The pharynx is a funnel-shaped muscular tube that sits behind your nose, mouth, and voice box, serving as a shared passageway for both air and food. It stretches from the base of the skull down to the level of the sixth cervical vertebra (roughly mid-neck), where it connects to the esophagus in the back and the voice box in front. Though most people simply call it “the throat,” the pharynx is more precisely the section of the throat that handles two critical jobs: routing air toward your lungs and directing food toward your stomach.
Three Regions of the Pharynx
The pharynx is divided into three distinct sections stacked on top of each other, each with its own anatomy and role.
Nasopharynx
The nasopharynx is the uppermost section, sitting directly behind your nasal cavity. Air enters through your nose and passes through here on its way to your lungs. This region also houses the openings of your eustachian tubes, which connect to your middle ears and help equalize pressure (the reason your ears “pop” when you swallow during a flight). The adenoids, small immune glands that help fight off germs during childhood, sit here as well. They typically shrink and disappear by adulthood. The nasopharynx also plays a subtle role in shaping how your voice sounds, since it acts as a resonating chamber.
Oropharynx
The oropharynx is the middle section, directly behind your mouth. This is the part of your throat you can see when you open wide in front of a mirror. It handles both air and food, making it the crossroads where the respiratory and digestive paths overlap. The palatine tonsils, the familiar lumps on either side of the back of your throat, sit here between folds of tissue. Together with the adenoids above and the lingual tonsils at the base of the tongue, these tonsils form a ring of immune tissue that circles the entrance to the throat. This ring samples bacteria, viruses, and other particles that enter through the nose and mouth, helping your immune system recognize and respond to threats.
Laryngopharynx
The laryngopharynx (also called the hypopharynx) is the lowest section, sitting just behind the voice box. It begins below the epiglottis, the flap of cartilage that covers your airway during swallowing, and ends where the esophagus begins. This region contains two pear-shaped pockets called piriform sinuses, one on each side of the airway opening. These recesses help channel food and liquid around the voice box and into the esophagus. They also play a role in speech. The laryngopharynx is clinically significant because a relatively high proportion of throat cancers originate here, with the piriform sinuses being the most common site.
How Swallowing Works
Swallowing is one of the pharynx’s most complex jobs. When you chew food and push it to the back of your mouth with your tongue, the pharynx takes over with a rapid, coordinated sequence. The soft palate rises to seal off the nasopharynx so food doesn’t enter your nasal cavity. The epiglottis folds down to cover the airway. Then a series of constrictor muscles squeeze in a wave from top to bottom, pushing the food down through the oropharynx and laryngopharynx into the esophagus. This entire pharyngeal phase of swallowing takes roughly one second and is involuntary. You can choose when to start a swallow, but once the process is triggered, the muscles carry it out automatically.
Tissue Lining Differs by Region
The type of tissue lining the pharynx changes depending on what each section is exposed to. The nasopharynx, which only handles air, is lined with the same mucus-producing respiratory tissue found inside your nose and windpipe. This lining filters dust, debris, and germs from the air you breathe. The oropharynx and laryngopharynx, which must withstand the friction of food passing through, are lined with tougher, layered tissue similar to what’s inside your mouth. This difference in lining is one reason cancers in each region can behave differently.
Nerve and Blood Supply
The pharynx receives its nerve signals through a network called the pharyngeal plexus, formed mainly by two cranial nerves. The glossopharyngeal nerve (the ninth cranial nerve) handles much of the sensation and some motor control in the upper pharynx. The vagus nerve (the tenth cranial nerve) supplies the motor signals that drive most of the pharyngeal muscles during swallowing. Blood reaches the pharynx primarily through branches of the external carotid artery, with the ascending pharyngeal artery being the main supplier.
A simple way doctors test whether these nerves are working is the gag reflex. By gently touching the back of the throat with a cotton swab or tongue blade, they check for a symmetric gagging response. An absent or uneven gag on one side can signal nerve damage and prompts further investigation. In the most serious cases, a completely absent gag reflex is one of the criteria used to help confirm brain death.
Common Pharynx Problems
Pharyngitis, or a sore throat, is by far the most common issue affecting the pharynx. Viral infections cause the majority of cases, though bacterial infections like strep throat are also frequent. Tonsillitis, an infection of the palatine tonsils in the oropharynx, is especially common in children.
A less well-known but surprisingly common condition is globus pharyngeus, the persistent sensation of a lump in the throat even when nothing is there. It’s not painful, but it tends to linger, recur, and resist treatment. The exact cause isn’t fully understood, but acid reflux appears to be a major contributor, potentially accounting for 23% to 68% of cases. Other factors include upper esophageal sphincter problems, chronic sinusitis, thyroid disease, and psychological stress. The condition was historically called “globus hystericus” because doctors assumed it was psychological, but the name was updated in 1968 after research showed most patients had no hysterical personality traits.
Cancers of the pharynx, while less common, are a significant concern. Cancers in the laryngopharynx are particularly notable: squamous cell carcinoma accounts for 95% of cases there, with about 78% originating in the piriform sinuses. Nasopharyngeal cancers have distinct risk factors and staging criteria and are more common in certain geographic regions, particularly Southeast Asia.