Leonardo’s anatomical studies were among the most significant achievements of Renaissance science. However, during his lifetime, Leonardo’s medical investigations remained private. He did not consider himself a professional in the field of anatomy, and he neither taught nor published his findings.
Dr Abe V Rotor
Leonardo made many important discoveries. For instance, he produced the first accurate depiction of the human spine, while his notes documenting his dissection of the Florentine centenarian contain the earliest known description of cirrhosis of the liver. Had he published his treatise, he would be considered more important than the Belgian anatomist Andreas Vesalius, whose influential textbook On the Fabric of the Human Body appeared in 1543. But he never did.
Leonardo discovered several extraordinary things about the heart. Up until and after his time, the heart was believed to be a two-chambered structure. Leonardo drew the heart with four chambers. Moreover, he discovered that the atria or filling chambers contract together while the pumping chambers or ventricles are relaxing, and vice versa. He observed the heart’s rotational movement. The heart is a complex cone that empties itself with a twisting motion – it wrings itself out, like the wringing out of a towel. In heart failure it loses this twist, which Leonardo may have understood.
Not only as an artist and anatomist, Leonardo experimented as a scientist comparable to modern technique today. Perhaps most impressive of all, were Leonardo’s observations about the aortic valve, which he made while experimenting with an ox’s heart.
This is how Alastair Sooke* describes Leonardo's finding.
"Intrigued by the way the aortic valve opens and closes to ensure blood flows in one direction, Leonardo set about constructing a model by filling a bovine heart with wax. Once the wax had hardened, he recreated the structure in glass, and then pumped a mixture of grass seeds suspended in water through it. This allowed him to observe little vortices as the seeds swirled around in the widening at the root of the aorta. As a result, Leonardo correctly posited that these vortices helped to close the aortic valve. Yet because he never published his far-sighted research, this remained unknown for centuries."
Alastair Sooke looks through the ultimate Renaissance man’s anatomical sketchbooks – scientific masterpieces full of lucid insights into the functioning of the human body.
Further than the Renaissance, in 2700 BC China, people back then rightly recognized goiters as a problem, but there was no mention of thyroid glands back then. Goiters are enlarged thyroid glands but didn't understand the source. Da Vinci had created the very first depiction of the normal thyroid, and in so doing, recognized it as an anatomical organ and not simply a pathological aberration.
Leonardo's study of the human skeleton, and a dissection of the human fetus.
Another contribution of Leonardo is the development of artificial limbs and synthetic organs. His studies on how limbs and organs work have influenced scientists today to create “replacements” of body parts in order for people to function normally..
To think that contact lens is a recent invention, is not accurate, Leonardo was the first to think up the idea of the contact lens - he invented it himself, The model was drawn in his notebook in 1508 which led to the invention of the contact lens in 1808. Today, millions of people use contact lenses, as they are convenient in certain activities like sports, fashion, and studies.
Leonardo was the first to describe atherosclerosis and hepatic cirrhosis. He used molten wax to define the anatomical cerebral ventricles, and made a model glass aorta to study the flow of blood across the aortic valve, using water containing grass seeds to observe patterns of flow. He described the coronary sinuses almost 200 years before Valsalva gave them his name, and, 120 years before Harvey, was surely only a heartbeat away from grasping the idea of the circulation of the blood.
Leonardo compiled a series of 18 mostly double-sided sheets exploding with more than 240 individual drawings and over 13,000 words of notes. He dissected some 30 corpses for his anatomical drawings and studies.
References and Readings
Medical Impact - Leonardo Da Vinci
Leonardo da Vinci's groundbreaking anatomical sketches - BBC
History of Medicine: Leonardo Da Vinci and the Elusive Thyroid ...
Leonardo da Vinci: anatomist - NCBI - National Institutes of Health
https://www.ncbi.nlm.nih.gov › NCBI › Literature › PubMed Central (PMC)
by R Jones - 2012