The Autonomic Nervous System

The human nervous system has two major divisions, the voluntary and the autonomic systems.  The voluntary system is concerned mainly with movement and sensation. The autonomic system mainly controls functions over which we have less conscious control.  These include the digestion of food, the blood pressure and the heart rate.  Its nerves leave the spine and connect to all the major parts of the body, either inhibiting or stimulating their activity.

The autonomic system has two branches.  These are called the sympathetic and the parasympathetic branches.


The sympathetic nervous system

The sympathetic branch activates the glands and organs that defend the body against attack.  It is called the fight-or-flight system.  Its nerves direct more blood to the muscles and the brain.  The heart rate and blood pressure increase, while it decreases the blood flow to the digestive and eliminative organs. It also activate the adrenal and thyroid glands so we can run away from danger!

The sympathetic nervous system also catabolic. This means it tears down the body stripping resources to use for defence rather than nourishment.  This means staying in sympathetic response for too long can damage the body. Nervousness, stress or feelings of panic are what one feels when in a sympathetic state of readiness. The feeling of an ‘adrenalin rush’ is a product of the sympathetic system.  It may feel good at first, but is always followed by a feeling of fatigue, as this system uses up energy and depletes the body.

The parasympathetic nervous system

The parasympathetic system of nerves is concerned with nourishing, healing and regeneration of the body.  It is anabolic, or concerned with rebuilding the body.  Its nerves stimulate digestion, and the immune and detox organs.  These organs include the liver, pancreas, stomach and intestines.  The parasympathetic system reduces the activity of the brain, the muscles, and the adrenal and thyroid glands. It is activated by rest, relaxation and happy thoughts. It is essential for balanced living and for all healing.  Moving yourself into a healthy parasympathetic state, and staying there as much of the time as possible, helps heal all health conditions, both physical and emotional ones as well.

The feeling often associated with the parasympathetic state can be one of lethargy or fatigue, as you are so relaxed.  Do not, however, believe this is unhealthy.  Rather, it indicates a state of repair and rebuilding in progress.

Autonomic Nervous System Functions

1. Sympathetic dominance

 When the sympathetic and parasympathetic systems are working as they should, the tendency is to rest often and easily.  One can, however, perform at “top speed” with equal ease. When challenged by stress, the balanced person is able to respond with vigour and fortitude.

Unfortunately due to the modern pace of life relatively few people today have a balanced autonomic system.  Most people favour the sympathetic branch.  As a result they do not spend enough time in a parasympathetic state to fully rebuild their bodies.  Their bodies eventually become nutritionally depleted and they become quite literally ‘burned out’.

The causes for sympathetic dominance are mainly lifestyle based and include things such as taking on too much work, over analysing things and worrying excessively.  Sometimes people are driven by fear, anger or resentment or they may simply live too fast; talking, thinking, eating or working at a rapid pace.

A vicious cycle often occurs. A person can become so used to being tired that if, by chance, they get a lot of rest one day, they use up their energy the next day, instead of continuing to rest.  Such people do not allow their bodies to use the energy they accumulated for healing and rebuilding.  As a result, they tend to stay depleted and out of balance.

The early signs of staying in a sympathetic dominant state too much of the time are fatigue or even feelings of exhaustion.  As the condition progresses, one may feel depressed, apathetic or moody.  Other physical symptoms include aches and pains, weakness, disturbed digestion or insomnia.  If this continues, the stage is set for more serious illness.

2. Sympathetic and Parasympathetic Balance

The sympathetic and parasympathetic systems are antagonistic. When one is on the other is off! However, the sympathetic system always takes precedence because it is concerned with our survival.

Time spent working, studying, exercising or other stressful activities is sympathetic

Time spent relaxing, enjoying restful meals and sleeping is parasympathetic

To promote balance and healing, the goal is to keep the sympathetic system turned off as much as possible. This allows the maximum healing to occur. Simple ways to do this are to rest, relax and think happy thoughts.  As soon as you think fearful or angry thoughts, or become too physically active, the body shifts into a sympathetic stance.

Keeping the autonomic nervous system healthy

Reduce stress – Stress is the main activator of the sympathetic nervous system.  It can arise from within the body due to fatigue, muscle tension, spinal misalignment or nutritional deficiencies, among other reasons.  Stress can also come from outside, such as financial, work or family stress.  Other types of stress to minimise or avoid are living in a noisy environment, or in one with contaminated air and water.

Rest often – Aim for at least 8 hours or more of sleep each night.  The hours before midnight are by far the best for sleeping.  Avoid excessive activity of any kind.  Even exercise is often overdone.  Exercise is a powerful sympathetic stimulant.  Avoid getting exhausted by any activity you engage in.  Be careful when using exercise to “run away” from stress, for example.  More rest is often what is really required. Make time to do something relaxing that you enjoy every day

Practice breathing deeply – Slow, deep breathing by itself turns off the sympathetic system. Focus on making the out breath longer than the in breath

Eat well – The nervous system must be properly nourished to function correctly.  Regular meals based on good quality proteins, low GI carbohydrates, healthy fats and plenty of fruits and vegetables help to support a balanced autonomic nervous system.

Stay positive – Try to see the positive side of every situation. Being grateful for what you have, forgiving and forgetting and cultivating contentment can all help to encourage a parasympathetic state. Negative emotions turn on the sympathetic system and keep it active