. A treatise on practical anatomy: for students of anatomy and surgery . he canal above and transmits the tensortympani muscle. The membrana tympani is an oval, translucent mem-brane, which is placed obliquely at the bottom of theexternal auditory canal. It presents three layers,—ex-ternal, or cuticular; middle, or fibrous; and internal, ormucous. The handle of the malleus descends betweenthe fibrous and mucous layers to about the it is concave, but it changes its positionslightly under the pressure of the air within the tym-panum. THE MIDDLE EAR. 427 The ossicles of the tymp
. A treatise on practical anatomy: for students of anatomy and surgery . he canal above and transmits the tensortympani muscle. The membrana tympani is an oval, translucent mem-brane, which is placed obliquely at the bottom of theexternal auditory canal. It presents three layers,—ex-ternal, or cuticular; middle, or fibrous; and internal, ormucous. The handle of the malleus descends betweenthe fibrous and mucous layers to about the it is concave, but it changes its positionslightly under the pressure of the air within the tym-panum. THE MIDDLE EAR. 427 The ossicles of the tympanum are the malleus, incus,and stapes. They constitute a chain of bones, which trans-mit the vibrations of sound from the membrana tym-pani to the internal ear. The malleus presents a head,neck, and three processes. The head articulates with theincus. The handle is the vertical process attached to themembrana tympani. The processus gracilis gives attach-ment to the laxator tympani muscle. It passes outwardnearly at right angles to the handle, and lies in the Glase-. Fig. 186.—I. The Mechanics of the \t ditor\ Os-, II SECTIO^ OF THE :MIDDLE E.\R. I. a, malleas; h, incus: am, long process of incus; s, stapes: the arrows show the direc-tion of motion. II. G, external auditory canal; M. t., membrana tympani; C, tympanum ;H, malleus; L S., superior ligament: S, stapes. rian fissure. The short process is a tubercle on the rootof the handle. It gives attachment to the tensor incus presents a body and two processes. Thebody articulates with the malleus. The processes are:the long and short, at right angles witli one short process is attached to the posterior wall; thelong process, parallel with the handle of the malleus,terminates in the lenticular process, which articulateswdth the head of the stapes. 428 PRACTICAL ANATOMY. The stapes, or stirrup, presents a head, neck, twobranches, and an oval-shaped base, which is apphed tothe fenestra ovahs. The o
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanatomy, bookyear1891
