Sympathetic
Parasympathetic
(Adrenergic)
(Cholinergic)
1.
Dilates pupils.
1.
Contracts pupils.
2.
Lessens tonus of ciliary
2.
Contracts ciliary muscles, so
muscles, so that the eyes are
that the eyes are
accommodated to see distant
accommodated to see objects
objects.
near at hand.
3.
Dilates bronchial tubes.
3.
Contracts bronchial tubes.
4.
Quickens and strengthens the
4.
Slows the action of the heart.
action of the heart.
5.
Contracts blood vessels of the
5.
Dilates blood vessels.
skin and viscera so that more
blood goes to the muscles
Where it is needed for "fight or
flight."
6.
Inhabits peristalsis. Food "sits
6.
Increases peristalsis. (Thus,
like a lump" in the stomach.
digestion is promoted.)
7.
Decreases secretions of glands
7.
Increases secretions of glands
(except the sweat glands and
(except the sweat glands and
the adrenal glands, which
the adrenal glands). Glands
secrete more).
Involved in digestion are
stimulated.
8.
Causes contraction of
8.
Relaxes sphincters so that
sphincters to prevent emptying
waste matter can be removed.
of bowels or bladder.
Table 4-1. Functions of the sympathetic and parasympathetic nervous systems.
MD0913
4-3