The Human
ENDOCANNABINOIDSystem
CBD, CBN, and THC fit like a lock and key into existing human receptors. These receptors are part of your endocannabanoid system which impact physiological processes affecting modulation of pain, memory, appetite, inflammation, and other immune system responses. The endocannabanoid system comprises two types of receptors, CB1 and CB2, which serve distinct functions in human health.
THC > CB1: 
CB1 receptors are essential for a healthy functioning brain and nervous system. They can be moderators of memory, mood, motor function, and pain perception. CB1 receptors also have roles in pregnancy, hormone production, cardiovascular health and digestion.
CBD: 
CBD doesn’t directly unlock either receptor. Instead, it modifies the receptors ability to bind to cannabinoids, influences other types of receptors, and enhances your natural levels of endocannabinoids.CBN > CB2: 
CB2 receptors are most found on the cells of our immune system. They help moderate inflammation and our immune response to pathogens.