continued

The Sympathetic Branch
of the Autonomic Nervous System

We can't resist giving you the above fancy piece of terminology to casually drop in polite conversation at school or in your family.

When a stimulus in your environment is perceived as threatening, or is conjured up in your mind (remember the section on perception in Chapter 4, What Is Stress, Anyway?), the specific pathway in the central nervous system that is activated is the sympathetic branch.


When the sympathetic branch is activated,
all the following occur:

Pupils dilate

Windpipes expand and respiration rate increases

Bladder functions less efficient

Digestive functions slowed and blood flow diverted to the heart, brain, and major muscle groups

Salivation suppressed

Sweat glands stimulated to process bodily waste products

Adrenal gland stimulated, and adrenaline
pumped into blood causing:

Increased heart rate
and blood pressure

Increased blood sugar

Increased red cell count

Dilation of heart's
blood vessels;
surface vessels constrict

Contraction of muscles
near surface of skin