Epiglottis
From Wikipedia, the free encyclopedia
| Latin = | |
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| Laryngoscopic view of interior of larynx | |
| Gray's | subject #236 1095 |
| Precursor | 4th and 6th branchial arch[1] |
The epiglottis is a lid-like flap of elastic cartilage tissue covered with a mucous membrane, attached to the root of the tongue. It projects obliquely upwards behind the tongue and the hyoid bone.
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[edit] Anatomy and function
The epiglottis guards the entrance of the glottis, the opening between the vocal folds.
It is normally pointed upward, but during swallowing, elevation of the hyoid bone draws the larynx upward; as a result, the epiglottis folds down to a more horizontal position. In this manner it prevents food from going into the trachea and instead directs it to the esophagus, which is more posterior.
The epiglottis is one of nine cartilaginous structures that make up the larynx (voice box). (There are 3 single laryngeal cartilages: thyroid, epiglottis, cricoid and also 3 paired laryngeal cartilages: arytenoid, cuneiform and corniculate).
[edit] Clinical significance
[edit] Reflexes
The glossopharyngeal nerve (CN IX) sends fibers to the upper epiglottis that contribute to the afferent limb of the gag reflex. The superior laryngeal branch of the vagus nerve (CN X) sends fibers to the lower epiglottis that contribute to the afferent limb of the cough reflex. [2]
[edit] Infection of the epiglottis
In children, the epiglottis will occasionally become infected with Haemophilus influenzae or Streptocoche in the trachea, causing massive inflammation. This condition has become rare in countries where vaccination against Haemophilus influenzae (HIB) is administered.
[edit] Additional images
 Larynx |
 Cut through the larynx of a horse |
 The cartilages of the larynx. Posterior view. |
 Ligaments of the larynx. Posterior view. |
 Coronal section of larynx and upper part of trachea. |
 The entrance to the larynx, viewed from behind. |
 Muscles of larynx. Posterior view. |
 Muscles of larynx. Side view. Right lamina of thyroid cartilage removed. |
 Sagittal section of nose mouth, pharynx, and larynx. |
[edit] References
- ^ hednk-025d — Embryology at UNC
- ^ April, Ernest. Clinical Anatomy, 3rd ed. Lippincott, Williams, and Wilkins.
[edit] External links
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