Central nervous system depressant
Drinkers often perceive alcohol to be stimulating.
This perception, which usually occurs at lower levels of alcohol intake, results from a depression of inhibitory control mechanisms in the brain.
Alcohol is classified as a general anesthetic, which produces a range of central nervous system (CNS) effects similar to those of other sedative/hypnotic drugs.
First it destroys the integrating control of the brain which may cause thought processes to become disorganized and chaotic. The drinker may become confused and disoriented. In addition motor functions may become less fluid.
Alcohol is absorbed from the stomach and small intestine by diffusion.
Most absorption occurs from the small intestine due to its large surface area and rich blood supply.
The rate of absorption varies with the emptying time of the stomach.
The higher the alcohol concentration of the beverage, the faster the rate of absorption. Above a certain concentration, the rate of absorption may decrease due to the delayed passage of alcohol from the stomach into the small intestine.
The maximum absorption rate is obtained with the consumption of an alcoholic beverage containing approximately 20-25% (by volume or v/v) alcohol solution on an empty stomach.
The absorption rate may be less when alcohol is consumed with food or when a 40% (v/v) alcohol solution is consumed on an empty stomach.
The rate may also slow down when high fluid volume/low alcohol content beverages, such as beer, are consumed.
Elimination of alcohol
Alcohol is eliminated from the body by excretion and metabolism.
Most alcohol is metabolized, or burned, in a manner similar to food, yielding carbon dioxide and water.
A small portion of alcohol is excreted, such as through the breath, leaving the body as alcohol, unchanged.
It is this latter process that allows for breath alcohol testing.
Average rate of elimination
Elimination occurs at a constant rate for a given individual.
The median rate of decrease in BAC is considered to be 15 milligrams percent (mg %) per hour.
The range of decrease in BAC is 10-20 mg% per hour.
This range represents the extreme ends of the rate encountered in a normal population.
Most people eliminate at a rate of between 13 and 18 mg% per hour.
The majority eliminates at the higher end.
Very few people eliminate at as low a rate as 10 mg% per hour.
Time consumption began
Time consumption ceased
Approximate time at which each drink was consumed
— Evenly spaced
— More drinks at the beginning
–more at the end of the drinking time interval)
Meals eaten (times and description).
Each drink should be identified by beverage size and alcohol content.
Container type (cans, bottles, draft glasses etc.)
Whether it was light, regular or extra-strength.
Wine glasses should be described by beverage volume.
Liquor, liqueurs and shooters
Alcohol content whenever possible.
Shooters with multiple ingredients should be identified according to the components used to formulate the mixture and the proportions used.
Drug Affect on synapse and physiological effects
- Vision: (visual acuity, depth perception; peripheral vision; and glare recovery)
- Reaction time: simple, choice and complex reaction times
- Tracking tasks: compensatory and pursuit tracking
- Cognitive functions: concentrated attention; divided attention; rates of information processing; judgments; and decision-making.
- Psychomotor skills: coordination; body sway; manual dexterity; and general walking
- Driving simulators and closed course driving experiments: braking and stopping efficiency; steering; lane position; evasive maneuvers; parking; and emergency response
- Other aspects: memory; risk-taking; overcompensation
- Epidemiological studies: increased risk of accident with increasing BACs
Drinking profoundly alters mood, arousal, behavior, and neuropsychological functioning.
Studies have found that the specific effects depend not just on how much someone drinks, but also on whether blood alcohol content (BAC) is rising or falling.
While in the process of drinking, alcohol acts as a stimulant
As drinking tapers off it begins to act more as a sedative.
As BAC ascends, drinkers report increases in elation, excitement and extroversion, with simultaneous decreases in fatigue, restlessness, depression and tension.
A descending BAC corresponds to a decrease in vigor and an increase in fatigue, relaxation, confusion, and depression.
Researchers found that drinking increases levels of norepinephrine, the neurotransmitter responsible for arousal, which would account for heightened excitement when someone begins drinking.
The regions of the brain with the greatest decrease in activity were the prefrontal cortex and the temporal cortex.
Decreased activity in the prefrontal cortex, the region responsible for decision making and rational thought. Explains why alcohol causes us to act without thinking.
The prefrontal cortex also plays a role in preventing aggressive behavior, so this might help explain the relationship between alcohol and violence.
The temporal cortex houses the hippocampus, the brain region responsible for forming new memories.
Reduced activity in the hippocampus might account for why people black out when drinking.
Alcohol also decreases energy consumption in the cerebellum
A brain structure that coordinates motor activity.
With a cerebellum running at half-speed, it would be hard to walk a straight line or operate heavy machinery
Six Stages of Alcohol Intoxication
Brighter color in the face
Fine motor skills are lacking
Senses are dulled
Beginnings of erratic behavior
Slow reaction time
Pain is dulled
Low body temperature
Death as a result of respiratory arrest
Cannot stand or walk
Unconsciousness is possible
Decreased response to stimuli