Morphology and function of Bast's valve: additional insight in its functioning using 3D-reconstruction.
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.
Hofman
R
R
Department of Otorhinolaryngology, University Medical Center Groningen, PO Box 30001, 9700 RB, Groningen, The Netherlands. r.hofman@kno.umcg.nl
Segenhout
J M
JM
Buytaert
J A N
JA
Dirckx
J J J
JJ
Wit
H P
HP
D004711:Endolymphatic Duct / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008856:Microscopy, Fluorescence / Q000379:methods; D013506:Otologic Surgical Procedures / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012444:Saccule and Utricle / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery