What physiological reaction is triggered during the fight or flight response?

The fight or flight response is a physiological reaction that occurs in response to perceived threats or danger, allowing the body to prepare for quick action. One of the hallmark features of this response is the release of adrenaline (also known as epinephrine) from the adrenal glands. This adrenaline rush leads to various bodily changes that are designed to optimize physical performance in a crisis situation.

When adrenaline is released, it increases heart rate, elevates blood pressure, and boosts energy supplies by increasing the availability of glucose and fatty acids. These changes prepare the body to either confront the threat or flee from it, which is the essence of the fight or flight response. Other hormones and neurotransmitters may be involved as well, but adrenaline is the primary driver of the immediate changes that occur in response to stress. This physiological cascade is essential for survival in potentially dangerous situations.