Pharynx

The pharynx plays a dual role; it is part of the respiratory system and also functions as part of the digestive system. It is a funnel shaped passageway that connects the back opening of the nose to the esophagus, which transports food to the stomach and in respiration, tunnels air to the larynx and trachea. The pharynx is divided into three regions, the nasopharynx, oropharynx and the laryngopharynx. The nasopharynx is the uppermost division that extends from the back of the nose to the roof of the mouth. This is a respiratory division. The nasopharynx also has connections with the middle ear cavities via the paired auditory and Eustachian tubes. The oropharynx or throat is the part that extends from the roof of the mouth to the level of the hyoid bone (just above the larynx). The base of the tongue forms the front of the oropharynx. Along the rear wall are the paired palatine tonsils. This portion of the pharynx performs both respiratory and digestive functions. The laryngopharynx portion extends from the hyoid bone to the esophagus at which point the respiratory and digestive systems become distinct. Food is passed to the esophagus and air to the trachea