Download alcohol in the human body

ALCOHOL IN THE HUMAN BODY
The Alcolizer instrument measures the blood alcohol concentration (BAC) simply by breath analysis.
When a person consumes an alcoholic drink (beer, wine, spirits, etc.,) the liquid passes quickly from the
mouth into the stomach and, ultimately into the small intestine. However, the alcoholic fluid can only pass
from the stomach through to the small intestine when the stomach valve opens. This process is known as
gastric emptying. Alcohol, particularly in strong solution, is able to delay the opening of this valve and this
may explain the fact that a person may sometimes consume two or three straight spirits and yet show a low
BAC for some appreciable time afterwards.
It is in the upper part of the small intestine, the duodenum, that the alcohol is absorbed into the blood
stream.
As the blood flows from the duodenum it eventually passes through the liver, where a certain small
quantity of alcohol is constantly removed. This elimination process proceeds at a fixed rate, but is fairly
slow, so that only a small quantity of alcohol can be removed at any time. Eventually, however, about 90%
of the ingested alcohol will have been removed by the liver as the blood flows back through it from the
body, with the remainder being removed through urine, breath and the skin with sweat. In the liver, the
alcohol is broken down chemically to produce, eventually, carbon dioxide. This is carried by the blood and
excreted from the body via the breath from the lungs.
The concentration of alcohol for most rapid absorption is about 20% by volume, which corresponds to
scotch and water 50/50, or sherry. Because strong solutions of alcohol depress the rate of opening of the
valve connecting the stomach to the duodenum, drinks like neat sprits (typically 40% alcohol by volume)
have a slower rate of absorption. Beers, because of their low concentration (typically 4% alcohol by
volume), are also more slowly absorbed.
Carbon dioxide, as in soda water, dry ginger or champagne, hastens the passage of alcohol into the blood
and hence increases the maximum BAC.
In general, the slower the rate of absorption, the lower the maximum BAC will be, all other factors being
equal.
All the time a person is drinking, alcohol is being absorbed into the bloodstream, so that they are increasing
their BAC. Even when they have finished actual consumption, alcohol is still present in the stomach and
intestine so that the alcohol absorption phase is not actually completed until some time later. If the
intestine and stomach are empty of solid food then absorption of alcohol is unimpeded and may take only
30 minutes to reach completion after the last drink has been swallowed. However, if the stomach is
relatively full of food from a recent, or current meal, then the absorption of alcohol into the blood is slowed
and may take 90 minutes, or even longer, to reach completion.
The presence of food in the stomach will also influence the maximum BAC that can be attained after the
consumption of a certain quantity of alcohol.
If the alcohol is consumed over a long period of time, then the rate of increase in the BAC due to its
absorption may be close to the simultaneous breakdown rate in the liver. This breakdown rate is roughly
equivalent to removing the alcohol from 285mL or a single measure of spirits every hour.
Body Weight
Nearly two thirds of body weight is water. Absorbed alcohol is distributed by the blood and mixes evenly
throughout this water. The larger the body, the more water contained, and so the lower the final alcohol
concentration.
The larger the person, the lower the BAC after drinking a certain quantity of alcohol.
ALCOLIZER TECHNOLOGY
PO Box 1856 Cleveland DC
Unit 8 132-140 Ross Court
Queensland 4165 Australia
Cleveland QLD 4163 Australia
Phone 617 3821 1606  Fax 617 3821 1633  Web Site www.alcolizer.com
Deep Lung Air
A true measurement of the blood alcohol concentration can only be obtained by analysing deep lung air
since only this has been in close contact with the blood. See Fig 1. Air from the mouth and the upper parts
of the respiratory tract has not been in close contact with the blood and so is low in alcohol. In most
people, deep lung air is reached after the first 1 litre of breath has been expired.
Shallow Lung Air
Deep Lung Air
Blood in closest
contact with air at
end of the lungs
Fig. 1 Alcohol and the lungs
Mouth Alcohol
The concentration of alcohol in the mouth is much higher than would ever be present in the blood so that, if
a breath sample were analyzed soon after the subject had consumed his or her drink, the reading would be
very high due to residual alcohol remaining in the mouth. Some of this mouth alcohol would evaporate
into the expired air but this breath alcohol reading would not reflect the true blood alcohol concentration.
It is important therefore that a period of at least 15 minutes has elapsed since the subject had his or her last
drink. This fifteen minute period allows for any mouth alcohol to be dispersed, so that a valid breath
alcohol analysis can be carried out to determine the blood alcohol concentration.
It should always be remembered that, breath analysis looks to measure the representative portion of alcohol
coming from the blood and not alcohol remaining from the last drink.
Effects of Alcohol the Human Body
Alcohol is a central nervous system depressant. This means that it slows down the processes occurring in
the higher centres of the brain resulting in the classical symptoms of alcohol intoxication. These symptoms
include, among others, loss of balance, poor coordination of the eyes and limbs, tunnel vision and the
inability to make self criticism, with the result that the drunken driver genuinely believes himself to be
driving better and mores safely than he really is. The common though mistaken idea that alcohol is a
stimulant stems from the appearance and behaviour of a person under its influence. This behaviour is
caused by the depression or removal of shyness or those normal restraints imposed on the sober individual
by society or the environment.
ALCOLIZER TECHNOLOGY
PO Box 1856 Cleveland DC
Unit 8 132-140 Ross Court
Queensland 4165 Australia
Cleveland QLD 4163 Australia
Phone 617 3821 1606  Fax 617 3821 1633  Web Site www.alcolizer.com