Quain's elements of anatomy . rminated bythe membrana tympani, which is placed obliquely, being inclined down-wards, forwards, and towards the mesial plane ; and thus, as shown in.fig. 369, the floor of the meatus is longer than its roof. The meatus is composed partly of cartilage, and partly of bone, and islined by a prolongation of the skin. The cartikiginous part occupies somewhat less than half the length ofthe passage. It is formed, as already mentioned, by an inflection of thedeep part of the cartilage of the pinna. The osseous portion is a little longer and rather narrower than the car-
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Quain's elements of anatomy . rminated bythe membrana tympani, which is placed obliquely, being inclined down-wards, forwards, and towards the mesial plane ; and thus, as shown in.fig. 369, the floor of the meatus is longer than its roof. The meatus is composed partly of cartilage, and partly of bone, and islined by a prolongation of the skin. The cartikiginous part occupies somewhat less than half the length ofthe passage. It is formed, as already mentioned, by an inflection of thedeep part of the cartilage of the pinna. The osseous portion is a little longer and rather narrower than the car- VOL. ir. F F 434 THE EAE. tilaginous part. At its inner end is a narrow groove, which extendsround the sides and floor of the meatus, but is deficient above ; into thisthe margin of the membraua tympani is inserted. The skin of the meatus is continuous with that covering the pinna, but is very thin, especially in the osseous part, and becomes graduallythinner towards the bottom of the passage. In the osseous part it Fig. 372.. Fig. 372.—View op the lower half op the auricle and meatus in the left ear DIVIDED B-T A NEARLY HORIZONTAL SECTION (after Ruclinger). 1. Posterior wall; 2, anterior wall of the cartilaginous meatus ; 3, posterior wall ofthe bony meatus ; 4 to 5, membrane of the tympanum, with the handle of the malleuscut; 6, stapes, to the right of 6, section of the cochlea ; 7, stapedius muscle ; 8, section of facial nerve ; 10, branches of the auditory nerve to the cochlea, saccule, andutricle, 11. adheres very closely to the periosteum, and at the bottom of the tube isstretched over the surface of the membrana tympani, forming the outerlayer of that structure. Towards the outer part the skin possesses finehairs and sebaceous glands ; and in the thick subdermic tissue over thecartilage are many smaU oval glands of a brownish yellow colour, agreeingin form and structure with the sweat glands, l3ut larger (fig. 237 onp. 254). The cerumen or ear-wax is secreted by these g