Lecture 1 Flashcards Preview

Toxicology > Lecture 1 > Flashcards

Flashcards in Lecture 1 Deck (43)
Loading flashcards...
0

father of toxicology

Paracelsus
"all substances are poisons. the right dose differentiates poison from remedy."

1

give examples of manmade chemicals and natural products

manmade chemicals = pesticides, cleaning products, pharmaceuticals, industrial chemicals, etc.

natural products = vitamins, minerals, animal venoms

2

toxic =

poisonous

3

toxicology is concerned with

identifications, treatment, and assessing risks of poisons

4

toxicant =

compound that causes toxicity

5

xenobiotic =

foreign substance

6

what are the 4 factors that influence toxicity

toxicant, exposure, subject, environment

7

what are examples of factors related to toxicant

chemical and biological properties - mechanism of action, potency, size, charge, etc.

8

examples of factors related to exposure

dose, concentration, route, duration, etc

9

examples of factors related to subject

breed, species, age, etc

10

examples of factors related to the environment

temperature, bioavailability

11

what are the 3 classifications of chemical interactions in toxicity

additive - 2 + 2 = 4 most chemicals act this way
antagonistic - some chemicals block toxicosis
synergism - very rare when 2 + 2 = 6. chemicals have greater effect when together

12

No Observable Adverse Effect Level (NOAEL):

the maximum dose that causes no adverse effect

13

Lowest Observable Adverse Effect Level (LOAEL):

the minimum dose that can cause an adverse effect

14

threshold dose

minimum dose to produce reaction; indicates there is a "safe" dose

15

LD50 =

dose producing death in 50% of animals

16

exposure classifications:

acute
sub-acute/sub-chronic: exposure over 7 to 90 days
chronic: prolonged exposure (6 months to lifetime)

17

definition of ADME

study of the movement and disposition of the toxicant in the organism

18

what does ADME stand for

adsorption - uptake of material
distribution - from blood to tissues
metabolism - enzymatic conversion
excretion - elimination from body

19

in what 3 discussed ways can chemcials be absorbed into the body?

lungs
gut
dermis

20

the most important toxicants are absorbed by what 2 routes?

skin and GI (oral and dermal)

21

list routes of absorption from fastest to slowest

IV --> pulmonary --> IM --> intraperitoneal --> oral --> cutaneous

22

what is the central medium of distribution of chemicals that targets organs?

blood

23

what makes a certain tissue susceptible to particular chemicals?

electric charge, transporters, co-transporters, etc.

24

definition of biotransformation

biological conversion of a chemical compound (exogenous or endogenous) into a second compound or metabolite

25

what is the primary biochemical pathway of xenobiotic metabolism?

biotransformation

26

what requires enzyme catalysts?

biotransformation

27

enzyme catalysts are divided into what 2 groups?

phase 1 and phase 2 reactions

28

what are the two main sites of biotransformation reactions?

liver and kidney

29

why are the liver and kidney the most common sites of biotransformation reactions?

1. highest enzymatic concentration
2. highest blood flow