Beta receptors are a type of protein found on the surface of cells that respond to hormones like epinephrine and norepinephrine. They play a crucial role in the body's response to stress, helping to regulate functions such as heart rate, blood pressure, and energy metabolism. There are three main types of beta receptors: beta-1, beta-2, and beta-3, each with specific roles in different tissues. When activated, beta receptors can lead to various physiological effects. For example, beta-1 receptors primarily influence the heart, increasing heart rate and contractility, while beta-2 receptors are found in the lungs and blood vessels, promoting relaxation and dilation. Understanding these receptors is essential for developing medications that target conditions like asthma and heart disease.