The adrenergic system is a part of the body's nervous system that responds to stress and regulates various physiological functions. It primarily involves the release of adrenaline (also known as epinephrine) and norepinephrine, which are hormones produced by the adrenal glands. These chemicals help prepare the body for "fight or flight" responses, increasing heart rate, blood pressure, and energy availability. The adrenergic system operates through specific receptors known as adrenergic receptors, which are classified into two main types: alpha and beta receptors. These receptors are found throughout the body, including in the heart, lungs, and blood vessels, and they play a crucial role in managing responses to stress, regulating blood flow, and influencing metabolism.