Beta-1 adrenergic receptors are a type of protein found on the surface of certain cells in the body, particularly in the heart. They play a crucial role in the body's response to stress by binding to hormones like epinephrine and norepinephrine. When activated, these receptors increase heart rate and the force of heart contractions, helping to pump more blood during times of physical activity or stress. These receptors are part of the adrenergic receptor family, which also includes beta-2 and alpha receptors. Beta-1 adrenergic receptors are primarily located in the heart, but they can also be found in the kidneys, where they help regulate blood pressure. Medications that target these receptors are often used to treat conditions like heart failure and hypertension.