The pharynx is a muscular tube that starts at the base of the skull behind the nasal cavity and extends down to the larynx (voice box) and esophagus (the tube that leads to the stomach).
This article explains the structure and function of the pharynx. It also discusses medical conditions that can affect the pharynx, as well as some of the tests and treatment options used for them.
Anatomy
The pharynx consists of three major sections:
The nasopharynx is the top part of the throat In the back of the nose. The oropharynx makes up the middle part behind your mouth. The hypopharynx is the lowest part. It is found behind the voice box.
Structure
The pharynx as a whole is about 13 centimeters (cm) in length. While the tube is largely made up of muscle, some areas consist of soft tissue.
For example, the nasopharynx is made up of respiratory epithelium. This is a protective mucous membrane that coats the airways and respiratory tract.
The nasopharynx is also where your adenoid and part of your tonsils are located; the oropharynx contains the rest, as well as the back part of your tongue and a muscle that helps you to swallow.
The hypopharynx contains two groups of pharyngeal constrictor muscles. Together, these muscles help push food down into the esophagus for digestion.
Apart from these more circular constrictor muscles, the pharynx also has several longer muscles to shorten and expand its space and push the larynx up when swallowing.
The vagus nerve is another key part of the anatomy of the pharynx. It runs through the face, neck, and abdomen and transmits messages to and from the brain. Among other things, the vagus nerve helps control the motor and sensory functions of the pharynx, including swallowing.
Anatomical Variations
For the pharynx to work properly, its structure needs to be healthy. Changes from the norm are called anatomical variants, and they can have health impacts.
For example, some people have changes in the lateral (side) wall of the oropharynx. Researchers have noted a link between these changes and sleep apnea, a condition that causes people to stop breathing on and off while sleeping.
Some changes may be considered “normal variants.” The thyrohyoid membrane, for example, can become weak in older people. It also shows changes in younger people who engage in activities that involve pressure in the pharynx, like playing the trumpet. This can change the lateral pharynx wall too.
Function
Because of its location, the pharynx helps the respiratory system by allowing air to pass through the trachea, or windpipe, to your lungs.
For digestion, the muscles surrounding the pharynx work together to send food and drink into the esophagus. The circular muscles push food and drink toward the esophagus, while the longer muscles widen and lift the pharynx, making it possible to swallow.
The pharynx also plays a role in speech. It is an enclosed space that can change shape thanks to its muscles, so air is able to travel through the pharynx to the voice box. As vocal cords work to make sound and the larynx opens up, the pharynx is able to amplify that sound.
Associated Conditions
Medical conditions that affect the pharynx range from the mild to severe. Some may go away on their own, while others require treatment. They also will be treated differently depending on the cause.
Among the conditions that may affect the pharynx are:
Tonsillitis Croup Flu Chronic fatigue syndrome Mumps Herpangina (a viral infection) Throat cancer
A number of remedies may be used to treat some of these common ailments and help to heal the pharynx. For example, over-the-counter sore throat remedies, or simply gargling warm salt water, may help relieve discomfort from a simple sore throat from a virus or cold.
Other cases will need to be treated on the basis of the specific diagnosis. If the cause is strep throat, for instance, antibiotics are needed to treat the bacterial infection.
If you have throat irritation due to gastroesophageal reflux disease (GERD), you will likely need medication to reduce the acid that’s coming up and affecting the pharynx.
Tests
Your healthcare provider may order some tests to help determine the cause of your pharynx pain. These tests may include a laryngoscopy, which lets your healthcare provider look directly at the larynx and pharynx using a small device that contains tiny fiberoptics.
If you have a chronic cough or sore throat, voice changes, or difficulty breathing, this test may be the next step in determining the cause behind your symptoms.
Other tests may be needed, although they aren’t necessarily to evaluate the pharynx. They include:
A pH test for acid reflux Barium swallow to detect abnormalities in the digestive tract Esophageal manometry test used to diagnose any issues with the esophagus
Summary
The pharynx, or throat, plays a key role in serving both your respiratory and digestive systems. Its structures allow air to pass through your windpipe and on to your lungs, while also working to ensure food and drink pass into the esophagus and stomach. It also helps you to speak.
Many of the health conditions that affect the pharynx are common. They include the common cold, the flu, and strep throat. On the other hand, serious conditions such as throat cancer also may affect the pharynx.
