Diseases of the nose and throat; a text-book for students and practitioners . musclesand mucous membrane. Thislayer of elastic tissue is dis-posed in such a manner asto afford protection to someparts and greater roundnessand symmetry to others. Proceeding from the car-tilages toward the laryngealcavity, the next form of tissueto be considered is the miis-cidar. Although there areboth intrinsic and extrinsicmuscles, it is only necessaryto describe the former, as tothem belong, chiefly, the dutiesof controlling voice and res-piration, in so far as thelarynx has to do with thesefunctions. There a
Diseases of the nose and throat; a text-book for students and practitioners . musclesand mucous membrane. Thislayer of elastic tissue is dis-posed in such a manner asto afford protection to someparts and greater roundnessand symmetry to others. Proceeding from the car-tilages toward the laryngealcavity, the next form of tissueto be considered is the miis-cidar. Although there areboth intrinsic and extrinsicmuscles, it is only necessaryto describe the former, as tothem belong, chiefly, the dutiesof controlling voice and res-piration, in so far as thelarynx has to do with thesefunctions. There are elevenof these intrinsic muscles, tenof which are in pairs: thecrico-thyroidei, the crico-ary-tenoidei postici, the crico-arytcnoidei laterali, the thyro- fig. side of larynx, show- . T ... , - , ixG Epiglottis, Left Thyroid Plate arv-epi<^lottici, and the tlivro- (kight half of thyroid removed), ^ Crico-Thykoid Muscle, Posterior Edge arvfenoidei • tlip plpvpnfVi ic t)F cricoid cartilage, andj )lCllUlUCl , LUe eievenin is (From a photograph.). 328 DISEASES OF THE NOSE AND THROAT. a single muscle, the arytenoideus. The sterno-thyroid, thethyro-hyoid, and the mferior constrictor of the pharynx are thechief extrinsic muscles, and act upon the entire larynx either toelevate or depress it, or to fix it in any desired position. The crico-thyrokl (tensor) muscles (Fig. 87) arise from theantero-lateral portion of the cricoid cartilage and are inserted intothe lower and inner borders of the thyroid; some fibres pass to the outer surface. These are theonly intrinsic laryngeal musclesthat are placed in front of thelarynx; in certain subjects theycan be felt under the skin duringtheir contraction. Their action isto tilt the anterior portion of thethyroid downward, thus bringingthe thyroid and cricoid cartilagescloser together anteriorly ; the tilt-ing motion serving to increase thedistance between the vocal proc-esses of the arytenoid cartilagesand the anterior
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Keywords: ., bookcentury1800, bookdecade1890, bookpublisherph, booksubjectnose
