ABSTRACT
The fornix and its surrounding gyrus founicatus are two examples, among the numerous terms with a sexual connotation, that have adorned neuroanatomical terminology in the last several centuries. Others are, as some examples, nates (buttocks), testes for the colliculi of the mesencephalon (Vesale, 1604; Diemerbroeck, 1695), glans for the pineal gland (Vesale, 1604), cerebral vulva between the habenulae (Colombo, 1559), and vulvar triangle between the columns of fornix and the posterior commis-sure (Vieussens, 1685). Rather than being related to behavior, as one might conclude, the term “fornix” has its roots in Roman architecture. At the time of Vitruve (first century B.C.) Roman architects used two different terms to describe vaulted-ceilinged rooms (Hyrtl, 1880): either “Camera” (from the Latin camera: vault) if the roof were made of brick, or “Fornix” (from the Latin fornix: arch) if it were constructed of wood. The first of these two terms was widely used in anatomical terminology over the last centuries; for example, camerae cranii (Albinus) and camera pericardiaca (Bauhin) for the cranial recesses and the pericardium, respectively. The second term, fornix, was also used for many anatomical structures, such as fornix conjunctivae, f. pharyngis, f. sacci lacrimalis or f. vaginae (De Terra, 1913). At present, this term belongs mainly to neuroanatomy, and seems to have been used in its current meaning for the first time by Thomas Willis (1664). The third ventricle was therefore compared with a vaulted-ceilinged room, and its roof was called fornix.
