Some basics up front you may already know – the nervous system is divided into 2 main parts: the central nervous system, which is the control centre and consists of the brain and spinal cord, and the peripheral nervous system, which, several subcategories later, leads us to the autonomic nervous system. This is the one that conducts impulses from the brain/spinal cord to cardiac and smooth muscle tissue, as well as to glands, and is considered “involuntary,” which is why we don’t have to think about our heartbeat, or breathing and digesting.
The autonomic nervous system is further divided into three parts: the sympathetic nervous system (fight-or-flight) is a quickly responding system that mobilizes the body for action and helps prepare it to cope with stress and threats, whereas the parasympathetic nervous system (rest and digest) acts more slowly to dampen responses, returning the body to a resting state afterward (enteric – gastrointestinal – is the third).
Ah, a resting state…where the heart can be at peace, so to speak; the star of this wonderful parasympathetic nervous system is the 10th cranial nerve, the longest and most complex of the 12 pairs of cranial nerves, called the vagus nerve, and it supplies fibres to all the major organs of the head, neck, chest and abdomen. . It is so named because it “wanders” from the brain stem to the visceral organs (think “vagabond”).
And what does it do within this circuit? The vagus nerve, via a neurotransmitter (acetylcholine), tells your lungs to breathe, and it is in communication with the diaphragm – deep belly breathing will stimulate the nerve and you will feel more relaxed. This chemical also offsets the fight-or-flight hormones (cortisol, adrenaline), while the nerve’s tendrils also send instructions to release enzymes and proteins which calm you down.
Your gut uses the vagus nerve to tell your brain how you’re feeling by way of electric impulses. These signals help a person recover from stress, anxiety, and fear – think “gut feelings,” they are very real! The vagus nerve is also responsible for controlling your heart rate, via electrical impulses and acetylcholine. Take this to “heart” – people with a stronger vagus response seem to recover more quickly from illness, injury or STRESS.
Stimulating the vagus nerve also releases a neurotransmitter that consolidates memories, as studies in rats and humans have suggested. Another signal sent by the vagus nerve regulates the body’s immune response, its network of fibres alerts the brain and draws out neurotransmitters that counteract inflammation when it occurs. This has been huge in the area of rheumatoid arthritis and other serious and chronic inflammatory syndromes.
In 2005 the FDA approved the use of vagus nerve stimulation as a treatment for depression. It has also been found to be helpful with bipolar disorder, anxiety disorders and inflammation from Crohn’s disease. How about something simple and every-day-like? If you ever need to equalize the pressure in your ears (scuba diver/flying?) or if you have hiccups that won’t go away….
You can momentarily increase the tone of the vagus nerve by using the Valsalva maneuver, which increases pressure inside the naval sinuses and especially the chest cavity. This is done by keeping your mouth closed and pinching your nose while trying to exhale forcefully. In order to actually increase the vagal tone, you must continue the effort for 10-to-15 seconds. Check out our Facebook Page, Aug 25 Blog, for more tips:
The vagus nerve has been described as “largely responsible for the mind-body connection” for its role as a mediator between thinking and feeling. Years ago a Psychology Today writer said, “When people say ‘trust your gut,’ they really mean ‘trust your vagus nerve.’”
We truly are amazing, yes? “When we give ourselves the chance to let go of all our tension, the body’s natural capacity to heal itself can begin to work.” – Nhat Hanh