What is the primary hormone secreted by the adrenal glands during stress?

The primary hormone secreted by the adrenal glands during stress is adrenaline, also known as epinephrine. When a person encounters a stressor, the body activates its fight-or-flight response, which is largely mediated by the adrenal glands. Adrenaline plays a crucial role in preparing the body to respond to immediate threats by increasing heart rate, dilating air passages, and mobilizing energy sources. It facilitates quick responses needed for high-stress situations, allowing an individual to react swiftly.

While cortisol, norepinephrine, and insulin are also involved in the body's response to stress, adrenaline is the key player in the acute phase of stress responses. Cortisol, for example, takes longer to act and is more related to longer-term stress responses and metabolic regulation. Norepinephrine is involved in focus and attention during stress but does not have the same immediate effects as adrenaline. Insulin primarily regulates blood sugar and is not directly related to the stress response. Thus, adrenaline is recognized as the primary hormone produced in response to stress, making it the correct answer.