TOX 300 MIDTERM 2 EXAM QUESTIONS
AND ANSWERS GRADED A+ 2026
Toxicodynamics - ANS process of interaction of chemical substances with target sites and the
subsequent reactions leading to adverse health effects. what the xenobiotic does to the body.
idiosyncratic effects - ANS genetically based toxic reactions that occur only in small
proportions of individuals with no known cause
spectrum of toxic effects: local vs systemic - ANS systemic: in the systemic circulation, can be
distributed to other organs
local: seen with strong acids and caustic substances, as well as inhaling toxic gases like chlorine
or ammonia
spectrum of toxic effects: reversible vs irreversible - ANS most toxic effects are reversible.
cancer or teratogenic effects are irreversible.
spectrum of toxic effects: immediate (acute) vs delayed (chronic) - ANS acute = hours to days.
e.g. chlorine gas. acute toxic effect.
delayed = cancer, something that takes months to years to set on.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
1
, spectrum of toxic effects: morphological, functional, and biochemical effects - ANS 1.
morphological effects are commonly irreversible. can be effects to limbs, or effects to
morphology of cells.
2. functional: toxicant can affect a critical function in the body, e.g. liver/kidney function.
generally reversible effects.
3. vast majority of xeno effects are initiated by some type of molecular event. e.g. cancer is
initiated by cellular dysfunction.
spectrum of toxic effects: allergic vs idiosyncratic reactions - ANS 1. hypersensitivity/allergic
reactions: initially exposed to an antigen (e.g. bee venom) can get delayed hypersensitivity.
2. idiosyncratic reactions: genetically based toxic reactions that occur only in small proportions
of individuals with no known cause
spectrum of toxic effects: graded (continuous) vs. quantal (all or none) responses - ANS 1.
continuous data have an infinite # of values: e.g. body weight
modifying factors of toxicity: dose - ANS dose defines the poison
modifying factors of toxicity: duration and frequency of exposure - ANS e.g. smoking one
cigarette vs a pack a day for several years. can be important in workplace exposure where you
cannot avoid constant exposure.
modifying factors of toxicity: species, genetic strain, individual - ANS interspecific differences
- difficult to say effects in one species will translate to effects in another. due to enzymes,
receptors, etc
modifying factors of toxicity: sex, pregnancy - ANS differences between males and females
usually related to differential expression of genes. males are much more susceptible to heart
disease - thought that estrogens have a protective effect.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
2
AND ANSWERS GRADED A+ 2026
Toxicodynamics - ANS process of interaction of chemical substances with target sites and the
subsequent reactions leading to adverse health effects. what the xenobiotic does to the body.
idiosyncratic effects - ANS genetically based toxic reactions that occur only in small
proportions of individuals with no known cause
spectrum of toxic effects: local vs systemic - ANS systemic: in the systemic circulation, can be
distributed to other organs
local: seen with strong acids and caustic substances, as well as inhaling toxic gases like chlorine
or ammonia
spectrum of toxic effects: reversible vs irreversible - ANS most toxic effects are reversible.
cancer or teratogenic effects are irreversible.
spectrum of toxic effects: immediate (acute) vs delayed (chronic) - ANS acute = hours to days.
e.g. chlorine gas. acute toxic effect.
delayed = cancer, something that takes months to years to set on.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
1
, spectrum of toxic effects: morphological, functional, and biochemical effects - ANS 1.
morphological effects are commonly irreversible. can be effects to limbs, or effects to
morphology of cells.
2. functional: toxicant can affect a critical function in the body, e.g. liver/kidney function.
generally reversible effects.
3. vast majority of xeno effects are initiated by some type of molecular event. e.g. cancer is
initiated by cellular dysfunction.
spectrum of toxic effects: allergic vs idiosyncratic reactions - ANS 1. hypersensitivity/allergic
reactions: initially exposed to an antigen (e.g. bee venom) can get delayed hypersensitivity.
2. idiosyncratic reactions: genetically based toxic reactions that occur only in small proportions
of individuals with no known cause
spectrum of toxic effects: graded (continuous) vs. quantal (all or none) responses - ANS 1.
continuous data have an infinite # of values: e.g. body weight
modifying factors of toxicity: dose - ANS dose defines the poison
modifying factors of toxicity: duration and frequency of exposure - ANS e.g. smoking one
cigarette vs a pack a day for several years. can be important in workplace exposure where you
cannot avoid constant exposure.
modifying factors of toxicity: species, genetic strain, individual - ANS interspecific differences
- difficult to say effects in one species will translate to effects in another. due to enzymes,
receptors, etc
modifying factors of toxicity: sex, pregnancy - ANS differences between males and females
usually related to differential expression of genes. males are much more susceptible to heart
disease - thought that estrogens have a protective effect.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
2
