Introduction to Toxicology
, TOXICOLOGY-Definition
Traditional definition
“The branch of science that deals with study of poisons"
Descriptive definition
“The study of the adverse effects of chemicals or physical
agents(toxicants) on living organisms“
Broader definition of toxicology
“The study of the detection, occurrence, properties,
effects, and regulation of toxic substances”
, BASIC TERMINOLOGIES
Xenobiotic is the general term that is used for a
foreign substance taken into the body.
It is derived from the Greek term xeno which means
"foreigner."
Xenobiotics may produce beneficial effects (such as a
pharmaceuticals) or they may be toxic (such as lead).
A xenobiotic in small amounts may be non-toxic and even
beneficial but when the dose is increased, toxic and
lethal effects may result.
, BASIC TERMINOLOGIES cont’d
Toxicants -Substances that produces adverse biological effects of
any nature
-May be chemical or physical in nature
-Effects may be various types (acute, chronic etc.)
Toxin -Specific proteins produced by living organisms (mushroom
toxins or tetanus toxins)
-Most exhibit immediate effects
Poisons -Toxicants that cause immediate death or illness when
experienced in very small amounts
-any substance that causes a harmful effect when
administered, either by accident or design, to a
living organism
, TOXICOLOGY-Definition
Traditional definition
“The branch of science that deals with study of poisons"
Descriptive definition
“The study of the adverse effects of chemicals or physical
agents(toxicants) on living organisms“
Broader definition of toxicology
“The study of the detection, occurrence, properties,
effects, and regulation of toxic substances”
, BASIC TERMINOLOGIES
Xenobiotic is the general term that is used for a
foreign substance taken into the body.
It is derived from the Greek term xeno which means
"foreigner."
Xenobiotics may produce beneficial effects (such as a
pharmaceuticals) or they may be toxic (such as lead).
A xenobiotic in small amounts may be non-toxic and even
beneficial but when the dose is increased, toxic and
lethal effects may result.
, BASIC TERMINOLOGIES cont’d
Toxicants -Substances that produces adverse biological effects of
any nature
-May be chemical or physical in nature
-Effects may be various types (acute, chronic etc.)
Toxin -Specific proteins produced by living organisms (mushroom
toxins or tetanus toxins)
-Most exhibit immediate effects
Poisons -Toxicants that cause immediate death or illness when
experienced in very small amounts
-any substance that causes a harmful effect when
administered, either by accident or design, to a
living organism
