Joe Pistack MS/ED

 Automatic response-the body’s way of unconsciously and automatically making decisions and carrying them out for you.  The autonomic nervous system-is part of the peripheral nervous system that supplies motor activity to the visceral effector organs, glands, smooth muscles within the organs and the heart.

 The two divisions of the ANS are:  sympathetic  Parasympathetic  Dual Innervation a single organ receives nerve fibers from both divisions of the ANS  Sympathetic nervous system- is activated during periods of stress or times when a person feels threatened.  Called the “fight or flight” response.

 Causes you to either confront (fight) or remove yourself from the threatening situation (flight). Sympathetic nervous system is activated during periods of stress, normally short-lived periods.

 Heart rate increases  Bronchial tubes dilate(increase airflow)  Iris of the eye dilates (pupils enlarge)  Blood vessels constrict  Sweat glands stimulated  Inhibited intestinal mobility  Adrenal medulla stimulates secretion of epinephrine and norepinephrine  Salivary glands stimulate thick secretions

 Parasympathetic nervous system-most active during quiet, non-stressful conditions.  Has a calming effect on the body.  Plays an important role in the regulation of digestion and reproductive function.  Referred to as “feed and breed” or resting and digesting.

 The parasympathetic system is activated in situations that are perceived hopeless and where “fight or flight” seems futile.  Symptoms are the opposite of sympathetic nervous system  Body’s reaction to a more restful situation. Ex. Nice spring day, sitting under a tree.

 Decreased heart rate  Bronchial tubes constrict  Pupils Constrict  Salivary glands are stimulated with a watery secretion  Increased motility and secretion of the intestine

 Stimulus that can effect the parasympathetic nervous system may be stimulation of the vagus nerve, diagnostic testing that may stimulate a parasympathetic response. Ex. Colonoscopy.  A massive parasympathetic response may result in uncontrolled urination or defecation.  Bradycardia

 There is a decrease in the speed of nerve conduction.  Decrease in reflexes.  Less efficient sympathetic nervous system response may cause transient hypotension and fainting.  Decline in nerve activity supplying changes in pupillary response and reactivity.  Decrease in the cranial nerves mediating taste and smell.