syrinx

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Music See panpipe.
2. n. Zoology The vocal organ of a bird, consisting of thin vibrating muscles at or close to the division of the trachea into the bronchi.

Century Dictionary and Cyclopedia

1. Same as Pan's pipes (which see, under pipe).
2. In Egypt. archæol., a narrow and deep rock-cut channel or tunnel forming a characteristic feature of Egyptian tombs of the New Empire.
3. In anatomy, the Eustachian tube.
4. In ornithology, the voice-organ of birds; the lower larynx, situated at or near the bifurcation of the trachea into the bronchi, and serving to modulate the voice, as in singing. This is usually a more complicated structure than the larynx proper (at the top of the trachea), and so differently constructed in different birds that it affords characters of great significance in classification. The highest group of Passeres (namely, the suborder Oscines, which contains the singing birds) is signalized by the elaboration of this musical organ, especially with reference to its intrinsic musculation. A few birds have no syrinx; some have one, yet without intrinsic muscles; in some the syringes arc wholly bronchial, and consequently paired; in others the syrinx is wholly tracheal, and single. But in nearly all birds the syrinx is bronchotracheal, and results from a special modification of the lower end of the trachea and upper end of each bronchus. The lowermost tracheal ring, or a piece composed of several such rings, is enlarged and otherwise modified, and crossed by a bolt-bar (see cut under pessulus), which separates the single tracheal tube into right and left openings of the bronchi. Amedian septum rises from the pessulus into the trachea, between the two bronchial oriflces, and the free upper margin of this septum, called the semilunar membrane, forms the inner lip of a rima syringis, whose outer lip is a fold of mucous membrane from the opposite side of each bronchus. These membranes are vibratile in the act of singing, and constitute vocal cords. Several upper bronchial half-rings, enlarged and otherwise modified, are completed in circumference by a single continuous membrane, the internal tympaniform membrane, which is attached to the pessulus above. The syrinx is actuated by a pair, or several pairs, of intrinsic singiug-muscles, called syringomya, which vary much in different birds in their attachments as well as in their number. (See song-muscle.) In the Oscines at least five pairs are recognized, though their nomenclature is by no means settled, owing to their description under different names by different authors, and to the difficulty of homologizing the individual muscles under their many modifications in different birds. The insertion of the syringomya into the ends and not into the middle of the bronchial half-rings is characteristic of the true Oscines. See Acromyodi, Mesomyodi.
5. In surgery, a fistula.
6. n. In some of the brachiopods, like Syringothyris, a split tubular structure developed from the deltidial plates, lying within the umbonal region of the ventral valve, and inclosing or forming a passage for the pedicle.

Wiktionary

1. n. A set of pan-pipes.
2. n. A narrow channel cut in rock, especially in ancient Egyptian tombs.
3. n. The voice organ in birds.
4. n. A rare, fluid-filled neuroglial cavity within the spinal cord or in the brain stem

GNU Webster's 1913

1. n. A wind instrument made of reeds tied together; -- called also pandean pipes.
2. n. The lower larynx in birds.

WordNet 3.0

1. n. the vocal organ of a bird
2. n. a primitive wind instrument consisting of several parallel pipes bound together