21. The Immune System

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

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 is to make a true statement.

In the primary immune response, the lag phase lasts about 5 days, during which time B cells proliferate and differentiate.

Epitopes are:

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.

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.

Many phagocytic immune cells such as macrophages and dendritic cells commonly engulf foreign or dangerous materials in the body. If these cells engulf antigens, the cells will present the antigens on their surface. Which immune cells will respond to these “presented” antigens and trigger an immune response if necessary?