Which hormone is primarily associated with the body's stress response?

Cortisol is primarily associated with the body's stress response because it plays a crucial role in the body's reaction to stressors. Produced by the adrenal glands, cortisol is often referred to as the "stress hormone," as it is released in higher quantities during stressful situations. This hormone helps to regulate various functions in the body, including metabolism, immune response, and blood pressure, all of which are vital when responding to stress.

During a stressful encounter, the hypothalamus signals the adrenal glands to release cortisol, which prepares the body for a "fight or flight" reaction. It increases glucose availability for energy, suppresses non-essential functions like digestion and reproduction, and modulates the immune response to prevent excessive inflammation, allowing the individual to more effectively deal with the stressor.

In contrast, adrenaline (or epinephrine) also plays a role in the immediate stress response but is more involved in the initial burst of energy and heightened alertness. Insulin’s primary function is related to blood sugar regulation rather than stress response. Serotonin is primarily associated with mood regulation and does not have a direct role in managing stress like cortisol does.