Marijuana is the most commonly used illicit drug in the United States.
A dry, shredded green/brown mix of flowers, stems, seeds, and leaves of
the hemp plant Cannabis sativa, it usually is smoked as a cigarette
(joint, nail), or in a pipe (bong). It also is smoked in blunts, which
are cigars that have been emptied of tobacco and refilled with
marijuana, often in combination with another drug. Use also might
include mixing marijuana in food or brewing it as a tea. As a more
concentrated, resinous form it is called hashish and, as a sticky black
liquid, hash oil. Marijuana smoke has a pungent and distinctive,
usually sweet-and-sour odor. There are countless street terms for
marijuana including pot, herb, weed, grass, widow, ganja, and hash, as
well as terms derived from trademarked varieties of cannabis, such as
Bubble Gum®, Northern Lights®, Juicy Fruit®, Afghani #1®, and a number
of Skunk varieties.
The main active chemical in marijuana is THC The membranes of certain
nerve cells in the brain contain protein receptors that bind to THC.
Once securely in place, THC kicks off a series of cellular reactions
that ultimately lead to the high that users experience when they smoke
marijuana.
Scientists have learned a great deal about how THC acts in the brain to
produce its many effects. When someone smokes marijuana, THC rapidly
passes from the lungs into the bloodstream, which carries the chemical
to organs throughout the body, including the brain.
In the brain, THC connects to specific sites called cannabinoid
receptors on nerve cells and influences the activity of those cells.
Some brain areas have many cannabinoid receptors; others have few or
none. Many canna ...