Transcript Chapter 6 - Madison Public Schools

Chapter 6
Forensic Toxicology
The Role of Forensic Toxicology
What does a forensic toxicologist do?
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detect and identify drugs and poisons in body
fluids, tissues, and organs
What types of cases are investigated by forensic
toxicologists?
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drug-related deaths
Accidental poisonings
Suicidal poisonings
Homicidal poisonings
Toxicology of Alcohol
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knowing how the body metabolizes
alcohol allows one to understand its
effects and detect its presence
Metabolism-the transformation of
substances in the body in order to
facilitate elimination from the body.
Metabolism of Alcohol
3 Basic Steps:
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Absorption-alcohol is absorbed into the blood
stream from the walls of the stomach and small
intestine
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Distribution- alcohol becomes distributed
uniformly throughout the body’s fluids.
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Elimination- occurs by oxidation and
excretion
Factors that Affect Absorption
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Alcohol content of
beverage
Amount consumed
Rate of
consumption
Quantity and type
of food in the
stomach
90
80
70
60
50
East
West
North
40
30
20
10
0
1st 2nd 3rd 4th
Qtr Qtr Qtr Qtr
Elimination
Alcohol is eliminated from the body by:
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Oxidation- alcohol is converted to carbon
dioxide and water; process starts in the
liver; 95-98 % of alcohol is oxidized
Excretion- The remaining alcohol is
released in breath, urine, and perspiration
Blood Alcohol Concentration
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Amount of alcohol exhaled is directly
proportional to the amount of alcohol in
the blood
Blood alcohol concentration is directly
proportional to the alcohol content in the
brain
Circulation Definitions
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Artery—a blood vessel that carries blood
away from the heart
Vein—a blood vessel that transports blood
toward the heart
Capillary—a tiny blood vessel—walls
exchange materials between blood and
tissues
Alveoli—small sacs in lungs—exchange
vapors between breath and blood
Circulation
Circulation