Ultrastructure of the middle ear mucosa.

Histologic studies of recent years have definitely concluded that the epithelium of the middle ear is a modified respiratory epithelium with ciliated and secretory cells, including goblet cells. These cells, like the ciliated cells, are developd from the basal cell and are just ordinary secretory cells completely filled with secretory granules. For different reasons it is postulated, that the dark secretory granules are prestages of the actual secretory product presenting as light granules and that dark and light granules do not represent different secretory capacities of the cell. The subepithelial layer which consists of loose connective tissue is a structure of just as great importance as the epithelial layer.