Pharynx: What to Know

Medically Reviewed by Dany Paul Baby, MD on September 01, 2022
4 min read

The human body is made up of many amazing parts and systems that all work together to keep us healthy. One of the key components of both the respiratory system and the digestive system is the pharynx, but most people don’t call it that.

The pharynx, also known as the throat, is the muscular tunnel that connects the mouth and nose to the esophagus and the larynx. The esophagus is the tube that leads to the stomach. The larynx, also called the voice box, is the muscle that creates vocal sounds and prevents food and drink from getting into your trachea. Your trachea, also called the windpipe, stretches down into your lungs. 

Pharynx anatomy consists of three key segments:

  • Nasopharynx, the top segment which connects to the nose and allows air to pass through
  • Oropharynx, the middle segment which connects to the mouth and lets air, food, and fluid through
  • Laryngopharynx, also called the hypopharynx, which is the bottom segment near the voice box that regulates the flow of air into the lungs and food and drink into the esophagus

Other pharynx parts include the eustachian tubes and the tonsils. The eustachian tubes, also called auditory tubes, are the tubes that connect your middle ear, behind your eardrum, to the back of your nose and throat.  Tonsils are lymph nodes, small structures that are part of your body’s immune system. You have three sets of tonsils that can be found at the back of your throat and the base of your tongue.

The pharynx begins in the skull, above the mouth, and stretches down to the esophagus and trachea.

The nasopharynx starts at the back of your nasal cavity and stretches down to the roof of your mouth. It connects the nose and mouth but doesn’t include any of the mouth or what is typically thought of as the “throat.”

The oropharynx is the part of the pharynx behind the mouth. It consists of the walls of the throat, tonsils, last third of the tongue, and the soft palate. The soft palate is the soft, muscular part of the roof of your mouth. 

The laryngopharynx is the segment of the pharynx below the base of the tongue and above the esophagus and trachea.

The pharynx is essentially a key connection point for both your respiratory system and your digestive system. Each segment of the pharynx has its own jobs.

The main job of the first segment, the nasopharynx, is to connect your nose to your trachea. The air breathed in through your nose goes through your pharynx to get to your trachea and into your lungs.

The nasopharynx is also responsible for tasks such as:

  • Producing your voice
  • Filtering out debris, dust, and germs from the air you breathe in
  • Controlling the pressure between your pharynx and inner ear

The job of the oropharynx is essentially to act as a passageway between the nasopharynx, mouth, and laryngopharynx. The oropharynx also contains the muscles that allow you to swallow. Additionally, the oropharynx contains the mechanisms that prevent food from entering the nasal cavity.

The laryngopharynx is the final segment that food and air pass through before reaching the trachea and esophagus. The laryngopharynx also is responsible for keeping food and fluids out of the trachea.

Many different health conditions can affect the pharynx. Most common are bacterial and viral infections, such as the common cold and sore throat. Other common conditions include:

  • Cancer. Multiple types of cancer can attack the throat, including nasopharyngeal cancer, oropharyngeal cancer, and hypopharyngeal cancer.
  • Dysphagia. Dysphagia is a condition in which muscle weakness, disease, or nerve damage makes it difficult to swallow.
  • Inflammation of the auditory tubes. Problems with the eustachian tubes can cause hearing difficulties and pain.
  • Mononucleosis. Mononucleosis, or mono, is a condition caused by a virus that results in symptoms such as fatigue, fever, and sore throat.
  • Sleep apnea. Sleep apnea is a disorder in which you stop breathing while you’re asleep. It can happen when the muscles at the back of the throat relax improperly.
  • Strep throat. Strep throat is a common throat infection caused by bacteria. It can cause symptoms such as throat pain and difficulty swallowing.
  • Tonsillitis. Tonsillitis is a condition that causes your tonsils to become inflamed, usually caused by a virus but sometimes also a bacterial infection. In addition to swollen tonsils it may cause symptoms such as a sore throat and difficulty swallowing.

Your pharynx is lined with mucus membranes. Mucus membranes are membranes within your digestive, respiratory, and reproductive system that create mucus as the first line of defense for your immune system. Often when we get sick, our body produces a response that creates more mucus, which can cause irritation to the pharynx.

The best way to keep your pharynx healthy is to take steps to avoid infection. This includes frequent hand-washing or use of hand sanitizer, keeping a distance from those that might be contagious, and wearing a mask when contagion levels are high in your community.

Other ways you can protect your pharynx and keep your throat healthy include:

  • Drinking enough water
  • Using a humidifier if the air is dry
  • Do not smoke and avoid secondhand smoke
  • Avoid drinking or eating things that are too hot or too cold

Smoking in particular is very hard on your pharynx and respiratory tract. It can cause symptoms such as coughing, nasal congestion, nasal discharge, and snoring. Throat cancers are significantly higher in those who smoke or use tobacco.