The Vagus Nerve is a major part of the parasympathetic nervous system, and when it is not functioning properly our emotions and physical well-being can suffer dramatically.
Welcome to our Vagus Nerve Series! The vagus nerve has gained a lot of attention in recent years. This is, in part, due to vagus nerve involvement in patients suffering with anxiety and with symptoms of chronic illness and chronic pain conditions, including Long COVID and PTSD. Its proper function is imperative to our emotional and physical well-being health.
This article highlights the very basic anatomy and function of the vagus nerve. The next three articles in this series will discuss what can happen when the vagus nerve is no longer functioning properly, alternative medicine treatment options, how McKinney Physical Therapy can help, and simple activities that you can do at home to balance out vagus nerve function.
NERVOUS SYSTEM ANATOMY
Our nervous systems are extremely complex, but they can be categorized into two basic parts- the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS includes the brain and spinal cord. The PNS is comprised of all the nerves that come off the spinal cord that go out to the rest of our bodies, as well as our cranial nerves.
There are twelve cranial nerves that originate directly in the brain and provide sensory input for vision, hearing, taste, smell, and the vestibular system. They also provide sensation and motor function for the ear, mouth, face, tongue, and some neck muscles. The tenth cranial nerve (CNX) is the vagus nerve.
THE VAGUS NERVE (CN X)
The vagus nerve is a major part of the parasympathetic nervous system; performing about 75% of its function. Its job is to provide two way communication between the body and the brain on a moment to moment basis so that bodily functions can be regulated appropriately for a given situation. It provides sensory, motor, and parasympathetic functions throughout the body. This results in the stimulation of reflexes and functions such as heat rate, blood pressure, breathing, sweating, gagging, swallowing, coughing, mucus production, digestive processes, and more.
The vagus nerve starts at the base of the brain and traveling down to the abdomen and pelvis. It has two distinct branches that originate from the right and left side of the brain. Each side serves a very different function.
1. Dorsal Vagus Nerve
This nerve originates from the right side of your brain descends down the right side of your neck into your thorax where it joins the ventral vagus nerve.
2. Ventral Vagus Nerve
This nerve originates from the left side of your brain and descends down the left side of your neck into your thorax where it joints the dorsal vagus nerve. These two branches come together and then, as one nerve, it branches out horizontally to connect your thoracic and abdominal organs to the brain. As it descends into the body, the vagus nerve splits off into several branches:
-
- Pharyngeal and laryngeal branches go to the pharynx and larynx. This can affect the quality of your voice and ability to swallow. It can also affect your blood pressure.
- Cardiac branches go to the heart. This can affect your heart rate.
-
Pulmonary branches go to the bronchi. This can affect your breathing.
-
Esophageal branches go to the esophagus, stomach, gallbladder, pancreas, and small intestines and the cervix (in women). This helps to regulate many detailed digestive and sexual functions.
AUTONOMIC NERVOUS SYSTEM
The autonomic nervous system (ANS) pathways regulate involuntary body activity such as heart rate, blood pressure, respiration, sweating, digestion, and sexual arousal. As the name implies, these are the automatic functions that you don’t have to think about to control.
The ANS is further separated into two main components; the sympathetic and parasympathetic systems. The sympathetic nervous system controls your body’s “fight or flight” response- it helps us to stay safe (physically and emotionally) and survive. The parasympathetic nervous system helps to control your body’s response during times of rest and safety- it helps us to engage in life and thrive.
Your parasympathetic nervous system controls “rest and digest” functions. It’s the opposite of your sympathetic nervous system’s “fight or flight” response. When a threat or a moment of stress has passed, the parasympathetic nervous system will balance out the sympathetic nervous system so that we can return to a state of emotional regulation and healthy body function. The vagus nerve performs approximately 75% of the work of the parasympathetic nervous system.
Continue on to the next article in our series: Vagus Nerve Series, Part 2- When Vagus Nerve Function Goes Awry
RESOURCES
Hayden, Wendy. The Vagus Nerve Gut Brain Connection: Heal your Vagus Nerve and Improve Gut Health. 2021.
Park, Yumi. Unleash Your Vagus Nerve. Stimulate Your Vagal Tone and Activate Its Healing Power with Daily Exercises to overcome Anxiety, Depression, Inflammation, Autoimmunity, Brain Fog, and Gut Sensitivities. 2022.
Rosenberg, S; Shield; B, Porges, S. Accessing the Healing Power of the Vagus Nerve: Self-Help Exercises for Anxiety, Depression, Trauma, and Autism. North Atlantic Books, 2017.
https://my.clevelandclinic.org/health/body/22279-vagus-nerve
https://www.medicalnewstoday.com/articles/318128#further-research-and-considerations