CHAPTER 2: Principles of Toxicology

Chapter 2. Principles of Toxicology

Five identical experimental animals are treated with 1 mg of one of the following toxins. The animal treated with which toxin is most likely to die?

a. ethyl alcohol (LD₅₀ = 10,000 mg/kg).

b. botulinum toxin (LD₅₀ = 0.00001 mg/kg).

c. nicotine (LD₅₀ = 1 mg/kg).

d. ferrous sulfate (LD₅₀ = 1500 mg/kg).

e. picrotoxin (LD₅₀ = 5 mg/kg).

Place the following mechanisms of toxin delivery in order from most effective to least effective—1: intravenous; 2: subcutaneous; 3: oral; 4: inhalation; 5: dermal.

a. 1, 5, 2, 4, 3.

b. 4, 1, 2, 3, 5.

c. 1, 4, 2, 3, 5.

d. 4, 2, 1, 5, 3.

e. 1, 4, 3, 2, 5.

A toxin with a half-life of 12 h is administered every 12 h. Which of the following is true?

a. The chemical is eliminated from the body before the next dose is administered.

b. The concentration of the chemical in the body will slowly increase until the toxic concentration is attained.

c. A toxic level will not be reached, regardless of how many doses are administered.

d. Acute exposure to the chemical will produce immediate toxic effects.

e. The elimination rate of the toxin is much shorter than the dosing interval.

Urushiol is the toxin found in poison ivy. It must first react and combine with proteins in the skin in order for the immune system to recognize and mount a response against it. Urushiol is an example of which of the following?

a. antigen.

b. auto-antibody.

c. superantigen.

d. hapten.

e. cytokine.

Toxic chemicals are most likely to be biotransformed in which of the following organs?

a. central nervous system.

b. heart.

c. lung.

d. pancreas.

e. liver.

When chemicals A and B are administered simultaneously, their combined effects are far ...