FRSC1030 Foundations in Forensic Science Chapter 6

Key Terms from Chapter 6

Antibody

Protein molecule manufactured by the immune system to bind with an antigen, usually Y-shaped

Antigen

A substance that stimulates a response by the immune system when introduced into the body. Could be a protein, a lipid, a polysaccharide, or a similar compound. Can be foreign, such as a virus or bacteria, or it can originate from within the body.

Aqueous

Water-based

Blood alcohol

Also called BAC, the concentration of ethanol in the blood

Breath alcohol

Also called BrAC, the concentration of ethanol in the air being exhaled.

Central blood

A sample of the blood from the heart

Cross-reactivity

The ability of more than one drug to bind to the antibody receptor, producing a positive result on an immunoassay

Drug

A compound that causes a physiological effect in the body

Effective dose

The amount of a drug needed to produce a physiological response

First-pass metabolism

Also called the first pass effect, a phenomenon of drug metabolism at a specific location in the body which leads to a reduction in the concentration of the active drug before in reaches the site of action or systemic circulation

Gastric contents

Material found in the stomach, whose analysis may be beneficial in cases of sudden death

GI tract

A long, winding, muscular tube that includes all organs of the digestive system, responsible for digestion, absorption of nutrients, and expelling waste

Henry’s law

A gas law that states that the amount of gas that dissolves in a liquid is proportional to it's partial pressure. For BAC, this means that at a constant temperature, the concentration of alcohol vapor in the breath is proportional to the concentration of alcohol in the blood, with a blood-to-breath ratio of about 2100:1

Immunoassay

The most widely used screening test in forensic toxicology, based on the reaction between an antigen and an antibody. Relatively simple and fast, requiring minimal preparation, but targets drug families rather than specific compounds because of cross-reactivity

Immunoglobin

A large Y-shaped protein molecule produced by the immune system to identify and neutralize foreign substances, or antigens

Ingestion

The process of taking a substance into the body by swallowing, injecting, smoking or otherwise absorbing it.

Lethal dose

A dose of a drug large enough to be fatal.

Mass spectrometry

An analytical technique used to measure mass-to-charge ratio of ions in a sample, for the identification and quantification of compounds.

Mode of ingestion

Also called mode of administration, how a substance gets into the body

Opiates

Drugs derived from opium plants, such as morphine, heroin, codeine, and other substances

Opioid

Synthetic opiates, including oxycodone, hydrocodone, hydromorphone, fentanyl, carfentanil, and other drugs

Peripheral blood

A sample of the blood from a peripheral site away from the heart, such as the femoral vein in the leg

Poison

A substance that, when ingested, results in a toxic or damaging physiological effect or effects

Post-mortem toxicology

The analyssi of biological samples from a deceased person to detect and quantify drugs, alcohol, and poisons, helping to determine the cause and manner of death

Post-mortem redistribution

Also called PMR, the process where drug concentrations in the blood change after death due to movement from organs and tissues into the bloodstream

Therapeutic dose

The dose of a substance that provides the desired level of therapy or relief.

Toxin

Any substance that results in a toxic or damaging physiological effect in the body, such as drugs or poisons

Vitreous humor

Gelatinous fluid in the eyeball that resists putrefaction and preserves concentrations of drugs, toxins, or metabolites longer that blood and urine, because it is relatively isolated from general circulation

Xenobiotic

The label given to substances that are foreign to the body