Laryngopharynx

The laryngopharynx, or hypopharynx, is the inferior portion of the pharynx. It extends from the opening of the laryngeal inlet behind the epiglottis to the inferior border of the cricoid cartilage at about the C6 level, continuing with the esophagus. It lies posterior to the larynx, with the laryngeal inlet anteriorly and laterally placed piriform fossae on its sides.

Anatomy and relations: The walls are formed by the superior, middle, and inferior pharyngeal constrictor muscles, reinforced by the longitudinal pharyngeal muscles. The mucosa is lined by stratified squamous epithelium. The piriform fossae are recesses located on each side of the laryngeal inlet and are clinically relevant as potential sites for foreign-body impaction. The laryngopharynx communicates superiorly with the oropharynx and nasopharynx and inferiorly with the esophagus.

Innervation and blood supply: The pharyngeal plexus, formed by branches of the glossopharyngeal (CN IX) and vagus (CN X) nerves, provides motor and sensory innervation. The arterial supply comes from branches of the superior and inferior thyroid arteries, with venous drainage into the pharyngeal venous plexus and the internal jugular system.

Function: It serves as a conduit for both air and swallowed material, with the constrictor muscles propelling the bolus into the esophagus during swallowing while the larynx is protected by the epiglottis. The laryngopharynx also participates in reflexes that coordinate swallowing and airway protection.

Clinical relevance: Hypopharyngeal tumors, especially in the piriform recess, can cause dysphagia or referred otalgia. Laryngopharyngeal reflux is the backflow of gastric contents into this region, contributing to throat irritation and related symptoms.