Principles of Toxicology Flashcards
the study of adverse effects of chemical or physical agents on living organisms
toxicology
trained to examine and communicate the nature of those effects on human, animal, and environmental health
toxicologist
the quantitative estimate of the potential effects on human health an environmental significance of various types of chemical exposures
risk assessment
fundamental issue of toxicology
linking dose or exposure to response and effects
three main categories of toxicology
mechanistic
descriptive
regulatory
concerned with identifying and understanding the cellular, biochemical, and molecular mechanisms by which chemicals exert toxic effects on living organisms
mechanistic toxicologist
concerned directly with toxicity testing, which provides information for safety evaluation and regulatory requirements
descriptive toxicologist
what does REACH stand for
Registration
Evaluation
Authorisation
restriction of CHemicals
the responsibility for deciding on the basis of data provided by descriptive and mechanistic toxicologists, whether a drug or other chemical poses a sufficiently low risk to be marketed for a stated purpose or subsequent human or environmental exposure resulting from its use
regulatory toxicologist
responsible for allowing drugs, cosmetics, and food additives to be sold in the market
Food and Drug administration
responsible for regulating most other chemicals according to a variety of different legislative acts
US environmental Protection Agency
established to ensure that safe and healthful conditions exist in the workplace
Occupational Safety and Health Administration
ensures that materials shipped in interstate commerce are labeled and packaged in a manner consistent with the degree of hazard they present
Department of Transportation
a hybrid of analytic chemistry and fundamental toxicological principles that is concerned primarily with the medicolegal aspects of the harmful effects of chemicals on humans and animals
forensic toxicology
designates an area of professional emphasis in the realm of medical science that is concerned with disease caused by or uniquely associated with toxic substances
clinical toxicology
focuses on the impacts of chemical pollutants in the environment on biologicals organisms that are mostly non human
environmental toxicology
generally refers to toxic substances that are produced by biological systems such as plants, animals, fungi, and bacteria
toxin
used in speaking of toxic substances that are produced by or are a by-product of anthropogenic activities
toxicant
four general classifications of toxic agents
organ specific
use
source
effects
immunologically mediated adverse reaction to a chemical resulting from previous sensitization to that chemical or to a structurally similar one
chemical allergy
used to describe this allergic state
hypersensitivity
situation when preexposure of the chemical is required to produce toxic effects
allergic reaction
refers to a genetically determined abnormal reactivity to a chemical
chemical idiosyncrasy
defined as those that occur or develop rapidly after a single administration of a substance
immediate toxic effect
occur after a lapse of some time after administration of a substance
delayed toxic effect
toxic to all cells in the body
systemic effects
specific organs
local effects
effects occurs when the combined effect of two chemicals is equal to the sum of the effects of each agent given alone
additive effects
occurs when the combined effects of two chemicals are much greater than the sum of the effects of each agent given along
synergistic effects
occurs when one substance does not have a toxic effect on a certain organ or system but when added to another chemical makes that chemical much more toxic
Potentiation
when two chemicals administered together interfere with each other’s actions or one interferes with the action of the other
antagonism
occurs when two chemicals counterbalance each other by producing opposite effects on the same physiological function
functional antagonism
a chemical reaction between two compounds that produces a less toxic product
chemical antagonism or inactivation
occur when the absorption, distribution, biotransformation, or excretion of a chemical - is altered so hat the concentration and /or duration of the chemical at the target organ are diminished
Dispositional antagonism
occurs when two chemicals that bind to the same receptor produce less of an effect when given together than the addition of their separate effects or when one chemical antagonizes the effects of the second chemical
receptor antagonism
receptor antagonism is also termed
blockers
a state of decreased responsiveness to a toxic effect of a chemical resulting from prior exposure to that chemical or to a structurally related chemical
tolerance
due to decreased amount of toxicant reaching the site where the toxic effect is produced
dispositional tolerance
What are the basic rules of toxicity
- reach target site
- in a high enough concentration
- for a long enough time
what are the major routes by which toxic agents gain access to the body
gastrointestinal tract
lungs
skin
directly through injection to bloodstream
the material in which the chemical is dissolved
vehicle
exposure to a chemical for less than 24 hours
acute exposure
repeated exposure to a chemical for one month or less
subacute exposure
repeated exposure to a chemical for one to three months
subchronic exposure
repeated exposure to a chemical for more than three months
chronic exposure
