What is toxicology?
The science and study of the adverse effects of chemicals on living organisms
What is the general approach to major toxicants?
Source of exposure, susceptible species, toxicity/risk, ADME and mechanism of action, clinical and anatomical pathology, clinical signs, tentative or definitive diagnosis, and treatment
What is a poison?
Any substance, whether solid, liquid, gas or energy emitting that, when introduced into or applied to a living entity, can by its inherent chemical and physical properties interfere with normal physiological function.
What is a toxin?
Toxicant (poison) that originate from biological processes
What is a xenobiotic?
Any substance, harmful or not, that is foreign to the body
What is toxicity?
The relative potency of a toxicant or can refer to the outcome of exposure
What is toxicosis?
A pathologic condition that results from exposure to a toxicant
What is a hazard?
Intrinsic capability of a substance to cause harm
What is a risk?
Likelihood of poisoning occurring under specified conditions of usage
How can you classify a toxic substance?
By target organ, intended use, source, effect, chemical composition, mechanism of action, type of toxic response or toxicity
What is a threshold dose?
Minimally effective dose that evokes a stated all or none response, above which effects can be detected
What is a graded response?
The toxic effects become more severe as the dose increases
What is a quantal response?
An all or none response
When is the dose-response relationship used?
In risk assessment to establish quantitative estimates of the potential health and environmental significance of various types of chemical exposures
What are the two types of dose-response relationships?
Individual or graded (dose related increase in the severity of the response) and quantal (distribution of responses in a population to different doses, used to define susceptibility and resistance due to biological variation)
A measurable biological effect is proportional to the amount of ___________
Xenobiotic received
The response is due to ______
The chemical administered
The magnitude of the response is related to ________
The dose
What is NOEL?
No observed effect level (highest dose at which no significant adverse effect found)
What is LOEL?
Lowest observed effect level (lowest dose at which a significant adverse effect found)
What is NOAEL?
No observable adverse effect level
