1.中文與英文相关文章 中文 http://forum.chasedream.com/dispbbs.asp?boardID=22&ID=348102&page=1 英文 Two minuscule（微小的） muscles are located in the middle ear. The longer muscle, calledthe tensor（张肌） tympani, emerges from a bony（骨的） canal （渠河）just above the opening of theeustachian tube and runs backward then outward as it changes direction inpassing over a pulleylike projection of bone. The tendon of this muscle isattached to the upper part of the handle of the malleus. When contracted, thetensor tympani tends to pull the malleus inward and thus maintains or increasesthe tension of the tympanic membrane. The shorter, stouter muscle, called thestapedius, arises from the back wall of the middle-ear cavity and extendsforward and attaches to the neck of the head of the stapes. Its reflexcontractions tend to tip the stapes backward, as if to pull it out of the ovalwindow. Thus it selectively reduces the intensity of sounds entering the innerear, especially those of lower frequency. Another piece of information There are two small muscles in the middle ear: thetensor tympani and the stapedius muscles.The former pulls the manubrium of themalleus inward, while the latter is attached to the stapes and pulls the stapesin a direction that is perpendicular to its pistonlike motion. The stapediusmuscle is the smallest striated muscle in the body, and it contracts inresponse to an intense sound (of about 85 dB above the threshold of hearing).This is known as the acoustic middle-ear reflex. The muscle's contractionreduces sound transmission through the middle ear and thus acts as a regulatorof input to the cochlea. Perhaps a more important function of the stapediusmuscle is that it contracts immediately before and during a person's ownvocalization, reducing the sensitivity of the speaker's ears to his or her ownvoice and possibly reducing the masking effect of an individual's own voice.The role of the tensor tympani muscle is less well understood, but it isthought that contraction of the tensor tympani muscle facilitates proper ventilationof the middle-ear cavity.