Laryngopharynx

At a glance

English

Laryngopharynx

Latin (TA2)

Pars laryngea pharyngis

System

Respiratory

Region

Whole body

Side

Single, on the midline

About the laryngopharynx

The laryngopharynx, also called the hypopharynx, is the lower third of the pharynx. It lies behind the larynx, between the level of the tip of the epiglottis and the hyoid bone above and the lower border of the cricoid cartilage below, a stretch that matches roughly the fourth to sixth cervical vertebrae. Above it the oropharynx continues, and below it narrows into the oesophagus at the pharyngo-oesophageal junction, the narrowest point of the upper digestive tract.

Its front wall is made by the larynx itself: the inlet of the larynx bounded by the epiglottis and aryepiglottic folds, and below that the back of the arytenoid and cricoid cartilages. On each side of the laryngeal inlet a deep recess, the piriform fossa, lies between the aryepiglottic fold and the inner surface of the thyroid cartilage. Three regions are recognised clinically: the piriform fossae, the postcricoid area behind the cricoid cartilage, and the posterior pharyngeal wall. The wall is lined by stratified squamous epithelium, suited to the friction of food, and covered outside by the middle and inferior pharyngeal constrictors.

It is a shared passage. Swallowed food and drink run down its sides through the piriform fossae and into the oesophagus behind, while air passes forward into the larynx. During a swallow, breathing stops briefly, the larynx rises and closes, and the bolus is moved on by contraction of the constrictors.

Its sensory nerve fibres come through the vagus, and the same nerve has an auricular branch to the ear canal. Cancer of the laryngopharynx may therefore show itself as pain referred to the ear, and the shared supply also explains why touching the ear canal can trigger a cough. Swallowed fish bones and other objects often catch in the piriform fossa.

Function and supply

Begins at

Continues from the oropharynx at the level of the tip of the epiglottis and the hyoid bone.

Ends at

Becomes the oesophagus at the lower border of the cricoid cartilage, about the sixth cervical vertebra.

Function

A shared channel through which food passes to the oesophagus and air passes to the larynx; its constrictor muscles drive the swallowed bolus downwards.

Nerve supply

Pharyngeal plexus, with sensory fibres mainly from the vagus (including the internal laryngeal nerve) and some from the glossopharyngeal nerve; motor fibres from the vagus.

Blood supply

Superior thyroid, lingual and ascending pharyngeal arteries; venous blood to the pharyngeal plexus and internal jugular vein.