Editing Leonardo da Vinci (section)

=== Anatomy and physiology ===
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| image1 = Leonardo da Vinci - RCIN 919000, Verso The bones and muscles of the arm c.1510-11.jpg
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| caption1 = Anatomical study of the arm ({{circa|1510|lk=no}})
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| caption2 = Leonardo's physiological sketch of the human brain and skull ({{circa|1510|lk=no}})
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Leonardo started his study in the [[anatomy]] of the [[human body]] under the apprenticeship of Verrocchio, who demanded that his students develop a deep knowledge of the subject. As an artist, he quickly became master of ''topographic anatomy'', drawing many studies of [[muscle]]s, [[tendon]]s and other visible anatomical features.{{citation needed|date=January 2023}}

As a successful artist, Leonardo was given permission to [[Dissection|dissect]] human corpses at the [[Hospital of Santa Maria Nuova]] in Florence and later at hospitals in Milan and Rome. From 1510 to 1511 he collaborated in his studies with the doctor [[Marcantonio della Torre]], professor of Anatomy at the [[University of Pavia]].<ref>{{cite encyclopedia |url=https://www.britannica.com/biography/Leonardo-da-Vinci/Second-Florentine-period-1500-08 |title=Leonardo da Vinci |encyclopedia=Britannica|access-date=9 August 2022|archive-date=9 August 2022|archive-url=https://web.archive.org/web/20220809222523/https://www.britannica.com/biography/Leonardo-da-Vinci/Second-Florentine-period-1500-08|url-status=live}}</ref> Leonardo made over 240 detailed drawings and wrote about 13,000 words toward a treatise on anatomy.<ref name=Sooke /> Only a small amount of the material on anatomy was published in Leonardo's ''Treatise on Painting''.<ref name=KDK /> During the time that Melzi was ordering the material into chapters for publication, they were examined by anatomists and artists, including [[Giorgio Vasari|Vasari]], [[Benvenuto Cellini|Cellini]] and [[Albrecht Dürer]], who made drawings from them.<ref name=KDK />

Leonardo's anatomical drawings include many studies of the [[human skeleton]] and its parts, and of muscles and sinews. He studied the mechanical functions of the skeleton and the muscular forces that are applied to it in a manner that prefigured the modern science of [[biomechanics]].<ref name=Mason>{{cite book |last=Mason |first=Stephen F. |title=A History of the Sciences |url=https://archive.org/details/historyofscience00maso |url-access=registration |publisher=Collier Books |year=1962 |location=New York |page=[https://archive.org/details/historyofscience00maso/page/550 550]}}</ref> He drew the heart and [[Circulatory system|vascular system]], the [[sex organs]] and other internal organs, making one of the first scientific drawings of a [[fetus]] ''in utero''.<ref name=Popham /> The drawings and notation are far ahead of their time, and if published would undoubtedly have made a major contribution to medical science.<ref name=Sooke>[[Alastair Sooke]],  [https://www.telegraph.co.uk/culture/art/leonardo-da-vinci/10202124/Leonardo-da-Vinci-Anatomy-of-an-artist.html "Leonardo da Vinci: Anatomy of an artist"], ''Daily Telegraph'', 28 July 2013. {{Webarchive|url=https://web.archive.org/web/20191202055415/https://www.telegraph.co.uk/art/artists/leonardo-da-vinci-met-death-dissected-corpses-embryos-hearts/ |date=2 December 2019 }}, accessed 29 July 2013.</ref>

Leonardo also closely observed and recorded the effects of age and of human emotion on the physiology, studying in particular the effects of rage. He drew many figures who had significant facial deformities or signs of illness.{{sfn|Arasse|1998}}<ref name=Popham /> Leonardo also studied and drew the anatomy of many animals, dissecting cows, birds, monkeys, bears, and frogs, and comparing in his drawings their anatomical structure with that of humans. He also made studies of horses.<ref name=Popham />

Leonardo's dissections and documentation of muscles, nerves, and vessels helped to describe the physiology and mechanics of movement. He attempted to identify the source of 'emotions' and their expression. He found it difficult to incorporate the prevailing system and theories of [[humorism|bodily humours]], but eventually he abandoned these physiological explanations of bodily functions. He made the observations that humours were not located in cerebral spaces or [[Ventricular system|ventricles]]. He documented that the humours were not contained in the heart or the liver, and that it was the heart that defined the circulatory system. He was the first to define [[atherosclerosis]] and liver [[cirrhosis]]. He created models of the cerebral ventricles with the use of melted wax and constructed a glass [[aorta]] to observe the circulation of blood through the aortic valve by using water and grass seed to watch flow patterns.<ref name="Jones2012">{{cite journal |last1=Jones |first1=Roger |title=Leonardo da Vinci: anatomist |journal=British Journal of General Practice |volume=62 |issue=599 |year=2012 |page=319 |issn=0960-1643 |doi=10.3399/bjgp12X649241 |pmid=22687222 |pmc=3361109}}</ref>