Which hormone is primarily involved in the stress response system?

• A. Adrenaline
• B. Melatonin
• C. Cortisol
• D. Prolactin

Answer: (C)

Cortisol is the primary hormone involved in the stress response system, often referred to as the "stress hormone." When faced with a stressor, the body activates the hypothalamic-pituitary-adrenal (HPA) axis, leading to the release of corticotropin-releasing hormone (CRH) from the hypothalamus. This, in turn, stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH), which prompts the adrenal glands to produce cortisol.

Cortisol plays a crucial role in how the body responds to stress by mobilizing energy sources, increasing glucose availability, and modulating various immune and inflammatory processes. It also helps regulate blood pressure and cardiovascular function during times of stress, making it essential for maintaining homeostasis in challenging situations.

While adrenaline (also known as epinephrine) is certainly involved in the acute fight-or-flight response, its action is more rapid and short-lived compared to cortisol, which has longer-lasting effects. Melatonin, primarily involved in regulating sleep-wake cycles, and prolactin, which is mainly responsible for lactation and reproductive functions, do not play significant roles in the stress response. Thus, cortisol's function in mediating the body's prolonged reactions to stress