Exam 2

Question 1

Administering a syustemic antidote that acts like a chemical "claw" to bind and accelerate elimination of absorbed metals after exposure is referred to as:
A) competitive inhibition	
B) chelation
C) phase 1 biotransformation
D) neutralization

Answer 1

B) chelation

Question 2

Detectable and measurable exogenous environmental chemicals, such as lead, in a person's (or animal's) blood and/or urine sample, represents a biomarker of
A) effects
B) elimination
C) excretion
D) exposure

Answer 2

D) exposure

Question 3

Detectable and measurable elevation of endogenous chemicals, such as liver enzymes, in a person's (or animal's) blood sample, represent a biomarker of:	
A) effects
B) elimination
C) excretion
D) exposure

Answer 3

A) effects

Question 4

The most common biological matrix to sample and analyze for systemically absorbed toxic chemicals, their metabolites, and/or related biochemical changes is
A) saliva
B) adipose tissue	
C) hair		
D) blood

Answer 4

D) blood

Question 5

**Select which of the following is NOT a biomarker from the perspective of clinical toxicology:
A) cadmium in urine
B) arsenic in hair
C) chlorinated hydrocarbons (e.g., PCBs) in adipose tissue
D) chelator in blood

Answer 5

D) chelator in blood

Question 6

**One matrix to consider for screening of a person's exposure to a highly volatile and relatively blood (water) insoluble environmental chemical such as the organic solvent benzene is:
A) adipose tissue
B) hair
C) saliva
D) exhaled air

Answer 6

D) exhaled air

Question 7

One clinical toxicology approach is to collect and analyze a biologic matrix such as blood or urine for a chemical parent compound to determine if internal exposure occurred, but instead, or as well, internal exposure can be documented by measuring:
A) another parent compound
B) a biotransformed parent compound or molecule
C) an antidote
D) a physiological response

Answer 7

B) a biotransformed parent compound or molecule

Question 8

**Absorption across the skin
A) occurs equally well across the skin from all parts of the body
B) occurs predominantly by active transport across the stratum corneum
C) involves passive diffusion across the dried, keratin-filled cells of the stratum corneum
D) occurs predominantly via passive diffusion across the hair follicles, sweat ducts, and sebaceous glands

Answer 8

C) involves passive diffusion across the dried, keratin-filled cells of the stratum corneum

**answer was C) on the last test, and D) on this one (occurs predominantly via passive diffusion across the hair follicles, sweat ducts, and sebaceous glands). In the review session, Tyler stated that C) was in fact the better answer. Though absorption across the skin can occur across hair follicles/sweat ducts/sebaceous glands, crossing the stratum corneum is more common. Therefore since D) says “predominantly,” it’s factually incorrect

Question 9

In primary irritation testing
A) the test animal is always given an analgesic
B) the test chemical is placed on normal and abraded skin under a patch for 24h
C) the test animal is usually a rat
D) the skin is evaluated only once

Answer 9

B) the test chemical is placed on normal and abraded skin under a patch for 24h

Question 10

**The skin:
A) is a fairly permeable barrier to environmental toxicants
B) is not responsive to UV light
C) is fairly static as stratum corneum cells typically are not replaced with any regularity
D) is in a constant state of change as statum corneum cells typically are replaced monthly

Answer 10

D) is in a constant state of change as statum corneum cells typically are replaced monthly

Question 11

Acute dermal irritation may be defined as:
A) wheal and flair reactions induced very shortly after cutaneous exposure to chemicals
B) reversible chemical-induced changes in sebaceous gland secretions
C) a local reversible inflammation of normal living skin that occurs shortly after a single exposure of the skin to a toxicant
D) a toxic effect resulting from DNA damage

Answer 11

C) a local reversible inflammation of normal living skin that occurs shortly after a single exposure of the skin to a toxicant

Question 12

Which of the following mechanisms does NOT apply to percutaneous toxicity?
A) biliary excretion of the toxicant
B) integrity of the skin to the toxicant
C) physiochemical properties of the toxicant
D) vehicle used to dissolve the toxicant

Answer 12

A) biliary excretion of the toxicant

Question 13

The blood-brain barrier:
A) is a semi-permeable barrier that excludes molecules great than 40kD
B) is found around all parts of the brain and spinal cord
C) is formed by having keratinocytes surround the neurons
D) is not an effective barrier

Answer 13

A) is a semi-permeable barrier that excludes molecules great than 40kD

Question 14

**Axons:
A) are involved in receiving messages from other nerve cells
B) are short extensions of the cell body of the neuron
C) are fairly tolerant of the toxic effects of chemicals
D) are involved in the synthesis and release of neurotransmitters

Answer 14

D) are involved in the synthesis and release of neurotransmitters

Question 15

**The autonomic nervous system normally does NOT function to:
A) control heart rate
B) stimulate breathing
C) stimulate skeletal muscle contractions
D) control pupil diameter

Answer 15

C) stimulate skeletal muscle contractions

Question 16

Which of the following is a toxic effect on the nervous system? 	
A) nephropathy	
B) cardiomyopathy	
C) retinopathy	
D) axonopathy

Answer 16

D) axonopathy

Question 17

Which of the following morphologic descriptions of nerve damage is accurate?
A) loss of the white layer around myelinated neurons indicates myelinopathy
B) Nissl substance is increased markedly in neuronopathy
C) damage to the cell body is called axonopathy
D) loss of the white layer around myelinated neurons indicated a transmission defect

Answer 17

A) loss of the white layer around myelinated neurons indicates myelinopathy

Question 18

**Which of the following is NOT a criterion for a chemical to be called a neurotransmitter?
A) the chemical must cause the same response as stimulation of the nerve
B) synthesis of the chemical must be able to occur in the nerve
C) the chemical must be present in all nerves
D) the nerve must possess the ability to terminate the action of the chemical

Answer 18

C) the chemical must be present in all nerves

Question 19

Toxicant effects on the nervous system do NOT include:
A) alteration in neurotransmission	
B) nephropathy
C) axonopathy
D) demyelination

Answer 19

B) nephropathy

Question 20

**Particles approximately 1 micro-meter in diameter typically deposit in which part of the respiratory system?

Answer 20

Alveoli

Question 21

True or False: Asthma is characterized by open airways and easy gas exchange.

Answer 21

False

Question 22

In the conducting airway, what are the anatomic structures that induce protective effects?
1.
2.
3.

Answer 22

mucous
cilia
mucous layer

Question 23

What are the anatomic structures of the blood-gas barrier?
1.
2.
3.

Answer 23

epithelium
interstitial tissue
endothelium

Question 24

Which cells produce pulmonary surfactants?

Answer 24

alveolar type II cells

Question 25

**What is the definition of PM2.5?

Answer 25

ambient particles with diameters less than 2.5 micrometers

Question 26

**The critical effect is defined as…
A) The first adverse effect of a chemical that occurs as dose increases
B) The first effect of a chemical that occurs as dose increases
C) The most significant effect that is seen upon a clinical evaluation of a patient
D) The most severe effect that a chemical causes in a population of sensitive individuals

Answer 26

A) The first adverse effect of a chemical that occurs as dose increases

Question 27

Clear advantages and disadvantages exist in the use of a benchmark dose (BMD). Which item below is a disadvantage?
A) uses responses near the range of observation
B) includes a measure of variability in the response
C) determines consistent measure of response
D) applies to fewer, more robust, toxicity data sets
E) accounts for more dose response of critical effect

Answer 27

D) applies to fewer, more robust, toxicity data sets

Question 28

**Toxicology testing in the 21st century will include in silico testing of chemicals. Advantages are numerous when compared with standard bioassays, but some problems still need to be worked out. These problems include:
A) Cheaper and high throughput
B) Predictive analyses, more informative, and efficient
C) Minimize animal testing and focus on relevant dose levels
D) Human cells- minimal interspecies extrapolation

Answer 28

B) Predictive analyses, more informative, and efficient

Question 29

Research needs for the in silico testing of chemicals include all but which of the following:
A) Phenotypic anchoring for clinical, critical, or adverse effects
B) Markers for common critical effects, such as decreased body weight and models for specific “itices”- e.g., neurotoxicity
C) Address communication among tissues; endocrine effects, in vitro and in vivo extrapolation
D) Incorporate metabolism, differences in individauls, and durations
E) Testing for non-volatile chemicals

Answer 29

E) Testing for non-volatile chemicals

Question 30

**A properly executed assessment of risk considers all of the following EXCEPT
A) Evaluation of data from human exposures
B) Evaluation of data from laboratory animal studies
C) Evaluation of public perception of risks versus benefits
D) Evaluation of data regarding chemical production

Answer 30

D) Evaluation of data regarding chemical production

Question 31

Quantitative risk assessment:
A) is always influenced by political and financial concerns
B) ascertains the quality of the available experimental data
C) readily places little importance on animal data when scanty human data are available
D) readily ignores all data that may contain flaws from their collection

Answer 31

B) ascertains the quality of the available experimental data

Question 32

Cancer is a group of diseases characterized by uncontrolled what?
A) Pain
B) Cell proliferation
C) Mitochondrial growth
D) Gene expression

Answer 32

B) Cell proliferation

Question 33

Which of the following established cancer risk factors combinations are attributable to the most cancer deaths?
A) Environmental pollution and tobacco
B) Tobacco and excess weight/obesity
C) Excess weight/obesity and alcohol
D) Family history (hereditary) and UV radiation

Answer 33

B) Tobacco and excess weight/obesity

Question 34

Which of the following is NOT a feature of genotoxic carcinogens?
A) mutagenic 	
B) can be complete carcinogens 	
C) no threshold	
D) no direct DNA damage

Answer 34

D) no direct DNA damage

Question 35

Promoters:
A) Cause a change in DNA (i.e., mutations)
B) Increase expression of genes associated with cell proliferation
C) Induce DNA repair enzyme systems
D) Are effective modifier of carcinogenesis with a single exposure

Answer 35

B) Increase expression of genes associated with cell proliferation

Question 36

There can be a long period of time between exposure to carcinogens and the clinical appearance of cancer. This is known as the:
A) Treatment window
B) Initiation period
C) Latency period
D) Rest period

Answer 36

C) Latency period

Question 37

**A benign tumor found within the bone is known as a:	
A) Osteosarcoma
B) Osteoma
C) Fibroma
D) Squamous cell adenoma
E) Squamous cell carcinoma

Answer 37

B) Osteoma

Question 38

Which of the following is NOT a characteristic of cancer compared to normal cells?
A) Large number of dividing cells
B) Large, variable shaped cells
C) Small cytoplasmic volume relative to nuclei
D) Variation in cell size and shape
E) Well organized arrangement of cells

Answer 38

E) Well organized arrangement of cells