Pharynx
The pharynx, commonly known as the throat, is a vital tube-shaped passageway that connects the nasal cavity to the esophagus and trachea. It is organized into three main sections: the nasopharynx (behind the nose), the oropharynx (behind the mouth), and the laryngopharynx (above the esophagus). This structure plays several essential roles, including facilitating the passage of food and air, initiating the swallowing process, and contributing to sound production during vocalization. Notably, the pharynx contains lymphatic tissues, such as adenoids and tonsils, which help combat infections.
The pharynx can be susceptible to various disorders, particularly those related to infection and inflammation, such as pharyngitis and tonsillitis. Other conditions include epiglottitis, throat abscesses, and potentially throat cancers. Those with certain conditions, like cleft palates, may experience challenges with normal function, affecting both swallowing and speech. Understanding the structure and function of the pharynx is crucial for recognizing its importance in both respiratory and digestive health.
Subject Terms
Pharynx
Also known as: Throat
Anatomy or system affected: Ear, gastrointestinal system, head, immune system, mouth, neck, nose, respiratory system, throat
Definition: The cavity behind the nose and mouth through which air enters the lungs and food and water enter the esophagus
Structure and Functions
The pharynx, or throat, is the tube-shaped passageway that begins at the back of the nasal cavity, extends downward behind the mouth, and terminates at the fork of the esophagus and trachea, or windpipe. It comprises three sections: the nasopharynx, just behind the nose; the oropharynx, behind the mouth; and the laryngopharynx or hypopharynx, the remaining area above the esophagus. The pharynx contains lymphatic tissue to fight infection: the adenoids in the nasopharynx and the tonsils in the oropharynx. The left and right Eustachian tubes connect the nasopharynx to the ears and balance air pressure between the middle and outer ear.
Food enters the pharynx from the mouth, while air enters from the nose and mouth. The act of swallowing begins as a voluntary contraction of muscles and continues involuntarily until food passes into the esophagus. In the laryngopharynx, the epiglottis, a flap of connective tissue, prevents food and water from entering the trachea, while the soft palate of the mouth rises to block the nasopharynx so that material stays out of the nose. During vocalization, the pharynx plays a role in shaping the sounds made by the vocal cords, located just below it in the larynx.
Disorders and Diseases
Most problems in the pharynx arise from infection and inflammation. Pharyngitis, or sore throat, is an acute infection, usually from a virus or streptococcus bacteria, that is most common in children. Similarly, tonsillitis is an infection of the tonsils, quinsy (peritonsillar cellulitis and abscess) affects tissue near the tonsils, and epiglottitis is a bacterial infection of the epiglottis. Abscesses, with or without inflammation, may also occur in the pharynx; cysts known as Tornwaldt cysts may occur in the midline of the nasopharynx; and contact ulcers may result from damage to the pharyngeal tissue caused by swallowing something chemically harsh or physically abrasive or jagged.
Although not common, throat cancers can occur in the nasopharynx and tonsils. They are usually squamous cell carcinomas and occur predominantly in males, usually due to smoking and alcohol consumption.
People with cleft palates may not have complete closure of the nasal passage during swallowing, a condition called velopharyngeal insufficiency. The condition can impair speech and give it a marked nasal sound.
Bibliography
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