Written by Dr Sircus on December 26, 2014
Human Beings have an Autonomic Nervous System (ANS) that is actually comprised of three separate subsystems, the Parasympathetic Nervous System (PNS), the Sympathetic Nervous System (SNS) and the Enteric Nervous System (ENS). The enteric nervous system has been described as a "second brain," which communicates with the central nervous system (CNS) through the parasympathetic (e.g., via the vagus nerve) and sympathetic nervous systems. However, vertebrate studies show that when the vagus nerve is severed, the enteric nervous system continues to function.
We now know that the ENS is not just capable of autonomy but also influences the brain. In fact, about 90 per cent of the signals passing along the vagus nerve come not from above, but from the ENS and that is why many consider it as a backup brain centered in our solar plexus. Our gut instincts are not fantasies but real nervous signals that guide much of our lives.
It is our vagus nerve that provides the gateway between the two parts of the autonomic systems. The vagus acts as a bio-informational data bus that routes impulses going in two directions. Since the vagus nerve acts as the central switchboard it should come as no surprise that impaired functioning of this one nerve can lead to so many different conditions and problems. Some neurological diseases actually come up from the gut spreading to the brain via the vagus nerve.
Christopher Bergland, writing for Psychology Today, said, “The vagus nerve is the commander-in-chief when it comes to having grace under pressure. The autonomic nervous system is comprised of two polar opposite systems that create a complementary tug-of-war, which allows your body to maintain homeostasis (inner-stability). The sympathetic nervous system is geared to rev you up like the gas pedal in an automobile – it thrives on adrenaline and cortisol and is part of the fight-or-flight response. The parasympathetic nervous system is the polar opposite. The vagus nerve is command central for the function of your parasympathetic nervous system. Unfortunately, the vagus nerve’s reflexive responses can backfire and turn it from comrade into saboteur.”
The vagus nerve is known as the "wandering nerve" because it has multiple branches that diverge from two thick stems rooted in the cerebellum and brainstem that wander to the lowest viscera of our abdomen touching our hearts and most major organs along the way. Vagus means "wandering" in Latin. It meanders all the way down, into the belly, spreading fibers to the tongue, pharynx, vocal chords, lungs, heart, stomach, intestines and glands that produce anti-stress enzymes and hormones (like Acetylcholine, Prolactin, Vasopressin, Oxytocin), influencing digestion, metabolism and the relaxation response.
The vagus nerve uses the neurotransmitter, acetylcholine. If our brain cannot communicate with our diaphragm via the release of acetylcholine from the vagus nerve then you will stop breathing. Botox is a toxic substance that has the power to damage the nervous system and shut down the vagus causing death.
It is interesting to note that the heavy metal mercury blocks the action of acetylcholine, the neurotransmitter that passes the nerve impulse from the vagus nerve to the heart muscle. Both acetylcholine and the nerve receptors in the heart muscle contain thiol (sulfur/hydrogen) proteins. When mercury attaches to the thiol protein in the heart muscle receptors and in the acetylcholine, the heart muscle cannot receive the vagus nerve electrical impulse for contraction. Mercury accumulates in the heart muscle and heart valves, causing damage by attaching to thiol (SH-) proteins. This damage is indicated by EKG and confirmed by histologic study.
“The frequently observed rocking and swinging behaviors in autistic individuals may reflect a naturally occurring bio-behavioral strategy to stimulate and regulate a vagal system that is not efficiently functioning.” Dr. Stephen Porges
Dr. Stephen Porges talks about how vagus disturbances are found in Autistic children.
The vagus nerve is one of the largest nerve systems in the body. Only the spinal column is bigger. Sometimes this nerve is referred to as cranial nerve X, the 10th cranial nerve. The vagus is used to send a variety of signals throughout the body, but will also transfer signals back to the brain. The vagus nerve is constantly sending updated sensory information about the state of the body’s organs "upstream" to your brain via afferent nerves. In fact, 80-90% of the nerve fibers in the vagus nerve are dedicated to communicating the state of your viscera up to your brain.
The vagus nerve helps manage the complex processes in your digestive tract, including signaling the muscles in your stomach to contract and push food into the small intestine. A damaged vagus nerve cannot send signals to your stomach muscles. This may cause food to remain in your stomach longer, rather than move normally into your small intestine to be digested, which is part of the GERD complex.
Because the vagus nerve supplies motor parasympathetic fibers to every organ from the neck down to the second segment of the transverse colon (except the adrenal glands), its effect can be far reaching. Stress can raise the body’s level of epinephrine and norepinephrine, which stimulates the sympathetic nervous system to over-ride the parasympathetic nervous system, of which the vagus nerve is the main component.
The vagus nerve is used to regulate the heartbeat and the muscle movement necessary to keep you breathing. This nerve also regulates the chemical levels in the digestive system so that the intestines can process food and keep track of what types of nutrients are being gained from the food that is taken in.
There are two main types of vagus nerve disorders. One is caused by an under-active or inactive vagus nerve, while the other is caused by a vagus nerve that overreacts to ordinary stimuli. Vagus nerve disorders that stem from an under-active vagus nerve often lead to a condition known as gastroparesis which is a frequent and severe complication of diabetes. Patients suffering from this disorder may experience pain in the stomach, nausea, heartburn, stomach spasms, and weight loss. Patients with under-active vagus nerves often experience severe gastrointestinal problems. Those with overactive vagus nerves may faint.
Acupuncturist Jill Blakeway asks, “So how does the vagus nerve get irritated in the first place? Any kind of GI distress can put pressure on the nerve and irritate it, with a hiatal hernia being a frequent culprit. Poor posture along with muscular imbalances can also cause the vagus nerve to misfire, as can excess alcohol or spicy foods. Stress can inflame the nerve, along with fatigue and anxiety.”
Many of the patients who present with symptoms of an irritated vagus nerve have what could be described as a Gall Bladder and Heart Complex in Chinese medicine. This traditionally has been a diagnosis used to describe a collection of symptoms such as esophagitis, hiatal hernia, gastritis, insomnia, palpitations, fearfulness, being easily startled, chest fullness, and a bitter taste in the mouth. In these patients, I have found that accessing the Gall Bladder Divergent Channel can bring almost immediate relief. I usually use the separating and convergent points of the channel GB 30 and GB 1, along with GB 34, LIV 3, PC6, SP 4, LIV 14, and UB 19.
How can patients suffering from an irritated vagus nerve help themselves? Here is the advice I give my patients, with one caveat: Because these symptoms can be caused by so many disorders, I always refer my patients to their MD to rule out more serious pathologies before giving self-help suggestions.
- Regular acupuncture reduces the inflammation that is often at the root of this disorder and calms the irritated nerve.
- During an attack, patients often find that moving, stretching and/or burping can relieve the pressure and calm the heart.
- During an episode of tachycardia, vagal maneuvers can be used to slow the heart rate. These simple maneuvers stimulate the vagus nerve to slow down the electrical impulses through the atrioventricular (AV) node of the heart. Vagal maneuvers that you can try to slow a speedy heart rate include: Herbal formulas that support digestion (and calm the heart) along with probiotics and digestive enzymes can really help remove the GI inflammation that is part of this syndrome.
- Holding your breath and bearing down (Valsalva maneuver)
- Immersing your face in ice-cold water (diving reflex)
- Likewise, diaphragmatic breathing, yoga, and meditation help the parasympathetic nervous system over-ride the sympathetic nervous system and calm the vagus nerve.
Researchers confirm that daily habits of mindset and behavior along with conscious breathing and yoga can create a positive snowball effect through a feedback loop linked to stimulating your vagus nerve. In order to maintain homeostasis, the central nervous system responds constantly, via neural feedback, to environmental cues. Stressful events disrupt the rhythmic structure of autonomic states, and subsequently, behaviors. Since the vagus plays such an integral role in the regulation of heart rate and heart rate variability it follows that how we breathe when under stress makes all the difference in the world.
Dr. Stephen Porges, gives us a great clue to the connection between the sensory nervous system and the very center of our emotional makeup. Darwin (1872) noted in The Expression of Emotions in Man and Animals the importance of the bi-directional neural communication between the heart and the brain via the "pneumogastric" nerve, now known as the vagus nerve. According to Dr. Porges, “Darwin’s statement is important, because it emphasized two points: 1) afferent feedback from the heart to the brain through the vagus was independent of the spinal cord and the sympathetic nervous system, and 2) the vagus played a regulatory role in the expression of emotions. The Darwinian description of the vagus, emphasizing the bi-directional communication between the periphery and central nervous system, assumes that the vagus is part of a feedback system. Implicit in this “vagal system” are motor pathways to change visceral state, sensory pathways to monitor visceral state, and brain structures involved in the evaluation of the input and the regulation of the output.”
We all have an internal assessment mechanism thought to be housed in the amygdala, the hypothalamus or mid-brain which acts as a central intelligence agency challenging every situation, scanning every perception; reacting instantly to the one key question, will it hurt “me.” Will it make “me” feel more or less secure? Will it fulfill or deny me my basic needs? Will it enrich my life or lead to separation and life alienating feelings? The heart is the center that houses our sense of self, the “me” or the ultimate “I.”