l8 Forensic Toxicology Flashcards
metabolism
The transformation of a chemical
in the body to another chemical to
facilitate its elimination from the
body
absorption
Passage of alcohol across the wall
of the stomach and small intestine
into the bloodstream.
oxidation
-combination of oxygen with other substances to produce new products
-takes place in liver
-enzyme alcohol dehydrogenase converts alcohol–> acetic acid then into carbon dioxide + water
-fate of 95 – 98% of absorbed alcohol
excretion
-Elimination of alcohol from the body in an unchanged state;
-normally excreted in breath and urine
-about 5%
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 across whose
walls exchange of materials
between the blood and the tissues
takes place; it receives blood from
arteries and carries it to veins.
alveoli
Small sacs in the lungs through
whose walls air and other vapors
are exchanged between the breath
and the blood.
fuel cell detector
device that uses a fuel cell sensor to detect the presence and concentration of a specific gas, most commonly alcohol in breath
anticoagulant
A substance that prevents coagulation or clotting of blood.
preservative
A substance that stops the growth of microorganisms in blood.
toxicologist
An individual charged with the
responsibility of detecting and
identifying the presence of drugs
and poisons in body fluids, tissues,
and organs.
acid
A compound capable of donating
a hydrogen ion (H+) to another
compound
base
A compound capable of accepting
a hydrogen ion (H+).
pH scale
A scale used to express the basicity
or acidity of a substance; a pH of 7
is neutral, whereas lower values are
acidic and higher values are basic.
two reasons that drugs cause thousands of deaths per year
a) administration of drugs
b) erratic/uncontrollable behavior of individuals under the influence of drugs
two responsibilities of forensic toxicologists
a) detecting and identifying the presence of drugs and poisons
b) level of impairment
Blood alcohol concentration (BAC) is proportional to..?
directly proportional to the concentration of alcohol in the brain
three steps of metabolism
absorption, distribution, elimination
how long after ingestion does alcohol appear in the blood?
within minutes
examples of factors affecting the rate of absorption of alcohol into the bloodstream
- Total time taken to consume the drink
- Alcohol content of the beverage
- The amount consumed
- Quantity and type of food present in the stomach
what is blood alcohol concentration (BAC)? what are two ways it can be measured?
-measure of the extent to which an individual may be under the
influence of alcohol
- Measuring the quantity of alcohol present in the blood system
- Measuring the alcohol content in the breath
amount of alcohol exhaled in the breath is in direct proportion to..?
blood concentration, and therefore directly proportional to the amount of alcohol in the brain
what is the current legal measure of drunk driving in the US and Canada?
blood-alcohol concentration of 0.08 percent, or 0.08 grams of alcohol per 100 milliliters of blood
what are two challenges toxicologists face in general screening?
-Dealing with very low concentrations, having been dissipated and distributed throughout the body
-Many drugs are chemically changed or are metabolized in the body to different chemical substances
