Das Leben des Menschen was a journal issued in Germany in the 1920s which sought to explain neurological and physiological processes to a non-academic audience by means of diagrams, often depicting the body as a factory or machine. The illustrators (who are not fully credited, although the names “Trester” and “Edelstein” recur) created elegant, often sublime images depicting – among other things – an aquarium of innards, a pickled organ presented like a Damien Hirst shark, and a schematic representation of Nietzsche’s insanity.
Further reading
Matoloni | therapy diagrams
Strange Flowers 
Wonderful! I especially like Zebra Man.