Beta-2 refers to a type of receptor known as a beta-adrenergic receptor, which plays a crucial role in the body's response to stress and regulation of various physiological functions. These receptors are primarily found in the lungs, heart, and blood vessels, and they help manage processes such as airway dilation and heart rate. In medicine, beta-2 agonists are commonly used as bronchodilators to treat conditions like asthma and chronic obstructive pulmonary disease (COPD). By stimulating the Beta-2 receptors, these medications relax the muscles in the airways, making it easier to breathe and improving overall lung function.