Dictionary » S » Spiracle



1. (Science: anatomy) The nostril, or one of the nostrils, of whales, porpoises, and allied animals.

2. (Science: zoology) One of the external openings communicating with the air tubes or tracheae of insects, myriapods, and arachnids. They are variable in number, and are usually situated on the sides of the thorax and abdomen, a pair to a segment. These openings are usually elliptical, and capable of being closed. A tubular orifice communicating with the gill cavity of certain ganoid and all elasmobranch fishes. It is the modified first gill cleft.

3. Any small aperture or vent for air or other fluid.

Origin: L. Spiraculum, fr. Spirare to breathe: cf. F. Spiracule. See Spirit.

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... 3/ What are three important adaptations in the mammalian respiratory system? What advantages do these adaptations provide? 4/Among lenticel, spiracle and stoma. a/ Which of these structures open and close? b/ Does opening and closing serve the same purpose for the different structures? Thanks ...

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by vhpk
Tue May 06, 2008 9:47 am
Forum: Cell Biology
Topic: Respiration
Replies: 2
Views: 2628


As far as I can remember, air goes in and out through each spiracle. Each spiracle is connected to one area of inner tissues I also seem to recall that "inhale" and "exhale" doesn't always apply to tracheal systems. Some high-metabolism ...

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by Darby
Fri Jun 02, 2006 8:58 pm
Forum: Zoology Discussion
Topic: Animalia-Arthropoda-Insecta-Grasshopper-Spiracles?
Replies: 2
Views: 3092

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