What is the fine-grained topic of the following text: But the “mysterious” meridians are “nothing more than a rudimentary and prescientific model of blood vessels and nerves” (Kavoussi), because until about a hundred years ago, acupuncture was pretty much the Eastern version of bloodletting, and its needles were more like little knives. Only return the topic.
Acupuncture's historical connection to bloodletting and meridians as rudimentary models of blood vessels and nerves.