Toxicology Exam 1 Questions

Class E

Mitochondrial DNA → protein synthesis

Dispositional antagonism

altered concentration @ target organ

Which of the following classes causes depletion of ATP through inhibiting electron transport? a. Class A b. Class B c. Class C d. Class D

b. Class B

1. Which of the following is NOT a mechanism of abnormal reactivity? a. Metabolic Variation b. Environmental Variation c. Genetic Variation d. Immunologic Variation

b. Environmental Variation

Which is the MOST COMMON interaction of chemicals? a. Potentiation b. Antagonism c. Additive effects d. Synergism

c. Additive effects

Are allergic reactions type A or type B?

type B

necrosis

unprogrammed tissue death

What are the 2 responses of inflammation?

vascular response cellular response

NOAEL and LOAEL along with LD50, ED10, and others are used to:

- Calculate daily acceptable or tolerable intakes - To designate chemical as nontoxic, mildly toxic, etc.

True or False: Chronic inflammation is characterized by an influx of lymphocytes and macrophages.

True

Which is NOT a way a toxicant impairs cell maintenance? a.ATP depletion b.Increased accumulation of Ca2+ c.Covalent Irreversible bonding d.Free radical formation

c.Covalent Irreversible bonding

Stimuli of inflammation

• Infection • Trauma and physical or chemical agents • Tissue necrosis • Foreign bodies • Immune reactions

Increased intracellular Ca2+

• Inhibits ATPase - Mitochondrial Ca2+ cycling • Dysfunction of cytoskeleton • Activation of hydrolytic enzymes - Phospholipases and endonucleases • Generation of ROS/RNS - Activation of electron transport chain

Class D

-Inhibit ATP synthase - ADP delivery - Phosphate delivery - Separate ATP synthase from proton gradient

What substance eats holes in the membrane of lipid bilayers? a. acids b. electrophiles c. free radicals d. nucleophiles

...

Key assumptions in animal testing

1. Effects produced by a compound in animals are applicable to humans 2. Exposure of animals at high doses is a valid method of assessing potential human toxicity - High dose = higher incidence of effect - Enables reduction of sample size

Primary mechanisms of toxicity

ATP depletion increased intracellular calcium Free radical formation

What is the first pass effect? a. Removal of an ingested compound by the liver before it reaches systemic circulation b. Enzymes added to the ingested compound to the kidney before it reaches systemic circulation c. Removal of an ingested compound by the kidney after it reaches the systemic circulation d. All of the above

All of the above

Free radicals are most commonly known to have adverse effects on which attribute of a target molecule A. Proteins B. DNA C. Membranes D. Enzymes

C. Membranes

Define tolerance

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

True or False: Local effects require absorption and distribution to target organs.

False

True or False: Type B reactions are pharmacological reactions and most commonly reported in humans.

False

True or False: Type-A pharmacologic reactions are dose-related but completely unpredictable

False

True or false: Type A reactions are not related to the pharmacology of the drug

False

True/False: A toxin is related to human activity and is usually a chemical poison or drug

False

True or False: Ingestion of a toxicant/toxin is faster than inhalation

False, inhalation is faster

intracellular calcium

Highly regulated - High Ca2+ is an early morphologic sign of impending cell death - Cell and organelle membranes block influx - Transporters pump out • Extracellularly • Into ER and mitochondria

Class A

Inhibit H+ delivery to electron chain

Class B

Inhibit electron transport

Class C

Inhibit oxygen delivery to cytochrome oxidase

Put sites of exposure in order from fastest (1) to slowest (4) in speed of reaching the bloodstream: a. Ingestion b. intravenous c. intramuscular d. inhalation

Intravenous Inhalation Intramuscular Ingestion

Functional antagonism

Opposite effects on same physiologic function

risk assessment

Process of estimating association between an exposure to a chemical or physical agent and the incidence of some adverse outcome

What are the 5 R's of inflammation?

Recognition Recruitment Removal Regulation Resolution

True or False: Chlorine gas is considered to be highly reactive, and it is most likely to show local symptoms

True

True or False: Covalent bond formation irreversibly alters the target molecule.

True

True or False: Haptens and protein cause an allergic/immune reaction.

True

True or False: delivery is enhanced by the presence of fenestrated capillaries?

True

True or False: detoxification is part of the process of enzymatic metabolism.

True

True or False: localized burning is from highly reactive toxins?

True

True or false: Calcium is always higher outside of the cell due to free radicals

True

Which type of effect could be predicted by the individual's age, size, gender, and health status?

Type A

Chemical antagonism

a chemical reaction between two compounds that produces a less toxic product

receptor antagonist

a drug that binds to a receptor and inhibits its function

Which of the following promotes delivery? a. Absorption b. Reabsorption c. Specialized barriers d. High Lipophillicity

a. Absorption

In what 4 four ways is distribution enhanced?

a. Absorption b. Distribution toward target c. Reabsorption d. Toxicant

Which below has the correct toxicant exposure steps, in order? a. Delivery, interaction with a target molecule, cellular dysfunction, and repair/dysrepair b. Interaction with a target molecule, delivery, repair/dysrepair, and cellular dysfunction c. Delivery, conjugation of free radicals, non-covalent bond formation, and a target molecule d. Conjugation of free radicals, non-covalent bond formation, delivery, repair/dysrepair

a. Delivery, interaction with a target molecule, cellular dysfunction, and repair/dysrepair

What response curve has an "all or none" response? a. Quantal dose b. Cumulative dose c. Probit d. Individual

a. Quantal dose

What is the definition of risk assessment? a. The systematic scientific characterization of potential adverse health effects b. The probability of an adverse outcome under specified conditions c. The process by which policy actions are chosen to control hazards d. None of the above

a. The systematic scientific characterization of potential adverse health effects

Which compound would be more easily absorbed? a. a lipid-soluble compound b. a water-soluble compound c. a charged compound

a. a lipid-soluble compound

Which is not true of Type B Reactions? a.Predictable b.Resolve only when treatment is discontinued c.Atypical d.Caused by variation in individuals

a.Predictable

What is the third step of the path of the toxicant from the site of exposure (dose) to the target (toxic effect)? a. Repair or disrepair b. Cellular dysfunction and resulting toxicity c. Interaction with target molecule d. Delivery

b. Cellular dysfunction and resulting toxicity

The hormones insulin (lowering blood glucose) and glucagon (increasing blood glucose) are antagonistic of each other. Which category of antagonists do they demonstrate? a. Chemical b. Functional c. Dispositional d. Receptor

b. Functional

Which of the following is not a feature of a Type A reaction? a. Dose-dependent b. Idiosyncratic c. predictable pharmacokinetics d. predictable pharmacodynamics

b. Idiosyncratic

A horse is found dead in a field and several other horses look unbalanced and confused. They are all located in a pasture with only grass and a few trees. What is NOT a likely source of exposure from the toxin? a. Inhalation b. Intravenous c. Oral d. Dermal

b. Intravenous

Which two routes of exposure are the most effective? a. Intravenous and subcutaneous b. Intravenous and inhalation c. Inhalation and ingestion d. Intramuscular and ingestion

b. Intravenous and inhalation

Which of the following terms is defined by, "A toxic agent attributed to human activity"? a. Toxin b. Toxicant c. None of the above d. All of the above

b. Toxicant

1.A child goes to see his pediatrician because he has a sore throat. He is diagnosed with strep throat and is prescribed Amoxicillin. The next day, he develops hives all over his body. What type of adverse drug reaction is this? a.Type A reaction b.Type B reaction c.Pharmacologic reaction d.B and C

b. Type B reaction

Which molecule would MOST readily cross the Blood Brain Barrier? a. a small molecule b. a very lipid soluble molecule c. a very water soluble molecule d. a small, water soluble molecule

b. a very lipid soluble molecule

What term describes the u-shaped dose-response curve shown when a substance has beneficial and harmful effects? a. homeostasis b. hormesis c. benefit curve d. therapeutic index

b. hormesis

1Which of these is/are a barrier preventing a toxic agent from reaching a target site? i. pre-systematic elimination ii. reabsorption iii. excretion a. i only b. i and iii c. ii and iii d. all of the above

b. i and iii

1. Reabsorption ________ delivery and presynaptic elimination _________ delivery? a. promotes, promotes b. promotes, inhibits c. inhibits, promotes d. inhibits, inhibits

b. promotes, inhibits

First Pass Effect will cause a.Low bioavailability due to decrease metabolism in the liver b.Low bioavailability due to increase metabolism in the liver c.High bioavailability due to increase metabolism in the liver d.High bioavailability due to decrease metabolism in the liver

b.Low bioavailability due to increase metabolism in the liver

Which is not a common target of a toxin? a. DNA b. Proteins or Enzymes c. Lysosomes d. Membranes.

c. Lysosomes

What is the second step in the key features of inflammation (5 R's)? a. Resolution/Repair b. Removal of the agent c. Recruitment of leukocytes d. Recognition of the injurious agents e. Regulation of the immune response

c. Recruitment of leukocytes

Free radicals are all of the above except: a. Unstable b. Highly reactive c. Stable d. Prone to Propagation

c. Stable

What characteristic is FALSE about an acute inflammatory response in the lung? a. wet tissue b. increased number of neutrophils c. salmon pink coloration d. increased blood flow

c. salmon pink coloration

What characteristics are consistent with acute inflammation? a.short time course, fluid leakage, fibrous tissue proliferation b.long time course, neutrophilic leukocyte response, influx of macrophages c.vasodilation, tissue edema, leukocyte migration

c. vasodilation, tissue edema, leukocyte mirgation

1What was one of the main reasons for the birth of The Food and Drug Act of 1906? a.A widespread cholera outbreak b.A insect infestation of many food production factories c.A rise in misbranded and tampered medications d.A series of poisonings

c.A rise in misbranded and tampered medications

Please choose the answer MOST correct definition of a toxicant: a.A toxic agent of biological origin. b.A biological agent toxic to humans specifically c.A toxic agent attributed to human activity, usually chemical poisons or drugs D. A chemical released from the body to combat a toxic interaction in the body.

c.A toxic agent attributed to human activity, usually chemical poisons or drugs

The type of antagonism that alters the concentration at the target organ is: a.Functional antagonism b.Chemical antagonism c.Dispositional antagonism d.Receptor antagonism

c.Dispositional antagonism

1.Which of the following describes a type B reaction? a.Most commonly reported in humans b.Predictable c.Resolves only when treatment is discontinued d.Dose-dependent

c.Resolves only when treatment is discontinued

Who is the father of Toxicology? a.Charles Darwin b.Louis Pasteur c.James Watson d.Philippus Aureolus Theophrastus Bombastus von Hohenheim

d .Philippus Aureolus Theophrastus Bombastus von Hohenheim

Inflammation can be caused by: a. Foreign bodies b. Trauma c. Immune reactions d. All of the above

d. All of the above

Increased cellular Ca2+ can cause: a. Activation of hydrolytic enzymes b. Dysfunction of cytoskeleton c. Generation of ROS d. All of the above.

d. All of the above.

Which of the following are key cell functions? a. Membrane and organelle maintenance b. Maintain intracellular environment (pH, ion balance) c. Produce energy (ATP) d. All of the above.

d. All of the above.

Which interaction describes a case when two chemicals react and the effect of both chemicals is cancelled out? a. Additive b. Synergism c. Potentiation d. Antagonism

d. Antagonism

Type A reactions: a. Are idiosyncratic reactions b. Do not show normal-dose response relationships c. Resolve only when treatment is discontinued d. Are more commonly reported in humans than type B reactions

d. Are more commonly reported in humans than type B reactions

When a patient takes a barbiturate-based medication in conjunction with a dose of epinephrine, there is no resulting effect. What type of reaction is this? a. Synergism b. Functional Antagonism c. Potentiation d. Dispositional Antagonism

d. Dispositional Antagonism

Cyanide decreases ATP production by inhibiting: a. Oxygen delivery to cytochrome oxidase b. ATP synthase c. H+ delivery to the electron transport chain d. Electron transport

d. Electron transport

Which type of antagonism is the opposite effect on a same physiologic function? a.Chemical b. Receptor c. Disposition d. Functional

d. Functional

Characterization of Class C depletion of ATP would be: a. Inhibit H+ delivery b. Inhibit electron transport c. Inhibit ATP synthase d. Inhibit oxygen delivery to cytochrome oxidase

d. Inhibit oxygen delivery to cytochrome oxidase

There are three primary mechanisms of toxicity, which is not a mechanism? a. Free radical formation b. Increased intracellular calcium c. ATP Depletion d. Oxidative phosphorylation

d. Oxidative phosphorylation

1. Chronic inflammation is characterized by the influx of ________? a. neutrophils b. eosinophils c. mast cells d. macrophages

d. macrophages

1.Which of these requirements are necessary before a toxic effect can occur? a.Toxicant must reach target organ at effective concentration b.Toxicant must reach target organ for a sufficient length of time c.Toxicant must reach target organ in a susceptible biological system d.All of the above

d.All of the above

Termination of inflammation occurs when: a.The original stimulus is removed b.The host passes out c.Mediators are dissipated or inhibited d.Both A and C

d.Both A and C

Which organ most frequently experiences systemic toxicity? a. Muscles and bones b. Blood and hematopoietic tissue c. Viscera d. CNS

d.CNS

1.Naloxone is a medication that quickly reverses an opioid overdose. Which is the least likely to be used as a route of administration? a.Intramuscular b.Inhalation c.Intravenous d.Dermal

d.Dermal

Which of the following is NOT true about chronic inflammation? a.Occurs over a prolonged duration b.May be caused by autoimmune disease c.May lead to fibrosis d.Involves fluid and plasma leakage from capillaries

d.Involves fluid and plasma leakage from capillaries

Which is FALSE regarding free radicals a.Unstable due to the unpaired electrons b.Can propagate to create other radicles c.Linked to heart disease and cancer d.Our bodies cannot combat them

d.Our bodies cannot combat them

Name one effect of toxicant on target molecules

dysregulation of gene expression

LOAEL

lowest observed adverse effect level lowest data point at which there was an effect

Threshold

no detectable response below this point

NOAEL

no observed adverse effect level highest data point at which there was not an effect

Apoptosis

programmed cell death

Tolerance

the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect

therapeutic index

the ratio between the toxic and therapeutic concentrations of a drug

Effects of free radicals

• Reduced ATP reserve - Inhibit cytochrome c and electron transport - Inhibit glycolysis • DNA strand breaks • Inactivation of Ca2+ pump • Membrane lipid peroxidation

Limitations of animal testing

• Species differences • Genetic strain mutants may not reflect a "real" population • Epigenetic and environmental effects • Complex mixtures • Dose equivalent to environmentally-relevant levels? • Mixed endpoints