The pharyngeal opening of the auditory tube lies higher the hind margin of the palate which is not yet fused. It directs ventral and a little cephalic, so the margin of the opening is a little swollen dorsal and caudal. The tube continues almost horizontally hind and lateralward immediately before the ascending internal carotid artery and reaches lateral of it where lies the tympanic opening of the tube. This crossing artery has a thick nerve net immediately around it. The great superficial petrosal nerve from the ganglion geniculi comes from behind and lateral to lateral of the artery and turns foreward, continues parallel with the profound petrosal nerve from the nerve net of the artery and reaches the pterygopalatine ganglion. The auditory tube has a elliptic or trapeziform with a vertical long axis in thefrontal cut. (Fig. 5) The epithel of the tube consists of 4-5 layered flimmer cells, no, praecartilageous nor glandular tissue.
The tympanic cavity begins lateral to the internal carotid artery which passes vertically on the lateral surface of the apex of the cochlear part of the otic capsule, and expands backward upon the surface of the cartilage. This foremost part of the cavity lies medial and beneath the otic ganglion, medial to the Meckel's cartilage. The cavity itself is in its middle part compressed mediolateralward, its vertical diameter is directed from dorsolateral to medioventral as one can understand in the figures. The Meckel's cartilage which lies lateral to the middle part of the cavity continues backward gradually higher to the cavity, so its continuation to the malleus comes very high to the hind part of the cavity. The manubrium mallei projects vertically down and a little medialward to the most hind part of the cavity, so can be the cavity in upper and lower parts divided. The upper half is mediolaterally a little wide, but it becomes smaller gradually backward and out of sight, the lower part extends backward beyond the upper part, becoming more and more horizontally and ends on the under surface of the cartilage completely horizontally. The fundus extension of the external auditory meatus is not so large as that of the cavity, so that that of the thin mesenchymal tympanic membrane a little smaller than that of the cavity. The epithel of the cavity is cubic 2-3 cells layered. The tympanic nerv and its rami caroticotympanici lie on the surface of the cartilage which covered with the epithel of the cavity.

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