Forensics Chapter 6 Flashcards

Questions and Answers

Who is the father of forensic toxicology?

Mathieu Orfila

What is the difference between a toxicologist and a forensic toxicologist?

A toxicologist's job is to detect drugs and poisons in the body while a forensic toxicologist does the same thing while also relating it back to criminal law.

What is the primary duty of a forensic toxicologist?

To detect and identify drugs and poisons in body fluids, tissues, and organs in the body in violation of criminal law.

What is the most widely abused drug in Western countries?

Alcohol Signup and view all the answers

What are the requirements of a suitable test for alcohol intoxication?

Provide a reliable diagnosis that can be supported in the legal system and also be designed to test hundreds of people safely. Signup and view all the answers

List three factors that determine the rate at which alcohol is absorbed in the bloodstream.

<ol> <li>The time it takes to consume a drink 2. Alcohol content in the drink 3. Amount of the alcohol consumed</li> </ol> Signup and view all the answers

Name the process by which most alcohol is eliminated from the body.

Oxidation Signup and view all the answers

What are the 2 products from the reaction in oxidation?

Carbon dioxide and water Signup and view all the answers

What is the key to the accuracy of a breath tester?

Ensure to capture alcohol in alveolar breath. Signup and view all the answers

Describe 2 steps the operator takes to ensure that alveolar breath is captured.

<ol> <li>Avoid measuring mouth alcohol 2. Make sure suspect blows for at least 6 seconds</li> </ol> Signup and view all the answers

What is a divided attention task?

Tests the subject's ability to comprehend and execute 2 or more simple instructions at 1 time. Signup and view all the answers

What does the walk and turn task require?

Requires the suspect to maintain balance while standing heel to toe and listen to instructions. Signup and view all the answers

What does the one leg stand task require?

Suspect must maintain balance while standing with heels together and listen to instructions. Signup and view all the answers

What is horizontal-gaze nystagmus?

Involuntary jerk of the eye as it moves to the side. Signup and view all the answers

List 2 significant challenges a forensic toxicologist faces when attempting to identify drugs present in a body.

<ol> <li>Few substances enter and leave the body in the same chemical state 2. Not dealing with full concentration of drugs in the specimens</li> </ol> Signup and view all the answers

What bodily fluids should be collected from any suspected drug user?

Blood and urine Signup and view all the answers

What 3 drugs account for 90% or more of the drugs encountered in a typical toxicology lab?

Alcohol, marijuana, cocaine Signup and view all the answers

What are acids?

Compound donates H+ Signup and view all the answers

What are bases?

Compound accepts H+ Signup and view all the answers

Which drugs are classified as acids?

Barbiturates Signup and view all the answers

Which drugs are classified as bases?

PCP, methadone, amphetamines, cocaine Signup and view all the answers

How is the remaining alcohol eliminated from the body?

Excretion; It is proportional to concentration in blood. Signup and view all the answers

Why is a blood test for alcohol taken shortly after drinking more advantageous for the suspect?

The alcohol hasn't settled into their blood yet. Signup and view all the answers

What 2 substances are typically added to blood before it is sent to a toxicology lab?

Anticoagulant (substance that prevents coagulation) and preservatives (stops growth of microorganisms). Signup and view all the answers

Why is it best to collect blood samples from different body sites for postmortem blood-alcohol determination?

Bacteria can add to the rate of alcohol in the body. Signup and view all the answers

At what blood-alcohol level is a typical driver in the US considered legally intoxicated?

.08 Signup and view all the answers

At what blood level is a commercial truck or bus driver in the US considered legally intoxicated?

.04 Signup and view all the answers

At what blood level is one legally intoxicated in Sweden?

.02 Signup and view all the answers

At what blood level is one legally intoxicated in France?

.05 Signup and view all the answers

Study Notes

Forensic Toxicology Overview

Father of forensic toxicology is Mathieu Orfila.
Toxicologists detect substances in the body; forensic toxicologists also relate findings to criminal law.
Primary duty of a forensic toxicologist is to identify drugs and poisons in biological samples related to criminal violations.

Alcohol Abuse and Testing

Alcohol is the most widely abused drug in Western countries.
Suitable alcohol intoxication tests must provide reliable legal evidence and safely assess many individuals.

Factors Influencing Alcohol Absorption

Rate of alcohol absorption is influenced by:
- Time taken to consume the drink.
- Alcohol content of the beverage.
- Quantity of alcohol consumed.

Alcohol Elimination Process

Most alcohol is eliminated through oxidation, producing carbon dioxide and water.
Breath tester accuracy relies on capturing alcohol from alveolar breath.

Breath Testing Procedures

To ensure accuracy in breath testing:
- Avoid measuring mouth alcohol.
- Ensure the suspect exhales for at least 6 seconds.

Divided Attention Tasks

Divided attention tasks assess the ability to follow multiple simple instructions simultaneously.
"Walk and turn" requires balancing while listening to instructions.
"One leg stand" involves balancing with heels together while following instructions.

Blood Alcohol Concentration

Horizontal-gaze nystagmus indicates blood alcohol levels; a BAC of 0.10 results in an eye jerk before moving 45 degrees.

Challenges in Toxicology

Forensic toxicologists face challenges such as:
- Few substances retain the same chemical state during bodily processes.
- Specimens may not contain full drug concentrations.

Drug Testing Procedures

Blood and urine are key bodily fluids to collect from suspected drug users.
Alcohol, marijuana, and cocaine account for over 90% of substances in toxicology labs.

Acid and Base Concepts

Acids donate H+ ions; bases accept H+ ions.
Barbiturates are categorized as acids, while PCP, methadone, amphetamines, and cocaine are categorized as bases.

Alcohol Testing and Elimination

Remaining alcohol is eliminated via excretion, correlating with blood concentration.
Taking blood tests shortly after drinking is more advantageous than testing after a delay due to the settling of alcohol in the bloodstream.

Blood Sample Collection for Toxicology

Anticoagulants and preservatives are added to blood samples to prevent clotting and microbial growth, respectively.
Collecting blood from different body sites is critical for accurate postmortem alcohol determination to account for bacterial effects.

Legal Intoxication Levels

Legal intoxication levels vary:
- US standard for typical drivers is 0.08 BAC.
- Commercial drivers are considered intoxicated at 0.04 BAC.
- Sweden's legal limit is 0.02 BAC; France’s is 0.05 BAC.

Metabolism Impacts

Metabolism complicates the interpretation of alcohol testing results.

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Test your knowledge on forensic toxicology with these flashcards from Chapter 6. Learn about key figures, roles, and differences in the field. Perfect for students and professionals alike!