Essentials of Anatomy and Physiology

The Endocrine System 239

Norepinephrine Epinephrine

Dilates bronchioles

Increases conversion

of

glycogen to glucose

Increases use of

fats for energy

Increases cell

respiration

Increases rate and

force of contraction

Vasoconstriction

in skin

Vasoconstriction

in viscera

Decreases

peristalsis

Vasodilation

in

skeletal muscle

Vasoconstriction in

skeletal muscle

Adrenal medulla

Figure 10–9. Functions of epinephrine and norepinephrine.

QUESTION:Do epinephrine and norepinephrine have the same effect on skeletal muscle?

Explain your answer.

sex hormones. The sex hormones, “female” estrogens
and “male” androgens (similar to testosterone), are
produced in very small amounts, and their importance
is not known with certainty. They may contribute to

rapid body growth during early puberty. They may

also be important in supplying estrogen to women

after menopause and to men throughout life (see the

“Estrogen” section later in this chapter).