Toxicology Exam 2 Flashcards Preview

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Flashcards in Toxicology Exam 2 Deck (21):
1

What are the four routes of exposure?

Absorption, Dermal, Inhalation and Injection

2

What are the steps of exposure?

Exposure - Delivery - Reaction - Dysfunction - Repair or Failure to repair

3

What is first pass elimination/ pre systemic elimination?

Where chemicals are redirected away from target organs and toxicity is successfully prevented

4

What does the term absorption refer to?

Putting chemicals into systemic circulation

5

What factors influence whether or not a chemical/toxicant is absorbed?

Concentration, Surface area of exposure, characteristics of epithereal layer where absorbed

6

What is the most important chemical property influencing absorption?

Lipophilic aka lipid soluble/ nonpolar/ hydrophobic

7

Properties of hydrophilic molecules are what?

Water soluble, charged aka polar molecules, polar with polar, water mixes with polar

8

Properties of hydrophobic molecules?

Non water soluble, uncharged molecules, nonpolar mixes with nonpolar, (lipids are an example)

9

How to mix polar and nonpolar?

Soap Micelle

10

What is passive transport?

Diffusion from high to low concentration where no energy is required (no ATP necessary)

11

What is facilitated diffusion?

Channels through membrane that allow diffusion down the gradient from high to low concentration (no energy or ATP required)

12

What is active transport?

Transport up gradient low to high concentration (energy and ATP required)

13

How do most toxicants cross the membrane?

Simple Diffusion

14

Rate of diffusion depends on what three things?

Lipid solubility, Molecular size, PKA

15

What is PC and how is it measured?

Partition coefficient and a measure of the substance in a lipid over an aqueous solution

16

PC of 10 = ?

Very lipophilic

17

PC 0.1 = ?

Very hydrophilic

18

Describe molecular size?

Molecular weight of less than 600 and hydrophilic enter via aqueous pores while larger hydrophobic molecules diffuse across the lipid domain

19

Describe PKA?

pH where the toxin is 50% charged and 50% uncharged and it mimics he pH scale of 0-14

20

What are examples of specialized barriers for preventing the transport of harmful agents to sensitive organs?

Blood brain barrier, placental, blood testes, oocytes

21

What is ADME?

Absorption, distribution, metabolism, excretion