Editing Trachea (section)

{{short description|Cartilaginous tube that connects the pharynx and larynx to the lungs}}
{{About||the genus of moth|Trachea (moth){{!}}''Trachea'' (moth)|the cup-shaped Byzantine coins|Trachy (currency)}}
{{Use dmy dates|date=April 2017}}
{{Infobox anatomy
| Name        = Trachea
| Latin       = trachea
| pronunciation = {{IPAc-en|t|r|ə|ˈ|k|iː|ə|,_|ˈ|t|r|eɪ|k|i|ə}}<ref>{{cite web |title=Trachea {{!}} Definition of Trachea by Lexico |url=https://www.lexico.com/en/definition/trachea |archive-url=https://web.archive.org/web/20200707001255/https://www.lexico.com/en/definition/trachea |url-status=dead |archive-date=7 July 2020 |website=Lexico Dictionaries {{!}} English |access-date=27 October 2019 |language=en}}</ref>
| Image      = Illu_conducting_passages.svg
| Caption     = Human trachea
| Width       = 
| Image2      =
| Caption2    =
| Precursor   = 
| System      = 
| Artery      = [[Tracheal branches of inferior thyroid artery]]
| Vein        = [[Brachiocephalic vein]], [[azygos vein]] [[accessory hemiazygos vein]]
| Nerve       = 
| PartOf      = [[Respiratory tract]]
| Lymph       = 
}}
The '''trachea''' ({{plural form}}: '''tracheae''' or '''tracheas'''), also known as the '''windpipe''', is a [[cartilaginous]] tube that connects the [[larynx]] to the [[bronchi]] of the [[lung]]s, allowing the passage of [[air]], and so is present in almost all [[animal]]s' 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 [[annular ligaments of trachea|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. Its [[epithelium]] is lined with [[columnar epithelium|column-shaped cells]] that have hair-like extensions called [[cilia]], with scattered [[goblet cell]]s that produce protective [[mucin]]s. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts of the [[respiratory tract]], such as the larynx and bronchi, called [[croup]], that can result in a cough. Infection with [[bacteria]] usually affects the trachea only and can cause narrowing or even obstruction. As a major part of the respiratory tract, the trachea, when obstructed, prevents air from entering the lungs; thus, a [[tracheostomy]] may be required. Additionally, during surgery, if [[mechanical ventilation]] is required during anaesthesia, [[tracheal tube|a&nbsp;tube]] is inserted into the trachea: this is called [[tracheal intubation]].

The word ''trachea'' is used to define a very different organ in [[invertebrate]]s than in [[vertebrate]]s. [[Insect]]s have an open [[respiratory system of insects|respiratory system]] made up of [[Spiracle (arthropods)|spiracles]], tracheae, and [[tracheole]]s to transport [[metabolic]] gases to and from tissues.