Transcript PPT12Chapter12Autonomicnervoussystem

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.