trachea

(trā`kēə) or

windpipe,

principal tube that carries air to and from the lungs. It is about 4 1-2 in. (11.4 cm) long and about 3-4 in. (1.9 cm) in diameter in the adult. It extends from the larynxlarynx
, organ of voice in mammals. Commonly known as the voice box, the larynx is a tubular chamber about 2 in. (5 cm) high, consisting of walls of cartilage bound by ligaments and membranes, and moved by muscles. The human larynx extends from the trachea, or windpipe.
..... Click the link for more information. to the bronchial tubes and is situated in front of the esophagus (see respirationrespiration,
process by which an organism exchanges gases with its environment. The term now refers to the overall process by which oxygen is abstracted from air and is transported to the cells for the oxidation of organic molecules while carbon dioxide (CO₂
..... Click the link for more information. ). The trachea consists of a supporting layer of connective and muscular tissue in which are embedded from 16 to 20 U-shaped rings of hard cartilage that encircle the front of the tube. Tiny hairs, or cilia, in the mucous membrane lining keep dust and other foreign particles from entering the lungs. The foreign material becomes trapped in the mucus and is swept by the beating cilia to the nose or mouth, where it is discharged from the body. The air tubes of insects and other arthropods are also called trachea.

Trachea

an organ of the respiratory tract in vertebrates, including man, that is situated between the larynx and bronchi.

In amphibians, the trachea is not divided into bronchi, as the lungs start at the trachea. Nor is it separate from the larynx in all species; for example, it is absent in tailless amphibians, where the lungs start at the trachea. In tailed amphibians, the trachea is usually long and has paired cartilages that sometimes grow together.

In reptiles, birds, and mammals, the trachea is distinctly separate from the larynx and is divided into bronchi. The length of the trachea is directly proportional to the length of the neck and inversely proportional to the length of the bronchi. The trachea in reptiles consists of closed or horseshoe-shaped cartilaginous rings, while in birds it usually consists of closed, partially ossified rings, which in some species form numerous windings and widenings that together reverberate sound. In many birds, the lower rings form the syrinx.

In mammals, the trachea consists of cartilaginous half-rings; closed rings are found in beavers, agoutis, flying lemurs, and representatives of the genus Lemur. The dorsal side of the trachea is usually membranous and contiguous with the esophagus. In whales and Sirenia, the cartilages partly fuse together to form a type of spiral. The trachea is usually divided into two bronchi in the thorax. A supplementary bronchus usually branches off the trachea in toothed whales, ruminants, and swine.

The human trachea or windpipe is a direct continuation of the larynx. It is a tube 11–13 cm long, consisting of 16–20 cartilaginous half-rings that are joined by fibrous connective tissue. It is lined with a mucous membrane. The submucous layer contains many mixed mucous glands. Inflammation of the tracheal mucosa is called tracheitis.

Trachea

(1) A respiratory organ of terrestrial arthropods in the form of an air-conveying tubule that threads through the body and opens at the body surface, forming a spiracle or stigma.

Tracheae are deep invaginations in the body surface and are lined with a thin layer of chitin, which forms a supportive spiral filament that prevents collapse of the tubule walls. In insects and solpugids, extremely slender branchings of the tracheae, tracheoles, thread through the entire body, entwining the organs and even penetrating the interiors of some cells. Thus, oxygen is delivered directly to the site where it is required, and gases are exchanged without the help of a circulatory system.

Many arthropods with highly developed tracheal systems make respiratory movements, such as rhythmic contractions and expansions of the abdomen. In more primitive myriapods and insects, almost all segments of the body have a pair of tracheal bundles and stigmata. In centipedes and most insects, bundles of tracheae that are at first independent later unite as larger longitudinal bundles to form a single respiratory system, and some segments lack stigmata. Many arachnids breathe by means of tracheae, for example, solpugids, phalangids, pseudoscorpions, and many spiders, ticks, and mites. The tracheae and stigmata of these arachnids are located in various parts of the body and are developed independently in the evolutionary process, so that they are not homologous. The tracheae of terrestrial arthropods of other classes also originated independently. In the Onycho-phora, primitive tracheae are represented by numerous bundles of extremely slender tubules, which open into a common stigma; the stigmata are distributed in more or less disorderly fashion throughout the entire body. Some oniscoideans have rudimentary tracheae in the form of tubular branched invaginations on the surfaces of the exopodites of the anterior abdominal legs.

(2) In plants, water-conveying vessels of the xylem.

REFERENCES

Dogel’, V. A. Sravnitel’naia anatomiia bespozvonochnykh, part 1. Leningrad, 1938. Pages 411–35.
Beklemishev, V. N. Osnovy sravnitel’noi anatomii bespozvonochnykh, 3rd ed., vol. 2. Moscow, 1964. Pages 54–60.

A. V. IVANOV

trachea

[′trā·kē·ə] (anatomy) The cartilaginous and membranous tube by which air passes to and from the lungs in humans and many vertebrates. (botany) A xylem vessel resembling the trachea of vertebrates. (invertebrate zoology) One of the anastomosing air-conveying tubules composing the respiratory system in most insects.

trachea

1. Anatomy Zoology the membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi 2. any of the tubes in insects and related animals that convey air from the spiracles to the tissues 3. Botany another name for vessel

trachea

[tra´ke-ah] (pl. tra´cheae) the air passage extending from the throat and larynx to the main bronchi; it is about 1.5 cm (0.6 in) wide and 10 cm (4 in) long and is reinforced at the front and sides by a series of C-shaped rings of cartilage that keep the passage uniformly open. The gaps between the rings are bridged by strong fibroelastic membranes. The trachea is lined with mucous membrane covered with small hairlike processes called cilia that continuously sweep foreign material out of the breathing passages toward the mouth, a process retarded by cold but speeded by heat. Called also windpipe. adj., adj tra´cheal.
Although the trachea is closed off by the lidlike epiglottis during swallowing, a foreign body such as a piece of meat occasionally becomes lodged in the trachea and causes choking. If a heimlich maneuver does not succeed in dislodging the foreign body, emergency tracheostomy (surgical incision of the trachea) may be necessary. Another reason for tracheostomy is in order to insert a tube for passage of air when the trachea is obstructed by swelling due to infection or allergic reaction, by accumulation of tracheobronchial secretions, or by a growth such as a polyp or tumor.

tra·che·a

, pl.

tra·che·ae

(trā'kē-ă, -kē-ē), [TA] The air tube extending from the larynx into the thorax to the level of the fifth or sixth thoracic vertebra where it bifurcates into the right and left bronchi. The trachea is composed of 16-20 incomplete rings of hyaline cartilage connected by a membrane (anular ligament); posteriorly, the rings are deficient for one fifth to one third of their circumference, the interval forming the membranous wall being closed by a fibrous membrane containing smooth muscular fibers. Internally, the mucosa is composed of a pseudostratified ciliated columnar epithelium with mucous goblet cells; numerous small mixed mucous and serous glands occur, the ducts of which open to the surface of the epithelium. Synonym(s): windpipe [G. tracheia artēria, rough artery]

trachea

(trā′kē-ə)n. pl. tra·cheae (-kē-ē′) or tra·cheas 1. Anatomy A thin-walled, cartilaginous tube descending from the larynx to the bronchi and carrying air to the lungs. Also called windpipe.2. Zoology One of the internal respiratory tubes of insects and some other terrestrial arthropods, which are connected to the spiracles and are used for gas exchange.

tra′che·al adj.

trachea

The tubular structure which connects the larynx to the primary bronchi. In non-smokers, it is covered by pseudostratified ciliated columnar epithelium, that transfers particulates out of the bronchi and bronchioles, aided by secretions from mucus-producing goblet cells.
Pronunciation
Medspeak-UK: pronounced, truh KEY uh
Medspeak-US: pronounced, TRAY key uh

tra·che·a

, pl. tracheae (trā'kē-ă, -ē) [TA] The air tube extending from the larynx into the thorax (level of the fifth or sixth thoracic vertebra), where it bifurcates into the right and left main bronchi. The trachea is composed of 16-20 rings of hyaline cartilage connected by a membrane (anular ligament); posteriorly, the rings are deficient for one fifth to one third of their circumference, the interval forming the membranous wall being closed by a fibrous membrane containing smooth muscular fibers. Internally, the mucosa is composed of a pseudostratified ciliated columnar epithelium with mucous goblet cells; numerous small mixed mucous and serous glands occur, the ducts of which open to the surface of the epithelium.
Synonym(s): windpipe. [G. tracheia artēria, rough artery]

trachea

The windpipe. A cylindrical tube of mucous membrane and muscle reinforced by rings of CARTILAGE, that extends downwards into the chest from the bottom of the LARYNX for about 10 cm. The trachea terminates when it branches into two main bronchi.

trachea

(in vertebrates; also called windpipe) the main tube leading from the glottis in the neck to the point where the bronchia branch to the lungs. It consists of a fibrous pipe supported by C-shaped cartilage rings to prevent collapse when the head is turned.
(in insects) a series of TRACHEOLES by which air is conducted into the body from external openings called spiracles. See also TRACHEAL GILL.
(in plants) see XYLEM VESSEL.

trachea

an empty tube formed from the longitudinal fusion of several cells with strong walls reinforced with LIGNIN, whose function is the mass transport of water for TRANSPIRATION. Vessels are aggregated into XYLEM tissue within the VASCULAR BUNDLES of ANGIOSPERMS.

Trachea

The tube that leads from the larynx or voice box to two major air passages that bring oxygen to each lung. The trachea is sometimes called the windpipe.Mentioned in: Bronchoscopy, Choking, Croup, Epiglottitis, Heimlich Maneuver, Inhalation Therapies, Laryngitis, Thoracoscopy, Tracheotomy

tra·che·a

, pl. tracheae (trā'kē-ă, -ē) [TA] Air tube extending from larynx into thorax to level of the fifth or sixth thoracic vertebra where it bifurcates into right and left bronchi.
Synonym(s): windpipe. [G. tracheia artēria, rough artery]

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Synonyms for trachea

noun membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi

Synonyms

Related Words

noun one of the tubules forming the respiratory system of most insects and many arachnids

Related Words