Lecture 10-18 Quizzes

Human embryos/fetuses are high sensitive to toxicant exposures during a certain period of gestation. Either blue or red line correctly represents their sensitivities. What is the major developmental process during the period B? Which of red or blue correctly represents their sensitivity? What is the major developmental process during the period A?

Histogenesis; Red; Organogenesis

Blue and red lines are dose-response curves of two different chemicals. What do these dose response curves illustrate?

LD50 may not exactly tell the toxicity of chemicals

The following hormones are involved in the Hypothalamic-Pituitary-Gonadal axis of the female reproductive system:

Lutenizing Hormone (LH); Gonadatropin releasing hormone (GnRH); Follicle stimulating hormone (FSH); Progesterone

The following hormones are involved in the Hypothalamic-Pituitary-Gonadal axis of the male reproductive system:

Lutenizing hormone (LH); Follicle stimulating hormone (FSH); Gonadatropin releasing hormone (GnRH); Inhibin B; Testosterone/estradiol

Match the following stages of developmental exposure to the appropriate outcomes: Implantation to time of organogenesis

Morphological defects

Identify any components and/or characteristics of the innate immune response listed below:

NK cells; inflammation; phagocytosis

Peripheral nervous system (PNS) cells are myelinated by:

Schwann cells

Which of the following determines cancer susceptibility?

age; environment; genetic make-up

Some antidotes for AChE toxicity include:

atropine; pralidoxime or 2-PAM (N-methyl-1,6-dihropyridine-2-carbaldoxime); diazepam

Hexane is a toxicant that causes:

axonopathy

If nucleotide(s) deletion occurs, resulting DNA will:

be shorter than the original length

Liver is susceptible to chemical damage because it is:

bio-activation; large organ; getting chemicals by direct transportation from GI tract

The three main functions of the liver are:

biosynthesis of enzymes and lipid-protein complexes; storage of glycogen, vitamins and nutrients; metabolism of endogenous and exogenous compounds

Which of the following are a potential contact sensitizers?

cosmetics and fragrances; dyes; metals; pesticides

The age adjusted incidence and mortality rate of cancer __________ with age.

increases

Which of the following is NOT a mechanism of tumor promotion?

induction of cell death of initiated cells

Hypersensitivity is always mediated through two stages. The first stage is __________ which is followed by the 2nd stage __________.

induction; elicitation

Suppression of the immune system can lead to which of the following responses?

infections; neoplasia

Major mechanisms for acute toxicity include:

ion channel modulation; inhibition of cellular respiration; disrupting lipid bilayer of cell membranes

Renal elimination is determined by the chemical's (select all that apply):

ionization (charge); size; protein binding; water solubility

LD50 is the dose of a chemical that is __________ to __________ of the exposed populations. LC50 is the exposure _________ of a chemical that is _________ to __________ of the exposed population.

lethal; 50%; concentration; lethal; 50%

Lipophilic chemicals are transported by (select all that apply):

lipoprotein complexes; albumin

Malignant neoplasms

locally invasive, infiltrates into surrounding normal tissues

The functional unit of the kidney is the

nephron

Level of immune responses at each hypersensitivity stage: Sensitization

no responses

Central Nervous System (CNS) cells are myelinated by:

oligodendrocytes

Targets of these chemicals are: organophosphorus insecticides cyanide DDT barbiturates sarin (nerve gas)

organophosphorus insecticides: acetylcholinesterase cyanide: cellular respiration DDT: calcium channel barbiturates: chloride channel sarin (nerve gas): acetylcholinesterase

The rate of elimination from the lungs depends on (select all that apply):

respiration rate; lung perfusion (blood flow); blood (air partition coefficient); solubility in the lymph

Cholestasis can be described as a/an __________ of bile flow

suppression or blockage

Genetic polymorphism can be defined as monogenetic traits that exist in the population in at least two genotypes, and is stably inherited

true

T/F Alveolar macrophages serve (in part) to eliminate inhaled particles:

true

T/F An antigen is a molecule that evokes an immune response

true

T/F Immunosuppressive toxicants may cause neoplasia and possibly promote carcinogenesis

true

T/F Kidney diseases can result in the prolongation of drug half life

true

T/F MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) easily crosses the blood brain barrier (BBB) and is ready taken up by astrocytes.

true

T/F Metabolic activity generally declines with old age

true

T/F Non-chemical teratogens exist

true

T/F Radiation and Reactive Oxygen Species (ROS) can cause direct and direct DNA damage

true

T/F The central nervous system nervous system is a general target for narcosis

true

T/F Two compounds with identical LD50 values can have vastly different dose-response curves

true

Routes of elimination (including minor pathways) include (select all that apply):

urine; saliva; hair; milk; sweat

If you have a severe kidney disease, the ability to oxidize drugs in the kidney would be expected to:

decrease

Which of the following apply pregnancy-associated changes?

decreased glucuronide conjugation; decreased monoamine oxidase

Low protein, high carbohydrate diets will have the effect of:

decreasing monooxygenase activity

Neurons consist of three general components:

dendrites; cell body; axon

The following factors can influence metabolism:

development; diet; gender; diseases; diurnal rhythm

An endocrine disrupting chemical (EDC) that acts like estrogen would be referred to as a/an __________ chemcial

estrogenic

Level of immune responses at each hypersensitivity stage: Subsequent exposure

excessive responses

T/F All animal metabolize xenobiotics at similar rates

false

T/F All carcinogens directly cause DNA damage.

false

T/F All toxicants affect all organisms the same

false

T/F DNA mutation always results in carcinogenesis

false

T/F Dose-response curves of chemical toxicity are linear if exposed population is normally distributed.

false

T/F Exchange of gases between inhaled air and the blood is actively mediated

false

T/F In most cases, a person can be allergic to poison ivy even through she/he has never come across it or other related poison plants (poison oak, poison sumac, etc)

false

T/F Many types of cancers are not associated with genetic alterations (DNA mutations or genome modifications)

false

T/F Monoamine oxidase (MAO) and acetylcholinesterase (AChE) work at the same side of the neuromuscular junction and do the same job.

false

T/F One cancer mass always possess the same DNA mutation

false

T/F Necrosis is a programmed cell death that normally occurs as a part of tissue growth and differentiation

false >that is describing apoptosis

Select the diseases associated with liver toxicity:

hepatitis; cirrhosis; glycogen storage disease; fatty liver; cholestasis

The kidneys are susceptible to toxicants due to

high renal blood flow

Which of the following is/are epigenetic agent(s) associated with carcinogenesis?

hormones; solid state agents; immunosuppressive xenobiotics; tumor promoters

Match the Toxicity Rating to the appropriate LD50 (mg/kg). 500-5000 <50 50-500 >5000

500-5000: moderately toxic <50: extremely toxic 50-500: very toxic >5000: relatively toxic

Which of the following is true regarding epigenetic agents associated with carcinogenesis?

Alters the expression of certain genes

Match the following stages of developmental exposure to the appropriate outcomes: Pre-implantation

Embryonic lethality

Which of the FMO enzymes is not developmentally regulated?

FMO5

Match the following stages of developmental exposure to the appropriate outcomes: Fetal to neonatal

Functional disorders, growth retardation, carcinogenesis

Testosterone synthesis take place primarily in the ______ cells.

Leydig

Death of the entire neuron is referred to as:

Neuronopathy

A toxicant that inhibits Monoamine Oxidase (MAO) can induce:

Neurotransmission toxicity

National __________ program routinely performs carcinogenesis tests mostly using a __________ model, which takes about __________ (duration) to obtain results.

Toxicology; rodent; 2 years

Cancer can be described as:

a group of abnormal cells that invade surrounding tissue; a large group of diseases; the uncontrolled growth of an abnormal cell

An endocrine disrupting chemical (EDC) that blocks the effects of testosterone would be referred to as a/an __________ chemical

antiandrogenic

Immune responses can be mediated through these substances:

antibodies; cytokines; complement factors

What does this graph illustrate?

cancer development is likely to require not only one time DNA damage (mutation) but accumulation of damaging insults; gender may affect susceptibility to colon/rectum insults

Benign neoplasms

do not invade surrounding normal tissues

Toxicants including air pollutants can be:

immuno-suppressor; adjuvant (enhancer of immune responses); antigen

Mutations in critical genes can be caused by:

imperfect DNA replication or repair; oxidative DNA damage; DNA damage by environmental agents

What types of chemicals are eliminated through the liver and kidney?

kidney: water soluble liver: lipophilic

Which of these are considered as nephrotoxicants?

lead; halogenated hydrocarbons; acetaminophen

A mutation that produces an altered protein in which a correct amino acid is converted to an incorrect one is called a/an

missense mutation

What are the major functions of the kidneys?

regulation of homeostasis; hormone synthesis; elimination of waste products

Water soluble chemicals are transported by:

plasma

Oncogenes function in the cell to:

promote uncontrolled cell growth

Drag and drop the names of the structures and their primary functions in the nephron

proximal tubule: reabsorption glomerular: filtration

A chemical that causes abnormalities or dysmorphogensis in the developing fetus is referred to as:

teratogen

What kinds of substances can cross blood-brain barrier?

very small water soluble chemicals; lipid soluble chemicals; glucose

Lungs efficiently eliminate __________ chemicals through gas exchange, and small atmospheric particles through __________.

volatile; mucociliary escalator