. The anatomy of the horse, a dissection guide. Horses. DISSECTION OP THE LARYNX. 235. Fig. 30. Larynx, Side View. 1. Glossal Process of Hyoid; 2. Small Cornu; 3. Great Cornu; 4. Arytenoid Cartilage; 5. Tliyro- Hyoideus; 6. Insertion of Sterno-Thyroid; 7. Crico- Thyroidens; S. Crico-arytenoideus Posticus ; 9. Ist Ring of Trachea ; 10. Thyroid Body. The Hyo-epiglottideus Muscle (Fig. 31) takes origin from the upper face of the body of the hyoid bone; and, passing backwards in the middle line, it is inserted into the anterior surface of the epiglottis at its lower part. Its fibres are mixed with
. The anatomy of the horse, a dissection guide. Horses. DISSECTION OP THE LARYNX. 235. Fig. 30. Larynx, Side View. 1. Glossal Process of Hyoid; 2. Small Cornu; 3. Great Cornu; 4. Arytenoid Cartilage; 5. Tliyro- Hyoideus; 6. Insertion of Sterno-Thyroid; 7. Crico- Thyroidens; S. Crico-arytenoideus Posticus ; 9. Ist Ring of Trachea ; 10. Thyroid Body. The Hyo-epiglottideus Muscle (Fig. 31) takes origin from the upper face of the body of the hyoid bone; and, passing backwards in the middle line, it is inserted into the anterior surface of the epiglottis at its lower part. Its fibres are mixed with a quantity of fatty- elastic tissue. Action. — To assist the natural elasticity of the epig- lottis in restoring the cartilage to the erect position at the close of the act of deglutition. Intrinsic Group.—This in- cludes four pairs of muscles, viz., the crico - thyroid, the thyro-arytenoid, the posterior crico-arytenoid, and the lateral crico-arytenoid; and a single muscle—the arytenoideus. The Crioo-thyroid Muscle (Fig. 30) arises from the side of the cricoid cartilage; and its fibres, passing obliquely upwards and backwards, are inserted into the lower edge of the thyroid wing. Action.—This muscle acts on the crico-thyroid joint, increasing the tension of the vocal cord by increasing the distance between the fore- part of the thyroid and the base of the arytenoid cartilage. In this action either the cricoid or thyroid attachment may be the fixed point of the fibres. Directions.—The thyro-arytenoid and lateral crico-arytenoid muscles lie under cover of the thyroid wing, which must therefore be removed on one side. This is to be done by removing the thyro-hyoid and crico-thyroid muscles, disarticulating the crico-thyroid joint, and in- cising the ala a little behind the body of the thyroid, after the manner of Fig. 31. The Thyro-arytenoid Muscle (Fig. 31) consists of two parallel bundles, between which the mucous membrane of the ventricle of the larynx protrudes as
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecthorses, bookyear1902
