Epiglottis
The epiglottis (pl.: epiglottises or epiglottides) is a leaf-shaped flap in the throat that prevents food and water from entering the trachea and the lungs. It stays open during breathing, allowing air into the larynx. During swallowing, it closes to prevent aspiration of food into the lungs, forcing the swallowed liquids or food to go along the esophagus toward the stomach instead. It is thus the valve that diverts passage to either the trachea or the esophagus.
Epiglottis
The epiglottis is made of elastic cartilage covered with a mucous membrane, attached to the entrance of the larynx. It projects upwards and backwards behind the tongue and the hyoid bone.
The epiglottis may be inflamed in a condition called epiglottitis, which is most commonly due to the vaccine-preventable bacterium Haemophilus influenzae. Dysfunction may cause the inhalation of food, called aspiration, which may lead to pneumonia or airway obstruction. The epiglottis is also an important landmark for intubation.
The epiglottis has been identified as early as Aristotle, and gets its name from being above the glottis (epi- + glottis).
Other animals[edit]
The epiglottis is present in mammals,[15] including land mammals and cetaceans,[16] also as a cartilaginous structure.[17] Like in humans, it functions to prevent entry of food into the trachea during swallowing.[17] The position of the larynx is flat in mice and other rodents, as well as rabbits.[4] For this reason, because the epiglottis is located behind the soft palate in rabbits, they are obligate nose breathers,[18][19] as are mice and other rodents.[4] In rodents and mice, there is a unique pouch in front of the epiglottis, and the epiglottis is commonly injured by inhaled substances, particularly at the transition zone between the flattened and cuboidal epithelium.[20][4] It is also common to see taste buds on the epiglottis in these species.[4]
History[edit]
The epiglottis was noted by Aristotle,[15] although the epiglottis' function was first defined by Vesalius in 1543.[21] The word has Greek roots.[22] The epiglottis gets its name from being above (Ancient Greek: ἐπί, romanized: epi-) the glottis (Ancient Greek: γλωττίς, romanized: glottis, lit. 'tongue').[23]
Cross-section of the larynx, with structures including the epiglottis labelled.
Cross-section of the larynx of a horse. The epiglottis here is shown as '2'.
Structures of the larynx as viewed during laryngoscopy. The leaf-like epiglottis is shown as number '3'. Other structures: 1=vocal folds, 2=vestibular fold, 3=epiglottis, 4=plica aryepiglottica, 5=arytenoid cartilage, 6=sinus piriformis, 7=dorsum of the tongue
