Autonomic Nervous System

The autonomic nervous system is more of an internal system, connecting the central nervous system to the endocrine glands, the muscles controlling the heart, and the primarily involuntary smooth muscles controlling the other internal organs, such as the stomach, intestines, liver, and lungs. The autonomic nervous system is very important in emotion.

The autonomic nervous system is further divided into two branches: the sympathetic nervous system, which is more active in emergencies, and the parasympathetic nervous system, which is more active under normal circumstances. When you are calm and quiet, the parasympathetic nervous system causes your heart rate to slow down, your blood pressure to be lowered, and breathing to become normal. It also activates the stomach and intestines so that normal digestions can occur. The primary neurotransmitter found in the parasympathetic nervous system is acetylcholine, whose effects mainly inhibit muscle action. The parasympathetic system can be thought of as in the maintenance system that is in control during relaxation. Your parasympathetic nervous system was dominant as you begin to walk home and were not yet in any danger form the day.