What do you know about the vagus nerve?
What are the manifestations if the vagus nerve is damaged?
If you want to get acquainted with the symptoms of vagal nerve dysfunction, if you want to know what symptoms will occur in case of vagus nerve damage, read more.
In this article, we have gathered everything you need to know about the symptoms of vagal nerve injury and we will present it.
Get acquainted with vagus nerve
Autopsies have shown that twelve pairs of nerves emerge from the human brain, which doctors call cranial nerves.
That means twelve nerve cords will come out of each hemisphere of your brain.
Each of these twelve pairs of cranial nerves has a specific path, specific branches, and a very specific function.
If you can see If you can hear If you can smell or even taste If your facial muscles are moving, if your scalp and face feel and… all due to the proper functioning of these twelve pairs
The longest of these twelve nerves on each side of the body is the tenth cranial nerve. The vagus is the name of the tenth nerve.
Among the twelve pairs of cranial, the vagus travels the longest path in our body. This nerve starts on the lower two sides of the brain or brainstem and extends to both sides of your abdomen.
What does the vagus nerve do?
Doctors believe that the vagus nerve is one of the vital nerves in our human body
This nerve carries a very large group of directional messages from the brain to the organs inside our body.
On the other hand, it receives a wide range of sensory messages from these organs and carries them to the brain, both the messages that reach the internal organs and the messages that go to the brain through the vagus, regulate a large number of activities and subconscious responses of our body. Autonomic nervous system that does not require our will, intervention and decision. Heart rate, respiration, gastrointestinal function, vasodilation and contraction, and blood pressure control are all controlled by the autonomic nervous system. The vagus nerve is a very important member of this vital system.
Generally, people will not notice the action of the vagus nerve until a disorder in the function of the vagus nerve is caused by an injury. Without the proper functioning of the vagus nerve, our heart and breathing will become disordered and abnormal. Our swallowing, talking, eating and drinking will be disrupted.
What does vagus mean?
In Latin, vagus means (wanderer) !
Perhaps this is the best explanation for this nervousness. Because the vagus exits from the bottom and back of the brain and moves downward, it enters the neck and chest and eventually enters the abdomen. In this long path, it will have branches, for example, it will irritate your ears, throat and larynx, your lungs and heart will work under the vagus nerve. This nerve is sometimes called the pneumogastric nerve because it affects both the lungs (pneumo) and the stomach (gastric).
Acts and duties of vague
We said that the vague nerve carries both the messages of the brain to the organs of the body and the messages received from the internal organs of our body to the brain.
The main centers of activity control of the organs mentioned above are mainly concentrated in the brainstem and the responses of the autonomic nervous system are transmitted from this part. Also, by the vagus nerve, movement messages will be transmitted from the brain to the organs.
In other words, the vagus carries messages from the brain to the organs and by them coordinates a large part of the reflex messages.
During its movement path, it receives sensory messages from the outer ear and the outer ear canal. Sensory messages received from the throat and above the larynx will also enter the efferent pathways of the vague nerve.
These received messages go to the brainstem and will be transmitted to these areas as a reaction to movement messages or messages of special reflexes in the afferent pathways of the vagus nerve endings.
If a foreign object or stimulant is in our throat and the airways below our throat, the afferent vagus fibers will be stimulated and this message carries the sense of these stimuli to the brain, and in contrast, the brain’s message, which is to induce coughing (cough reflex), is transmitted to the muscles by the vagus fibers and…
It is said that 80- 90% of the nerve fibers in the trunk of the vagus nerve are afferent fibers
The afferent strings carry sensory messages from the organs to the brain. The efferent strings transmit messages and commands of reflexes or movements from the brain to the organs. We said that there is a pair of vagal nerves in our body
- Right vagus
- Left vagus
The direction of movement of the right vagus and the left vagus will be different. The right vagus is responsible for innervating our heart, lungs and esophagus.
The left vagus, after branching into the heart, forms a neural network for the lungs and esophagus, then enters the abdomen through the esophageal perforation and innervates half of the large intestine.
In the trunk of the vagus nerve, there are strands of parasympathetic nerves that are a type of autonomic nerve in the body. Parasympathetic nerve is the organs of the body from the neck to the large intestine with the vagus nerve. The laryngeal muscles are also under the command of the vagus nerve.
It may have happened to you that they cough when cleaning the inside of the ear with an ear cleaner, the cause of this phenomenon is that through the vagus, afferent fibers go to the external ear canal and the membranes around the brain.
So it can be said briefly that the main functions of the vagus nerve are:
- Regulation of activity and regulation of heart rate
- Gastrointestinal movements
- Sweat regulation
- Keep the larynx open when breathing
- Speaking (with the help of the laryngeal recurrent nerve)
Exercises of the vagus nerve in the body
Doctors say the vagus nerve has special filaments that actually transmit certain motor disorders.
This part is actually the most important part of our parasympathetic autonomic nervous system, these are the nervous systems that regulate the involuntary activities of our organs such as heart rate, respiration, sweating and bowel movements.
The autonomic nervous system is divided into two groups of nerve fibers under the heading of sympathetic and parasympathetic and the trunk of the vagus nerve is considered to be the main part that contains parasympathetic fibers. At the bottom of these filaments, a substance called acetylcholine is secreted on the surface of the cells in the organs of the body, causing our intestines, heart and lungs to function in a special way. It is certain that in a vagal nerve injury, there will be signs and symptoms that will be caused by dysfunction of the throat, larynx, heart, lungs, stomach and intestines.
Parasympathetic effects of vagus
- Effect on the lungs:
Vagus stimulation stimulates the airway wall muscles and increases the airway resistance to air.
In other words, vagal stimulation will be associated with contraction of the airways inside the lungs or bronchi.
- Effect on the digestive system:
- Stimulation of intestinal and gastric wall muscles
- Loosen the gastric outlet sphincter or pyloric valve
- Stimulation of gastric acid secretion
- Stimulation of the secretion of digestive enzymes that are released from the intestines and stomach
- Stimulation of bile outflow from the gallbladder
- Stimulation of pancreatic hormone secretion
In general, parasympathetic stimulates the digestive system during and after eating, in other words, it accelerates the work of the intestines and empties the stomach.
- Effect on the heart:
The nerve endings of the vagus are located at the site of the atrial sinus node, and when the vagus is stimulated, acetylcholine is released from the end of this terminal, the effects of which on the heart muscle will be:
- Decreased cardiac contractility
- Decreased heart rate
- Severe vagus stimulation will lead to cardiac arrest
What will be the signs and symptoms when the vagus nerve is damaged or severely irritated?
What will happen if the vagus is stimulated?
When the vagus is stimulated, the parasympathetic distribution of the vagus will be activated.
And you will experience hypotension (due to dilation of the arterial wall), decreased heart rate, accelerated gastric emptying, increased intestinal motility, increased saliva, and…
What factors will be associated with vagal stimulation?
Here’s how the vagus nerve will be stimulated.
- Acute viral inflammation in the gastrointestinal tract
- Inflammation of the gallbladder or acute cystitis
- Carotid sinus massage in the neck
- Valsalva maneuver
- Bleeding from a vein
Vasovagal syncope refers to a condition in which parasympathetic activation is highly active. In severe emotional stress, the sympathetic becomes overactive and sometimes the parasympathetic becomes compensatory and overstimulated. At these times, the person suffers from a severe decrease in heart rate and a sudden drop in blood pressure and faints. According to some scientific sources, the vagus plays a very important role in regulating human appetite. According to doctors and researchers in the life sciences, damage to the vagus nerve can cause obesity.
Another result of research on the role and functions of the vagus nerve is that stimulating the vagus during deep breathing can reduce the number of heartbeats. Today, this way is used as a deep breathing method to control the heartbeat caused by anxiety.
In order to get acquainted with the signs and symptoms of vagus nerve injury, it is better to have a brief look at the functions of the vagus in the body.
Vagus nerve and its function on the brain
One of the ways to control and treat epilepsy is to stimulate the vagus nerve. It has been proven that when the vagus is stimulated, signals reach the brain, which reduces the number of epilepsy. In addition, vagus function may be associated with many mental disorders.
It is interesting to know that the function of the vagus will probably be related to your mood. According to credible research, it has been stated that if the function of the vagus nerve decreases for any reason, a person with depression and anxiety may suffer from vagus irritation. Vagus stimulation is sometimes used to help reduce anxiety and depression.
It has also been shown to stimulate the vagus nerve in the central nervous system. Following the method of deep breathing, meditation and… can be effective on intestinal health
On the other hand, the normal function of the vagus is necessary for the secretion of IF. Without this factor, you will be deficient in vitamin B12.
Vagus nerve is needed to control appetite, if the vagus nerve has the right function, the feeling of satiety will overcome hunger. The vagus sends signals to the brain that make you feel full and therefore reduce overeating.
More research is needed to reach more certainty and devise methods to control appetite by stimulating the vagus. Increased vagus stimulation increases nitric oxide levels and reduces inflammation, both of which are good for cardiovascular health.
Vagus stimulation improves blood flow to the kidneys and makes the kidneys work better and remove toxins. It also has been proven to reduce and control inflammatory processes in the body and can control inflammatory responses.
Long-term inflammation will be associated with heart disease, lung disease, diabetes, allergies and cancers. Increased activity of the vagus nerve can reduce the complications of diabetes, autoimmune diseases, cardiovascular disease and adequate
Vagus nerve damage symptoms
You get familiar with the movement of the vagus above and some of its functions. Now the question arises that if you see a damaged vagus nerve, what signs and symptoms will occur, in other words, what symptoms will be accompanied with the injured vagal nerve?
The injured vagus nerve will not be able to transmit peripheral organ perceptions to the brain and transmit appropriate signals from the brain to elicit appropriate reflexes in those organs. The following symptoms are more likely to occur in a person with a damaged vagus nerve.
We said that the vagus nerve controls our speech with its passive branch called the recurrent laryngeal nerve, so in the case of a vagal nerve injury, two things can happen:
- Difficulty speaking
- Loss of voice
- Wheezy voice
The vagus provides sensation and stimulation of the throat and upper larynx.
In vagus injuries, the pharyngeal reflex (gag reflex) may be impaired. The pharyngeal reflex is actually a laryngeal spasm, a completely involuntary reflex that actually prevents water, food, and foreign objects from entering the throat.
You will notice this reflex if you touch or stimulate the tip of your tongue, or around your tonsils, or your little tongue. The neural arch of this reflex is precise and fast, which will prevent a foreign body from entering the throat.
Receiving the sensation of irritation of the throat and upper larynx and the end of the tongue is transmitted to the brain through the afferent fibers and the brain in response will send a suitable message called Gag reflex through the efferent fibers to the cells of those areas.
What will happen when the gag reflex is disrupted?
- Drinking fluids and sometimes swallowing saliva becomes difficult due to damage to the vagus nerve. Swallowing and disruption will also be difficult.
- We said that the sensory fibers of the vagus nerve are responsible for receiving the sensation of the external ear and the external ear canal.
- Decreased heart rate will have the effect of reducing vagal activity following nerve damage.
- Disorders of the digestive system:
- Decreased gastric acid secretion and gastrointestinal enzymes
- Slow gastric emptying
- Slow bowel movements
- Abdominal pain
- Stomach paralysis or gastroparesis
Gastroparesis is one of the most common manifestations of vagus nerve injuries during trauma or surgery.
During gastroparesis, involuntary contractions of the gastric wall that lead to gastric emptying will stop and therefore complete and timely gastric emptying will not be performed.
Symptoms and manifestations in gastroparesis are as follows:
- Vomiting (usually in gastroparesis a few hours after eating, a person will vomit that contains food eaten and not digested)
- Feeling full
- Early satiety
- Lack of appetite
- Abdominal pain
- Unexplained weight loss
- Fluctuations in blood sugar levels
What is Vasovagal Syncope?
- The sudden increase in parasympathetic vagus activity, often followed by one of the following, is called the vasovagal reflex. Vasovagal syncope occurs following exposure to the following:
- Too much heat
- the pain
- the fear
- Seeing blood or bleeding
- to urinate or defecate with force
- Standing for a long time
What happens during a vasovagal shock?
We said that stimulation of the vagus due to stimulation of parasympathetic fibers inside will be accompanied by slowing of heart activity, decreased heart rate and a sudden drop in blood pressure. All of the above events, such as decreased blood pumping from the heart and a sudden drop in blood pressure, will be accompanied by fainting. Doctors call this condition vasovagal syncope.