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THE ARTICULATORY APPARATUS. 33
called Turbinated Bones, which, being very vascular, are arranged somewhat like hot-water coils, and heat the air as it passes into the body through the nose (Fig. 16) ; the lining membrane of the nose is also freely supplied with glands which secrete a fluid to moisten the air, and its peculiar ciliated cells actually filter the air. It is always advisable therefore to breathe in through the nose as much as possible, for thereby the air becomes warmed, moistened, and filtered.
42. Resonating Cavities.—Besides being in itself a good resonating chamber the nose communicates with many other cavities which are excellent for resonating purposes. Hollow chambers exist in the upper jaw, in the forehead just above the eyes (Fig. 16), and in the bones at the back of the nose (Fig. 16), and all these hollow chambers open into the nose itself. The nose and its accessory chambers may be regarded as the resonating chamber par excellence. Just as it is necessary to compress the column of vibrating air for voice so is it necessary to compress the air throughout the resonating chamber, and the column of air must be resisted by the roof of the nose as well as by the roof of the mouth.
43. The Pharynx.—The pharynx is a muscular tube situated at the back of the larynx, the mouth, and the nose, and may for practical purposes be divided into three parts of about equal size, which may be called the laryngeal pharynx, the oral (mouth) pharynx, and the nasal pharynx. It is the funnel which connects the breathing and vibratory portion with the nose and the mouth. It is about four inches long, and reaches from the level of the Cricoid Cartilage to the level of the top of the nose. It is mainly composed of three circularly arranged muscles
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