Morphology and function of Bast's valve: additional insight in its functioning using 3D-reconstruction
Hofman, R × Segenhout, J. M Buytaert, Jan Dirckx, J. J. J Wit, H. P #
European Archives of Oto-Rhino-Laryngology vol:265 issue:2 pages:153-157
The utriculo-endolymphatic valve was discovered by Bast in 1928. The function of Bast's valve is still unclear. By means of orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy 3D-reconstructions of the valve and its surrounding region are depicted. The shape of the duct at the utricular side is that of a flattened funnel. In the direction of the endolymphatic duct and sac this funnel runs into a very narrow duct. The valve itself has a rigid 'arch-like' configuration. The opposing thin, one cell-layer thick, utricular membrane is highly compliant. We propose that opening and closure of the valve occurs through movement of the flexible base/utricular membrane away from and toward the relatively rigid valve lip.