pharynx

pharynx , area of the gastrointestinal and respiratory tracts which lies between the mouth and the esophagus. In humans, the pharynx is a cone-shaped tube about 4 1/2 in. (11.43 cm) long. At its upper end, it is continuous with the mouth and nasal passages, and connects with the ears via the Eustachian tubes . The lower end of the pharynx is continuous with the esophagus (see digestive system ). It is also connected to the larynx by an opening that is covered by the epiglottis during swallowing, thus preventing food from entering the trachea. The pharyngeal area is the embryological source of several important structures in vertebrates. For example, the breathing apparatus (gill pouches of fish and lungs of land animals) arises in this area (see respiration ). In humans, the pharynx is particularly important as an instrument of speech: it functions with the various parts of the mouth to articulate the initial sounds produced in the larynx .

pharynx Derived from the Greek for throat, the pharynx is the continuous space behind the nose and the mouth that leads down both to the passage for food and to the passage for air. It has three parts; nasal, oral, and laryngeal. As well as being open to the nose, the nasopharynx is connected to the middle ears by the eustachian (pharyngotympanic) tubes. A passage behind the soft palate leads down to the oral part. When looking at the back of the throat, the arch that can be seen behind the uvula centrally, and behind the tonsils at the sides, is a muscular fold around the opening into the oropharynx. Further down behind the base of the tongue, where the epiglottis stands guard in front of the entry into the larynx (the glottis), the laryngeal part of the pharynx leads down behind that opening to reach the oesophagus. In the wall of the pharynx there are pairs of muscles that join at the centre back and encircle it to reach various attachments in front, including the hyoid bone at the base of the tongue and the cartilage of the ‘Adam's apple’. These muscles can constrict the passages, change the shape of the spaces, or help to close off the different apertures in the various ways that are necessary, for example, during swallowing, speaking, singing, or blowing.

Sheila Jennett

pharynx Cavity at the back of the nose and mouth that extends down towards the oesophagus and trachea. It has muscles for swallowing and is part of the digestive system. Inflammation of the pharynx, usually caused by viral or bacterial infection, is known as pharyngitis.