title: Leonardo da Vinci's studies of the heart.
abstract: Leonardo da Vinci's detailed drawings are justly celebrated; however, less well known are his accounts of the structures and functions of the organs. In this paper, we focus on his illustrations of the heart, his conjectures about heart and blood vessel function, his experiments on model systems to test those conjectures, and his unprecedented conclusions about the way in which the cardiovascular system operates. In particular, da Vinci seems to have been the first to recognize that the heart is a muscle and that systole is the active phase of the pump. He also seems to have understood the functions of the auricles and pulmonary veins, identified the relationship between the cardiac cycle and the pulse, and explained the hemodynamic mechanism of valve opening and closure. He also described anatomical variations and changes in structure and function that occurred with age. We outline da Vinci's varied career and suggest ways in which his personality, experience, skills and intellectual heritage contributed to these advances in understanding. We also consider his influence on later studies in anatomy and physiology.
authors.affiliation: Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. amohadjel@yahoo.com
authors.forename: Mohammadali M
authors.initials: MM
authors.lastname: Shoja
authors.forename: Paul S
authors.initials: PS
authors.lastname: Agutter
authors.forename: Marios
authors.initials: M
authors.lastname: Loukas
authors.forename: Brion
authors.initials: B
authors.lastname: Benninger
authors.forename: Ghaffar
authors.initials: G
authors.lastname: Shokouhi
authors.forename: Husain
authors.initials: H
authors.lastname: Namdar
authors.forename: Kamyar
authors.initials: K
authors.lastname: Ghabili
authors.forename: Majid
authors.initials: M
authors.lastname: Khalili
authors.forename: R Shane
authors.initials: RS
authors.lastname: Tubbs
mesh_terms: D002309:Cardiology / Q000266:history*; D005197:Famous Persons; D006321:Heart / Q000033:anatomy & histology*; D049668:History, 15th Century; D049669:History, 16th Century; D006801:Humans; D008512:Medicine in the Arts