Reach way back to your high school biology class and remember how the sympathetic and parasympathetic systems work. The sympathetic nervous system is our “fight or flight” system. It raises heart rate and increases blood flow to the muscles and brain. We tense up and become more alert and perceptive as our body releases adrenaline in preparation for “fight or flight”. These are responses that we work hard to avoid in labor.
The parasympathetic nervous system works in the opposite way. It helps us calm down. The parasympathetic system lowers our heart rate and blood pressure, relaxes our mind, makes us sleepy, and redirects blood flow away from our locomotive muscles and toward our digestive and reproductive organs. These two systems work together like Yin and Yang to excite us and calm us as needed.
The parasympathetic system can bring huge benefits to labor. It helps mom stay calm and relaxed. It also releases key anti-stress enzymes and hormones such as acetylcholine, prolactin, vasopressin, and oxytocin. The Vagus nerve is the key to the parasympathetic nervous system. When stimulated, the vagus nerve puts the parasympathetic system into action.
The vagus nerve runs downward from the base of the brain and branches out in the chest, continuing down into the abdomen. The word “vagus” means “wandering” in Latin—and that’s exactly what the vagus nerve does. As it travels down the body it touches the vocal chords, heart, lungs, and almost every other major organ. The vagus nerve is one we do not consciously have control over. That’s why we don’t have to think about breathing or our hearts beating, like we have to consciously move our arms or legs.
Even though we cannot control our parasympathetic system, we can “hack” it by indirectly stimulating the vagus nerve ourselves.
There are three easily accessible ways to stimulate your vagus nerve,
- Slow, rhythmic, diaphragmatic breathing. Belly breathing. Almost every childbirth education method uses this as a key to relaxation. You already knew it works, and now you know why. Breathing deeply from your diaphragm, rather than shallowly from the top of your lungs stimulates and tones the vagus nerve.
- Humming. moaning, chanting or singing. This lesser known method works well because the vagus nerve is connected to the vocal cords. Using any of these methods to create vibrations of the vocal cords mechanically stimulates the vagus nerve. This is why chanting of the word “Om” is used to help deepen the meditative state. The lower the tone of the sounds created, the more effective the stimulation of the vagus nerve, Low moaning is more effective than high pitched screaming.
- Washing your face with cold water. Cold water on your face stimulates the vagus nerve. It is part of something called the mammalian diving reflex which helps mammals remain underwater longer by slowing respiration and heart rate.