21. The Immune System

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

A decrease in which population of lymphocytes would impair all aspects of an immune response?

(a) Cytotoxic T cells

(b) Helper T cells

(c) Regulatory T cells

(d) B cells

(e) Plasma cells

Perforins are proteins associated with the activity of

(a) T cells

(b) B cells

(c) NK cells

(d) Plasma cells

Which of the following statements about effector T cells is NOT true?

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

The secondary immune response is mediated by plasma cells.

CD markers differentiate the two types of effector T cells. Cytotoxic T cells have _________ markers while helper T cells have _________ markers.

How does a cytotoxic T cell destroy another cell displaying antigens bound to class I MHC proteins?

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

A naive lymphocyte:

Mr. White developed neutropenia as a consequence of cancer chemotherapy, which destroyed much of his bone marrow. What other components of the immune system would be harmed by bone marrow destruction? Would you expect his hematocrit to be elevated or decreased? What effects would you expect to see from this change in hematocrit?

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.