The muscles of the pharynx can be divided into two groups:.Middle and inferior pharyngeal constrictors.Squamous cell carcinoma of the hypopharynx most commonly develops in this region.Food particles can become trapped in these spaces.Piriform recess: a set of depressions in the hypopharynx located posterolaterally to both sides of the laryngeal opening.Inferiorly: esophagus at the level of the cricoid cartilage.Superiorly: upper margin of the epiglottis.Extends from the epiglottis to the beginning of the esophagus.Part of the conducting zone of the respiratory system.Inferiorly: upper margin of the epiglottis.Extends from the inferior border of the soft palate to the superior aspect of the epiglottis.Formed by the cartilaginous portion of the medial end of the eustachian tube.A mucosal prominence in the lateral aspect of the nasopharynx that protects the opening of the eustachian tube.Laterally: pharyngeal openings of the eustachian tube (connecting with the tympanic cavities), fossa of Rosenmueller, medial pterygoid plates, and superior pharyngeal constrictor muscles.Posteriorly: clivus, prevertebral musculature covering C1–C2.Extends from the base of the skull to the soft palate.Diseases that may affect the pharynx include infections ( pharyngitis, tonsillitis, diphtheria, infectious mononucleosis), sleep apnea, dysphagia, and pharyngeal cancer. The pharyngeal mucosa is lined by both stratified squamous epithelium and ciliated pseudostratified epithelium with goblet cells. Motor and sensory innervation are mainly via branches of the vagus and glossopharyngeal nerves. The lymphatics drain directly into the deep cervical nodes, either directly or through the retropharyngeal or paratracheal nodes. The pharyngeal veins drain into the internal jugular vein. The arterial supply is derived from branches of the external carotid artery, the ascending palatine and tonsillar branches of the facial artery, the maxillary artery, and the dorsal lingual branches of the lingual artery. The pharynx plays a role in deglutition, vocalization, and air conduction. from the uvula to the level of the hyoid bone), and the laryngopharynx (extending approx. from the base of the skull to the soft palate), the oropharynx (extending approx. It is divided into the nasopharynx (extending approx. The pharynx is a musculomembranous cavity that connects the oral and nasal cavities to the larynx and esophagus.