The Craniosacral Connection: A Look into the Autonomic Nervous System Part-2


Written by Dr. Georgia Tetlow, MD and Clare Abercrombie, BS “We don't directly react to outer circumstances, but to our own thoughts, feelings and sensations that arise from outer phenomena. This means there is a choice, awareness or opportunity of how to respond...and we don't need to control outer circumstances, or be 100% healthy to be in a relaxed state. We can be in a relaxed state as we are now, by being aware of our own feelings and sensations and not reacting to ourselves with fear, but instead with acceptance.” –Dr. Georgia Tetlow, MD

Part 1 of our series on the Autonomic Nervous System explored the Sympathetic Nervous System (SNS). We learned about the importance of this system when we experience stressful or dangerous situations. But, what about when we are calm? What system is active during relaxation? This post will detail the ins and outs of the parasympathetic nervous system (PNS), the part of our autonomic nervous system that controls rest and relaxation.


The parasympathetic nervous system or the “calming” side of the autonomic nervous system activates when the sympathetic nervous system (SNS) is no longer dominant. The PNS manages all our bodily systems on a functional and daily basis. This system calms you down in times of stress, allows you to digest food, reproduce, excrete waste and maintains an intelligent immune system. While SNS nerves stem from the thoracolumbar area of the spinal cord, PNS nerves stem from your brain and your sacral region, otherwise known as your craniosacral axis. While the ganglia or “stopping points for neurons” of the SNS are close to the spinal cord, the ganglia for the PNS are closer to or within the effector organs or “end destinations”. This means most of our PNS nerves run directly from our brain to our organs, bypassing the spinal cord.

Cranial Nerves

Aside from a few nerves in the sacral region that link up to your bladder and sexual organs, a majority of PNS nerves stem from the brain. These 12 nerves, referred to as cranial nerves, affect everything from facial and eye muscles to your stomach. Some of the cranial nerves involve motor fibers that control voluntary motor function, some contain sensory fibers that relay sensory information to sensory organs (i.e. smell to your olfactory nerve to your brain), and other cranial nerves control autonomic or involuntary function. Some cranial nerves actually contain both motor and sensory neurons! But let’s not get lost on the intricacies of these nerves and the PNS. Instead let’s explore one important nerve in the PNS…

Have you ever heard of the “Gut-Brain Connection”?

Cranial Nerve X (ten), also known as the Vagus Nerve, is a cranial nerve that contains both sensory and motor neurons. It is the longest nerve in the body and innervates various bodily systems. This nerve acts as a two-way street controlling the involuntary function of organs like your heart, lungs, esophagus, and gastrointestinal organs. It also relays information on the functionality or signals from these organs to your brain. The Vagus Nerve quite literally connects your gastrointestinal tract to you brain. When this nerve is stimulated, your gastrointestinal system properly digests foods and absorbs nutrients. However, when the SNS is activated, the PNS does not stimulate this all important cranial nerve, thus leading to a variety of gastrointestinal issues. In short, when you’re stressed and anxious, your GI health suffers!

Activating the PNS to relieve GI Issues

Part of our integrative approach to treating patients holistically involves taking into account “whole body systems”. We frequently ask our patients if they are under stress, or experience feelings of depression and anxiety. These factors can play a significant role in the health and wellness of our bodily systems. Through reading this post, you may have  learned about the importance in stimulating the PNS to maintain proper functioning organ systems, like our GI tract. We know that the average American leads hectic, fast-paced, stressful lives, yet many healthcare providers do not connect this constant state of stress to your other health conditions. Integrative medicine recognizes that each patient could benefit from practices that stimulate the PNS and inactivate the SNS. Incorporating this mentality into our patients’ treatments stimulates to proper functioning bodily systems and allows our patients to heal from within.

So, how can we activate the PNS and inactive the SNS? On of the best ways is to breath deeply, thus increasing intrathoracic pressure and stimulating the Vagus Nerve as it travels down the body, through the torso down.Craniosacral therapy is a very effective way to engage the parasympathetic nervous system. This hands-on modality can be profoundly balancing, and is sometimes an important aspect of an integrative treatment plan. Additionally, lifestyle choices can also help to emphasize our rest and digest system, including healthy exercise, massage, playing or listening to music, being in nature, etc. We also frequently recommend mindfulness stress reduction training--to help you develop a home mind body practice. Mindfulness means paying attention to the present moment, taking in our surroundings, environment, and sensations. It gives you a moment to be aware of your senses in that moment. Other forms of meditation work well, too! We encourage our patients to incorporate techniques that stimulate the PNS such as breathing, mindfulness and other meditation techniques--both sitting and movement based--even if it just 5 minutes a day before sleep!


Interested in learning about Foods that Fight Stress, check out our next class led by the PIM nutritionists!

When: December 6th, 2016 from 6:30-8:00PM Where: Tredyffrin Public Library, 582 Upper Gulph Road Strafford, PA 19087 Admission is free! Click here to register, and bring a friend! 🙂