Medieval Europeans knew more about the body than we think
Medieval Europe is generally known for its animosity toward actually testing things out, favoring tradition over experimentation and earning a reputation as being soundly anti-science. In particular, it's easy to get the impression that nobody was doing human dissections at all, prior to the Renaissance. But it turns out that isn't true. In fact, some dissections were even prompted (not just condoned) by the Catholic Church
. The knowledge medieval dissectors learned from their experiments didn't get widely disseminated at the time, but their work offers some interesting insight into the development of science. The quest for knowledge in Europe didn't just appear out of nowhere in the 1400s and 1500s.