PPT12Chapter12Autonomicnervoussystem
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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.