Morphological Relationship Between the Tectorial Membrane and the Organ of Corti: A Scanning Electron Microscopic Study

Abstract

Scanning electron microscopy on the cochlea of guinea pig elucidated the morphological relationships between the tectorial membrane and the organ of Corti, more precisely. The tectorial membrane consists of two layers; one is the upper, fibrous layer and the other is the lower, thinner, granular layer made of amorphous, granular substance. With the latter it is attached to the surface of the inner sulcus cell as well as hair cells. The manners of attachment, however, are different in the outer hair cells and the inner ones. The outer hair cells make a fairly firm attachment to the tectorial membrane by inserting the tips of hairs of the outermost row of each hair cell into the granular layer. On the other hand, the inner hair cells are attached to the granular layer through the protruding granular substance at the top of hairs of the outermost row. Though the fibrous layer of the tectorial membrane terminates in the vicinity of the outermost Deiters' cell phalanx, the granular layer extends more outwards and communicates along the junction of the phalanx and Hensen's cell and covers the surface of Hensen's cells.