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Unformatted text preview: Ethanol
(Alcohol) Made by : ghadeer naama
Dr. Ali Shottar Alcohol and forensic medicine Alcohol assumes an importance in
clinical forensic medicine because of its
link with criminal activity.
link Traffic accidents, suicide, and rape are
suicide and rape
correlated with the concurrent use of
alcohol. Child physical and sexual abuse,
spouse abuse, and elder abuse are also
associated with alcohol use.
Ethanol Overview. Kinetics and Dynamics. Effects on different body organs. Clinical features of ethanol intake. Ethanol
Ethanol Ethanol, also known as ethyl alcohol, drinking
alcohol or grain alcohol.
alcohol It is produced by the enzymatic action of yeast
on carbohydrate in the absence of oxygen
(fermentation). It is a flammable, toxic chemical compound
with a distinctive odor which has been used by
human since prehistoric times.
human Its molecular formula is C2H5OH.
Its It is found in alcoholic beverages. Alcohol concentration of
some Beer, lager ,stout
Beer, Cider (variable)
Cider Table wines (unfortified)
Table Fortified wines (sherry, port, vermouth)
Spirits (brandy, gin, whisky, rum, vodka)
15-55% Measurement of alcohol concentration in units
Measurement 1 unit of alcohol = 10g pure ethanol.
= 12.78 ml pure ethanol
12.78 1 unit of alcohol = 300ml of beer, 100ml
of table wine, 25ml of spirits.
* Safe limits for drinking to avoid liver
damage: 21 units/week for men. 14 units/week for women. Spectrum of alcohol
2. Social drinkers
Drink socially, < 4 units per day
3. Heavy drinkers
Regularly and heavily
Men >7 units per day
Women>5 units per day
4. Binge drinkers
Irregularly and heavily
Irregularly 5. Alcohol abuser
Physical , psychological and social problems
Dependence criteria are not met
6. Dependent( addicted) drinker
Subjective awareness of compulsion to drink
Drink seeking behavior
Tolerant to alcohol
Physical , psychological and social problems Alcohol kinetics Ethanol is a small molecule that is easily
miscible with the whole of the aqueous
compartment of the body.
compartment This excludes adipose tissues as ethanol is
almost insoluble in fat. This fact has an
important practical significance, as people with
large fat stores will produce a higher bloodlarge
alcohol level for a given intake of alcohol than
persons of the same weight who are lean as
the aqueous compartment is smaller.
the Alcohol readily passes the blood-brain barrier. Absorption of Alcohol Absorption is by passive diffusion. Can happen in any part of the
gastrointestinal Mostly in stomach (20%) and upper small
intestine Peak concentration is reached 30-60
minutes after ingestion. the duodenum and jejunum – has the
maximum capacity for absorption,
compared with the gastric mucosa. Accordingly, any condition that delivers
alcohol into the small intestine more
quickly than normal will lead to more
rapid absorption. Factors increasing
absorption Empty stomach, as fluid passes
through the pylorus with almost no
Gastrectomy (alcohol go faster to the
small intestine where higher absorption
10-20% concentration of alcohol.
Optimum for rapid absorption. Factors decreasing
absorption Food in the stomach (especially fatty
food which delay the emptying of the
stomach and dilutes alcohol
High concentration of alcohol (higher
concentration than 20% will irritate the
stomach and increase mucous
secretion). Distribution Distributed through portal blood stream
to all tissues
to Equilibrium between the blood and
tissues is reached 1-2 hours after
ingestion Factors that affect blood alcohol concentration
(BAC): absorption Body fat content. The higher the fat content, the
higher the BAC.
higher Duration of drinking. If the volume of alcohol is
consumed over a prolonged period, it may be
eliminated almost as quickly as it is absorbed,
giving rise to a much lower peak alcohol
**1 unit of alcohol will elevate BAC within the 1st
hour by 15mg/100ml in men and 20mg/100ml in
women. Measurement of absorbed alcohol:
Measurement In blood: it is the most useful measurement, but
depends on several factors like gender, drinking
history, amount and nature of the meal and the timing,
so it’s not very accurate.
so In urine: it is more concentrated than blood. Ratio 4:3 In breath: small concentration 1:2300 to that of blood.
At 37 C 1mg/100ml in blood = 0.43 µg/100ml in breath.
Blood/breath ratio depends on the temperature,
concentration of alcohol and depth of respiration.
concentration Elimination Almost all alcohol is detoxified by the liver, only
2-10% being excreted unchanged by kidneys,
lungs, sweat, salivary and mammary glands.
lungs, Alcohol( by alcohol dehydrogenase)
acetaldehyde Acetaldehyde (by acetaldehyde
dehydrogenase) acetic acid acetic acid( by Krebs cycle)CO2 and water. Elimination can vary from 12 to 27
mg/100ml/hour. Taking the mean of 18mg
mg/100ml/hour. In chronic alcoholics the rate may reach
40 Effects of ethanol on different
Brain Direct effect. It easily passes BBB. Reduces activity
of neural cells in a similar way to hypoxia.
of In lower conc. -> action on upper cerebral cortex. In higher conc. -> action on lower cerebral level
(midbrain/medulla), leading to cardiovascular failure
and heat regulation failure.
and Indirect effect. malnutrition. Accidents and head trauma. ...
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- Fall '11