Definitions Flashcards
Toxicology
Science of poisons; can be defined as the science of chemical properties, their physical and chem properties, sources, toxicity, toxicokinetics, mechanisms of action, clinical signs, lesions, lab diagnosis, diagnosis, and DDx and treatment (or prevention) of dz caused by toxicants
Xenobiotics
Foreign chemicals that the body does not produce
Poison (toxicant)
Any substance (solid, liquid, gas) when applied or introduced into the body may interfere with life processes or biological functions of the cells of the animal
What are the sources of natural toxicants?
Plant
Animal
Mineral
Fungi or bacteria
What are the two sources of toxicants?
Natural
Synthetic
What is an example of a synthetic toxicant?
Organophosphate and chlorinated hydrocarbon insecticides
Organic herbicides
Give an example of each of the natural sources of toxicants.
Plant- poisonous plants
Animals- snake venom, insect stings, fish toxins
Mineral- lead, arsenic, nitrate
Fungi of bacteria- mycotoxins
Toxin (biotoxin)
A poison from a biological process
Toxic
Used to describe the deleterious or undesirable effects of poisons
Toxicosis (poisoning or intoxication)
Disease caused by exposure to a poison
Toxicity
Amount of poison that under certain circumstances will cause toxic effects
What is the toxicity expressed as in mammals? (With units)
LD 50 mg/kg BW
What is the toxicity expressed as in birds?
LC50 mg/kg Feed
What is the toxicity expressed as in fish?
LC50 in mg/L of water
Acute Toxicity
The effect of a single dose or multiple doses during a 24 hr period
Subacute toxicity
The effect produced by daily exposure from 1 day to 30 days
Subchronic toxicity
The effect of exposure from 30 days to 90 days
Chronic toxicity
The effect produced by daily exposure for a period of 3 months or more
Chronicity factor
The ratio between acute LD50 and chronic LD50
Compounds with cumulative effects have ____________ chronicity factors; compounds with non cumulative effects have ______________ chronicity factors.
High, Low
What does the chronicity factor have to be greater than to indicate cumulative toxicant?
2.0
Warfarin is a ________________ toxicant
Caffeine is a ________________ toxicant
Strychnine is a ______________ toxicant
Cumulative
Non
Non
Toxic dose
Produces a toxic effect
Highest nontoxic dose (HNTD)
The highest or largest dose which does not result in undesirable or toxic ulceration (clinical, hematologist, biochemical, or pathological alterations)
Maximum tolerated dose or minimal toxic dose (MTD)
Similar to the highest nontoxic dose- between effective dose range and toxic dose range
Toxic dose low (TDL)
The lowest dose which produces toxic alterations and administering twice this dose will not cause death
Toxic dose high (TDH)
The dose which produces toxic alterations and administering twice this dose will result in death
No effect level (maximum nontoxic level)
The amount of a chemical that can be ingested without causing any deaths, illness, or toxic alterations in any of the animals for the stated period (usually 90 days to two years or more depending on the species)
(Used for feed additives- also called HNTD)
Lethal dose
The dose that causes death in any animals during the period of observation
LD0
The highest dose that does not cause any death
LD50
The dose that kills 50% of animals in a group
LD100
The lowest dose that kills all the animals in a group
Hazard (risk)
The danger from the possibility of exposure (think about risk ratio table)
Toxicokinetics
Study of the absorption, distribution, biotransformation, and excretion or toxic agents
