20. The Lymphatic System

When are germinal centers most active?

Which of the following is not considered a type of lymphoid cell?

Which of the following does not describe the relationship between the lymphatic and immune systems?

a. Lymphoid organs and tissues house cells of the immune system.

b. Lymphoid organs and tissues trap pathogens for the immune system.

c. Lymphoid organs activate cells of the immune system.

d. Lymphoid organs and tissues create the surface barriers of the immune system.