Monkey and pig dissections: The history of anatomy knowledge

I started off wanting to write about fascia (the connective tissue that envelopes and separates muscles), but my reading and research quickly brought me to other discoveries that were so exciting and macabre, that I felt it appropriate to share on Halloween.

The book, "Anatomy Trains, Myofascial Meridians," by Thomas Myers, inspired me to find out more about the history of anatomical discoveries. A quote in the book stood out to me: "From Galen through Vesalius and beyond, it was the tools of hunting and butchery which were applied to the body, and presented to us the fundamental distinctions we now take for granted."

Anatomy Trains by Tom Myers book

Admittedly, I did not know much about those two names in that quote, Vesalius and Galen; and my curiosity of the history of the tools used for learning about the human anatomy led me on my research path. Moreover, as an artist myself, I was curious about the many talented illustrators of all the drawings that the medical world has gleaned so much of their knowledge from and still use in modern medicine. We are blessed to have this knowledge at our fingertips today, but it wasn't exactly a pretty journey to get here...

monkey dissections

To begin, before Vesalius was Galen, and before Galen was Herophilus. During the 4th century BC, in Alexandria, Egypt, this Greek physician was the first person to perform systematic dissection of the human body. Although he penned down several anatomical discoveries, they were all destroyed - perhaps in the fire of the library where is findings were kept. He was also accused of vivisections (the cutting of or operation on a living animal, or in this case, humans, usually for physiological or pathological investigation). Some believed his specimens were alive and breathing, and was labeled a "butcher!"

Even though his incredible anatomical knowledge was passed down, one could imagine how being labeled a butcher may have damaged his reputation, which could be the reason why Herophilus has not received as much recognition for his scientific investigations of the human body as Hippocrates, Galen or Vesalius.

Next up: Galen in 162 AD

The physician of Roman emperor, Marcus Aurelius and some gladiators, was Aelius Galenus or "Galen," gave public demonstrations in anatomy. Because of religious restrictions, he was forced to dissect and experiment on animals like African monkeys, pigs, goats and sheep. Just as Herophilus refuted his mentor's (Praxagoras) misconception that the pulse was not associated with the heart beat, Galen's work argued against the many long-held beliefs, such as the theory that the arteries contained air which carried it to all parts of the body from the heart and the lungs.

Galen identified seven pairs of cranial nerves, described heart valves, and differentiated between veins and arteries; and he showed that arteries carry blood not air. During his pig dissection experiments, he discovered the cranial nerve called the vagus.

These great medical discoveries, however, also included some mistakes along the way since he wasn't allowed to dissect human bodies. For example, his description of the human uterus was based on that of a dog.

pig dissections

After Galen, there was Mondino de Liuzzi (1270-1326)

Mondino was known for being the first to officially perform a sanctioned public dissection in Bologna in the presence of medical students and other spectators. In 1316, Mondino wrote his major work, Anathomia corporis humani, considered the first example of a modern dissection manual and the first true anatomical text.

And of course, there's Leoardo in the 1490's

Leonardo Da Vinci was an accomplished sculptor, engineer, architect, and he had an intuitive understanding of form, which made him an amazing artist of anatomy.

Leonardo dissected and investigated the human body and refuted what was written by Mondino on the insertion of the muscles of the leg. During his dissection of the leg, he wrote down his discoveries:

“I have stripped the skin from one who owing to an illness was so emaciated that the muscles were consumed and reduced to the state of a thin membrane so that the cords, instead of being transformed into muscle were converted into a wide sheet; and when the bones were clothed by this leather, they possessed little of their natural thickness”

Da Vince leg dissection

Next up: The guy who undermined Galen, Andreas Vesalius, 1512-1564

Vesalius is widely known for his book, The Seven Books on the Structure of the Human Body (De humani corporis farbica libri septem). Vesalius’s commitment to witness firsthand actual human organs, which had been prohibited in much of Europe prior to 1482, enabled him to record some of the most accurate accounts of human anatomy ever published. Along with his ocular evidence, he established the standard methodology by which dissection and anatomy would be practiced until the modern era.

Vesalius illustration

Vesalius illustration

Vesalius considered the body as an integrated whole, but he claimed the anatomist had to understand the body as “a fabric, a piece of workmanship by the Great Craftsman,” or, the human body is a work of art executed by a divine artisan.

The first anatomical theatre was built at the University of Padua in 1594, where Vesalius performed much of his dissections.

anatomical theater
anatomical theater

Vesalius's discoveries became the foundation for the next guy: William Harvey, in 1628.

Harvey developed a theory of the circulation of the blood, and published his work on anatomy and function in the book, Concerning the Motion of the Heart and Blood, (De Motu Cordis).

Just like all the others who broke away from the anatomy guru before him, Harvey also refuted Vesalian thinking by applying concepts of physics to his study of the movement of blood in the body. He shed the notion that the body was the product of a grand design and adopted the position that the body operated as a machine. He also believed that each organ has a specific function(s) which worked in relation to other organs in the body.

Around the time of Harvey's discoveries, another surgeon, John Hunter helped to improve understanding of human teeth, bone growth and remodeling, inflammation, gunshot wounds, venereal diseases, digestion, child development, the separateness of maternal and foetal blood supplies, and the role of the lymphatic system. While anatomists who preceded Hunter took a strict mechanistic view of the animal body, claiming that life in animal bodies resolved to the function of coordinate organs, Hunter refuted this with a materialist view. Instead, Hunter proposed that coordinate functions, not just organs, allowed life to occur in animal bodies.

In 1761, physician, Giovanni Battisti Morgagni was the first to show the necessity of basing diagnosis and treatment on a comprehensive knowledge of anatomy. He is considered the father of modern autopsy. His work in his published book, The Seats and Causes of Diseases Investigated by Anatomy, contained records of 640 dissections.

Which brings us to some of the incredibly talented artists of our medical history!

If you want to see a neat article showing several pieces of historical anatomical artwork, visit this link on It is really cool!

Here are a couple worth mentioning though...

German artist, Max Brodel established the profession of anatomical illustration in America and is considered to be the father of modern medical illustration.

Max Brodel illustration
Max Brodel illustration

In 1858, Henry Gray published first edition of his Anatomy: Descriptive and Surgical, later known simply as Gray’s Anatomy. The work covered 750 pages and contained 363 figures. A second edition was prepared by Gray and published in 1860. The 40th edition was published in 2008.

Gray's anatomy book

And of course, there was Frank Netter. Netter produced nearly 4,000 illustrations, which have been included in countless publications.

Frank Netter illustration

Frank Netter Illustration

If you've read all the way to the bottom of my article, congratulations! I know that was dense. I am no history buff by any means, but I wanted to share this awesome and grotesque history with you because of how important these discoveries were. They laid the foundation of our modern-day knowledge of the human body. It is clear to see from this history, however, that ideas, beliefs, and assertions are always being challenged. This is a good thing, otherwise we may still believe a woman's uterus looks like that of a dog's uterus!

And so it makes me wonder, what is to come next? Just recently, it was discovered that there may be a 5th muscle of the quadriceps, the tensor of the vastus intermedius! It is exciting to learn of new discoveries; and I sense that our world will continue to challenge what was told before us.

And on that note, Happy Halloween! Stay safe and have fun.

Thanks for reading. Please send a message with any comments, questions, or concerns.

Amy Jorge, 512-734-8050













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