
Illustration from Anatomy & Physiology, Connexions Web site. http://cnx.org/content/col11496/1.6/, Jun 19, 2013.
What happens in VAGUS does not stay in VAGUS! My apologies for drawing any kind of comparison to Las Vegas and the Vagus nerve, but it’s almost unavoidable! Everything that happens in and along the Vagus nerve informs our most important physiological systems. Unlike the secrets kept in Las Vegas, the Vagus nerve couldn’t keep a secret if life depended on it – in fact, our lives do depend on the Vagus nerve.
The “secrets” of the Vagus nerve are embedded in the messages sent via inputs from visceral receptors sending impulses between the brain and heart. Our cardiovascular system monitors this activity and either suppresses parasympathetic stimulation (rest and digest) or increases sympathetic stimulation (fight or flight) to provide the proper rate of blood flow to our systems.
In other words, our heart speaks to the brain and the Vagus nerve is the intimate link between the two. The dialogue between heart and brain happens through an exchange of signals via the Vagus nerve.
HRV (heart rate variability) allows us to see the autonomic nervous system activity by watching what happens BETWEEN each heart beat. Increased flexibility of the heart through variations between each heart beat is the goal of HRV yoga. By improving vagal tone, or what might be called the responsiveness of the heart, we set ourselves on the path to a healthier heart.
HRV yoga is a practice of heart-mind awareness. We use heart rate monitors before, during and after yoga practice to listen in on the secrets passing through the Vagus nerve. By looking at heart rate variability patterns over time we are able to see the impact of our yoga practice on our heart rate variability.