The fine surface view of the human adult eustachian tube.

The distribution pattern of ciliated cells and goblet cells in the mucosa of the normal adult human eustachian tube has been determined by means of SEM. In general, the density of the ciliated cells decreased from the pharyngeal to the tympanic orifice, and from the tubal floor to its roof. Most ciliated cells possessed about 100-200 cilia, and the average length of the cilia was approximately 8 mu. It is interesting to note that their number and length had a tendency to diminish towards the tympanic orifice of the tube. The ciliated epithelial cells at the tubal floor and lower parts of the walls undoubtedly play an important part in providing an active mucociliary mechanism, as in other parts of the upper respiratory system.