The vagus nerve has been mentioned recently all over the place on the news, and it’s time that we also address the issue. Check out all the interesting details about the matter below.
What is the vagus nerve?
Did you know that there are 12 pairs of cranial nerves in our body? These nerves are responsible for connecting our brain to different parts of our body, such as the head, neck, and torso. Some of them carry sensory information related to our senses like smell, sight, taste, and sound, while others control muscles and glands. These are known as motor functions. The vagus nerve, also called cranial nerve X, is a nerve that has both sensory and motor functions. The cranial nerves are classified using Roman numerals based on their location.
What does it affect?
The vagus nerve also called the pneumogastric nerve, is responsible for various internal organ functions.
reflex actions, such as coughing, sneezing, swallowing, and vomiting
The function of this component is to regulate the autonomic nervous system, which facilitates activities that individuals perform unconsciously, such as digestion and breathing. Additionally, it could serve as a connection between the gut and the brain, contributing to what scientists refer to as the gut-brain axis. In recent times, researchers have focused on studying the gut-brain axis to identify correlations between conditions like depression and obesity.
Anatomy and function
Did you know that the Latin term “vagus” means “wandering”? It’s quite fitting for the vagus nerve, which is the longest cranial nerve in the body and runs all the way from the brain stem to the colon. There are two sensory components to the vagus nerve: somatic and visceral.
Somatic components are responsible for sensations experienced on the skin or in the muscles, while visceral components are responsible for sensations felt in the body’s organs.
The vagus nerve has numerous sensory functions, including providing somatic sensation information for the skin behind the ear, external ear canal, and certain parts of the throat.
It also supplies visceral sensation information for the larynx, esophagus, lungs, trachea, heart, and most of the digestive tract. In addition, it plays a minor role in the sensation of taste near the root of the tongue.
By stimulating the muscles in the pharynx, larynx, and soft palate (the fleshy area near the back of the roof of the mouth), it can help with various functions such as breathing and speaking.
Additionally, it can help lower resting heart rate by stimulating muscles in the heart. It can also induce involuntary contractions in the digestive tract, which includes the esophagus, stomach, and most of the intestines, allowing for the movement of food through the tract.
Vagus nerve issues
When the vagus nerve is damaged, it can cause various symptoms due to its long reach and influence on multiple areas.
Some potential signs of damage to the vagus nerve include difficulty speaking, changes or loss of voice, difficulty swallowing, loss of the gag reflex, low blood pressure, slow or fast heart rate, alterations in the digestion process, nausea or vomiting, abdominal bloating or pain, and depression and anxiety in individuals with breathing issues or heart disease.
The specific symptoms experienced will depend on which part of the nerve has been affected.
Heart rate issues
When the vagal nerve is not functioning properly, it can result in either a slow or fast heart rate. Overactivity can cause bradycardia, while insufficient activity can lead to tachycardia. In some cases, management of tachycardia involves using vagal nerve maneuvers to increase vagal nerve activity and slow down the heart rate.
It is believed that damage to the vagus nerve can lead to a condition known as gastroparesis. This condition affects the involuntary contractions of the digestive system, which prevents the stomach from properly emptying.
Symptoms of gastroparesis include nausea or vomiting, loss of appetite, acid reflux, abdominal pain or bloating, unexplained weight loss, and fluctuations in blood sugar.
Some people develop gastroparesis after undergoing a vagotomy procedure, which involves the removal of all or part of the vagus nerve.
A 2020 study found that vagal nerve stimulation could be a useful therapy for people with mild to moderate gastroparesis without a known underlying cause, as participants experienced improvements in their symptoms after 4 weeks, including their ability to empty the bowel.
Sometimes, the vagus nerve activates particular heart muscles that aid in slowing down the heart rate. However, if it becomes too active, it can result in a sudden fall in blood pressure and heart rate, leading to fainting.
This condition is called vasovagal syncope, and it might occur without any apparent cause, although factors such as pregnancy, emotional stress, and pain may trigger it.
Aside from fainting, other symptoms may include warmth, nausea, tunnel vision, ringing in the ears, excessive sweating, low blood pressure, and slow or irregular heartbeat.
If you experience fainting, it is advisable to consult a doctor to exclude any severe underlying conditions. To prevent it, a doctor may recommend staying hydrated or avoiding sudden changes in position.