Abnormal Psychology

250 CHAPTER 7

7.1 • The Fight-or-Flight Response The fi ght-or-fl ight response activates the sympathetic

nervous system and prepares the body for a signifi cant expenditure of physical energy. Specifi cally,

the sympathetic nervous system gives rise to deeper and quicker breathing to deliver more oxygen to

the blood, increased blood fl ow to muscles and brain (to give them more oxygen), decreased blood

fl ow to skin (which is why people blanch when afraid), more glucose released from the liver into the

blood (to provide energy for muscles, organs, and brain), increased sweat on the palms (a small

amount, which improves the grip), pupil dilation for better visual acuity, slowed digestion in the

stomach and intestines (and an urge to empty the system through urination, defecation, or vomiting).

The parasympathetic nervous system typically brings these effects back to the normal state.

Figure 7.1

Pupil

Liver

Stomach

Brain

Heart

Bronchi

of lungs

Palms

Spinal cord

lifetimes (Somers et al., 2006). The prevalence rates of anxiety disorders diagnosed by

family doctors almost doubled from 1990 to 2003, but it is not clear whether this

trend represents a true increase in the number of cases, better recognition of anxiety

disorders by the physicians, or both (Skaer, Sclar, & Robison, 2008). Women are

twice as likely as men to be diagnosed with one of the anxiety disorders (Somers

et al., 2006), although the reasons for this difference are not well understood. Some