1. Chapter 9 Physiology of Alcohol and Poisons
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2. Introduction—Objectives
Describe the role of a forensic toxicologist.
Discuss the legal importance of blood alcohol levels.
Explain the effects of alcohol and specific drugs and poisons on the body.
Discuss chemical agents that may be used for bioterrorism.
Describe analytical techniques for detection and identification of alcohol, poisons, and toxins in bodily fluids.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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3. Introduction—Vocabulary
depressant—a chemical that slows the heart rate and brain activity and causes drowsiness
Immunoassay—a test that relies on the antigen-antibody response
Nystagmus—involuntary jerking movement of the eyes
Poison—a chemical that can harm the body if ingested, absorbed, or breathed in sufficiently high concentrations
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

4. Introduction—Vocabulary
Tolerance—in response to prolonged, heavy intake of alcohol or other drugs, the body’s need for progressively larger amounts of a chemical to cause the same levels of intoxication
Toxin—a type of poison produced naturally by living things
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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5. Michael Jackson June 25, 2009, an accidental homicide
Homicide—a person died at the hands of another person
An overdose of medicines prescribed by Jackson’s doctor, Conrad Murray
Coroner’s determination—the interaction of anesthetics and sedatives caused Jackson to stop breathing. 5
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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6. History (Obj 9.1)
Early 1700’s—first use of chemistry to detect poisons
Early 19th century—toxicology became a new scientific discipline
France in 1840—Charles Lafarge trial involved testing for arsenic
Forensic toxicologists—study the legal and medical aspects of alcohol, drugs, poisons, and toxins in bodily fluids.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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7. Alcohol (Obj 9.2, 9.3)
In everyday speech, alcohol usually refers to the ethanol used in alcoholic beverages.
In chemistry, alcohols are a group of substances with a hydroxyl group.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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8. Alcohol All alcohols are toxic in sufficient quantities
As little as 30 mL of methanol can kill
Ethanol, ethyl alcohol, is a colorless liquid obtained from fermented grains or fruits
Initial reaction to alcohol is euphoria
Alcohol is actually a depressant
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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9. Alcohol in the Body
Alcohol diffuses through the stomach and small intestines
As alcohol concentration increases:
ability to respond to stimuli decreases
temporary euphoria results from depressing inhibitions
lose coordination and become confused
memory diminishes
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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10. Alcohol in the Body
The liver metabolizes alcohol with an enzyme called alcohol dehydrogenase (ADH)
Resulting product is acetaldehyde
More enzymes break this into CO2 and H2O
The body can metabolize 15 to 30 mL of alcohol per hour
Excess alcohol is distributed to body tissues
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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11. Stages of Intoxication
A blood alcohol concentration of 0.08 means 8 g of alcohol per 10,000 mL of blood
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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12. Stages of Intoxication
Alcohol affects different people differently
Concentration
Behavior
0.01 to 0.05
Normal behavior
0.03 to 0.12
Euphoria begins
0.09 to 0.25
Vision blurs, loss of balance, sleepiness
0.18 to 0.30
Speech slurs, dizzy, disoriented, emotional
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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13. Stages of Intoxication (cont.)
Alcohol affects different people differently
Concentration
Behavior
0.25 to 0.40
Standing and walking is difficult
0.35 to 0.50
Impaired respiratory and circulatory systems
Over 0.45
Potentially fatal
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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14. Stages of Intoxication
Factors affecting alcohol absorption
Body weight
How much alcohol is consumed
Over what time period
Amount of food in the stomach
Frequency of drinking alcohol
Body fat percentage
Medications and popular energy drinks
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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15. Stages of Intoxication
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

16. Tolerance
Metabolic tolerance—the body produces larger amounts of alcohol dehydrogenase
Functional tolerance—a person displays fewer visible symptoms of intoxication without affecting blood alcohol concentration
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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17. Field Sobriety Tests Horizontal gaze nystagmus (HGN) test
Nystagmus is the involuntary jerking of human eyes, which increases with intoxication
Divided-attention tests
Breath tests
Direct correlation between alcohol in the breath and alcohol in the blood stream
Ratio is 1:2100
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

18. Blood and Urine Tests
Toxicology labs use gas chromatography/ mass spectrometry (GC/MS)
Gas chromatography separates the sample into individual components
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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19. Poisons (Obj 9.3, 9.4) Eaten (ingested) Inhaled Injected Absorbed
90% - at home, involving children
household cleaners
Inhaled
carbon monoxide
sarin, a nerve gas
Injected
heroin
Absorbed
Poison sumac, mustard gas, ricin, anthrax
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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20. Drugs
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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21. Toxicological Testing (Obj 9.5)
Detect trace amounts of drugs in the blood, urine, and body tissues with
thin layer chromatography,
gas chromatography, and
immunoassay techniques
Confirmation is achieved using GC/MS.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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22. Toxicological Testing
Reinsch test—for heavy metal poisoning
Certain metals dipped in hydrochloric acid produce a silver-colored coating on copper
Emission spectroscopy or atomic absorption spectrophotometry—identifies the specific metal
Blood gas screenings—detects level of CO in the blood stream
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
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23. Toxicological Testing
Immunoassay—measures the level of antibodies produced in response to antigens (poisons) entering the bloodstream
EMIT—enzyme-multiplied immunoassay technique
Rapidly detects several drugs and their metabolites
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

24. Chapter Summary
Poisons are chemicals that harm the body if ingested, inhaled, or absorbed through the skin.
Forensic toxicologists investigate the legal and medical aspects of alcohol, drugs, poisons, and toxins in the body; also
testifying as expert witnesses,
collaborating with the medical examiner, and
analyzing evidence.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

25. Chapter Summary The role of forensic toxicologist also includes:
testing employees for drug use,
screening athletes for drug use, and
testing sexual assault victims for the presence of date rape drugs.
In everyday speech, alcohol usually refers to the ethanol used in alcoholic beverages.
In chemistry, alcohols are a group of substances with a hydroxyl group.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

26. Chapter Summary Alcohol is a depressant.
Initially, it causes feelings of euphoria.
When more is consumed,
motor skills become impaired,
brain function is depressed, and
the person may even lapse into a coma and die.
The liver can metabolize about 15 to 30 mL of alcohol per hour. A person becomes intoxicated when consumption exceeds that.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

27. Chapter Summary
When a driver is suspected of intoxication, several field sobriety tests are given
Presumptive tests
horizontal gaze nystagmus and
divided-attention tests
Conclusive test
breath tests can determine blood alcohol levels.
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved

28. Chapter Summary
How the poison enters the body determines its effect on the body
inhaled poisons can cause asphyxia
ingested poisons often target specific organs
Testing procedures
Chromatography techniques, mass spectrometry, and immunoassay are used to detect various poisons and drugs in urine and blood
Reinsch test detects heavy-metal poisoning
Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9
© 2012 Cengage Learning. All Rights Reserved