Purinergic receptors are a type of cell surface receptor that respond to purines, which are organic compounds like adenosine and ATP (adenosine triphosphate). These receptors play a crucial role in various physiological processes, including neurotransmission, inflammation, and cellular signaling. They are classified into two main types: P1 receptors, which are activated by adenosine, and P2 receptors, which respond to ATP and other nucleotides. These receptors are found throughout the body, including in the brain, heart, and immune system. Their activation can lead to diverse effects, such as promoting relaxation of blood vessels or modulating pain perception. Research on purinergic receptors is ongoing, as they are potential targets for treating various diseases, including cardiovascular disorders and neurological conditions.