During the fight or flight response, which hormone is typically released?

During the fight or flight response, adrenaline, also known as epinephrine, is the primary hormone released by the adrenal glands. This release occurs in reaction to stress or danger and prepares the body for rapid action. Adrenaline increases heart rate, boosts energy supplies, dilates air passages, and enhances the ability to think quickly—all of which are crucial for either facing a threat or fleeing from it.

This hormone is part of the body's acute stress response system, enabling an immediate reaction to perceived threats. It effectively prepares the body for high-energy exertion and can enhance physical performance.

The other hormones mentioned, while important in various bodily functions, do not primarily relate to the immediate response to stress in the way that adrenaline does. For instance, cortisol functions to regulate metabolism and the immune response over a longer duration of stress, serotonin is primarily a mood-regulating neurotransmitter, and insulin is responsible for regulating blood sugar levels. Each plays vital roles in bodily functions, but they are not involved in the immediate physiological changes associated with the fight or flight response.