Fight or Flight

• The fight or flight response is a phenomenon where our body responds to an environmental stressor by changing our involuntary processes such as breathing, heart rate and digestion in order for us to be prepared to defend ourselves or escape. This phenomenon involves the endocrine system and the autonomic nervous system. The parasympathetic branch of the ANS is responsible for regulating your bodily functions when you are resting, but the sympathetic branch is responsible for preparing your body for fight or flight.
• The hypothalamus activates the SNS which prepares the body for fight or flight. Neurons from the SNS activate the adrenal medulla, which is part of your adrenal gland, which releases adrenaline into the bloodstream. This hormone has various effects on the pupils, heart, blood flow, lungs, digestive system and sweat glands. These changes enable the body to take action and protect itself in dangerous situations, either by running away or fighting – hence, the fight or flight response.
• To return everything back to normal the PNS kicks in. This system is slow acting, unlike its counterpart, and may take several minutes or even longer to get your body back to where it was before the scare. This decreases blood pressure, slows pulse rate and starts up your digestive system.