Defintions

Question 1

Toxicant

Answer 1

Poison

Question 2

Toxin

Answer 2

Poison that originates from biological processes

Question 3

Toxicosis

Answer 3

Disease state that results from exposure to a poison

Question 4

Toxicity

Answer 4

Quantity or amount of poison that causes a toxic effect

Question 5

Dose

Answer 5

Amount of toxicant received per animal

Question 6

Dosage

Answer 6

Amount of toxicant per unit animal mass or weight. +/- Time

Question 7

Route of exposure

Answer 7

How the animal is exposed to toxicant (oral, inhalation, dermal etc.)

Question 8

Threshold dose

Answer 8

Highest dose of a toxicant where no toxic effects are observed.

Question 9

Lethal Dose (LD)

Answer 9

Acute dose resulting in death. Usually presented as the dose resulting in death of 50% of animals (LD50)

Question 10

Lethal Concentration (LC)

Answer 10

Lowest concentration of a chemical in a matrix that causes death. (Mostly fish and wildlife)

Question 11

Median Lethal Dose (MLD)

Answer 11

Used interchangeably with LD50

Question 11

NOEL

Answer 11

No Observed Effect Level: Highest dose at which a significant effect could not be detected

Question 12

NOAEL

Answer 12

No Observed Adverse Effect Level: highest dose where an adverse effect could not be found

Question 13

LOEL

Answer 13

Lowest Observed Effect Level: Lowest dose at which a significant effect could be found

Question 14

LOAEL

Answer 14

Lowest Observed Adverse Effect Level: lowest dose where a significant adverse effect could be found

Question 15

Effective Dose (ED)

Answer 15

Dose of drug or toxicant that produces some desired effect in 50% of the population

Question 16

Therapeutic Index (TI)

Answer 16

TI = LD50/ED50

Question 17

Standard Safety Margin (SSM) or Margin of Safety (MoS)

Answer 17

SSM = LD1/ED99

Question 18

Exposure Duration

Answer 18

length of time an animal is exposed to a toxicant
Acute: 24 hrs
Subactute: 24 hrs - 30 days
Subchronic: 1-3 months
Chronic: 3 mo or longer

Question 19

Hazard (risk)

Answer 19

Liklihood a toxicant will cause harm under certain conditions.

Question 20

Pharmacokinetics ADME

Answer 20

Absorption
Distribution
Metabolism
Excretion

Question 21

Cmax

Answer 21

Maximal Concentration in a tissue conc by time graph (extent of toxicosis)

Question 22

Tmax

Answer 22

Time to reach Cmax

Question 23

AUC

Answer 23

Area under the (xenobiotic) curve

Question 24

Volume of Distribution (Vd)

Answer 24

Relates the conc. of a xenobiotic in the blood to the amount in the whole body

Vd = Dose/Co

Question 25

Bioavailability

Answer 25

degree and rate at which a substance is absorbed into a living system or is made available at the site of physiological activity

(AUCrouteX x Dose IV)/(AUCiv x Dose routex)

Question 26

Terminal/Elimination Half-Life (t1/2)

Answer 26

Time is takes the concentration of a xenobiotic to decrease by half in the linear terminal phase of the concentration v time curve

Question 27

Factors that affect the passage of toxicants through biological membranes

Answer 27

1. Concentration gradient across the membrane
2. Surface area of the membrane
3. Toxicant permeability
4. Macromolecule binding