Learn About the 12 Cranial Nerves and Their Functions
- The olfactory nerve is involved in the sense of smell.
- The optic nerve is involved in the sense of sight.
- The oculomotor nerve controls pupil constriction and eye movement.
- The trochlear nerve also plays a role in the movement of the eyes.
- The trigeminal nerve plays a role in controlling the muscles needed for chewing.
What are the 12 cranial nerves and their function?
Table: Overview of the 12 cranial nerves (CNs)NerveCNTypeOlfactoryISensory Nervous System: HistologyOpticIISensory Nervous System: HistologyOculomotorIIIMotor Nervous System: HistologyTrochlearIVMotor Nervous System: Histology8 more rows
What does cranial nerve affect?
The cranial nerves are those that arise directly from your brain or brainstem and often affect areas like the face and eyes.
What is the most important cranial nerve and what does it do?
V. The trigeminal nerve is the largest cranial nerve and has both motor and sensory functions. Its motor functions help a person to chew and clench the teeth. It also gives sensation to muscles in the tympanic membrane of the ear.
What is the function of cranial nerve 10?
The vagus nerve arises from the fourth branchial arch; this arch is also responsible for the development of the pharyngeal and laryngeal muscles, the laryngeal cartilages, the aortic arch, and subclavian artery.
What are the most common cranial nerve disorders?
These include:Infections. Infections in the spinal fluid can irritate cranial nerves. ... Cancer. ... Increased intracranial pressure from a tumor, head trauma, or brain swelling. ... Congenital cranial neuropathies. ... Microvascular cranial nerve palsy. ... Autoimmune abnormalities. ... Aneurysm. ... Inflammatory diseases.
Can damaged cranial nerves heal?
Treatment. If a cranial nerve is completely cut in two, it cannot be repaired. However, if it is stretched or bruised but the nerve remains intact, it can recover. This takes time and can cause a variety of unpleasant symptoms including tingling and pain.
What side of neck is vagus nerve?
The vagus nerve is also noted as being the tenth cranial nerve (designated as CN X). The vagus nerve is actually a set of two nerves, a vagus nerve right side of the neck and a vagus nerve left side of the neck.
What side is vagus nerve on?
Where is the vagus nerve? Your vagus nerves are the longest cranial nerve, running from your brain to your large intestine. Your left vagus nerve travels down the left side of your body. The right vagus nerve travels down the right side of your body.
What nerve controls facial expression?
facial nerve (VII)Sensation on the face is innervated by the trigeminal nerves (V) as are the muscles of mastication, but the muscles of facial expression are innervated mainly by the facial nerve (VII) as is the sensation of taste.
What is the vagus nerve responsible for?
The vagus nerve is responsible for the regulation of internal organ functions, such as digestion, heart rate, and respiratory rate, as well as vasomotor activity, and certain reflex actions, such as coughing, sneezing, swallowing, and vomiting (17).
What is the function of cranial nerve 5?
What is the trigeminal nerve? The trigeminal nerve is the part of the nervous system responsible for sending pain, touch and temperature sensations from your face to your brain. It's a large, three-part nerve in your head that provides sensation.
What is cranial nerve 6 called?
Cranial nerve six (CN VI), also known as the abducens nerve, is one of the nerves responsible for the extraocular motor functions of the eye, along with the oculomotor nerve (CN III) and the trochlear nerve (CN IV).
What happens if cranial nerve 10 is damaged?
The voice is hoarse and nasal. The vocal cord on the affected side is immobile. The result is dysphagia and dysphonia (trouble swallowing and trouble speaking).
What happens if cranial nerve 5 is damaged?
A trigeminal nerve injury may affect a small area, like part of your gum, or a large area, like one side of your face. The injury can cause problems with chewing and speaking. The extent depends on where the nerve damage occurs. You may have ongoing numbness or facial pain in the area that the nerve serves.
What happens when cranial nerve 2 is damaged?
Damage to the optic nerve anterior to the optic chiasm results in ipsilateral monocular vision loss. Damage at the optic chiasm disrupts the nasal retinal fibers of both eyes resulting in a loss of both temporal visual fields.
What happens when cranial nerve 3 is damaged?
The oculomotor (third) cranial nerve plays an important role in the efferent visual system by controlling ipsilateral eye movements, pupil constriction, and upper eyelid elevation. Accordingly, damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis.
How do I remember the 12 cranial nerves?
There are many mnemonics a person can use to remember the 12 cranial nerves. One example is: "Oh Oh Oh To Touch And Feel Very Good Velvet — Ah, Hea...
Which cranial nerve is largest?
The vagus nerve is the longest cranial nerve as it starts in the medulla — the bottom part of the brain — and extends to the abdomen.
Which is the shortest nerve?
The shortest cranial nerve is the trochlear nerve, as it has the lowest number of axons.
Overview
A number of cranial nerves send electrical signals between your brain and different parts of your neck, head and torso. These signals help you smell, taste, hear and move your facial muscles.
Function
Your cranial nerves play a role in controlling your sensations and motor skills.
Anatomy
Two of your cranial nerve pairs originate in your cerebrum. The cerebrum is the largest portion of your brain that sits above your brainstem. These two pairs of cranial nerves include:
Conditions and Disorders
Some conditions or injuries can damage parts of the brain where cranial nerves are located. In some cases, a condition may damage only one cranial nerve. Trauma or surgery could injure or sever a nerve.
Care
You can keep your brain, cranial nerves and entire nervous system healthier with a few lifestyle changes. You can:
How many cranial nerves are there?
The twelve cranial nerves are a group of nerves that start in the brain and provide motor and sensory functions to the head and neck. Each cranial nerve has its unique anatomical characteristics and functions. Doctors can identify neurological or psychiatric disorders by testing cranial nerve functions. Last medically reviewed on October 10, 2019.
What nerve helps the body sense changes in the position of the head with regard to gravity?
The vestibular nerve helps the body sense changes in the position of the head with regard to gravity. The body uses this information to maintain balance.
Which nerve provides movement to most of the muscles that move the eyeball and upper eyelid, known as extraocular?
The oculomotor nerve provides movement to most of the muscles that move the eyeball and upper eyelid, known as extraocular muscles.
What are the functions of the cranial nerves?
Each has a different function for sense or movement. The functions of the cranial nerves are sensory, motor, or both: Sensory cranial nerves help a person to see, smell, and hear. Motor cranial nerves help control muscle movements in the head and neck.
Which nerve is involved in eye movement?
The trochlear nerve is also involved in eye movement.
Which nerves help control muscle movements in the head and neck?
Motor cranial nerves help control muscle movements in the head and neck.
Where do olfactory receptors travel?
When a person inhales fragrant molecules, olfactory receptors within the nasal passage send the impulses to the cranial cavity, which then travel to the olfactory bulb. Specialized olfactory neurons and nerve fibers meet with other nerves, which pass into the olfactory tract. The olfactory tract then travels to the frontal lobe and other areas ...
What is the name of the nerve that carries impulses for the sense of smell?
The following are the list of cranial nerves, their functions, and tumor examples: The olfactory nerve carries impulses for the sense of smell.
Which nerve enervates the sternocleidomastoid muscles and the trapezius muscles?
The vagus nerve enervates the gut ( gastrointestinal tract ), heart and larynx. The accessory nerve enervates the sternocleidomastoid muscles and the trapezius muscles. The hypoglossal nerve enervates the muscles of the tongue.
Which nerve enervates the muscles of the face?
The abducent nerve enervates a muscle, which moves the eyeball. The facial nerve enervates the muscles of the face (facial expression). The vestibulocochlear nerve is responsible for the sense of hearing and balance (body position sense). The glossopharyngeal nerve enervates muscles involved in swallowing and taste.
Which nerve controls the facial muscles?
The trochlear nerve controls an extraocular muscle. The trigeminal nerve is responsible for sensory enervation of the face and motor enervation to muscles of mastication (chewing). The abducent nerve enervates a muscle, which moves the eyeball. The facial nerve enervates the muscles of the face (facial expression).
Which nerve controls the sense of smell?
The olfactory nerve carries impulses for the sense of smell. The optic nerve carries impulses for the sense of sight. The occulomotor nerve is responsible for motor enervation of upper eyelid muscle, extraocular muscle and pupillary muscle. The trochlear nerve controls an extraocular muscle.
What are cranial nerves?
Cranial nerves are a part of the peripheral nervous system. There are 12 cranial nerves in all, each with different functions. Some cranial nerves control facial muscle movement, others relay sensory information from the eyes or ears, and still, others help regulate vital body functions such as breathing and swallowing.
What do cranial nerves do?
The cranial nerves play a major role in sensory perception, facial expression, eye movement, balance and coordination of the head and neck regions, as well as speech production.
Summary
The twelve cranial nerves are responsible for relaying sensory information from all over your body to the brain. They also play a role in helping you coordinate many important voluntary movements like chewing or facial expressions.
What are cranial nerves?
The 12 cranial nerves extend from your brain and brain stem, responsible for helping you control different motor and sensory functions.
What causes double vision?
Damage to the lower part of the brain stem can lead to issues with your horizontal eye movement, sometimes leading to double vision. This cranial nerve disorder usually occurs when there is an injury to the fibers connecting the oculomotor nerve, the trochlear nerve, and the abducens nerve.
Why do cranial nerves malfunction?
When these nerves end up damaged and start malfunctioning because of an illness or injury , it affects your body’s ability to move and feel. Cranial nerve disorders are also called cranial neuropathies.
How do you know if you have cranial nerve disease?
Some of the most common signs that can indicate a cranial nerve disorder include: Pain in different regions of the body. Tingling sensations in places like your arms, legs, or neck. Skin sensitivity when touched.
What causes Bell's palsy?
The seventh cranial nerve controls the muscles of the face, and although scientists do not know the exact cause of Bell's palsy, they think it may be due to nerve damage from an infection , for example, the flu, common cold viruses, and more serious infections like meningitis. The symptoms of Bell's palsy vary from person to person, but can include mild weakness to total paralysis, dry eye, dry mouth, eyelid drooping, drooling, mouth drooping, dry mouth, changes in taste, and excessive tearing in one eye.
Which nerve feeds nerves to the lateral rectus muscles of the eyes that control their lateral movements?
Abducens nerve — It feeds nerves to the lateral rectus muscles of the eyes that control their lateral movements.
Which nerve controls the movement of the eye?
Optic nerve — It carries visual information from your retina to your brain. Oculomotor nerve — It controls most of your eye movements along with the way your pupil constricts and the ability to keep your eyelid open. Trochlear nerve — It feeds nerves to the major muscle around your eyes that controls how they rotate.
What nerve is responsible for hearing and balance?
Vestibulocochlear nerve (auditory vestibular nerve): Vestibulocochlear (auditory vestibular nerve) is responsible for hearing and balance. This helps eyes to keep track of moving objects while your head is stable. The sensation of spinning and dizziness are the symptoms of damage to this nerve.
What nerves help with double vision?
Damage to this nerve leads to distortion in vision or double vision and even problem in the coordination of eyes. Trochlear and Abducens nerves: These nerves also help in eye movement. Damage to the Trochlear nerve might cause inability to move eyeball downwards and damage to abducens nerve might result in diplopia.
What are the functions of cranial nerves?
Functions of Cranial Nerves. Following is the cranial nerves list along with the important functions they perform: Olfactory nerve: This nerve helps to feel the sense of smell. This is the primary nerve that is responsible for the smell. Damage to this nerve may result in distortion of smell and taste.
Why are cranial nerves mixed?
Others are mixed nerves because they include both sensory and motor fibres. Only cranial nerves I and II are purely sensory and are responsible for the sense of smell and vision (optic nerve II). The rest of the cranial nerves contain both afferent and efferent fibres and are therefore referred to as the mixed cranial nerves.
How many pairs of spinal nerves are there in the human body?
A spinal nerve is a mixed nerve that transmits sensory, motor or autonomic signals between the spinal cord to the body. There are 31 pairs of spinal nerves in the human body.
What nerve is responsible for the sensation of spinning?
The sensation of spinning and dizziness are the symptoms of damage to this nerve. This nerve branches into the vestibular nerve and cochlear nerve. Glossopharyngeal: Oral sensation and sense of taste are stimulated by this nerve. Damage to this nerve disables the sense of taste.
What happens if the vestibulocochlear nerve gets damaged?
If the vestibulocochlear nerve gets damaged it results in dizziness and spinning.
