NUFS150 - Basic Principles in Toxicology II Flashcards
(25 cards)
What are the 3 phases of drug/toxicant action?
Exposure, Toxokinetic, and Toxodynamic are the 3 phases of drug/toxicant action.
Describe: exposure phase of drug action.
Toxicant is vulnerable to environmental factors such as chemical transformation, degradation, biodegredation, and disintegration.
Describe: toxokinetic phase of drug action.
Toxicant is absorbed (through cell membrane), distributed (among tissues and organs), metabolized, and excreted by an organism.
Describe: toxodynamic of drug action.
Toxicant reacts to specific sites on/inside the cell; Toxicant produces toxic effect.
What is the crucial step for a xenobiotic to undergo the toxokinetic phase?
Absorption is needed for a xenobiotic to undergo the toxokinetic phase.
What are the 3 factors that affect xenobiotic absorption?
Route of exposure. Concentration of substance at contact. Chemical/physical properties of substance.
What are the 3 primary routes of xenobiotic exposure?
Gastrointestinal tract, respiratory tract, and skin are 3 major routes xenobiotics are absorbed.
What are the 3 primary types of specialized transport methods?
Facillitated diffusion, Active transport, and Endocytosis (phagocytosis, pinocytosis).
What are 2 factors that affect the toxicity of a compound?
2 factors that affect the toxicity of a compound are exogenous factors and endogenous factors.
Give a few examples of exogenous factors affecting toxicity.
Structure of compound, dose, frequency of exposure, route of exposure, and presence of other compounds.
Give a few examples of endogenous factors affecting toxicity.
PHYSIOLOGY and morphology of the GI TRACT, nature of INTESTINAL BACTERIA, METABOLIC ACTIVITY of the body.
Define: dose.
Dose is a quantity of a drug/medicine consumed.
What are the 2 types of biological effects occur with increasing dose?
Type I: No effect, toxic effect, fatal effect. Type II: no effect, beneficial effect, toxic effect, fatal effect (ex. Nutrition, therapeutic, nutrition+therapeutic).
What are the 4 types of doses?
Exposure, Absorbed, Administered, and Total dose.
Define: exposure dose.
Exposure dose is the amount of a xenobiotic encountered in the environment.
Define: absorbed dose.
Absorbed dose is the actual amount of exposed dose that enters the body.
Define: administered dose.
Administered dose is the quantity consumed/injected.
Define: total dose.
The sum of exposure, absorbed, and administered doses.
Describe the dose-response relationship concept.
Establishes: causality (observed effect), least amount of the dose (threshold effect), and rate at which harmfulness increases (response).
What factors effect dose-response.
Depends on the subject, group of subjects, half the population, and all of the population.
What is a lethal dose?
A lethal dose is the amount of a substance that will produce 50% mortality when administered.
How do long chain fatty acids interact with toxicants?
Long chain fatty acids react with metals, and create metallic soaps.
How do phosphates interact with toxicants?
Phosphates form insoluble salts with toxicants.
How does sugar interact with toxicants?
Sugars react with amines/amino acids, which lead to less absorption.
