Q: What are catecholamines?  

Catecholamines are a class of hormones that are produced by the adrenal medulla, which is located in the center of the adrenal gland. The two primary catecholamines are epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline). These hormones play a critical role in the body's "fight or flight" response to stress, as they increase heart rate, blood pressure, and respiration, while decreasing digestion and other non-essential functions. Additionally, catecholamines are involved in a variety of other physiological processes, including metabolism, mood regulation, and the immune response.