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 stressful situations. These receptors are part of the adrenergic receptor family and are primarily involved in the sympathetic nervous system's functions. They are important in regulating cardiovascular health and are often targeted by medications for conditions like heart failure and hypertension.