1. Dilates pupils.
1. Contracts pupils.
2. Contracts ciliary muscles, so that the
2. Lessens tonus of ciliary muscles so that
eyes are accommodated to see objects
the eyes are accommodated to see distant
near at hand.
3. Dilates bronchial tubes.
3. Contracts bronchial tubes.
4. Quickens and strengthens the action of
4. Slows the action of the heart.
5. Contracts blood vessels of the skin and
viscera so that more blood goes to the
5. Dilates blood vessels.
muscles where it is needed for "fight or
6. Inhibits peristalsis. Food "sits like a
6. Increases peristalsis.
lump" in the stomach.
7. Decreases secretions of glands
7. Increases secretions of glands (except
(except the sweat glands and the adrenal
the sweat glands and the adrenal glands).
glands, which secrete more).
8. Causes contraction of sphincters to
8. Relaxes sphincters so that waste
prevent emptying of bowels or bladder.
matter can be removed.
Table 21. Functions of the autonomic nervous system.
Section VII. THE ENDOCRINE SYSTEM
239. ENDOCRINE GLANDS
Hormones are produced by specialized glands called endocrine, or ductless,
glands (figure 220) and are secreted directly into the bloodstream. Glands such as the
salivary, mucous, and gastric glands produce substances, which they secrete by means
of ducts into the organ on which they are to act. They are glands of external secretion.
The hormoneproducing endocrine glands are glands of internal secretion since they do
not secrete their products into an organ or cavity but directly into the blood or lymph.
Table 22 lists the ductless glands along with their locations and the substances which