Which hormone is produced by the adrenal cortex and what is its action?

The hormone produced by the adrenal cortex is cortisol, and its primary action includes promoting the use of fatty acids as an energy source. Cortisol is known as a glucocorticoid and plays a crucial role in the body's stress response, regulating metabolism, and maintaining homeostasis. During times of stress or fasting, cortisol helps mobilize energy stores by increasing the availability of fatty acids and glucose for use by tissues, allowing the body to sustain energy levels.

By enhancing the breakdown of fats and proteins, cortisol ensures that the body can meet its energy demands during periods when food intake may be inadequate. This action is vital for supporting prolonged physical activity and maintaining blood sugar levels, particularly during stressful situations.

The other hormones listed in the choices have different functions and are produced by other glands. For example, norepinephrine functions primarily as a neurotransmitter and is involved in the body's fight-or-flight response, while IGF-1 is primarily associated with growth and development, affecting cellular processes rather than directly promoting energy usage. Insulin, produced by the pancreas, is crucial for lowering blood glucose levels rather than influencing fatty acid metabolism as cortisol does. Understanding the specific roles of these hormones helps clarify the unique contributions of the adrenal cortex's cortisol to energy metabolism.