From an evolutionary perspective, stress is related to our fight-flight mechanism. Our brain is constantly searching for potential danger in the surroundings and ready to mobilize our resources or prompt us for immediate action. Following many years of natural evolution, our brain has registered the dangers of confronting with deadly predators and other day-to-day dangers that man has been dealing with and adapting to.
The areas of our brain responsible for prompting us to take immediate action are very quick-tempered. They usually hijack the slow-paced reasoning of our frontal cortex as this swiftness of action may be the difference between life and death. This mechanism, constantly analysing our surroundings and ready to intervene in a split of a second has, as its primary focus, the mission of keeping us in safe boundaries. Whenever the “alarm” is strong enough, our “protective fight-flight brain area” hijacks activity away from rational thought and trusts entirely on an automatic emergency rescue-type response.
Fight/flight reaction is instantaneous
Have you ever been driving and find yourself suddenly pressing the breaks only to realize you have avoided an accident with another car without even noticing the close presence of it? This is a classic example of the behavioural hijack of our primitive “fight-or-flight” system when it senses immediate danger. Can you imagine what would happen if one was to initially access the situation logically before taking some form of abrupt action? Before we had reached a conclusion and taken any kind of action… it would have probably been too late.
Our emergency-mode is internally activated: the hypothalamus sends an alarm signal to the adrenal glands, generating a multitude of simultaneous responses. These glands will immediately release adrenaline and, as a consequence, the heart rate goes up, blood is sent to the muscles the organs and to the brain, which, together with the lungs, is flooded with oxygen. To provide us with quick energy to fuel the needed reaction, glucose is released and fatty acids are mobilized as a quick source of energy. The vessels near the surface of the skin contract and the blood clotting ability is increased in case the “event” may involve bleeding. At the same time, endorphins lock into cell receptors to block the eventual sensation of pain.
Once the fight-or-flight mechanism kicks in, one becomes hyper-alert and ready to respond to the upcoming threat. Time seems to slow down as our brain synapses go into overdrive and our vision alters, ready to detect any dangerous movement in the proximity.