Larynx vs Pharynx

What Is the Difference Between the Larynx and Pharynx?

The difference between the larynx and pharynx is that the pharynx is a shared muscular passage for air and food, while the larynx is a cartilage-walled passage for air alone, built to protect the airway and produce the voice. The pharynx belongs to both the respiratory and the digestive system; the larynx belongs only to the respiratory system.

They also differ in shape and build. The pharynx is a long, soft funnel of skeletal muscle hanging from the base of the skull, open in front to the nose, the mouth and the larynx. The larynx is a short, rigid box of nine cartilages that sits below the hyoid bone and leads straight into the trachea.

What is the larynx vs pharynx in one line?

The pharynx is the crossroads where air and food travel together; the larynx is the guarded gate that lets only air turn off toward the lungs.

Explained simply

Picture a hallway that leads to two doors. The hallway is the pharynx: both air and food walk down it. At the bottom, air goes through the front door, the larynx, into the windpipe, and food goes through the back door into the food pipe. The larynx has a lid and a set of folds that slam shut whenever food goes by, so nothing goes through the wrong door.

Where Is the Larynx vs Pharynx?

The pharynx lies behind the nasal cavity, the mouth and the larynx, running from the base of the skull down to the level of the cricoid cartilage, about the sixth cervical vertebra. The larynx lies in the front of the neck, in front of the lowest part of the pharynx, from about the third to the sixth cervical vertebra in an adult.

The three parts of the pharynx

• Nasopharynx: behind the nasal cavity and above the soft palate; normally only air passes through it.
• Oropharynx: behind the mouth, from the soft palate to the tip of the epiglottis; air and food share it.
• Laryngopharynx: behind the larynx, from the epiglottis to the start of the esophagus; air and food still share it.

Laryngopharynx and larynx

The laryngopharynx and the larynx sit side by side at the same height, which is why their names are easy to mix up. The laryngopharynx is the back part, a passage of the throat, while the larynx is the organ in front of it. The opening of the larynx, called the laryngeal inlet, faces backward into the laryngopharynx, and on each side of it a small gutter called the piriform recess guides swallowed food around the larynx toward the esophagus.

The larynx can be felt from the outside: its thyroid cartilage forms the Adam's apple, and the ring of the cricoid cartilage lies just below it. The pharynx cannot be felt through the neck, but its back wall is visible behind the uvula when the mouth is opened wide.

Larynx and Pharynx Anatomy: How Are They Built?

The pharynx is built of skeletal muscle layers on a fibrous sheet with no cartilage, while the larynx is built on a framework of cartilages linked by ligaments, membranes and small muscles. This difference explains why the pharynx can squeeze food downward, while the larynx always stays open for air.

Pharynx wall

From the inside out, the pharynx wall has a mucous membrane, a tough fibrous layer called the pharyngobasilar fascia, a muscle layer and a thin outer fascia. The muscle layer has three overlapping constrictor muscles, superior, middle and inferior, which squeeze in sequence during swallowing, and three longitudinal muscles, the stylopharyngeus, palatopharyngeus and salpingopharyngeus, which lift and shorten the pharynx. The nasopharynx is lined by ciliated respiratory epithelium, while the oropharynx and laryngopharynx have tougher stratified squamous epithelium that resists the rubbing of food.

Larynx framework

The larynx has nine laryngeal cartilages: three single ones, the thyroid, cricoid and epiglottis, and three pairs, the arytenoid, corniculate and cuneiform cartilages. Inside, two pairs of folds project into the airway: the upper vestibular folds, or false vocal cords, and the lower true vocal cords. Small intrinsic muscles move the arytenoid cartilages to open, close and tighten the vocal cords. Most of the larynx is lined by respiratory epithelium, but the vocal cords carry stratified squamous epithelium that withstands constant vibration.

Nerves and blood supply

Both organs are controlled mainly by branches of the vagus nerve. The pharynx is supplied by the pharyngeal plexus, which carries motor fibers from the vagus and sensory fibers from the glossopharyngeal nerve. The larynx is supplied by the superior and recurrent laryngeal nerves, and its blood comes from the superior and inferior laryngeal arteries, branches of the thyroid arteries.

What Do the Larynx and Pharynx Do?

The pharynx moves air between the nose and the larynx and pushes food from the mouth into the esophagus, while the larynx keeps food and liquid out of the airway and produces the voice. Each organ also has a few extra jobs.

Pharynx functions

• Air passage: carries air from the nasal cavity and mouth down to the larynx.
• Swallowing: its constrictor muscles squeeze each mouthful down into the esophagus.
• Immune defense: a ring of lymphoid tissue, including the adenoids and the palatine tonsils, samples germs entering through the nose and mouth.
• Ear pressure: the openings of the auditory tubes in the nasopharynx let air reach the middle ears.
• Voice resonance: its changing shape colors the sound made by the larynx.

Larynx functions

• Airway: keeps an open, cartilage-supported passage between the pharynx and the trachea.
• Protection: closes tightly during swallowing and triggers a cough if anything enters it.
• Voice: the vibrating vocal cords produce the sound used for speech and singing.
• Holding the breath: by closing, it traps air in the chest to steady the trunk during lifting, straining or a cough.

What Do the Larynx and Pharynx Have in Common?

The larynx and pharynx are neighboring parts of the upper airway that share a location in the neck, a nerve supply and an origin in the embryo, and they work as a single unit during swallowing and speech. Both carry air on every breath.

• Same region: both lie in the neck, in front of the cervical vertebrae, and both are part of the upper respiratory tract.
• Same main nerve: the vagus nerve controls most of the muscles of both organs.
• Shared lining: both are lined by a moist mucous membrane, ciliated in places and kept moist by mucus glands.
• Shared origin: both develop from the pharyngeal arches and the front end of the embryonic gut, the same region that forms the lower airways, as described on our respiratory system development page.
• Shared movements: both rise when you swallow, pulled up by muscles attached to the hyoid bone.

Because they are so close, problems often spread between them. A throat infection can reach the larynx and change the voice, and acid or mucus from below can irritate both.

How Do the Larynx and Pharynx Work Together?

The larynx and pharynx work together by taking turns with the same space: during breathing the pharynx stays open and the larynx lets air through, and during swallowing the pharynx squeezes food downward while the larynx shuts and moves out of the way. The switch takes less than a second and is controlled by a reflex in the brainstem.

During swallowing

When food reaches the back of the mouth, the soft palate seals off the nasopharynx and the larynx is pulled upward and forward under the base of the tongue. The epiglottis tips back over the laryngeal inlet, and the vocal cords and vestibular folds close beneath it. The pharyngeal constrictors then squeeze the food past the closed larynx into the esophagus, and breathing pauses briefly. The full sequence is shown step by step on our trachea vs esophagus page.

During speech

The larynx is the sound source: air from the lungs makes the vocal cords vibrate and produce a buzz. The pharynx, mouth and nasal cavity above it act as a resonating tube that shapes this buzz into recognizable vowels and gives each voice its own tone. Changing the shape of the pharynx is a large part of how singers change their sound, as explained in how the voice is produced.

During breathing

On each breath, muscles keep the soft walls of the pharynx from collapsing, while the larynx widens the gap between the vocal cords slightly to let air in. During sleep the pharyngeal muscles relax, which is why the throat, not the larynx, is the usual site of snoring.

Pharynx vs Larynx vs Trachea vs Esophagus: Where Does Each Lead?

The pharynx comes first and is shared by air and food; below it, air turns forward into the larynx and then the trachea, while food continues backward into the esophagus. These four tubes form a Y shape in the neck, with the pharynx as the stem.

1. Pharynx: the throat, shared by air and food, from behind the nose to the level of the cricoid cartilage.
2. Larynx: the voice box, air only, in front of the laryngopharynx.
3. Trachea: the windpipe, air only, continuing straight down from the larynx to the bronchi in the chest.
4. Esophagus: the food pipe, food only, continuing down from the laryngopharynx behind the trachea to the stomach.

Laryngopharynx and oropharynx

The oropharynx and laryngopharynx are both shared air and food passages, divided by the level of the tip of the epiglottis. The oropharynx lies behind the mouth and holds the palatine tonsils, while the laryngopharynx lies behind the larynx and opens into the esophagus. To follow the air all the way to the lungs, see our pathway of air guide and upper vs lower respiratory tract.

Common Conditions That Affect the Larynx and Pharynx

Infections and inflammation are the most common problems of both organs: in the pharynx they cause a sore throat, and in the larynx they cause hoarseness or loss of voice. Our respiratory diseases section covers them in more depth, and anyone with a lasting voice change or trouble swallowing or breathing should see a doctor.

• Pharyngitis: inflammation of the pharynx, usually from a viral infection, causing a sore throat.
• Tonsillitis: infection of the palatine tonsils in the oropharynx.
• Laryngitis: swelling of the larynx and vocal cords, causing hoarseness.
• Croup: a childhood viral infection that swells the larynx and trachea and causes a barking cough.
• Epiglottitis: a rare but dangerous swelling of the epiglottis that can block the airway.
• Obstructive sleep apnea: the walls of the pharynx collapse during sleep and briefly stop airflow.