Short answers, pulled from the story.
Herophilus of Alexandria performed the first systematic human dissections in the third century BCE. He used the bodies of condemned criminals to map the human form and distinguished arteries from veins. His work remained unchallenged for over a thousand years.
Andreas Vesalius published De humani corporis fabrica in 1543. This seven-volume book fundamentally altered the course of medical history by challenging the ancient teachings of Galen. Vesalius insisted on the necessity of direct observation as the primary judge of truth.
The Anatomy Act of 1832 halted the practice of body snatching in Britain. This legislation followed decades of grave-raiding and anatomy murder to supply dissection rooms. Similar legislation in the United States followed after physician William S. Forbes was found guilty in 1882.
Matthias Jakob Schleiden and Theodor Schwann identified that cells were the fundamental unit of organization of all living things in 1839. The invention of the microtome allowed for sufficiently thin slices of tissue to be examined. This microscopic revolution revealed that animal tissues are composed of four basic types.
The human heart has four chambers that keep oxygenated and deoxygenated blood entirely separate. This feature is shared with birds and crocodilians but is distinct from the three-chambered hearts of amphibians. Fish possess a two-chambered heart that pumps blood through gills in a single circulatory loop.
The tuatara possesses a parietal eye on its forehead and a single row of teeth that fits between two rows in the upper jaw. This primitive feature is lost in other reptiles. The tuatara is a living species of Sphenodon punctatus that provides a window into the past.