Cannabis sativa is believed to have evolved in the Steppes of Central Asia in an area that is now Mongolia and southern Siberia. Two additional strains, C. indica and C. ruderalis, are also native to Asia. It is a dioecious plant, meaning it appears as separate male and female forms, although hermaphroditism (expressing characteristics of both sexes) does occur. The highest concentration of psychotropic compounds comes from the flowers of the female plants. Cannabis produces a wide range of chemicals known as cannabinoids, of which tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most recognized and understood. When taken into the body, THC has a psychoactive effect (causes a “high”), whereas CBD does not. Both compounds, and potentially many other cannabinoids that are less well known, affect the endocannabinoid system, which consists of a group of specialized receptors in the brain and peripheral nervous system, and is found in all vertebrates. Because endocannabinoid receptors are so widespread throughout the body, numerous and diverse health benefits of Cannabis have been proposed, and because the receptors are closely associated with the nervous system, toxic effects usually appear as neurologic symptoms.
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