TOX 300 EXAM QUESTIONS WITH CORRECT
ANSWERS
In |context |to |toxic |effect |of |a |xeno |describe |local |vs. |systemic |effects
Local:
•Corrosive |chemicals |on |skin |(e.g., |strong |acids |and |bases)
•Irritating |gases |and |vapours |in |respiratory |tract |(e.g., |ammonia |and |chlorine |gas)
Systemic:
•Xenobiotic |must |be |absorbed |into |systemic |circulation |and |distributed |to |organs/tissues
•Many |xenobiotics |preferentially |cause |toxic |effects |in |one |or |a |few |specific |organs |(“target |
organs”)
•Target |organ |may |not |always
have |the |highest |xenobiotic
concentration
,In |context |to |toxic |effect |of |a |xeno |reversible |vs. |irreversible |effects
Reversible:
•Effects |disappear |after |exposure |ends
•Usually |short-term |and/or |low |dose |exposures
Irreversible:
•Effects |persist |or |even |worsen |after |exposure |ends
•e.g., |carcinomas, |teratogenic |effects, |neuronal |damage, |liver |cirrhosis
•Usually |long-term |and/or |high |dose |exposures
In |context |to |toxic |effect |of |a |xeno |Immediate |vs. |delayed |effects
Immediate |(acute):
•Timeframe |minutes |to |days
•e.g., |cyanide, |carbon |monoxide |poisoning
Delayed |(chronic):
, •Timeframe |months |to |years
•e.g., |cancer |develops |10-20 |years |after |exposure, |both |in |individuals |and |also |potentially |
their |offspring |- |recall |diethylstilbestrol |(DES)
•Illustrates |the |need |to |conduct |long-term |toxicological |studies |and |transgenerational |
toxicological |studies
In |context |to |toxic |effect |of |a |xeno |describe |the |morphological |effect |these |agents |can |have?
•Gross |or |microscopic |effects |on |tissues; |commonly |irreversible
•e.g., |thalidomide |teratogenicity
•e.g., |histopathological |effects |on |liver |cells
In |context |to |toxic |effect |of |a |xeno |describe |the |Functional |effect |these |agents |can |have?
•e.g., |liver |or |kidney |function, |reproduction
•Generally |reversible |effects
In |context |to |toxic |effect |of |a |xeno |describe |the |Biochemical |effect |these |agents |can |have?
•Virtually |all |toxic |effects |are |initiated |by |an |alteration |in |biochemical |processes |(e.g., |receptor
|binding, |enzyme |inhibition)
ANSWERS
In |context |to |toxic |effect |of |a |xeno |describe |local |vs. |systemic |effects
Local:
•Corrosive |chemicals |on |skin |(e.g., |strong |acids |and |bases)
•Irritating |gases |and |vapours |in |respiratory |tract |(e.g., |ammonia |and |chlorine |gas)
Systemic:
•Xenobiotic |must |be |absorbed |into |systemic |circulation |and |distributed |to |organs/tissues
•Many |xenobiotics |preferentially |cause |toxic |effects |in |one |or |a |few |specific |organs |(“target |
organs”)
•Target |organ |may |not |always
have |the |highest |xenobiotic
concentration
,In |context |to |toxic |effect |of |a |xeno |reversible |vs. |irreversible |effects
Reversible:
•Effects |disappear |after |exposure |ends
•Usually |short-term |and/or |low |dose |exposures
Irreversible:
•Effects |persist |or |even |worsen |after |exposure |ends
•e.g., |carcinomas, |teratogenic |effects, |neuronal |damage, |liver |cirrhosis
•Usually |long-term |and/or |high |dose |exposures
In |context |to |toxic |effect |of |a |xeno |Immediate |vs. |delayed |effects
Immediate |(acute):
•Timeframe |minutes |to |days
•e.g., |cyanide, |carbon |monoxide |poisoning
Delayed |(chronic):
, •Timeframe |months |to |years
•e.g., |cancer |develops |10-20 |years |after |exposure, |both |in |individuals |and |also |potentially |
their |offspring |- |recall |diethylstilbestrol |(DES)
•Illustrates |the |need |to |conduct |long-term |toxicological |studies |and |transgenerational |
toxicological |studies
In |context |to |toxic |effect |of |a |xeno |describe |the |morphological |effect |these |agents |can |have?
•Gross |or |microscopic |effects |on |tissues; |commonly |irreversible
•e.g., |thalidomide |teratogenicity
•e.g., |histopathological |effects |on |liver |cells
In |context |to |toxic |effect |of |a |xeno |describe |the |Functional |effect |these |agents |can |have?
•e.g., |liver |or |kidney |function, |reproduction
•Generally |reversible |effects
In |context |to |toxic |effect |of |a |xeno |describe |the |Biochemical |effect |these |agents |can |have?
•Virtually |all |toxic |effects |are |initiated |by |an |alteration |in |biochemical |processes |(e.g., |receptor
|binding, |enzyme |inhibition)
