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. It is often incorrectly used to refer to the uvula
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).
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
Infection of the epiglottis
In children, the epiglottis will occasionally become infected with Haemophilus influenzae
in the trachea, causing massive inflammation. This condition has become rare in countries where vaccination
against Haemophilus influenzae
(Hib) is administered.