The cranial nerves are the nerves responsible for connecting your brain to the various parts of your neck, trunk, and head. There are 12 nerves all in all and each is named according to its structure or function. Each nerve also comes with a corresponding Roman number from I to XII. The number is based on where they are located, from the front towards the back. For instance, if your olfactory nerve is near the front of your head, then this will be assigned with “I”.
The functions of the nerves are often categorized as either motor or sensory. Motor nerves are responsible for controlling the function and movement of the gland muscles.
Read on to learn more about the 12 different cranial nerves and how they work.
The Olfactory Nerve is responsible for transmitting sensory information towards your brain regarding the smells you have encountered. Once you start inhaling aromatic molecules, they get dissolved immediately in a moist lining at the roof portion of your nasal cavity, known as the olfactory epithelium. This is what stimulates the receptors responsible for generating the nerve impulses, which move into your olfactory bulb. The olfactory bulb is oval shaped and contains specialized nerve cells.
From the olfactory bulb, the nerve would pass towards your olfactory tract, which is located right below your brain’s frontal lobe. The nerve signals are then sent to the areas of the brain responsible for the memory as well as the recognition of smells.
The optic nerve is responsible for the sensory nerve involving the vision. As soon as the light gets into your eyes, it will get into contact with your retina’s special receptors known as the cones and rods. The rods are often found in large numbers and they are the most sensitive to light. They are more specialized for the night vision or the black and white vision.
On the other hand, cones present in smaller numbers than rods. They tend to have lower light sensitivity unlike rods and are often more involved with the color vision.
The information that the cones and rods would receive is transmitted from the retina towards the optic nerve. Once they are in your skull, both the optic nerves will meet in order to produce the optic chiasm. In the optic chiasm, the nerve fibers coming from half of each retina will create two separate optic tracts.
Through each of the optic tract, the nerve impulses will eventually get into your visual cortex and this will then process the information it receives. Your visual cortex is often found at the back portion of your brain.
The Oculomotor nerve comes with two motor functions and these are the pupil response and muscle function.
Pupil Response. This also helps in controlling the size of your pupil and the manner it responds to light.
Muscle Function. The oculomotor nerve provides a motor function to 4 of the 6 muscles in your eyes. These muscles assist your eyes in moving and focusing on certain objects.
The trochlear nerve is responsible for controlling the superior oblique muscle. This muscle is responsible for the inward and downward movements of the eyes. It comes from the back portion of the midbrain. Just like the oculomotor nerve, this nerve moves forward until such time that it reaches your eye sockets and this is where it stimulates the muscle for the superior oblique.
The trigeminal nerve is the biggest part of your cranial nerves and it has both the motor and sensory functions.
This nerve has three divisions and these are the following:
Ophthalmic. This sends sensory information coming from the upper portion of your face, which includes the scalp, forehead, as well as your upper eyelids.
Maxillary. This part communicates the sensory information coming from the middle part of your face, which includes your upper lip, nasal cavity, and cheeks.
Mandibular. This has both the motor and sensory function and it works by sending sensory information coming from your lower lip, chin, and ears. It’s also responsible for controlling the movements of the muscles in your ear and jaw.
The trigeminal nerve comes from a group of nuclei, which is a collection of nerve cells, within the midbrain and the medulla area of your brainstem. Soon, the nuclei will come up with a separate motor and sensory root.
The motor root of the trigeminal nerve passes underneath the sensory root and is distributed into the mandibular division. On the other hand, the sensory root branches towards the maxillary, ophthalmic, and the mandibular divisions.
The abducens nerve is responsible for controlling another muscle that’s linked to the eye movement known as the lateral rectus muscle. This is the muscle that’s involved in the outward eye movement. For instance, this is what you’ll use if you’re looking to the side direction.
The nerve, which is also known as the abducent nerve, begins in your brainstem’s pons region. It will soon get into your eye socket and will begin controlling the lateral rectus muscle.
The facial nerve is responsible for providing both motor and sensory functions, which include the following:
- Communicating the sensations coming from the outer parts of your ear.
- Moving the muscles used for facial expressions including some muscles in your jaw.
- Providing glands in your neck and head area, including the tear-producing glands and salivary glands.
- Providing a sense of taste for the most part of your tongue.
Your facial nerve consists of a very complex path, which originates from your brainstem’s pons area and this is where it has both the sensory and motor root. Soon, these two nerves will combine together in order to form a facial nerve.
The vestibulocochlear nerve consists of the sensory functions that involve balance and hearing. This consists of two parts, the vestibular portion, and the cochlear portion.
Vestibular Portion. This is a set of special cells that are capable of keeping track of both the rotational and linear movements of your head. The information is then passed into the vestibular nerve in order to adjust your equilibrium and balance.
Cochlear Portion. These are specialized cells in your ear and are capable of detecting vibrations coming from the sound based on the pitch and loudness of the sound. It generates nerve impulses that get transmitted towards the cochlear nerve.
Both the vestibular and cochlear portion of your vestibulocochlear nerve comes from the separate areas of your brain. The cochlear begins in the part of your brain known as the inferior cerebellar peduncle.
The glossopharyngeal nerve includes the following motor and sensory functions:
- Provides a sense of taste for your tongue’s back portion.
- Sending sensory information coming from your sinuses, parts of your inner ear, back of your throat and at the back part of your tongue.
- Stimulating for the voluntary movement of the muscle that’s at the back of the throat.
The glossopharyngeal nerve comes from that part of your brainstem known as the medulla oblongata. Eventually, it extends towards your throat and neck region.
The vagus nerve is a truly diverse nerve and it has both the motor and sensory functions that include:
- Allows motor control of the muscles in your throat.
- Communicating sensation information coming from your ear canal and some parts of your throat.
- Provides a sense of taste at your tongue’s root.
- Sending sensory information coming from the organs in your trunk and chest, including your intestines and heart.
- Stimulating the muscles of the organs in your trunk and chest that includes those that move food within your digestive tract.
Of all the cranial nerves, it is the vagus nerve that tends to have the longest pathway. It comes from the head and extends all the way to the abdomen. It came from the part of the brainstem known as the medulla.
The accessory nerve is a motor nerve responsible for controlling your neck muscles. The muscles allow you to extend, flex and rotate both your shoulders and neck.
It’s divided into two parts, the cranial and the spinal. The cranial portion begins in your medulla oblongata while the spinal portion comes from the upper part of the spinal cord. These parts would briefly meet before the nerve’s spinal part will move to supply the muscles of the neck.
The 12th cranial nerve is the hypoglossal nerve and it’s responsible for the movement of most of the muscles in your tongue. It begins in the medulla oblongata and then it moves towards the jaw before reaching the tongue.
Top 10 Foods for Your Nervous System
Eating healthy is important for both our physical and mental wellbeing. Yet there are times that our body would require specific nutrients for it to be healthier and more active. Since the brain is an important part of our body, it would also require some nutrients for it to be able to function well. So here’s a list of foods that can help to improve the functioning of both your brain as well as your nervous system.
Green Leafy Vegetables
Leafy greens are a good source of Vitamin C, B complex, Vitamin E, Magnesium, and all the other essential nutrients for the proper functioning of the nervous system. Vitamin B is important in circulating and synthesizing the neurotransmitters. These are brain chemicals that help to regulate respiration, digestion, and heartbeat. Magnesium also helps to calm the nerves while Vitamin C and E act as anti-aging.
The nerves are kept protected by the myelin sheaths, which has a high level of fatty acid. Thus, people who are fatty acid deficient could suffer from damages to their nerves. Fish contains a good amount of Omega 3 Fatty acid, which helps in the healing of the nervous system and the nerves.
Not all chocolates are created the same. As a matter of fact, 70% of the chocolates in the market is highly processed and don’t have that many benefits. But this is not the case with dark chocolates as it’s filled with anti-oxidant and anti-inflammatory properties. These properties can help to lower blood pressure and improve the flow of blood in both the heart and the brain. Milk chocolates and white chocolates must be avoided when it comes to chocolates. Instead, opt for the dark chocolates that have at least 70 percent of cocoa since they are minimally processed and can benefit your brain.
Broccoli is high in Vitamin K, a nutrient that’s known to improve cognitive skills and brainpower. Several studies show that because broccoli contains a good amount of glucosinolates, a compound that can minimize the breakdown of neurotransmitter that the central nervous system needs to be able to function properly, it can help keep our memory sharp and our brain healthy.
A study done at Boston University has observed 1,400 healthy adults who were asked to consume eggs daily. Results show that regular consumption of eggs could lead to better performance in a memory test. Eggs are rich in B vitamin and choline and the choline from the eggs is what the brain will use to produce acetylcholine. This is a neurotransmitter that’s essential for the communication and memory of our brain cells.
As mentioned above, the Omega 3 fatty acid plays an important role in the cognitive functioning. As stated by the NY Times Journal, a low level of the omega 3 could lead to poor mental performance. Furthermore, a research done in the University of Pittsburgh has shown that a group of adults who have increased their intake of the Omega 3 fatty acids over a 6-month period has shown great improvement in their test results.
Avocados are rich in both Folate and Vitamin K. They help to prevent blood clot and can, therefore, protect you against stroke. In addition, avocados also help to improve concentration and memory, and the best thing about avocados is that they have high protein but less sugar content, unlike other fruits.
Almonds contain high levels of the Omega 3 fatty acids, which greatly help to keep the brain healthy. Just like salmon, almonds are also rich in Vitamin E.
Pumpkin seeds are a great source of copper, iron, magnesium, and zinc. Aside from this, the seeds are rich in powerful antioxidants that keep the brain and the body protected against free radical damage. The magnesium in pumpkin seeds is also essential for memory and learning and having a low level of magnesium has been linked to several neurological diseases, which include depression, migraines, and epilepsy.
A study in 2014 has shown that nuts can greatly improve cognition skills while helping to prevent neurological disorders. Furthermore, another study has also found that those who eat nuts on a regular basis have sharper memory unlike those who don’t eat nuts. There are plenty of nutrients that one can get from nuts and these include antioxidants, healthy fats, and Vitamin E. All these are good for the brain.
How to Relax the Nervous System Naturally
In this modern life we live in, we’re often bombarded with information and lots of sensory input and this triggers our “fight or flight” response. As a result, the hypothalamus will trigger the adrenal glands to release stress hormones like the cortisol and adrenaline. The stress hormone level that’s chronically elevated could lead to anxiety, high blood pressure, obesity, insomnia, and depression.
Yoga, meditation, and breathing exercises can all help in relaxing the nervous system while maintaining a good physical and mental health.
You may not be able to avoid stress entirely but exercising regularly can somehow help you to manage it. Performing aerobic exercises can help to improve the flow of oxygen and blood in your body, which in turn normalizes your level of blood pressure and heart rate. This also helps to reduce fatigue and boost your energy level. Performing physical activity can also help to lower the level of cortisol, a stress hormone, and helps to stimulate the release of endorphins, a mood-elevating hormone.
Health experts recommend performing at least 30 minutes of exercise a day, such as swimming, bicycling, walking, or playing tennis. These activities can help to get your heart rate pumping and minimize tension.
There are certain breathing exercises that can help to calm the nervous system down. While stress stimulates the sympathetic nervous system, performing breathing exercises can help to supply the brain with an increased oxygen level. As a result, the parasympathetic system will be stimulated and elicits a relaxation response.
Serenity Instead of Stress
Meditation is a great way to quite your mind. It allows you to focus your thoughts, which calms your nerve in the process. Most of our daily stresses are out of our control. With meditation, you’ll learn to take charge of where your thoughts and energy should flow.
Meditation that includes guided imagery or visualization, as well as chanting, can help to clear your mind. Studies on neuroimaging have shown that meditation can greatly help to relieve pain, stress, and anxiety, which is beneficial for the brain.
Having an adequate social support has also been shown to enhance a person’s ability to cope better and manage life’s challenges and setbacks. One study has found that people who would often reach out to others fur support are more likely to be able to adopt healthy behaviors when it comes to managing stress. They are also more optimistic and confident about the future.
This is why the American Psychological Association has recommended talking your problems out to family members, friends, and co-workers. If you believe that you can benefit from stress management assistance, you may need to consult with a licensed psychologist or a mental health professional.
How to Hack Your Nervous System
Our vagus nerve is an important nerve, which not a lot of people know that they have.
The vagus nerve is basically long and meandering sensory fibers and a bundle of motors which connect the brain stem to the lungs, heart, and gut. It also branches out to connect with the spleen, liver, gallbladder, female fertility organs, ureter, ears, neck, kidneys, and tongue. The vagus nerve powers our involuntary nerve center and controls some of the unconscious body functions, including everything that’s keeping our heart rate constant, from breathing, sweating, to food digestion. Furthermore, it also helps to regulate the level of blood glucose and blood pressure and promotes proper functioning of the kidney. It also helps to release bile, testosterone, and assists in the secretion of saliva.
The vagus nerve comes with fibers that innervate all of the internal organs in our body. Processing and managing emotions take place within the vagal nerve in between the brain, gut, and the heart, and this is why we tend to have a strong gut reaction towards intense emotional and mental states.
Dysfunction of the vagus nerve can also result in a lot of problems in the body. This includes obesity, difficulty in swallowing, fainting, gastrointestinal diseases, mood disorders, chronic inflammation, deficiency of B12, seizures, and impaired cough.
On the other hand, the vagus nerve stimulation has also been shown to improve certain conditions, like:
- Alcohol addiction
- Anxiety disorder
- Bad blood circulation
- Heart disease
- Leaky Gut
- Mood disorder
A Closer Look at this Super Nerve
The vagus nerve is the longest of all the 12 cranial nerves and almost 80% of its nerve fibers work by driving information coming from the body towards the brain. However, its fifth lane runs towards the opposite direction and shuttles signals coming from the brain towards the different parts of the body.
The vagus nerve is anchored in the brain stem and travels into the neck and the chest and splits into the right and left vagus. Each of the lanes is composed of up to 10,000 of nerve fibers branching into the lungs, heart, pancreas, stomach, and in almost every organ at the abdomen.
The vagus nerve makes use of the acetylcholine, a neurotransmitter that stimulates the contraction of muscles in the parasympathetic nervous system. Neurotransmitter works like a chemical messenger that’s released at the end of the nerve fiber and allows for signals to be moved from one point to another, which helps to stimulate the various organs in the body. For instance, if your brain won’t be able to communicate with the diaphragm for the release of the acetylcholine coming from the vagus nerve, then that’s when we stop breathing.
There are certain substances that could intervene with the production of the acetylcholine. Examples are Botox and heavy metal mercury. Botox is said to trigger the possibility of shutting down of the vagus nerve that could cause death. On the other hand, mercury attaches with the thiol protein that’s on the heart muscle receptors, which makes it difficult for the heart muscles to receive the electrical impulse for vagus nerve. This will then lead to problems in the cardiovascular system. Furthermore, the mercury that gets into the atmosphere could interfere with the production of acetylcholine. Vaccines that are laden with mercury also could also affect the vagus nerve and may lead to autism among children.
The damage to the vagus nerve may also happen as a result of alcoholism, diabetes, and upper respiratory infections, or have part of the nerve accidentally severed during the operation. Stress can also lead to the inflammation of the nerve, as well as anxiety and fatigue.
Many also believe that diet plays an important role in the overall health of the vagus nerve. A cafeteria diet that comprises of high-fat and high-carb food full of junk has the tendency to reduce the sensitivity of the vagus nerve.
A Feeling in Your Gut
to as the second brain or the backup brain that’s centered within our solar plexus.
Keeping the vagus nerve and the gut healthy can greatly impact our mental health. A recent study shows that antibiotics could make us aggressive if they upset our gut’s microbiome balance. A significant study done last year in Ontario Canada has found that certain beneficial gut microbes can help to prevent PTSD. Probiotics can also help to keep the vagus nerve and the gut signals healthy, as per the reports of the NCBI or the National Center for Biotechnology Information.
Boosting with Electricity
Doctors have long been exploiting the nerve’s influence on the brain. Electrical stimulation of the vagus nerve, also known as the vagus nerve stimulation or VNS, is sometimes used to treat depression and epilepsy. The VNS is designed to help prevent seizures by sending mild and regular electrical pulses towards the brain via the vagus nerve.
A device that works like a pacemaker supplies the electrical pulses. This device is placed below the skin of the chest wall and a wire will run from it to get into the vagus nerve at the neck. A group of researchers who have been studying the effects of vagus stimulation in treating epilepsy have noticed that patients experienced another benefit that’s not related to seizure reduction, for their moods have also improved.
A study in 2016 has shown how stimulating the vagus nerve using the bio-electronic device can significantly improve the measures of the disease activity among patients suffering from rheumatoid arthritis, a chronic inflammatory condition that affects more than a million people in the US and has cost billions of dollars for the treatment.
Vagus Nerve Stimulation Techniques
The vagus nerve does not need to be shocked to shape. Just like the muscles, it can also be strengthened and toned.
Below are some of the things that you can do to significantly improve your health.
Positive Social Relationships
In one study, participants were asked to think compassionately about others and were asked to silently repeat positive phrases regarding their family and friends. The meditators have shown an overall increase in their positive emotions, such as joy, serenity, and hope right after they have completed the class. The positive thoughts they show unto others have led to the improvement of the vagal functions as seen in the variability of heart rate. The results also show a more toned vagus nerve as compared to when merely doing meditation.
Studies have shown that once your body adjusts to cold, your sympathetic system will decline and your parasympathetic system will increase. This is thanks to the vagus nerve. Any type of acute cold exposure, which includes drinking ice-cold water, could help to increase the vagus nerve activation.
Another home remedy used for an under-stimulated vagus nerve is gargling. Gargling can help to stimulate the muscles of the pallet that are fired by the vagus nerve. Patients will typically tear up a bit, which is a good sign. This has resulted in an improvement of the working memory performance.
Singing and Chanting
Mantra chanting, humming, and singing, can all increase the HRV or heart rate variability. When you sing, you’re like initiating a vagal pump, which sends out relaxing waves. If you sing at the top of your lungs, the muscles at the back of your throat will be worked on and this will activate the vagus. Singing in groups, which is usually done in churches, also helps to increase the vagus function and the HRV.
The vagus nerve can also be stimulated by massaging your feet, as well as your neck, along with the carotid sinus, which is located at the carotid arteries on any side of your neck. Neck massage can also help to minimize seizures, while a foot massage can help to lower blood pressure and heart rate. Pressure massage can also help to activate the vagus nerve.
Laughter and happiness are both natural immune boosters. Laughter can also help to stimulate the vagus nerve. Research shows that laughing can help to improve the HRV in a group environment.
There are several case reports about people fainting as a result of too much laughter and this may be due to the overstimulation of the vagus nerve. Fainting may also happen after urination, swallowing, coughing, and bowel movement. All of these activities are helped by the vagus activation.