Effects of Alcohol on Central Nervous System
Effects of Alcohol on Central Nervous System: Alcohol at any measurable concentration in blood can produce measurable slowing of reflexes, hence driving after consuming any amount of alcohol can be dangerous and the more amount of alcohol consumed, the greater the risk and danger. Because higher intake of alcohol leads to higher blood alcohol concentration, which in turn leads to greater slowing of reflexes.
Generally, performance is impaired, due to disturbance of precise movements and fine discrimination, hence the risk of error increases. However, there may sometimes be an improvement in performance due to the disappearance of fear of punishment and anxiety of failure.
Effects of Alcohol on Central Nervous System
The effects of alcohol on the central nervous system are more profound and marked when plasma concentration of alcohol is increasing, than falls. This phenomenon is most probably due to the development of tolerance.
Effects of Alcohol on Central Nervous System at low plasma concentration
Alcohol is primarily a neuronal depressant. The excitatory effects of alcohol (such as euphoria, apparent excitation, etc.) are seen at lower plasma alcohol concentrations at about 30-60 mg per 100 ml of blood. At first, hesitation, caution, restraint, and inhibition of self-criticism are lost. Next, mood and feeling can be altered and anxiety is allayed. All these are usually seen at a lower plasma concentration of alcohol at about 30-60 mg per 100 ml of blood.
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Effects of Alcohol on Central Nervous System at moderate plasma concentration
If plasma alcohol concentration rises a little higher to about 80-150 mg per 100 ml of blood, mental clouding, impairment of attention, disorganization of thoughts, memory disturbance, alteration of perception, alteration of gait and drowsiness occur.

Effects of alcohol on CNS at higher plasma concentration
At higher plasma alcohol concentration, i.e. 150-200 mg of alcohol per 100 ml of blood, the individual becomes drunk, sloppy, and ataxic. At high plasma alcohol concentration “blackout” can occur.
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Effects of Alcohol on Central Nervous System at very high plasma concentration
At very high plasma alcohol concentration, i.e. 200-300 mg of alcohol per 100 ml of blood, stupor can occur and above 300 mg of alcohol per 100 ml of blood unconsciousness results. At this concentration, death may occur due to paralysis of medullary centers.
Alcohol can induce sleep, but it cannot be used as a sleep medication, because it is not a dependable sleeping agent (known as hypnotic in medical terms). Alcoholics suffer from insomnia and there is a disturbance of sleep architecture. “Hangover” the next morning is common with alcohol consumption, which is characterized by dry mouth, headache, mood disturbance, laziness, and impaired performance.
Alcohol can precipitate seizures because it reduces the seizure threshold. Chronic alcoholism and chronic alcohol intoxication can cause brain atrophy by damaging the neurons of the brain.