Fight or FlightsHumans used to have to fight to survive. We had to hunt our food and fight off enormous predators. This stimulus directed our evolution and gave us biological systems that helped us survive life or death situations. In fact, our nervous system is split into two main functions: fight-or-flight and rest-and-digest.
The nervous system controls all parts of our bodies. One aspect of our nervous system is called the ‘autonomic’ nervous system. ‘Autonomic’ means that we are not in conscious control of the actions it makes. This partition of the nervous system is further divided into two parts: the sympathetic and parasympathetic. The sympathetic (fight or flight) nervous system overseas our internal resources to help us survive a life or death situation. The parasympathetic (rest and digest) nervous system is functioning in our daily life, when we are not under intense stress.
AdrenalineWhen our brain considers a situation to be life-threatening, the sympathetic nervous system kicks into gear and up regulates many processes to insure our survival. Hormones are then secreted, the main one being adrenaline (also called ‘epinephrine’ in the USA). When adrenaline is circulating in the body your heart rate increases, pupils dilate, digestion slows, and your circulation increases to skeletal muscle. All these changes happen to support decision making, reaction time, and increase muscle force production; all of which allow you to either run from danger or fight it off! All of this happens the moment your brain decides you are in danger. You enter a heightened state of awareness and physical strength.
Not only is adrenaline released when you are under stress, but endorphins can also be released. Dopamine, Serotonin, and Oxytocin are your primary endorphins and their job is to make you feel great and reduce pain! A stressor that produces endorphins is called ‘eustress.’ ‘Eu’ from Greek and means ‘good.’ Therefore, endorphin-producing stress is GOOD-stress! Which is why you may feel great after something like as a roller-coaster ride! You see, although we know roller coasters are relatively safe, our subconscious believes it is a life or death scenario and as soon as we go over that first drop, it prepares us for fight or flight! We get sweaty, are heart starts racing, our pupils dilate, and our reaction time improves! After we realize we aren’t going to die, our body dumps endorphins into the system and we feel great (if a little shaken up)!