The Anatomy of the Pons

Table of ContentsView AllTable of ContentsWhat Is the Function of the Pons?AnatomyAssociated ConditionsTests

Table of ContentsView All

View All

Table of Contents

What Is the Function of the Pons?

Anatomy

Associated Conditions

Tests

The pons is part of a highway-like structure between the brain and the body known as the brainstem. The brainstem is made up of three sections, and carries vital information to the body. The pons relays information about motor function, sensation, eye movement, hearing, taste, and more.

This article discusses the function and anatomy of the pons, as well as conditions that can affect this part of the brain.

Like the other parts of the brainstem, the pons plays an important role in the functioning of theautonomic nervous system. This system controls the body’s “automatic” functions, or things you do without thinking of, like breathing and digesting. The main functions of the pons deal with sensation and motor function, especially for the head and neck.

Four of the body’s12 cranial nervesare in the pons, as well as the reticular activating system. Thereticular activating systemoperates the body’s sleep-wake cycle, alertness, pain responses, and is part of the body’s fight-or-flight system.

Thecranial nervesthat arise from the pons focus on motor responses, and eye and facial movement. These are:

Cranial nerve five: Thetrigeminal nerveis the largest cranial nerve, controlling both motor and sensory function. This nerve provides sensation to the face and head, controls the muscles used to chew and bite, and conveys information about pain and temperature.

Cranial nerve six: Theabducens nervecontrols eye movement. It powers the lateral rectus muscle, housed on the outer part of the eye, that allows the eye to move outward and away from the nose.

Cranial nerve seven: Thefacial nervecontrols most of the muscles and sensation in the face. It makes the eyes water and the mouth salivate, and contributes to taste, hearing, and facial sensation and control.

Cranial nerve eight: Thevestibulocochlear nerveis responsible for hearing, but also helps to control balance and movement.

The pons is located in the brainstem, which is the area where the brain connects to the spinal cord. The brainstem includes three pieces—themidbrain, pons, andmedulla oblongata. Each piece plays a different role, relaying messages from the brain to the rest of the body.

Structure

The pons is divided into two sections—the pontine tegmentum on the interior part and the basilar pons on the outer part.

The basilar pons forms a bulb-like protrusion from the pons that is a notable feature on the brainstem.The basilar pons sits on the occipital bone (which forms the base of the skull) and contains thebasilar artery.

The pontine tectum makes up the bottom of the brain’s fourthventricleand is where fibers called peduncles originate to connect the cerebellum to the midbrain.

Injury can occur to the pons from trauma or other injury to the brainstem. An injury to the pons wouldimpair the cranial nerve functionsassociated with this part of the brain stem. You could experience damage to facial sensation, eye movement, hearing, taste, and more.

Damage to specific parts of the pons can result in a number of syndromes includinglocked-in syndrome. Locked-in syndrome is a rare condition where there is complete paralysis of voluntary muscles in all parts of the body except for the ones that control eye movement.

Verywell / Hilary Allison

Additionally, imaging may help provide more specific information about an injury to the pons and the extent of the damage. The following are a few examples of tests that may be done to determine the level of function in the brainstem.

Summary

The pons is one of three parts of the brainstem. Its functions include sensation and motor function, especially in the head and neck. Four of the 12 cranial nerves are present in the pons, as well as the reticular activating system.

Injuries or strokes affecting the pons may lead to problems with facial sensation, motor function, vision, hearing, taste, balance, and more. Damage to the pons can be assessed using functional tests and scans.

6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arguinchona JH, Tadi P.Neuroanatomy, reticular activating system. StatPearls.Haines DE, Mihailoff GA.Chapter 10: An overview of the brainstem. in:Fundamental Neuroscience for Basic and Clinical Applications. 2018:152-159. doi:10.1016/B978-0-323-39632-5.00010-4American Association of Neurological Surgeons.Anatomy of the brain.Rahman M, Tadi P.Neuroanatomy, pons. StatPearls.National Organization for Rare Disorders.Locked in syndrome.Damodaran O, Rizk E, Rodriguez J, Lee G.Cranial nerve assessment: a concise guide to clinical examination.Clin Anat. 2014;27(1):25-30. doi:10.1002/ca.22336

6 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Arguinchona JH, Tadi P.Neuroanatomy, reticular activating system. StatPearls.Haines DE, Mihailoff GA.Chapter 10: An overview of the brainstem. in:Fundamental Neuroscience for Basic and Clinical Applications. 2018:152-159. doi:10.1016/B978-0-323-39632-5.00010-4American Association of Neurological Surgeons.Anatomy of the brain.Rahman M, Tadi P.Neuroanatomy, pons. StatPearls.National Organization for Rare Disorders.Locked in syndrome.Damodaran O, Rizk E, Rodriguez J, Lee G.Cranial nerve assessment: a concise guide to clinical examination.Clin Anat. 2014;27(1):25-30. doi:10.1002/ca.22336

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Arguinchona JH, Tadi P.Neuroanatomy, reticular activating system. StatPearls.Haines DE, Mihailoff GA.Chapter 10: An overview of the brainstem. in:Fundamental Neuroscience for Basic and Clinical Applications. 2018:152-159. doi:10.1016/B978-0-323-39632-5.00010-4American Association of Neurological Surgeons.Anatomy of the brain.Rahman M, Tadi P.Neuroanatomy, pons. StatPearls.National Organization for Rare Disorders.Locked in syndrome.Damodaran O, Rizk E, Rodriguez J, Lee G.Cranial nerve assessment: a concise guide to clinical examination.Clin Anat. 2014;27(1):25-30. doi:10.1002/ca.22336

Arguinchona JH, Tadi P.Neuroanatomy, reticular activating system. StatPearls.

Haines DE, Mihailoff GA.Chapter 10: An overview of the brainstem. in:Fundamental Neuroscience for Basic and Clinical Applications. 2018:152-159. doi:10.1016/B978-0-323-39632-5.00010-4

American Association of Neurological Surgeons.Anatomy of the brain.

Rahman M, Tadi P.Neuroanatomy, pons. StatPearls.

National Organization for Rare Disorders.Locked in syndrome.

Damodaran O, Rizk E, Rodriguez J, Lee G.Cranial nerve assessment: a concise guide to clinical examination.Clin Anat. 2014;27(1):25-30. doi:10.1002/ca.22336

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