Marijuana Acute Effect

When smoking marijuana, its effects begin immediately after drug enter the brain and last 1-3 hours. If marijuana is consumed in food or drink, short-term effects begin more slowly, usually 1 / 2 to 1 hour, and last longer, as long as 4 hours. Smoking marijuana deposits several times more THC in the blood than eat or drinking drug.

Within a few minutes after inhaling marijuana smoke, The heart starts beating faster, the bronchial tract relax and become enlarged, and blood vessels in the eyes expand, making eyes red. Heart rate, usually 70-80 beats per minute may increase by 20 to 50 beats per minute, and in some cases, even double. This effect may be greater if other drugs are taken with marijuana.As THC enters the brain, it causes the user to feel euphoric - or "high" - by acting in the reward system of brain areas of the brain responsible for stimuli such as food and drink, and most drugs of abuse. THC activate the reward system in the same way that almost all drugs of abuse do, by stimulating brain cells to release chemical dopamine.
A marijuana user may experience pleasant sensations, colors and Sounds may seem more intense, and time seems so very slowly. the user's mouth feels dry, and he or she may suddenly become very hungry and thirsty. His hands may tremble and grow cold. In euphoria passes after awhile, after which the user can cause drowsiness or depressed. From time to time, the use of marijuana creates anxiety, fear, mistrust or panic. 

 Heavy marijuana use preclude a person's ability to form memories, recall events (see Marijuana, Memory, and the Hippocampus), and change attention from one thing to another. THC also impedes coordination and balance by binding to receptors in the cerebellum and basal ganglia, parts of the brain that regulate balance, posture, coordination of movement and reaction time. Through its effects on the brain and body, marijuana intoxication can cause accidents. Studies show that approximately 6 to 11% of fatal accident victims test positive for THC. In many of these cases, alcohol is detected as well.
A survey conducted by the National Highway Traffic Safety Administration, a moderate dose of marijuana only been shown to be affected dynamic characteristics, but the effects of even a small dose of marijuana in combination with alcohol were significantly greater than or Drug alone. Driving indices measured included reaction time, visual search frequency (driver checking side streets), and the ability to perceive and / or respond to changes in the relative speed of other vehicles.
Marijuana users who have taken high doses of the drug may experience acute toxic psychosis, including hallucinations, delusions and depersonalization - a loss of sense of identity or self recognition. Although the specific causes of these symptoms remain unknown, they seem to occur more frequently at high dose of cannabis is consumed in food or drink, not smoke.