Carpenter's principles of human physiology . 828 OF THE VOICE AND SPEECH. of articulating suface. The direction of the surface, and the mode in whichthese cartilages are otherwise attached, cause their movement to be a sort ofrotation in a plane which is nearly horizontal, but partly downwards ; so thattheir vertical planes may be made to separate from each other, and at the sametime to assume a slanting position. This change of place will be better under-stood when the action of the muscles is described. To the lower part of theanterior surface of the Arytenoid cartilages are attached the cho
Carpenter's principles of human physiology . 828 OF THE VOICE AND SPEECH. of articulating suface. The direction of the surface, and the mode in whichthese cartilages are otherwise attached, cause their movement to be a sort ofrotation in a plane which is nearly horizontal, but partly downwards ; so thattheir vertical planes may be made to separate from each other, and at the sametime to assume a slanting position. This change of place will be better under-stood when the action of the muscles is described. To the lower part of theanterior surface of the Arytenoid cartilages are attached the chordce vocalesor Vocal Ligaments (Fig. 300, e f, Fig. 302, t v), which stretch across to thefront of the Thyroid cartilage; and it is upon the condition and relativesituation of these ligaments that their action depends. It is evident that theymay be rendered more or less tense by the movement of the Thyroid cartilage Fig. 300 Fig. External and Sectional views of the Larynx:—a n b, the cricoid cartilage; kcg, the thyroidcartilage; g, its upper hoin; c,its lower horn, where it is articulated with the cricoid; f, thearytenoid cartilage; e f, the vocal ligament; a k, crico-thyroideus muscle; f e ; x e, crico-arytenoideus lateralis; s, transverse section of arytenoideus transversus; m n,space between thyroid and cricoid; b l, projection of axis of articulation of arytenoid with thyroid. thus described; being tightened by the depression of its front upon theCricoid cartilage, and slackened by its elevation. On the other hand, theymay be brought into more or less close apposition by the movement of theArytenoid cartilages; being made to approximate nearly, or to recede in suchmanner as to cause the rima glottidis to assume the form of a narrow V, bythe revolution of these cartilages.—We shall now inquire into the actions ofthe muscles upon the several parts of this apparatus; and first i
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
