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Tracheoles
Tracheole (trā'kē-ōl') is a fine respiratory tube of the Invertebrate trachea, trachea of an insect or a spider, part of the respiratory system of insects, respiratory system. Tracheoles are about 1 µm in diameter, and they convey oxygen to cells while providing a means for carbon dioxide to escape. Tracheoles branch from the larger tracheae (which can be several mm in diameter) much like capillaries branch from arteries, or twigs from branches of a tree. This increases the surface area for gas exchange in the insect. Areas of intense metabolic activity, such as the digestive tract and flight muscles, have very dense aggregations of tracheoles. Though usually closely associated with cells, tracheoles physically penetrate only the flight muscle cells which have the highest oxygen demands. Unlike the larger tracheae which are derived of ectodermal stem cells, tracheoles do not molt with the insect. Instead, they remain in place and fuse themselves to new tracheae at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate Trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing. The trachea begins to form in the second month of embryo development, becoming longer and more fixed in its position over time. It is epithelium lined with column-shaped cells that have hair-like extensions called cilia, with scattered goblet cells that produce protective mucins. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
