Cannabinoid receptors CB1 and CB2, located throughout the body, are part of the endocannabinoid system, which is involved in a variety of physiological processes. The Endocannabinoid system helps regulate appetite, energy balance, metabolism, stress responses, immune functions, the autonomic nervous system, thermo-regulation, sleep and many other important body systems.
The main reason that cannabis provides psychoactive effects as well as therapeutic benefits is because the cannabinoids in the plant interact with the receptors, much like a lock and key.The receptor is the lock and the cannabinoid molecule is the key.