Vesalius on the anatomy and function of the recurrent laryngeal nerves: medical illustration and reintroduction of a physiological demonstration from Galen.

The purpose of this article is to review the anatomical illustrations and physiological demonstrations of sixteenth-century Flemish-born anatomist and physician Andreas Vesalius concerning the recurrent laryngeal nerves. Although Vesalius was primarily an anatomist, he also used vivisection as a pedagogical device to help his students understand the function of structures within the fabric of the body that they had previously studied in anatomical detail. Vesalius's masterwork, De humani corporis fabrica or simply the Fabrica (1543, 1555), was ostensibly an anatomy text, but Vesalius included textual and figural references to his use of vivisection to explicate the function of specific structures. Even as he began to criticize the errors in Galen's anatomical works, Vesalius nevertheless adopted some of Galen's classic physiological demonstrations, in particular the ligation (and subsequent release) of the recurrent laryngeal nerves of a pig to demonstrate their role in generating the pig's squeal. Vesalius's illustrations concerning the recurrent laryngeal nerve in the Fabrica were of two types: elegant anatomical woodcut plates-unsurpassed for their clarity, accuracy, and detail - and the distinctly inelegant historiated initial Q, depicting a throng of putti busily engaged in vivisecting a pig. Vesalius' anatomical plates were heavily plagiarized while the historiated initials, showing the rough work of an anatomist or surgeon, were largely ignored and remain little recognized today. While Vesalius' anatomical illustrations of the recurrent laryngeal nerves contained some errors, they were a dramatic departure from prior meager efforts at medical illustration and indeed far surpassed all contemporary published illustrations by others. Vesalius was also influential in reviving Galen's approach to vivisection, at least for pedagogical purposes, if not really then yet as a full-fledged investigative technique.