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."

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...

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.

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”

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.