The vagus nerve. Why is it so important and what is it for?

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Imagine it's a Sunday afternoon. You've just eaten a delicious three-course meal and now you're sitting on the couch to kick back and relax. You feel completely at peace. So much so that you begin to doze off. Even though you may think the body is as relaxed as you are, in fact one area of the nervous system is working hard. The parasympathetic nervous system is busy slowing down the heart rate, regulating breathing and issuing commands to the organs of the digestive system. The period of "rest and digestion" is in full swing. And one nerve is working particularly diligently. This is the vagus nerve.

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What is the vagus nerve and what is its role?

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The vagus nerve in Latin nervus vagus refers to the tenth nerve, which connects information between the brain and internal organs. It controls body functions during rest and relaxation. This important nerve highway originates in the brain stem and from there branches to the ears, throat, lungs, heart and then returns through the trachea to the larynx. You can imagine the vagus nerve as a tree whose branches are connected to almost every organ in the body. The vagus nerve captures information about the functioning of the organs and also sends information from the brainstem back to the body, helping control digestion, heart rate, voice, mood and the immune system.

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Why is the vagus nerve so important?

• It helps the immune system and response to disease. 

• It is the main connection between the brain and internal organs, including the intestines.

• It has an effect on our mental state, our capacity for compassion and empathy.

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The vagus nerve is an essential part of the autonomic nervous system. Particularly the parasympathetic

part of the nervous system that brings the body into a state of rest. It is also responsible for controlling the swallowing muscles and tensioning the vocal cords. An important task of the vagus nerve is to send signals to various organs in the body. Its main function is then  to inform the central nervous system about the state of all these organs. And at the same time, it is basically a "switch" for diseases related to inflammation of the body, and also for diseases such as epilepsy, rheumatoid arthritis and syndrome leaky gut.

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It also helps support our intestinal microbiome, where more than 90% of serotonin - a hormone that stabilizes our mood. Unfortunately, the world in which we are literally absorbed by technology, puts our individual and collective nervous system out of balance. For this reason, it has become one of the most interesting topics for research in the scientific community.

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Most of us may think of our digestive system as a simple tube through which our food and fluids pass, when in fact the intestinal tract has its own highly complex nervous system. It may sound unbelievable, but the brain communicates with the intestines. This communication channel is called Gut-brain axis (GBA). It is denoted a two-way connection and communication between the gut and the brain. What happens in the gut can directly affect the function of the brain. And yes! The vagus nerve is responsible for all of this.

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The vagus nerve also plays a significant role in mental health care, allowing us to respond effectively to the emotional and physiological symptoms of depression and anxiety. The vagus nerve is the main nerve of the parasympathetic nervous system. Unlike the sympathetic nervous system, which is associated with the body's "fight or flight" response, the parasympathetic branch helps us rest, digest, and calm down. Whenever our brain detects a threat thanks to the sympathetic nervous system, it triggers the "fight or flight" response. The parasympathetic nervous system does the opposite - it calms us down and activates when the danger has passed.

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Today, you probably won't meet a saber-toothed tiger on the street. However, we are able to create our own predators in our heads. It may sound unbelievable, but with our visualization we can convince the body that we are in real danger of life. It can be an examiner at school, a presentation at work. In short, everything that negatively affects our nervous system and causes flushing cortisol. Thanks to cortisol the pulse quickens, muscles are tense and the body's defense mechanism is triggered. The body accumulates enough energy and our senses are sharpened in case of danger. At this moment, the sympathetic nervous system is activated. And this despite the fact that there is no predator standing in front of us! And that's the trouble. In short, the body is not capable of distinguishing between physical and mental stress. So it reacts in the same way when a bear appears at your home as when you realize that you have an important presentation at work the next day. In both cases, the body prepares for survival. This constant stress causes chronic difficulties, and the body reacts to stress as a kind of infection that it is trying to overcome. Stimulation of the vagus nerve can be a possible clue as to how to get out of it.