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Ultrastructure of the round window membrane
Author(s) -
Bellucci Richard J.,
Fisher Edward G.,
Rhodin Johannes
Publication year - 1972
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1288/00005537-197206000-00010
Subject(s) - basal lamina , ultrastructure , tight junction , biophysics , round window , membrane , inner ear , organelle , transmission electron microscopy , anatomy , cell junction , intracellular , chemistry , cell membrane , microbiology and biotechnology , biology , materials science , cell , nanotechnology , biochemistry
The round window membrane presents the only non‐osseous wall of the labyrinth. Electron microscopic study of the round window membrane was undertaken in order to determine whether it could act as a route of transmission from the middle to the inner ear. In the cat round window membrane three layers can be identified. The tympanic surface is composed of a single layer of flat cells resting on the basal lamina. Multiple desmosomes and tight cell junctions are present. The intermediate layer contains supporting elements collagen and elastic tissues. The labyrinthine layer is composed of a single layer of long squamous cells which lie end to end on the basal lamina. The absence of intracellular organelles and microvilli, and the lack of basal lamina involutions into the epithelial cells preclude the presence of an active transport mechanism. The tight cell junctions also seem to present a barrier to free diffusion across the membrane. The chemical agents which have been observed to pass from the middle ear into the inner ear may have done so by diffusion through the round window membrane after altering the cell junctions; however, a readily accessible route of transmission through the round window membrane does not appear to be present.