hypopharynx

The hypopharynx, sometimes called the laryngopharynx, is the inferior part of the pharynx. It lies behind and around the larynx, extending from the inferior border of the epiglottis and the laryngeal inlet to the upper border of the esophagus at the level of the cricoid cartilage. It serves as a conduit for food moving from the oropharynx to the esophagus and forms part of the airway in the swallow.

Anatomically, the hypopharynx comprises three principal regions: the pyriform sinuses (or fossae) on either side of the laryngeal inlet, the postcricoid region located behind the cricoid cartilage, and the posterior pharyngeal wall. The pyriform sinuses are particularly notable as common sites for foreign bodies and tumors. The mucosa here blends with the epithelium of the larynx above and the esophagus below, helping direct the swallowed bolus toward the esophagus.

Nerve supply and blood flow are mainly from branches of the external carotid system and the vagus nerve. The mucosal sensation is primarily via branches of the vagus, including the internal branch of the superior laryngeal nerve, while motor control of the pharyngeal constrictors is via the pharyngeal plexus. Blood supply comes from ascending pharyngeal, tonsillar, and superior thyroid arteries, with venous drainage to the pharyngeal venous plexus and the internal jugular system. Lymphatic drainage targets deep cervical nodes, contributing to the propensity of hypopharyngeal cancers to present with nodal metastases.

Clinical relevance includes hypopharyngeal cancers, most often arising in the pyriform sinuses. Presenting symptoms include dysphagia, throat pain, weight loss, and neck masses. Diagnosis involves endoscopy with biopsy and imaging. Treatment varies by stage and may include chemoradiation or surgery, with relatively guarded prognosis compared with other head and neck sites.