]|language=nl|date=31 December 2014|access-date=5 February 2015}}</ref>
* Vesalius introduced the notion of induction of the extraction of [[empyema]] through surgical means.
* Due to his study of the human skull and the variations in its features he is said to have been responsible for the launch of the study of [[physical anthropology]].
* Vesalius always encouraged his students to check their findings, and even his own findings, so that they could better understand the structure of the human body.
* In addition to his continual efforts to study anatomy he also worked on medicinal remedies and came to such conclusions as treating [[syphilis]] with [[Smilax glabra|chinaroot]].
* Vesalius claimed that medicine had three aspects: drugs, diet, and 'the use of hands'—mainly suggesting surgery and the knowledge of anatomy and physiology gained through dissection.
* Vesalius was a supporter of 'parallel dissections' in which an animal cadaver and a human cadaver are dissected simultaneously in order to demonstrate the anatomical differences and thus correct Galenic errors.