21. The Immune System

Give a function for each of the following:

(a) Cytotoxic T cells

(b) Helper T cells

(c) Regulatory T cells

(d) Plasma cells

(e) NK cells

Which of the following is/are examples of autoimmune disease?

a. Type 1 diabetes

b. Multiple sclerosis

c. Graves’ disease

d. Rheumatoid arthritis

Type I hypersensitivity is due to release of inflammatory mediators from_____, and type IV hypersensitivity is due to the actions of_____.

a. T_H cells; macrophages

b. neutrophils; T_H cells

c. B cells; T_C cells

d. mast cells; T_H cells

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

The immune response to a viral infection involves NK cells and different kinds of lymphocytes.

Although the adaptive immune system has two arms, it has been said, 'no T cells, no immunity.' Explain.

Caroline, a pregnant 29-year-old, has been HIV-positive for at least 10 years, dating back to when she was homeless and injecting heroin. While she currently has no symptoms of AIDS, she is taking several medications and is worried about the possibility that her baby might be infected. How do you think the HIV virus might be transferred from a mother to her offspring? Which of Caroline’s cells are infected by the virus, and why is the viral attack on these cells so devastating? Why is Caroline taking medication even though she has no symptoms?

Give a function for each of the following:

(f) Stromal cells

(g) Epithelial reticular cells

(h) Interferons

(i) Pyrogens

(j) T cells

(k) B cells

When naïve B cells are activated, they differentiate into:

a. Plasma cells

b. Memory cells

c. Both a and b

d. None of the above

What are the three classes of lymphocytes, and where does each class originate?

Name several cytokines and describe their role in the immune response.

Explain why a patient with AIDS due to HIV is at an increased risk of infection and of developing certain cancers.

While walking along the street, you and your friend see an elderly woman whose left arm appears to be swollen to several times its normal size. Your friend wonders aloud what might be its cause. You say that it may be likely that the woman had a radical mastectomy (the removal of a breast because of cancer). Explain the rationale behind your answer.