586. The beautiful mechanism of the vocal instrument, which produces every variety of sound, from a harsh, unmelodious tone, to a soft, sweet, flute-like sound, has, as yet, been imperfectly imitated by art. It has been compared, by many physiologists, to a wind, reed, and stringed instrument. This inimitable, yet simple instrument, is the Lar´ynx.
587. Incidentally, the different parts of the respiratory organs, as well as the larynx, are subservient to speaking and singing. The tongue, nasal passages, muscles of the fauces and face, are agents which aid in the intonation of the voice.
ANATOMY OF THE VOCAL ORGANS.
588. The LARYNX is a kind of cartilaginous tube, which, taken as a whole, has the general form of a hollow, reversed cone, with its base upward toward the tongue, in the shape of an expanded triangle. It opens into the pharynx, at its superior extremity, and communicates, by its inferior opening with the trachea. It is formed by the union of five cartilages, namely, the Thy´roid, the Cri´coid, the two A-ryt-e´noid, and the Ep-i-glot´tis. These are bound together by ligaments, and moved by muscles.
586. What is said of the structure of the vocal instrument? With what instrument have physiologists compared it? What is the vocal instrument called? 587. What organs are called into action in speaking beside the larynx? 588–596. Give the anatomy of the vocal organs. 588. Describe the larynx. Name the cartilages that form the larynx.
589. The THYROID CARTILAGE is the largest of the five, and forms the prominence in the front of the neck, called Po´mum A-da´mi, (Adam’s apple.) It is composed of two parts, and is connected with the bone of the tongue above, and with the cricoid cartilage below.
590. The CRICOID CARTILAGE takes its name from its resemblance to a ring. It is situated below the thyroid cartilage, it is narrow in front, broader at the sides, and still broader behind, where it is connected with the thyroid cartilage. Below, it connects with the first ring of the trachea.
Fig. 102.