Dissection
Human dissections were carried out by the Greek physicians Herophilus of Chalcedon and Erasistratus of Chios in the early part of the third century BC. During this period, the first exploration into full human anatomy was performed rather than a base knowledge gained from 'problem-solution' delving. While there was a deep taboo in Greek culture concerning human dissection, there was at the time a strong push by the Ptolemaic government to build Alexandria into a hub of scientific study. For a time, Roman law forbade dissection and autopsy of the human body, so physicians had to use other cadavers. Galen, for example, dissected the Barbary macaque and other primates, assuming their anatomy was basically the same as that of humans.
Cadaver
His approach to the depiction of the human body was much like that of the study of architecture, providing multiple views and three-dimensional perspectives of what he witnessed in person. One of the first examples of this is using the three dimensional perspectives to draw a skull in 1489. Further study under Verrocchio, some of Leonardo da Vinci's anatomical work was published in his book "A Treatise on Painting". A few years later, in 1516, he partnered with professor and anatomist Marcantonio della Torre in Florence, Italy to take his study further. The two began to conduct dissections on human corpses at the Hospital of Santa Maria Nuova and later at hospitals in Milan and Rome. Through his study, da Vinci was perhaps the first to accurately draw the natural position of the human fetus in the womb, via cadaver of a late mother and her unborn child. It is speculated that he conducted approximately 30 dissections total. His work with cadavers allowed him to portray the first drawings of the umbilical cord, uterus, cervix and vagina and ultimately dispute beliefs that the uterus had multiple chambers in the case of multiple births. It is reported that between 1504 and 1507, he experimented with the brain of an ox by injecting a tube into the ventricular cavities, injecting hot wax, and scraping off the brain leaving a cast of the ventricles. Da Vinci's efforts proved to be very helpful in the study of the brains ventricular system. Da Vinci gained an understanding of what was happening mechanically under the skin to better portray the body through art. For example, he removed the facial skin of the cadaver to more closely observe and draw the detailed muscles that move the lips to obtain a holistic understanding of that system. He also conducted a thorough study of the foot and ankle that continues to be consistent with current clinical theories and practice. His work with the shoulder also mirrors modern understanding of its movement and functions, utilizing a mechanical description likening it to ropes and pulleys. He also was one of the first to study neuroanatomy and made great advances regarding the understanding of the anatomy of the eye, optic nerves and the spine but unfortunately his later discovered notes were disorganized and difficult to decipher due to his practice of reverse script writing (mirror writing).