How marjuana works in our body?

It's a toxin: In the brain, marijuana causes distorted perceptions, impaired coordination, difficulty with thinking and problem solving, and disrupted learning and memory. Iq points may be lost and not recovered. In some it induces psychosis and paranoia; lowers motivation also. Further, it raises heart rate and increases risk of heart attack. When smoked, it's a lung irritant. http://tinyurl.com/7fxu9px.