The Automatic Nervous System
The Autonomic Nervous System has two main parts:
- The Sympathetic Nervous System
- The Parasympathetic Nervous System
Both systems have sensory and motor functions; the former sends information to the brain, while the latter sends messages to the body. These messages could, for example, speed up the heart or tighten muscles in the bowel or blood vessel walls.
The Sympathetic Nervous System activates our primitive fight-or-flight response in emergencies. This system is so finely tuned by millions of years of evolution that it operates automatically. It's part of our primitive, reptilian brain that enables protective reflexes, like closing our eyes before an object hits us or pulling our hand away from a hot surface before feeling the heat. However, in modern times, this system is often activated not just by genuine threats but also by stressors such as financial worries, job issues, or relationship concerns.
On the other hand, fewer people are familiar with the Parasympathetic Nervous System, which does the opposite. It helps us rest, digest, restore, and recover. Activities like releasing gastric enzymes or stimulating bowel muscles and peristalsis happen automatically, thanks to this system. The Parasympathetic Nervous System is mediated by the Vagus nerve.
The Vagus Nerve is the tenth of the 12 cranial nerves, originating from the base of the brain. These cranial nerves include the olfactory nerve for smell, the acoustic nerve for hearing, and the facial nerve for facial movements. Surprisingly, the Vagus Nerve is one of the largest and longest nerves in the body. It travels down the back of the throat, through the neck and chest, and extends to the heart, blood vessels, and gut. This nerve acts as a neuro-modulator, helping to regulate functions like digestion and returning the body to homeostasis.
If the Vagus Nerve becomes suppressed due to constant stress or physical illness, symptoms may include:
- Hoarseness, wheezing, or loss of voice
- Difficulties in swallowing or a loss of the gag reflex
- Changes in heart rate, blood pressure, or blood sugar levels
- Acid reflux
- Abdominal pain and/or bloating
Methods like slow breathing, meditation, and mindfulness can activate the Vagus Nerve and are practised worldwide for their calming effects on the nervous system. Immersion in cold water, such as ice baths or cold showers, also activates the Vagus Nerve. Even emergency responders use Vagus Nerve stimulation techniques, like asking patients with tachycardia to blow into a syringe, to help regulate heart rate.
For quick and effective stimulation of the Vagus Nerve, few methods compare to Transcutaneous Vagal Nerve Stimulation.