title: The ultrastructure of the round window membrane of the cat.
abstract: The ultrastructure of the round window membrane of the cat was investigated. Three distinct layers were recognised and described. It was established that the outer epithelial layer is non-ciliated, but often contains microvilli. The middle layer, under the basement membrane, contains a large amount of collagen and elastic fibres in addition to fibrocytes. The inner layer is a continuation of the epithelial layer of the perilymphatic space. The thickness of the membrane has been measured as being 15--20 micrometer. The latest human audiological and clinical observations concerning the function and rupture of the round window membrane emhasise the importance of the electron microscopic study of this membrane.
mesh_terms: D000818:Animals; D002415:Cats; D002462:Cell Membrane / Q000648:ultrastructure; D002923:Cilia / Q000648:ultrastructure; D003051:Cochlea / Q000648:ultrastructure*; D003094:Collagen; D003238:Connective Tissue / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D004547:Elastic Tissue / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D008297:Male; D008566:Membranes / Q000648:ultrastructure; D012405:Round Window, Ear / Q000648:ultrastructure*
chemical_list: D003094:Collagen