A host of involuntary reactions are controlled by the Sympathetic and the Parasympathetic branches of the Autonomic Nervous System.These systems are intended to automatically balance activities that allow healing and responses to emergencies.††† If one side of the Autonomic Nervous System is suppressed, then these activities are controlled by the other side and the control is imbalanced, so physical pressure on a nerve can inhibit nerve function and cause a control imbalance.The summary of the functions is listed below:

The Sympathetic nervous system prepares a person for FIGHT or FLIGHT even at NIGHT.It increases heart rate and blood pressure, breathing, the strength of voluntary muscles, mobilizes chemicals that give quick energy, increases blood vessel wall muscle tightness (causing pale skin), and stops urination and digestion.The Sympathetic nervous system also makes people irritable, and it increases the pupil diameter which makes it easier to see at night and makes it harder older people to focus.

The Sympathetic nervous system decreases the immune system, GI system motility and secretions, GI system and urinary bladder wall muscle tone, protein synthesis and slows injury repairs.It also decreases allergic reactions, opens sinus and lung passages, and improves breathing effort by increasing the strength of breathing muscles.

In contrast the Parasympathetic nervous system promotes relaxation and healing.It increases the activity of the immune system, food digestion, bowel mucus secretions, body repair and building of proteins.It also increases the activity of the bowels, tightens the urinary bladder walls, relaxes bowel and urinary sphincter muscles, decreases the heart rate and contraction force, slows down the bodyís efforts on breaking down fat, and relaxes the muscles in the blood vessel wall.  It also decreases the diameter of the eye pupils, which makes it easier for older people to focus.



SYMPATHETIC INNERVATION to the organs of the head is supplied by T1 - T4 via the Cervical Ganglion. The respiratory tract, bronchi & cardiac plexus are fed by T1 - T4.A chain of sympathetic ganglia & fibers follow a bilateral course anterior to the vertebral column from T1 to L2 or L3.The kidneys, bladder, liver, biliary tract and the GI tract from the stomach to the colon are supplied from T5 - L2 by the Celiac Plexus.The pelvis, sigmoid and descending colon are supplied by fibers from at least L1 - L2 (and as much as T11 through L3) via the splanchnic and hypogastric nerves. Sympathetic nerve fibers also closely follow motor neurons to target tissues. Often you can detect Sympathetic Nervous System activation by testing the skin above the tissue affected by the sympathetic nerve.If you feel non-slippery moist skin (as opposed to slippery dry skin) when you drag your finger across the skin above the affected area, it shows objectively that your patientís body believes it has a problem.


PARASYMPATHETIC INNERVATION to the organs of the head is supplied by the oculomotor, facial and glossopharyngeal nerves, with input from C1 - C2.The remaining visceral organs are supplied by the vagus nerve and the sacral axis.The vagus alone supplies the trachea, lungs, heart, spleen, kidneys, liver, esophagus, stomach, pancreas, gall bladder, small intestine, ascending and transverse colon.From S1 - S4, the sacral axis supplies the sex organs, external genitalia, bladder and its sphincters.The vagus is most often affected at the level of C2, and this can cause life threatening intestinal obstruction in the elderly or serious feeding problems in newborns.


Only the vagus nerve slows the heart rate, slows breathing, and increases digestion.If the top of your neck has stiff muscles or the upper neck vertebrae are injured, you may have autonomic system symptoms such as rapid heart rate, rapid breathing and poor digestion, or even bowel obstruction that might be helped by reducing swelling or relaxing the muscles in the upper neck.If you have these symptoms and a tight neck consider seeing an Osteopath.††††††††07/27/2012