introduction

Question 1

Toxicology

Answer 1

The study of the adverse effects of chemicals on
living organisms.

Question 2

Poison

Answer 2

Any agent capable of producing a deleterious
(harmful) response in a biological system,
seriously injuring function or producing death.

Question 3

Toxin

Answer 3

Toxic substances that are produced by biological
systems such as plants, animals, fungi or bacteria.

Question 4

Toxicant

Answer 4

Toxic substances that are produced by or are a by-
product of human activities.

Question 5

Xenobiotic

Answer 5

Any foreign substance not found normally in the
body

Question 6

Mechanistic

Answer 6

identifies the cellular, biochemical and molecular mechanisms by which chemicals exert toxic effects on living organisms

Question 7

Descriptive

Answer 7

concerned directly with toxicity testing, which provides information for safety evaluation and regulatory requirements.

Question 8

Regulatory

Answer 8

determines from available data whether a chemical poses a
sufficiently low risk to be marketed or a stated purpose and establishes standards or the amount of chemicals permitted in ambient air, industrial atmospheres, and drinking water

Question 9

Forensic

Answer 9

is a hybrid of analytic chemistry and fundamental toxicological
principles that focuses primarily on the medicolegal aspects (medical +legal) of the harmful effects of chemicals on humans and animals

Question 10

Clinical

Answer 10

is concerned with disease caused by or uniquely associated with toxic substances.

Question 11

Environmental

Answer 11

focuses on the impacts of chemical pollutants in the environment on biological organisms, specifically studying the impacts of chemicals on nonhuman organisms (fish, birds, terrestrial animals, plants)

Question 12

Developmental

Answer 12

study of adverse effects on the developing organism that may
result from exposure to chemical or physical agents before
conception (either parent), during prenatal development, or
postnatally <after> until the time of puberty.</after>

Question 13

Reproductive

Answer 13

study of the occurrence of adverse effects on the male or female reproductive system that may result from exposure to chemical or physical agent.

Question 14

What is LD50??

Answer 14

LD50 is the dosage (mg/kg body
weight) causing death in 50% of
exposed animals

lethal dose 50%

Question 15

What is a hapten

Answer 15

small molecules that are unrecognizable by the immune system as it binds to protein to form antigens

Question 16

Chemical Idiosyncratic:

Answer 16

a genetically determined abnormal activity to a chemical.
- take the form of extreme sensitivity to low doses or extreme insensitivity to high
doses.
- Why? Due to the interplay between an individual’s ability to form a reactive intermediate,
detoxify it, and/ or mount an immune response to adducted proteins (faulty).

Question 17

Tolerance

Answer 17

a state of decreased responsiveness to a toxic effect of a chemical resulting from prior exposure to that chemical or structurally related chemical

Question 18

What is the mechanism of tolerance?

Answer 18

decreased amount reaching the target site where effect is produced
reduce responsivness of a tissue to a chemical

Question 19

Immediate toxicity vs Delayed toxicity

Answer 19

immediate: develop after a single administration of a substance.
most substances have immediate
toxicity
delayed: Occur after the lapse of some time.
Carcinogenic effects require 20 – 30
years after initial exposure to be seen

Question 20

*Additive Effect ?
*Synergistic Effect?
*Potentiation?

Answer 20

he combined effect of two chemicals is equal to
the sum of the effect of each substance 1 +1 = 2

synergistic Effect
The combined effect of two chemicals are much
greater than the sum of the two 2 +2 =20

Potentiation
substance isn’t toxic to a certain organ or
system until it is added to another chemical
which makes it more toxic 0 +2 = 10

Question 21

*Antagonism and types

Answer 21

Two chemicals if administered together
interfere with the action of the other.

1. functional
2. chemical
3. dispositional
4. receptor blocker

Question 22

ffectiveness of toxic agents by
route of exposure

Answer 22

iv
inhale
ip
subcutnous
im
id
oral
dermal

Question 23

Acute
Subacute
Subchronic
Chronic

Answer 23

Acute: 24 Hrs single or repeated exposure
Inhalational 4 Hrs (HS: Single exposure)

subacute: Up to 1 month of exposure (multiple)

Subchronic: 1-3 months of repeated exposure

Chronic: Chronic (Over many months or years of repeated exposure)