14 - Ethanol Part1

14 - Ethanol Part1 - Ethanol Ethanol (Alcohol) (Alcohol)...

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Unformatted text preview: Ethanol Ethanol (Alcohol) (Alcohol) Made by : ghadeer naama Dr. Ali Shottar Alcohol and forensic medicine Alcohol assumes an importance in Alcohol 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. alcohol. Child physical and sexual abuse, sexual spouse abuse, and elder abuse are also associated with alcohol use. associated Ethanol Ethanol Overview. Kinetics and Dynamics. Effects on different body organs. Clinical features of ethanol intake. Ethanol Ethanol Ethanol, also known as ethyl alcohol, drinking Ethanol, alcohol or grain alcohol. alcohol It is produced by the enzymatic action of yeast It on carbohydrate in the absence of oxygen (fermentation). (fermentation). It is a flammable, toxic chemical compound It 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 drinks some Beer, lager ,stout Beer, Cider (variable) Cider Table wines (unfortified) Table Fortified wines (sherry, port, vermouth) Spirits (brandy, gin, whisky, rum, vodka) Liqueurs (variable) Liqueurs 2.5-4% 2.5-4% 3-5% 3-5% 9-12% 9-12% 18-20% 18-20% 37-42% 37-42% 15-55% 15-55% Measurement of alcohol concentration in units Measurement 1 unit of alcohol = 10g pure ethanol. unit = 12.78 ml pure ethanol 12.78 1 unit of alcohol = 300ml of beer, 100ml unit of table wine, 25ml of spirits. of * Safe limits for drinking to avoid liver damage: damage: 21 units/week for men. 14 units/week for women. Spectrum of alcohol use/abuse: use/abuse: 1. Non-drinkers 2. Social drinkers Drink socially, < 4 units per day Drink 3. Heavy drinkers Regularly and heavily Regularly Men >7 units per day Men Women>5 units per day 4. Binge drinkers 4. Irregularly and heavily Irregularly 5. Alcohol abuser 5. Physical , psychological and social problems Physical Dependence criteria are not met Dependence 6. Dependent( addicted) drinker Subjective awareness of compulsion to drink Subjective Drink seeking behavior Drink Tolerant to alcohol Tolerant Physical , psychological and social problems Alcohol kinetics Ethanol is a small molecule that is easily Ethanol miscible with the whole of the aqueous compartment of the body. compartment This excludes adipose tissues as ethanol is This 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 alcohol 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 tract. gastrointestinal Mostly in stomach (20%) and upper small Mostly intestine (80%). intestine Peak concentration is reached 30-60 Peak minutes after ingestion. the duodenum and jejunum – has the maximum capacity for absorption, compared with the gastric mucosa. Accordingly, any condition that delivers Accordingly, alcohol into the small intestine more quickly than normal will lead to more rapid absorption. Factors increasing absorption Empty stomach, as fluid passes Empty through the pylorus with almost no dealy. dealy. Gastrectomy (alcohol go faster to the Gastrectomy small intestine where higher absorption happens). happens). 10-20% concentration of alcohol. 10-20% Optimum for rapid absorption. Factors decreasing absorption Food in the stomach (especially fatty Food food which delay the emptying of the stomach and dilutes alcohol concentration). concentration). High concentration of alcohol (higher High concentration than 20% will irritate the stomach and increase mucous secretion). secretion). Distribution Distributed through portal blood stream Distributed to all tissues to Equilibrium between the blood and Equilibrium 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 Body higher the BAC. higher Duration of drinking. If the volume of alcohol is Duration consumed over a prolonged period, it may be eliminated almost as quickly as it is absorbed, giving rise to a much lower peak alcohol concentration. **1 unit of alcohol will elevate BAC within the 1st hour by 15mg/100ml in men and 20mg/100ml in women. women. Measurement of absorbed alcohol: Measurement In blood: it is the most useful measurement, but In 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. At 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 Almost 2-10% being excreted unchanged by kidneys, lungs, sweat, salivary and mammary glands. lungs, Alcohol( by alcohol dehydrogenase) Alcohol( acetaldehyde Acetaldehyde (by acetaldehyde Acetaldehyde dehydrogenase) acetic acid acetic acid( by Krebs cycle)CO2 and water. Elimination can vary from 12 to 27 Elimination mg/100ml/hour. Taking the mean of 18mg mg/100ml/hour. In chronic alcoholics the rate may reach In 40 mg/100ml/hour. 40 Effects of ethanol on different body organs body Brain 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 In (midbrain/medulla), leading to cardiovascular failure and heat regulation failure. and Indirect effect. malnutrition. Accidents and head trauma. ...
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