When Walking Home Alone Late One Night, You Are Startled

Essay

When walking home alone late one night, you are startled by a moving shadow that you glimpse out of the corner of your eye. Which division of the autonomic nervous system mobilizes your body's defenses? What does it do? Later, when you see that the shadow is just the neighbor's cat, what division of the autonomic nervous system is acting, and how does it lessen your physiological arousal? How do these autonomic divisions differ from the other main division, the somatic?