Pons

What is the pons?

Your pons is the second-lowest section of your brainstem, just above your medulla oblongata. It forms a key connection between your brain above it and your medulla oblongata and spinal cord below it.

Your pons is a key merging point for several of your cranial nerves, which are nerves with direct connections to your brain. Those nerve connections are vital, helping with several of the senses on or in your head, plus your ability to move various parts of your face and mouth.

What is the function of the pons?

Your pons is a part of your brainstem, which links your brain to your spinal cord. That makes your pons a vital section of your nervous system, providing a route for signals to travel to and from your brain. Several neurotransmitters in your pons facilitate brain function, particularly sleep.

Key jobs

Your pons handles several important jobs on its own.

• It influences your sleep cycle. Your pons sets your body’s level of alertness when you wake up.
• It manages pain signals. Your pons relays and regulates the signals that give you the sensation of pain from anywhere in your body below your neck.
• It works with other brain structures. Your pons is a key connection point to your cerebellum, another key part of your brain that handles balance and movement. It also works cooperatively with other parts of your brainstem that manage your breathing.

Cranial nerve connections

In addition, your pons contains several key junctions for four of your 12 cranial nerves, which are nerves that directly connect to your brain. Your cranial nerves (which use Roman numerals for their numbering) that connect to the pons are:

• Trigeminal nerve (Cranial Nerve V): Your trigeminal (try-gem-in-all) nerve provides the sense of touch and pain for your face and controls the muscles you use for chewing.
• Abducens nerve (CN VI): Your abducens (ab-DO-sens) nerve is one of the muscles that control eye movement. Damage to this nerve can cause double vision (diplopia).
• Facial nerve (CN VII): This nerve controls most of your facial expressions and your sense of taste from the front of your tongue.
• Vestibulocochlear nerve (CN VIII): Your vestibulocochlear (vest-ib-you-lo-co-klee-ar) nerve branches into your vestibular nerve and cochlear nerve. Your vestibular (vest-ib-you-lar) nerve gives you your sense of balance. Your cochlear (co-klee-ar) nerve gives you your sense of hearing.

How does it help with other organs?

Your pons helps with other organs by relaying sensory input and directly controlling some of your body’s unconscious processes. Those include your sleep-wake cycle and your breathing. Your ability to feel pain is also something your pons handles, and that sensation of pain can help you react to limit or prevent injuries.

Where is the pons located?

Your pons is one of the lowermost structures in your brain, located near the bottom of your skull. It’s just above your medulla oblongata, which then connects to your spinal cord through the opening at the bottom of your skull.

What does it look like?

Your pons is a beige or off-white color. Its shape is much like the upper stem of a branch of cauliflower.

How big is it?

Pons’ dimensions are:

• Height: 1.06 inches tall (27 millimeters [mm]).
• Width: 1.49 inches (38 mm).
• Depth: 0.98 inches (25 mm).

What is it made of?

Like the rest of your brain and nervous system, your pons consists of various types of nervous system cells and structures. The nuclei (the plural term for “nucleus”) are nerves or clusters of brain cells that have the same job or connect to the same places.

Making up the nuclei are the following types of cells (with more about them below):

• Neurons: These cells make up your brain and nerves, transmitting and relaying signals. They can also convert signals into either chemical or electrical forms.
• Glial cells: These are support cells in your nervous system. While they don’t transmit or relay nervous system signals, they help the neurons that do.

Neurons

Neurons are the cells that send and relay signals through your nervous system, using both electrical and chemical signals. Each neuron consists of the following:

• Cell body: This is the main part of the cell.
• Axon: This is a long, arm-like part that extends outward from the cell body. At the end of the axon are several finger-like extensions where the electrical signal in the neuron becomes a chemical signal. These extensions, called synapses, lead to nearby nerve cells.
• Dendrites: These are small branch-like extensions (their name comes from a Latin word that means “tree-like”) on the cell body. Dendrites are the receiving point for chemical signals from the synapses of other nearby neurons.
• Myelin: This thin, fatty layer surrounds the axon of many neurons and acts as a protective covering.

Neuron connections are incredibly complex, and the dendrites on a single neuron may connect to thousands of other synapses. Some neurons are longer or shorter, depending on their location in your body and what they do.

Glial cells

Glial (pronounced glee-uhl) cells have many different purposes, helping develop and maintain neurons when you’re young and managing how the neurons work throughout your entire life. They also protect your nervous system from infections, control the chemical balance in your nervous system and create the myelin coating on the neurons’ axons. Your nervous system has 10 times more glial cells than neurons.

What are the common conditions and disorders that affect the pons?

Many of the conditions that affect your brain can affect your pons. Some conditions affect your pons specifically. Examples include (in alphabetical order):

• Brain tumors (including cancer).
• Central pontine myelinolysis.
• Concussions and other traumatic brain injuries.
• Congenital disorders (conditions you have at birth), including genetic disorders (conditions you inherited from one or both parents).
• Heavy metal poisoning or other toxins.
• Immune and inflammatory conditions (such as multiple sclerosis).
• Infections (these can happen because of bacteria, viruses, parasites and fungi).
• Locked-in syndrome from trauma or stroke.
• Multiple system atrophy.
• Olivopontocerebellar atrophy.
• Stroke.

Common signs or symptoms of pons conditions?

The signs and symptoms of conditions that affect your pons depend strongly on the affected part. Damage to different areas of your pons will affect your body differently. Some of the most common symptoms include:

• Ataxia (lack of coordination).
• Deafness.
• Double vision (diplopia).
• Loss of sense of touch (including the ability to feel vibration, temperature or pain).
• Nystagmus.
• Nausea and vomiting.
• Paralysis (affects parts of your head, face, or specific parts of your body; extensive damage to the pons will cause paralysis to your entire body — other than your eye movement — in a condition known as locked-in syndrome).
• Vertigo.
• Tinnitus (ringing in your ears).

Common tests to check the health of the body organ?

The following tests are possible when healthcare providers are diagnosing conditions related to your pons:

• Blood tests (these can detect many problems, ranging from immune system issues to toxins and poisons, especially metals like copper, mercury or lead).
• Computerized tomography (CT) scan.
• Electroencephalogram (EEG).
• Electromyogram (nerve conduction test).
• Evoked potentials (sensory tests).
• Genetic testing.
• Magnetic resonance imaging (MRI).
• Positron emission tomography (PET) scan.

Common treatments for the pons?

The treatments for conditions that affect your pons are highly variable. Some conditions are treatable with medication, while others require more advanced care like surgery. Some conditions aren’t curable or treatable. The most likely approach will be to treat the symptoms in those cases. No one treatment exists for all conditions affecting your pons.

How can I prevent problems with the pons?

Some conditions that affect your pons are preventable, while others happen unpredictably. In many cases, you can reduce the risk of having certain conditions or problems. The best preventive actions you can take include:

• Eat a balanced diet. Unusually high or low vitamin levels can affect your brain and nervous system. Managing your diet also can help your circulatory health, which affects the health of your brain.
• Stay physically active and maintain a healthy weight. Your weight and activity level can prevent or delay conditions that affect your brain, especially heart and circulatory problems that could lead to problems like stroke.
• Use safety equipment. Head injuries, especially concussions and traumatic brain injuries, can damage your brain. In some cases, the damage is permanent. Safety equipment like helmets can help you avoid head injuries whether you’re at work or enjoying your time off.
• Take care of chronic conditions. Many conditions that affect your brain worsen over time, particularly uncontrolled high blood pressure. Treating those conditions can sometimes stop them or slow them down, helping you prevent more serious brain injury.

A note from Cleveland Clinic

Your pons is a small but significant part of your brain. Though it’s a section of your brain that often goes unnoticed, it’s still a vital part of how you live your life and get information about the world around you. It helps manage your breathing, balance, hearing and more. That’s why protecting your brain health from injuries and preventable conditions is an essential part of how you live your life.