Have you ever stopped and thought about how our bodies and brain just know what to do in certain situations? Well you can thank your autonomic nervous system for playing a large role in allowing our body to work in the way it does. The autonomic nervous system is a control system that regulates many bodily functions like heart rate, digestion, respiratory rate, and pupillary action. There are two main components of the autonomic system called the parasympathetic and sympathetic nervous system. The parasympathetic nervous system controls homeostasis and the bodies rest and digest response. This means that it controls the body’s response while at rest. These neurological pathways are longer and slower. The sympathetic nervous system’s main purpose is to mobilize the body’s fight-or-flight response. This system prepares the body to react to stressful environmental factors. When the sympathetic nervous system is active it results in muscle contraction, increase in heart rate, and pupils to dilate. These two systems do not usually function at the same time. This is because when each system is in action it requires more blood for the organs it has control over. When scared the body will divert blood from the digestive tract to sympathetic nerve functions to be able to carry out muscle contractions or run.
You can probably recall moments that you remember you sympathetic or parasympathetic nervous system in action. I can recall a moment last week when my roommate scared me. I walked into my apartment very late at night and did not think she was there. It was very dark and quite as I walked into my room. Once I was in my room, I heard the floor boards creaking and movements in the other room. I got so scared that my palms turned sweaty and I could feel my heartbeat racing. I thought a burglar was in my home. She then called my name and I immediately felt relief. My heart stopped beating hard in my chest and I all my tense muscles immediately relaxed. When I was scared my sympathetic nervous system kicked in which resulted in sweating, increased heart rate, and muscle contraction. Once I realized I was no longer in danger my parasympathetic nervous system took control. This explained why I felt more relaxed and stopped sweating.
This is just one simple example of the parasympathetic vs sympathetic nervous system. If you pay attention to your body throughout your daily life and can probably be able to tell when your sympathetic vs parasympathetic system is working.