ANATOMY & PHYSIOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site pharynx A fibromuscular passageway, commonly called the throat, that extends from the base of the skull to the level of the sixth cervical vertebra. It serves both the respiratory system and the digestive system by receiving air from the nasal cavity and air, food, and water from the oral cavity. Anatomy of the pharynx Inferiorly, the pharynx opens into the larynx and esophagus. It is divided into three regions according to location: the nasopharynx, the oropharynx, and the laryngopharynx or hypopharynx. The nasopharynx is the portion of the pharynx that is posterior to the nasal cavity and extends inferiorly to the uvula. The oropharynx is the portion of the pharynx that is posterior to the oral cavity. The most inferior portion of the pharynx is the laryngopharynx that extends from the hyoid bone down to the lower margin of the larynx. The upper part of the pharynx (throat) lets only air pass through. Lower parts permit air, foods, and fluids to pass. The pharyngeal, palatine, and lingual tonsils are located in the pharynx. They are also called Waldereyer's Ring. The retromolar trigone is the small area behind the wisdom teeth. Role of the pharynx in digestion The pharynx is part of the gastrointestinal tract, lying between the mouth and the esophagus. The oropharynx is the first region food enters when it is swallowed. The opening from the oral cavity into the oropharynx is called the fauces. Masses of lymphoid tissue – the palatine tonsils – are near the fauces. The lower region, posterior to the larynx, is the laryngopharynx, or hypopharynx. The laryngopharynx opens into both the esophagus and the larynx. Food is forced into the pharynx by the tongue. When food reaches the opening, sensory receptors around the fauces respond and initiate an involuntary swallowing reflex. This reflex action has several parts. The uvula is elevated to prevent food from entering the nasopharynx. The epiglottis drops downward to prevent food from entering the larynx and trachea in order to direct the food into the esophagus. Peristaltic movements propel the food from the pharynx into the esophagus. Related entry    • pharyngitis Related category    • ANATOMY AND PHYSIOLOGY Source: National Cancer Institute Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Transport Concepts & Designs (partner site) BACK TO TOP