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Flashcards in MIDTERM Deck (50)
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1
Q

The ability of a substance to cause harmful effects is referred to as:

A. Toxicity
B. Hazard
C. Side Effect
D. Therapeutic Effect

A

A. Toxicity

2
Q

The individual credited with recognizing the concept of Dose- Response relations is:

A. Hippocrates
B. Galen
C. Paracelsus
D. Orfila

A

C. Paracelsus

3
Q

Which of the following is a major target organ for the toxic effects of ingested chemicals:

A. Brain
B. Kidney
C. Bone Marrow
D. Liver

A

D. Liver

4
Q

The amount of a substance that shoes up in the blood stream is known as the:

A. Exposure dose
B. Toxic dose
C. Therapeutic dose
D. Absorbed dose

A

D. Absorbed dose

5
Q

Which of the following is/are correct regarding fractionating a total dose?

A. Intensity of toxic effects will decrease
B. Intensity of the therapeutic effect will increase
C. Intensity of side-effects will increase
D. A and B above are correct
E. A, B and C above are correct

A

A. Intensity of toxic effects will decrease

6
Q

When extrapolating animal data to apply to humans, the most common Safety factor used is:

A. 1
B. 10
C. 100
D. 1000

A

B. 10

7
Q

The minimal dose at which a toxic effect first appears is known as the:

A. Toxic dose
B. Absorbed dose
C. Effective dose
D. Lethal dose

A

A. Toxic dose

8
Q

Which of the following is NOT CORRECT regarding knowledge of the Dose-Response relationship for a chemical?

A. The Threshold Doses for each the chemicals effects can be determined.
B. The rate of buildup of the effects with increasing doses can be determined
C. The degree of metabolism and storage of the chemical in the body can be determined
D. The Therapeutic Index can be determined

A

C. The degree of metabolism and storage of the chemical in the body can be determined.

9
Q

The quantity of a substance administered to an individual over a period of time is known as the:

A. Exposure dose
B. Absorbed dose
C. Therapeutic dose
D. Total dose

A

D. Total dose

10
Q

The Margins of Safety for a therapeutic chemical is determined by which of the following ratios:

A. LD50/ED50
B. LD1/ED99
C. ED99/LD1
D. ED50/LD50

A

B. LD1/ED99

11
Q

Therapeutic agents that are considered to be relatively safe and therefore have no need for monitoring have Therapeutic Indices:

A. Less than 1
B. = 1
C. Between 1 and 10
D. Greater than 10

A

D. Greater than 10

12
Q

The route of exposure that has the greatest potential for toxic effects upon accidental overdose is:

A. Inhalation/ respiratory
B. Intravenous injection
C. Intramuscular Injection
D. Ingestion/ Gastrointestinal

A

B. Intravenous injection

13
Q

Which of the following factors is the MOST important determinant of the intensity of toxic effects?

A. Target Site concentration of the chemical
B. Gender of the individual exposed to the chemical
C. Age of the individual exposed to the chemical
D. Body weight of the individual exposed to the chemical

A

A. Target Site concentration of the chemical

14
Q

The unintentional route of exposure to chemicals that produces the fastest effects is which of the following?

A. Gastrointestinal exposure
B. Dermal exposure
C. Inhalation exposure

A

C. Inhalation exposure

15
Q

Which of the following is NOT CORRECT regarding the role of the liver in chemical toxicity?

A. Hepatic biotransformation generally reduces toxicity
B. Liver enzymes never cause an increase in toxicity
C. The detoxification process generally results in forming hydrophilic metabolites
D. The liver is a major target organ for toxicity for ingested chemicals.

A

B. Liver enzymes never cause an increase in toxicity

16
Q

Lipophilic chemicals (eg. DDT) are preferentially distributed from blood into which of the following storage tissues?

A. Adipose
B. Brain
C. Bone
D. Liver

A

A. Adipose

17
Q

Which of the following categories includes chemicals that will not cause toxic effects at any dose level?

A. Prescription medications
B. Non-Prescription medications
C. Vitamins
D. Health Supplements
E. None of the above
A

E. None of the above

18
Q

Which of the following routes of exposure that will cause the greatest magnitude of a toxic effect?

A. Intra-venous injection
B. Intra-muscular injection
C. Dermal exposure
D. Ingestion

A

A. Intra-venous injection

19
Q

The undesired effects that reproduced when the dose of a medication is within the recommended dose range are referred to as __________:

A. Lethal effects
B. Toxic effects
C. Side effects
D. Therapeutic effects

A

C. Side effects

20
Q

Majority of medications, particularly those marked OTC, have a Therapeutic Index of ___:

A. >10
B. 5-10
C. 1-5
D.

A

A. >10

21
Q

In general, the ability of any chemical to produce systemic (not local) toxic effects is primarily dependent upon which of the following factors:

A. Amount of detoxification enzymes in the liver
B. Thickness of the stratum corneum
C. Concentration of free chemical in plasma
D. Volume of urine output over 24 hours

A

C. Concentration of free chemical in plasma

22
Q

Which of the following will most likely cause the intensity of a toxic effect to decrease?

A. Reducing the thickness of the skin by shaving.
B. Decreased distribution to adipose tissue
C. Reducing water intake
D. Increasing liver enzyme activity by smoking.

A

D. Increasing liver enzyme activity by smoking

23
Q

When a toxic effect manifests following several years of exposure to a chemical the effect is known as:

A. Acute toxicity
B. Sub-acute toxicity
C. Sub-chronic toxicity
D. Chronic toxicity

A

D. Chronic toxicity

24
Q

The major difference between acute and chronic toxicity is:

A. Acute toxicity occurs after a single dose whereas chronic toxicity occurs after multiple doses.
B. The target organs for toxicity are different.
C. Acute toxicity appears soon after exposure whereas chronic toxicity occurs many months or years later.
D. Acute toxic effects are unpredictable whereas chronic toxic effects are predictable

A

C. Acute toxicity appears soon after exposure whereas chronic toxicity occurs many months or years later

25
Q

Toxic effects are most likely to be produced in the age group between:

A. 20-40 years
B. 40-50 years
C. 50-70 years
D. 70-75 years

A

D. 70-75 years

26
Q

What are the important factors that influence the degree of toxicity of a substance?

A. Innate chemical activity and dosage of the chemical
B. Rate of absorption, distribution, metabolism, and excretion.
C. Exposure route, biological factors, and presence of other chemicals.
D. All of the above influence the degree of toxicity of chemicals

A

D. All of the above influence the degree of toxicity of chemicals

27
Q

The use of antibiotics to manage infections with minimal damage to human tissues is based upon:

A. Differences in absorption of the antibiotic between bacteria and humans
B. Faster excretion of the antibiotic humans
C. Greater bio-inactivation of the antibiotic by humans
D. Selective toxicity of the antibiotic to bacteria

A

D. Selective toxicity of the antibiotic to bacteria

28
Q

Which of the following are the two general types of toxic effects?

A. Carcinogenic and teratogenic effects
B. Systemic and specific target organ effects
C. Hepatic and Nephrotoxic effects
D. Central and peripheral nervous system effects

A

B. Systemic and specific target organ effects

29
Q

“Antagonism” refers to an interaction in which:

A. A chemical produces less toxicity in the simultaneous presence of another chemical
B. Toxicity produced by the combined presence of two chemicals is equal to the sum of their individual toxicities
C. There is an increase in the toxicity due the presence of the second chemical
D. None of the above correctly describes “antagonism”

A

A. A chemical produces less toxicity in the simultaneous presence of another chemical

30
Q

A chemical that causes change in the DNA of a cell is a _______

A. Teratogen
B. Carcinogen
C. Mutagen
D. Androgen

A

C. Mutagen

31
Q

A dose of 4 mg of an insecticide causes 20% toxicity whereas the same dose of another insecticide produces 30% toxicity. If 8 mg of a formulation containing equal concentrations of the two insecticides causes 50% toxicity the interaction is known as:

A. additivity
B. antagonism
C. synergism
D. potentiation

A

A. Additivity

32
Q

The use of 100% oxygen to manage carbon monoxide poisoning is an example of _______ antagonism.

A. Physiological
B. Chemical
C. Dispositional
D. Receptor

A

D. Receptor

33
Q

The usual dosage unit that incorporates the amount of material administered or absorbed in accordance with the size of the individual over a period of time is:

A. ppm/hour
B. mg/kg/day
C. kg/100lb/week
D. mg

A

B. mg/kg/day

34
Q

The ED50 represents:

A. the effect level resulting from a threshold dose of 50 mg
B. the point at which 50% of the liver is destroyed
C. The estimated dose that produces the desired effect at a 50% rate
D. the medium lethal dose

A

C. the estimated dose that produces the desired effect at a 50% rate

35
Q

True or False

Every chemical can produce more than one biological effect.

A

True

36
Q

True or False

The CNS is a target organ for all toxic chemicals.

A

False

37
Q

True or False

Dehydration will increase the intensity of toxic effects.

A

True

38
Q

True or False

Lowering adipose content as part of a weight loss program can increase the intensity of toxic effects of lipophilic

A

True

39
Q

True or False

Only the free form of a chemical in plasma can cause biologic effects.

A

True

40
Q

True or False

Renal dysfunction can decrease intensity of toxic effects

A

False

41
Q

True or False

Liver damage will increase the percentage of a chemical in plasma that is bound to albumin

A

False

42
Q

True or False

Chemicals that undergo hepato-biliary excretion in addition to urinary excretion can be expected to have a relatively shorter duration effects compared to chemicals that undergo only urinary excretion.

A

False

43
Q

True or False

Methemoglobinemia is characterized by “chocolate cyanosis” of arterial blood

A

True

44
Q

True or False

Carbon monoxide has the smell of bitter almonds

A

False

45
Q

True or False

Nitrous oxide is a dental anesthetic and can cause methemoglobinemia.

A

True

46
Q

True or False

The enzyme that detoxifies superoxide anion in the body is a catalase

A

False

47
Q

True or False

Activation of molecular oxygen form “reactive oxygen species” is catalyzed by lead ions

A

False

48
Q

True or False

Hydration of the stratum corneum will decrease the toxic effects of chemicals that are absorbed through the skin

A

True

49
Q

True or False

Inhibition of acetylcholinesterase will cause skeletal muscle relaxation and sinus tachycardia

A

False

50
Q

True or False

Lead poisoning can cause iron-deficiency like anemia, basophilic stippling and GI cramps

A

True