21. The Immune System

How do antibodies help defend the body?

An anesthesia technician is advised that she should be vaccinated against hepatitis B, which is caused by a virus. She is given one injection and is told to come back for a second injection in a month and a third injection after 6 months. Why is this series of injections necessary?

Which of the following is not a role of T_H cells?

a. Stimulation of macrophages

b. Activation of naïve T_C cells

c. Stimulation of naïve B cells

d. Stimulation of clonal selection

Explain how active immunity and passive immunity differ.

Mark the following statements as true or false. If a statement is false, correct is to make a true statement.

Subunit vaccines consist of pathogens that are alive but unable to cause disease.

Which antibody class is abundant in body secretions?

a. IgA

b. IgD

c. IgE

d. IgG

e. IgM

The specificity of an antibody is determined by the

(a) Fixed segment

(b) Antigenic determinants

(c) Variable region

(d) Size of the antibody

(e) Antibody class

Give one example of each type of immunity: innate immunity, naturally acquired active immunity, artificially acquired active immunity, artificially acquired passive immunity, and naturally acquired passive immunity.

Your friend tests her snake-wrangling skills on an eastern diamondback rattlesnake, and is bitten and envenomated (injected with the snake's venom). In the emergency department, doctors administer the antivenin CroFab, which contains antibodies to the toxins in snake venom. Is this an example of active or passive immunity? Will this confer any lasting protection to your friend?