Leonardo da Vinci's Anatomical Drawings (c. 1510): Art as Science

Leonardo da Vinci’s anatomical drawings, produced mostly between about 1507 and 1513, are among the most accurate studies of the human body made before modern times. Based on his own dissections in Florence, Milan, Pavia and Rome, they show bones, muscles, the heart and a foetus in the womb with a clarity that combines the skills of an artist and an investigator. Yet because Leonardo never published them, they had almost no influence on medicine until centuries after his death.

Background: why a painter studied anatomy

Renaissance artists were expected to understand the body beneath the skin. The theorist Leon Battista Alberti advised painters to build a figure from the skeleton outwards, and several Florentine artists studied muscles to draw the nude convincingly. Leonardo (1452–1519) began in this tradition but went much further, treating anatomy as a field of knowledge in its own right.

His earliest surviving anatomical studies date from around 1489 in Milan, when he drew a series of human skulls with remarkable precision, including sections showing the sinuses and the eye sockets. At that stage he had limited access to human bodies and relied partly on animal dissection and on traditional ideas inherited from Galen and medieval writers.

The dissections of 1507–1513

The decisive phase began in Florence in the winter of 1507–1508. At the hospital of Santa Maria Nuova, Leonardo spoke with an old man who said he was over 100 years old and then died peacefully. Leonardo dissected the body “to see the cause of so sweet a death” and described narrowed, tortuous blood vessels and a shrunken liver. Historians of medicine often cite his notes as one of the earliest descriptions of what is now called atherosclerosis, the hardening and narrowing of the arteries.

Back in Milan, and at the University of Pavia, Leonardo is thought to have worked during 1510–1511 with Marcantonio della Torre, a young professor of anatomy who died of plague in 1511. In this period he produced the set of sheets known as Anatomical Manuscript A, around 18 pages of bones and muscles drawn from several angles, as if the viewer were walking round the body. He developed techniques still used in medical illustration: cross-sections, exploded views, and drawings that show the same structure layer by layer.

Leonardo’s last major anatomical project concerned the heart. Around 1511–1513 he studied ox hearts in detail, described four chambers rather than the two that many contemporaries accepted, and investigated the aortic valve. He even designed a glass model to observe how blood might swirl behind the valve cusps. His drawing of a foetus curled in the womb, from about 1511, is one of his most famous images, although it combines human and animal features, since he probably did not dissect a pregnant woman at the stage shown.

In Rome after 1513 he continued some dissection at the hospital of Santo Spirito but, according to his own complaints, was denounced to Pope Leo X and prevented from working on bodies there, around 1515.

Methods and accuracy

Leonardo wrote his notes in mirror script, right to left, alongside the drawings. He insisted that pictures conveyed anatomy better than words, writing that a description would need many pages to convey what one drawing shows. He compared parts of the body to mechanical systems, presenting muscles as cords pulling on levers and shoulders as complex joints.

The drawings were not always correct. Some early sheets show structures from Galenic tradition, such as features found in animals but not humans, and he sometimes combined observations from different species. Even so, his depictions of the spine’s curvature, the bones of the hand and foot, and the muscles of the shoulder were far more accurate than anything in print at the time.

He experimented with techniques of his own. To study the shape of the brain’s ventricles, the fluid-filled cavities inside it, he injected molten wax into an ox brain, let it harden and then removed the surrounding tissue, producing a cast of the cavities. To understand how muscles moved the limbs, he replaced them with copper wires or strings in his drawings, showing their lines of pull. He also drew the same joint from four or more angles, rotating it on the page, an approach close to modern three-dimensional anatomical imaging.

The practical conditions were grim. Dissections had to be completed quickly, before the body decayed, usually in winter, and Leonardo wrote of spending nights in the company of corpses that were frightful to behold. He listed the qualities a would-be anatomist needed, including a strong stomach, skill in drawing, knowledge of perspective and geometry, and patience.

Key people

• Leonardo da Vinci (1452–1519): painter, engineer and anatomist, who carried out the dissections himself.
• Marcantonio della Torre (1481–1511): professor of anatomy at Pavia, Leonardo’s probable collaborator around 1510–1511.
• Francesco Melzi (c. 1491–c. 1570): Leonardo’s pupil and heir, who kept the notebooks for half a century.
• Pompeo Leoni (c. 1533–1608): sculptor who acquired many of the papers and assembled them into albums.

What happened to the drawings

Leonardo planned a treatise on anatomy, and in 1517 a visitor, Antonio de Beatis, recorded him claiming to have dissected more than 30 bodies. But the treatise was never completed. When Leonardo died at Amboise in France in 1519, his papers went to Melzi, whose heirs later let them be sold. Pompeo Leoni bound many sheets into albums, and one of these, containing the anatomical drawings, reached England. It is recorded in the collection of the English crown by about 1690.

The drawings remained mostly unknown. The Scottish anatomist William Hunter saw them in the 1770s and declared Leonardo a great anatomist. Full facsimile publication came only in the late nineteenth and early twentieth centuries. Modern specialists have been struck by how much they anticipated. The cardiac surgeon Francis Wells, studying the heart drawings, argued that Leonardo’s description of how the aortic valve closes matches what modern imaging shows. By then, however, anatomy had long since been transformed by others, above all by Vesalius and his Fabrica of 1543.

Myths and facts

• Myth: Leonardo’s discoveries shaped Renaissance medicine. Fact: the drawings were private and unpublished; their influence on medicine before the 1700s was minimal.
• Myth: Leonardo discovered the circulation of the blood. Fact: he studied the heart in detail but retained traditional ideas about the movement of blood. Circulation was demonstrated by William Harvey in 1628.
• Myth: dissection was illegal and Leonardo worked in secret. Fact: dissection of human bodies was practised in Italian universities and hospitals; Leonardo’s Rome difficulties came from complaints and papal disfavour, not a general ban.

Timeline

• c. 1489: Leonardo draws detailed studies of the human skull in Milan.
• 1507–1508, winter: dissection of the “centenarian” at Santa Maria Nuova, Florence.
• 1510–1511: work at Pavia, probably with Marcantonio della Torre; Anatomical Manuscript A.
• c. 1511: studies of the foetus in the womb.
• c. 1511–1513: studies of the heart and aortic valve.
• c. 1515: Leonardo is barred from dissection at Santo Spirito in Rome.
• 1519, 2 May: Leonardo dies at Amboise; papers pass to Francesco Melzi.
• c. 1690: the anatomical album is recorded in the English royal collection.

Why it matters

Leonardo’s anatomical drawings show how close Renaissance art and science could come. They remain landmarks of observation and illustration, and they are a reminder that discovery has influence only when it is shared: a body of work that could have changed medicine stayed hidden in an album for nearly three centuries.