The two shallow pouches between its front surface and the base of the tongue, where the tip of a curved laryngoscope blade is placed
The valleculae in front of the epiglottis; the Macintosh blade lies in the vallecula
Anatomy · Head, neck & teeth
Epiglottis
The lid of the larynx
Larynx · behind the root of the tongue
A leaf-shaped flap of elastic cartilage that projects upwards behind the root of the tongue and the hyoid bone, in front of the opening (inlet) of the larynx. Its stalk is fixed to the inner surface of the thyroid cartilage, and its mucosa-covered upper part folds backwards over the airway during swallowing, helping to direct food and drink into the oesophagus rather than the trachea.
How to spot them
- ▸A leaf-shaped, pointed-at-the-base flap seen at the back of the tongue on laryngoscopy
- ▸Made of elastic (yellow fibro-) cartilage, unlike the hyaline cartilages of the larynx
- ▸Two small pouches between it and the tongue base, the valleculae
- ▸Fixed to the thyroid cartilage by the thyroepiglottic ligament and to the hyoid by the hyoepiglottic ligament
What to know
In a drooling child leaning forward in a tripod position, swelling of this structure threatens the airway; it was once commonly due to Haemophilus influenzae type b
Acute epiglottitis, made rare in the UK by the Hib vaccine (introduced 1992)
On a lateral neck X-ray, its swollen shadow resembles the end of a thumb
The 'thumb sign' of epiglottitis
A leaf of elastic cartilage that springs back into place after folding, unlike the hyaline cartilages around it
The epiglottis is elastic cartilage
Its sensory supply is the internal branch of the superior laryngeal nerve, a branch of the vagus, and its taste buds are supplied by the same nerve
The epiglottis; irritation triggers the cough reflex
Attached below to the inner surface of the thyroid cartilage, just under the notch, by a short ligament
The thyroepiglottic ligament of the epiglottis
During swallowing, the larynx rises and this structure tips backwards over the airway to help keep food out of the lungs
The epiglottis and swallowing; the larynx moves up and forward, and the base of the tongue pushes the flap down
Key ideas
- The epiglottis is only one of several protections of the airway. The vocal cords close and the larynx rises as well, which is why people whose epiglottis has been removed can still swallow safely.
- Its Greek name means 'upon the glottis', from epi (upon) and glottis (the opening between the vocal folds).
Quick-fire facts
- •Composed of elastic cartilage covered with mucous membrane; the only one of the unpaired laryngeal cartilages not made of hyaline cartilage
- •Its stalk attaches to the thyroid cartilage by the thyroepiglottic ligament and to the hyoid bone by the hyoepiglottic ligament
- •The median and lateral glossoepiglottic folds bound the valleculae between it and the tongue
- •Epiglottitis in children is a medical emergency; incidence fell sharply after Hib immunisation was introduced in the UK in 1992
- •Tripod position, drooling, muffled voice and stridor are classic signs of epiglottitis
- •The larynx extends from about the third to the sixth cervical vertebra, with the epiglottis at its upper end
- •The internal branch of the superior laryngeal nerve supplies sensation above the vocal folds; the recurrent laryngeal nerve supplies below
- •Intubation with a curved (Macintosh) blade lifts the epiglottis indirectly by pressing on the vallecula
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Sources
- OpenStax, Anatomy and Physiology 2e — 22.1 Organs and Structures of the Respiratory System
- NHS — Epiglottitis