The Human Body

Pharynx

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Pharynx, muscular tube located in the neck, lined with mucous membrane, that connects the nose and mouth with the trachea (windpipe) and esophagus and serves as a passageway for both air and food. About 13 cm (5 in) long in humans, it lies in the front of the spinal column. The pharynx contains the tonsils and, in children, the adenoids. Because it begins in the back of the nasal cavity, the upper part of the pharynx is called the nasopharynx. The lower part, or oropharynx, refers to the area in the back of the mouth. The pharynx ends at the epiglottis, a flap of cartilage that prevents food from entering the trachea but allows it to enter the esophagus. Two eustachian tubes connect the pharynx to the middle ear and help equalize air pressure that builds up on the eardrums.

The pharynx is subject to infections that enter through both the mouth and the nose. The symptoms of a sore throat generally involve inflammation or infection of the pharynx called pharyngitis. Causes of pharyngitis include viral infections such as the common cold, influenza, German measles (rubella), herpes, and infectious mononucleosis. In addition, diphtherial, chlamydial, streptococcal, and staphylococcal bacteria may rapidly multiply in the pharynx and cause soreness in the throat.