The Vagus Nerve
What Is The Vagus Nerve
Imagine a nerve responsible for your breathing, heart rate, immune system, and inflammatory response. Unfortunately, few nerves exist within the spine and cranium that perform such expansive tasks as the vagus nerve. This is because the vagus nerve is both afferent and efferent. This means that it communicates information from the brain to the body and from the body back to the brain. Another fantastic feature about the vagus nerve is its sharing of sensory and motor information. This means it can slow your heart rate (motor) and is responsible for those “gut” feelings you get when something doesn’t feel right.
To understand the vagus nerve more thoroughly, it is essential to briefly explain where within the body they exist.
The body has a total of 12 cranial nerves, starting near the brain. These nerves, which function in pairs, are responsible for communicating information from the brain to other body locations about sights, smells, sounds, and tastes. These are referred to as sensory nerves. Other nerves are responsible for sending information to glands and muscles, and these nerves are called motor nerves. The vagus nerve performs both functions and is the 10th cranial nerve, among the most complex.
The vagus nerve runs from the face to the abdomen, and it is often called the wandering nerve and rightly so as its branches span the length of the body.
What Does The Vagus Nerve Do?
The vagus nerve's top task is afferent, meaning it brings information in from areas of the body such as the heart and the gut. This helps the body keep the body in a state of homeostasis or balance.
The vagus nerve is responsible for lowering inflammation, controlling heart rate, breathing, and communicating information from the brain to the gut and the heart. It is also responsible for the formation of dreams.
Control of the Gut-Brain Axis
Neuronal cells within the vagus nerve relay information exclusively to the gut, making this a somewhat meaningful relationship between the brain and the gut. This action helps coordinate peristalsis (contraction of the intestines). Peristalsis helps move food through the stomach and intestines.
Activate The Vagus Nerve
There are many ways to stimulate the vagus nerve, such as deep breathing or splashing cold water on your face. Other methods are gargling loudly and singing (even gagging!) can help activate it.
Signs and Symptoms of Low Vagal Tone
Hoarseness and wheezing as well as difficulty speaking, are signs of low vagal tone. Other symptoms include abdominal pain and bloating loss of the gag reflex, and trouble drinking water.
Activating the vagus lowers stress, increases immunity, and brings the body into balance. Always good!
Breit, S., Kupferberg, A., Rogler, G., & Hasler, G. (2018). Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders. Frontiers in psychiatry, 9, 44. https://doi.org/10.3389/fpsyt.2018.00044
Howland R. H. (2014). Vagus Nerve Stimulation. Current behavioral neuroscience reports, 1(2), 64–73. https://doi.org/10.1007/s40473-014-0010-5
Seladi-Schulman, Jill Ph.D. (2018). Vagus Nerve Overview. Retrieved from https://www.healthline.com/human-body-maps/vagus-nerve#anatomy-and-function