Marijauna

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Marijuana

Marijuana is a green, brown, or gray mixture of dried, shredded leaves, stems, seeds, and flowers of the hemp plant. You may hear marijuana called by street names such as pot, herb, weed, grass, boom, Mary Jane, gangster, or chronic. There are more than 200 slang terms for marijuana.
Known in Central Asia and China as early as 3000 BC, marijuana was used as a folk medicine. From about 1900 it was used as a pleasure-inducing drug and by the 1960s and 1970s its use was widespread. It became, after alcohol, the second most popular drug. Although marijuana has not been proven physically addicting and no physical withdrawal symptoms occur when use is discontinued, psychological dependence can develop with consistent, long-term use.
All forms of marijuana are mind-altering. In other words, they change how the brain works. They all contain THC, the main active chemical in marijuana. They also contain more than 400 other chemicals. Marijuana's effects on the user depend on the strength or potency of the THC it contains. THC potency of marijuana has increased since the 1970s but has been about the same since the mid-1980s.
When someone uses marijuana, these chemicals travel through the bloodstream and quickly attach to special places on the brain's nerve cells. These places are called receptors, because they receive information from other nerve cells and from chemicals. When a receptor receives information, it causes changes in the nerve cell. The chemical in marijuana that has a big impact on the brain is THC. Scientists recently discovered that some areas of the brain have a lot of THC receptors, while others have very few or none.
THC in marijuana is strongly absorbed by fatty tissues in various organs. Generally, traces of THC can be detected by standard urine testing methods several days after a smoking session. However, in heavy chronic users, traces can sometimes be detected for weeks after they have stopped using mari...