Toxicology 1 Flashcards

1
Q

Define

Toxicology

A

Study of adverse effects of chemicals in biological systems

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2
Q

Who said

All things are poison and nothing is without poison, only the dose makes a thing not a poison

A

Paracelsus

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3
Q

Define

ecotoxicology

A

study of effects of pollution on entire ecosystem

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4
Q

Differentiate

Toxicology vs ecotoxicology

A

Toxicology: chemicals → bio system
Eco: pollution → entire ecosystem

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5
Q

Relative Toxicity

A

Relative to dose & relative to person taking dose

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6
Q

Dose-Response Relationship

A

Quantitative description of the association between exposure & toxic effects produced

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7
Q

Requirements for Dose-Response Relationship to have a toxic effect

3

A
  1. Chemical or active metabolite that causes an adverse reaction in the body
  2. Must have sufficient concentration to have an effect
  3. Must persist long enough to exert the effect
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8
Q

Considerations for a Dose-Response Relationship

3

A
  1. Must be known that response is due to compound exposure
  2. Response Magnitude should be a function of dose administered
  3. Should have a quantitative method for measuring response
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9
Q

LD50

Also: what are the units?

A

Lethal Dose 50

  • Dose of chemical that kills 50% of exposed population in a defined time frame
  • Dose per kg of bodyweight (mg/kg)
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10
Q

How do we determine LD50?

A

Rats (aka through toxicology! lol)

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11
Q

Major Routes of Exposure

A

Contact
Ingestion
Inhalation

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12
Q

Describe

Contact Exposure
What happens?
What does skin absorb & not absorb?

A

Absorption over time
skin is Hydrophobic & lypophilic

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13
Q

Describe

Ingestion Exposure

A
  • Guts absorb maximum amt of substances it can digest (Bc Body assumes you are responsible)
  • “Free for all” down there
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14
Q

Describe

Inhalation Exposure

A

Inside chest cavity – protection

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15
Q

Toxicant Classifications

3

A
  1. Chemical Class
  2. Source of Exposure
  3. Organ system affected
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16
Q

How do we classify chemical class?

A

accdg to functional group

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17
Q

Chemical class examples add for long exam

A
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17
Q

Source of exposure
To air: ____
To water: ___

A

To air: ‘emission’
To water: ‘discharge’

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18
Q

List

Organ Systems affected

5

A
  1. Liver
  2. Kidneys
  3. Spine
  4. DNA
  5. Fetus
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19
Q

Main organs usually affected

2

A

Liver, kidneys

20
Q

What does the liver do?

A

Liver breaks down things (alcohol, proteins), Detoxifier

21
Q

What do kidneys do?

A

filter waste from blood,
Can pee it out

22
Q

How is our DNA affected by toxicant?

A

Once DNA is damaged, DNA replication is at risk

23
Q

How does the fetus become affected by toxicant?

A
  • Umbilical cord & Amniotic fluid
  • Creates its own blood supply
24
Q

Why do toxicologists favor studying the organ system affected?

A

it’s easier for them to think about & target

25
Q

Define

Xenobiotic

A

chemical foreign to the body

26
Q

Sequence of response

4

A

Absorption
Distribution
Metabolism
Excretion

27
Q

Define

Toxicokinetics

A

processes in the toxicological sequence

28
Q

What is the importance of studying toxicokinetics?

A

Knowing process of response helps you develop treatment against substance
Or prevent it from spreading further

29
Q

Describe

Absorption

A

Traversing biological barrier (Aka blood)

30
Q

Common pathways of absorption

3

A

Gastrointestinal system
Pulmonary alveoli
Skin

31
Q

Describe

Absorption through Gastrointestinal system

A
  • Design: nutrient absorption
  • Large surface area with numerous transport systems
  • Most taken advantage of by pathogens (they will try to enter system)
  • Be careful of what you ingest!
32
Q

Describe

Absorption through Pulmonary alveoli

A

Gas exchange between air & blood

33
Q

What gets absorbed through Pulmonary alveoli?

A

Small particles & aerosols

  • Diffusion of most water-soluble compounds
  • Lipid-soluble compounds also absorbed
34
Q

How does Diffusion of most water-soluble compounds happen in the Pulmonary Alveoli?

A

Mucous lining
more explanation pls

35
Q

Absorption through Skin

What kinds of compounds can penatrate & not penetrate skin?

A
  • Effective barrier for water-soluble
  • Lipid-soluble compounds readily penetrate skin & enter blood stream
36
Q

2 ways Distribution takes place

A

Bloodstream
Intestines/Liver

37
Q

What law does Distribution follow?

A

laws of diffusion

38
Q

In distribution through the intestines & liver, [many/few] chemicals are excreted in an unchanged form

A

few

39
Q

How are water soluble chemicals excreted?

A

urine

40
Q

How are fat soluble chemicals excreted?

A

Converts to bile first, excreted through feces

41
Q

What happens when the body doesn’t know how to get rid of a substance?

A

Stores it (ex. lead deposit in bones)

42
Q

Define

Biotransformation

A

enzyme-mediated metabolic conversion

43
Q

Where does metabolism take place and why?

A

Mostly in liver, bc rich in metabolic enzymes
Nearly all cells have some capacity for metabolism
Recall: detoxifying organ

44
Q

What products are usually formed from metabolic transformations (metabolism)?

A

Products are most polar and less fat soluble (for excretion via urine)

45
Q

What does the field of carcinogenesis tackle?

A

When metabolism yields more toxic products than original

46
Q

T/F

Metabolites cannot combine with cellular nucleophiles

A

F
They can combine w/ DNA & RNA

47
Q

What do you call substances that affect the DNA?

A

mutagen