21. The Immune System

Blocking the antigen receptors on the surface of lymphocytes would interfere with

(a) Phagocytosis of the antigen

(b) That lymphocyte's ability to produce antibodies

(c) Antigen recognition

(d) The ability of the lymphocyte to present antigen

(e) Opsonization of the antigen

Differentiate between humoral and cellular adaptive immunity.

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.

CD4 markers are associated with

(a) Cytotoxic T cells

(b) Regulatory T cells

(c) Helper T cells

(d) All of these

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

Which of the following is NOT a consequence of the immune system lacking an immune tolerance?

Lymphocytes that develop immunocompetence in the bone marrow are:

a. T lymphocytes

b. B lymphocytes

c. NK cells

d. B and T lymphocytes

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

Cancer cells are destroyed by NK cells, T_C cells, and macrophages.

Complement proteins are crucial for stimulating phagocytes to clear immune complexes. Predict what type of hypersensitivity disorder might result from complement deficiencies. Explain what other consequences might arise from a complement deficiency.

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

Define immunocompetence and self-tolerance. How is self-tolerance achieved?

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

Dendritic cells may activate both T_H and T_C cells.