Cannabinoids work by connecting, or binding, to receptors in the body. These receptors make up a system called the endocannabinoid system (ECS). There are two types of receptors: CB (cannabinoid receptor type 1) and CB (cannabinoid receptor type 2). CB receptors are mostly found in the central nervous system, which is made up of the brain and spine. It is also found in other places in the body like sex organs. CB is found in the peripheral nervous system in other parts of the body. CB receptors are found in the immune system, which is the system that prevents us from getting sick.