Leonardo di ser piero da Vinci-a bridge between ancient and post-Galenic anatomy based on studies of the ventricular system of the brain.

When thinking about the beginning of modern anatomical drawings that reflect topography in detail, our thoughts often turn to the more than 200 woodcuts included in Andreas Vesalius's "De humani corporis fabrica libri septem." However, Leonardo da Vinci also produced detailed anatomical sketches before the publication of the Fabrica, including drawings that addressed the cerebral ventricular system. The goal of this narrative historical review is to examine how medical knowledge of the ventricular system evolved from antiquity, represented by Galen of Pergamon and Hippocrates of Kos, toward post-Galenic anatomy. This analysis is based on four sketches created between approximately 1487 and 1509, held in the collections of the Royal Library at Windsor, England, and the Schlossmuseum in Weimar, Germany. Although medical literature frequently references Leonardo's anatomical work, relatively few studies have focused specifically on the morphology of the ventricular system while also considering the physiology and philosophy of the turn of the 15th and 16th centuries. This study therefore analyzes Leonardo's ventricular drawings as an important transitional episode in the visual history of neuroanatomy. At the same time, it acknowledges that Leonardo's anatomical studies were largely unpublished during his lifetime, that their influence on later anatomists remains uncertain, and that retrospective interpretation of historical drawings requires caution.