There’s so much to learn about the human central nervous system. It basically controls everything you’re able to do. There’s actually a lot to learn about any one nerve within the system; for example, what is the vestibulocochlear nerve?

The vestibulocochlear nerve is probably not something that you think about on a daily basis. However, it’s something that affects your daily life. It becomes particularly important when you have a disease that affects it, or it’s not working properly.

So what is the vestibulocochlear nerve? If you want to know all about it, you’ll probably have to go to medical school. However, we can give you a brief snapshot right here and save you the tuition money!

What Is the Vestibulocochlear Nerve?

You’re probably curious now, exactly what is the vestibulocochlear nerve? It’s sometimes referred to as the auditory nerve, meaning it has to do with your ears and hearing.

The vestibulocochlear nerve is the 8th of 12 cranial nerves. The cranial nerves are all of the nerves that come from the cranium, or skull. There are other nerves that come from the vertebral column, rather than the cranium.

Now, you know a little bit more about the vestibulocochlear nerve. But this is hardly the whole picture. So, exactly what is the vestibulocochlear nerve?

Location

The vestibulocochlear nerve is actually a pair of nerves, one coming from each ear. This nerve is located in the internal auditory canal, which is a part of the temporal bone of the skull.

Specifically, the origin of the vestibulocochlear nerve is between the pons and the medulla oblongata. It’s behind the facial nerve and in front of the inferior cerebellar peduncle. It’s adjacent to the vestibular and cochlear roots.

The vestibulocochlear nerve ends in the form of a spiral close to the cochlea.

Purpose

You need to know the purpose of this nerve to have a complete answer to the question, what is the vestibulocochlear nerve? In fact, it’s very important. This nerve transfers information from your inner ear to your brain.

It plays a major role in both hearing and balance. The vestibulocochlear nerve basically determines your sense of equilibrium as well.

There are two organs that play a major role in helping this nerve do its job. These would be the cochlea and vestibular apparatus.

The cochlea converts sound waves into electrical signals. This is very important because the brain needs this information to be in this form in order to interpret it properly. The vestibular apparatus is very important as well, since it senses and processes information regarding the position of your head with respect to gravity.

Components

Many people who don’t know much about nerves would assume it’s just like a simple wire. However, each nerve is more complex than this. People who ask “What is the vestibulocochlear nerve?” should know about the components that make up this nerve.

In fact, the vestibulocochlear nerve is composed of two major parts. These would be the vestibular fibers and the cochlear fibers.

Basically, vestibular and cochlear parts of this nerve have different functions. They originate from different parts of the brain as well.

The vestibular component comes from the vestibular nuclei complex in the medulla and pons, while the cochlear component comes from the ventral and dorsal cochlear nuclei in the inferior cerebellar peduncle. Both of these parts start in different places, but they come together in the pons to form the vestibulocochlear nerve.

The vestibulocochlear nerve ends up splitting into two nerves, the vestibular nerve and the cochlear nerve, in the distal part of the internal acoustic meatus.

The vestibular system is responsible for sensing your balance, and the cochlear nerve is responsible for your hearing.

Vestibular fibers

The vestibular portion of this nerve is responsible for sensing changes in the position of your head with respect to gravity. The vestibular hair cells are located in the utricule and saccule, also known as the otolith organs. Here, they detect linear movements of your head.

In the three semicircular canals within your brain, cells detect rotational movements of your head. The cell bodies of the vestibular nerve are in the vestibular ganglion, which is located in the outer part of the internal acoustic meatus.

When the vestibulocochlear nerve collects information about the position of your head, it processes the information to coordinate your balance and your vestibulo-ocular reflex. This reflex stabilizes images on your retina when your head turns. It does this by moving your eyes in the opposite direction.

Cochlear fibers

The cochlea processes sound by sensing the frequency and magnitude of sound waves. The inner hair cells of the organ of Corti sense vibrations of the basilar membrane and activate ion channels as a result. This leads to action potentials moving from the spiral ganglia.

The magnitude of the sound determines the number of action potentials travel. Louder sounds will lead to bigger vibrations of the basilar membrane, which leads to more action potentials being transmitted from the spirals ganglia. The frequency, or pitch, of the sound affects the position of inner hair cells as they’re activated.

Common Disorders of the Vestibulocochlear Nerve

There’s a lot worth knowing about the vestibulocochlear nerve, in addition to the answer to the question, what is the vestibulocochlear nerve? There are many disorders that can afflict this nerve. Even if it is just one nerve, all of these are major disorders that can really impact your quality of life.

Tinnitus

Tinnitus isn’t actually a vestibular disorder in its own right, but it’s a pretty severe symptom of some other types of vestibular disorders. It can be pretty debilitating.

Tinnitus is a condition where you perceive abnormal noise and either one or both ears or inside your head. It could either be intermittent or continuous. You can hear a variety of sounds, including ringing, whistling, hissing, buzzing, or clicking; these sounds can vary widely in pitch as well.

Ototoxicity

Basically, ototoxicity is ear poisoning. This is a result of exposure to chemicals or drugs that damage the vestibulocochlear nerve or inner ear. The inner ear is involved in both hearing and balance, so ototoxicity can result in impairment of either or both of these senses.

Ototoxicity can be either temporary or permanent. It usually depends on the drug.

Neurotoxicity

Neurotoxicity, or neurotoxic vestibulopathy, is a poisoning of neurons in the areas of your brain that help control balance. There are different substances that can precipitate this condition. These include lead, mercury, and synthetic drugs known as quinolines.

Many quinolines have been gradually phased out because of harmful effects, including neurotoxicity. However, mefloquine, or Lariam, is still used for the prevention and treatment of malaria.

Ménière’s disease

People don’t know the exact cause of this disease. This is a chronic and interabled vestibular disorder. It creates a recurring set of symptoms that’s a result of abnormally large amounts of endolymph, which is a fluid, collecting in the inner ear.

It can develop at any age, but it’s more likely in people between 40 and 60. Hearing loss is common at the beginning. Eventually, it can progress to attacks of dizziness and vertigo.

Autoimmune inner ear disease

An autoimmune disorder is the result of a malfunction of the immune system. It’s supposed to defend the body against pathogens from the outside, but the immune system can sometimes mistake the body’s own cells for intruders and attack them. When this happens in the ear, this is known as autoimmune inner ear disease.

It can happen in a few different ways. The immune system can attack just the ear, the ear along with some other body part, or attack the entire body. In some cases, the autoimmune reaction can create debris that can end up deposited in the inner ear.

There are a few different autoimmune disorders that can affect the ear. These include Cogan’s syndrome, polyarteritis nodosa, Wegener’s granulomatosis, relapsing polychondritis, ulcerative colitis, rheumatoid arthritis, and others.

The main effect of an autoimmune problem on the ear is usually hearing loss. However, attacks can also occur on the vestibular system.

Concussion

You’ve probably heard of a concussion before. This can affect the vestibular system functioning in some cases. Concussions can take place when your head experiences trauma by colliding with an object or accelerating/decelerating too quickly.

With respect to the vestibular system, this can cause the brain to receive abnormal signals in regards to the movement and position of the head in space. Because of this, the brain has to rely on visual input to stabilize the position of the head on the body.

When the brain is working overtime to rely only on vision, this often leads to fatigue and hardship when trying to perform daily activities. Eye strain and tension headaches are very common in this situation.

Age-related disorders

There are also disorders that can affect the vestibulocochlear nerve that are primarily related to age. Usually, this affects people who are either really young or elderly.

Pediatric vestibular disorders

Until recently, the majority of medical professionals assumed that vestibular problems primarily affected adults. However, there is a growing body of evidence of vestibular system problems in children. Common problems include issues with gaze stability, balance, and dizziness.

These problems are quite a bit more common than the professionals once thought. Research shows that 1 out of 20 children in the United States has problems with dizziness and balance.

Dizziness and imbalance in the elderly

When elderly people experience dizziness, this can be a result of problems with the vestibular system, along with other systems. However, vestibular disorders are the most common cause of dizziness in elderly people. In fact, they’re thought to be responsible for about 50 percent of reported dizziness in the elderly.

Try Not to Get on Your Own Nerves…

You probably didn’t expect the vestibulocochlear nerve to be so important to anyone when you first wondered, what is the vestibulocochlear nerve? In fact, it plays a major role in your ability to process information and function. Even outside of the ability to hear, the vestibulocochlear nerve plays a major role in your sense of balance.

As you’ve now seen, a malfunction or problem with the vestibulocochlear nerve can really make life difficult. Any of these disorders can be considered a major disability. This nerve may be something that you take for granted, but you now know how crucial it is in your daily life.

So what is the vestibulocochlear nerve, exactly? It’s a nerve that allows people to hear their favorite music and what other people are saying, in addition to keeping you from feeling physically disoriented and even perhaps in pain. You probably won’t be taking it for granted anymore!

What do you have to say about our answer to the question, what is the vestibulocochlear nerve? Let us know by leaving a comment!

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