Think about a time you felt stressed. How did your body react? You may have noticed sweat on your palms, a faster heart rate, or quicker breathing. All of these responses, among many others, are part of your natural stress response, otherwise known as the “fight-or-flight” response.

The fight-or-flight response is a mechanism used by many mammals when they are in danger. As the name suggests, our early ancestors would either fight or flee in life-threatening situations. Because of evolution, we behave similarly today when encountering stressful events, though our situations may not be as serious. For example, as a student, you may have experienced the stress response right before a test, during a presentation, or when running late for school.

When we are faced with pressure from our environment, the amygdala, which is located in the brain, evaluates the information that we sense with our eyes and ears. Once it processes fear, it sends a signal to the hypothalamus at the base of the brain. The hypothalamus then communicates with the rest of the body using the sympathetic nervous system, which is responsible for setting off the fight-or-flight response. The sympathetic nervous system is a part of the autonomic nervous system. This means that it controls involuntary body functions, so they happen without you thinking about them. The signals from the hypothalamus tell the adrenal glands to release a hormone called adrenaline, which causes the heart to beat faster, airways to open, and blood sugar to be released. All of these responses allow the body to be more efficient: the muscles work harder, the brain is more attentive, and the senses are stronger.

The stress response plays a very important role in ensuring our survival. Without it, our bodies would not be able to work as effectively in times of emergency. It is truly impressive how we are equipped with the ability to automatically prioritize different body functions depending on the situation we are in!