1. The majority of lymph fluid in the body returns to the venous circulation via the

2. The thymus is where T-cell lymphocytes:

3. Which of the following are characteristics of free macrophages and microphages?

4. Phagocytosis takes place in:

5. Which of the following is an example of naturally acquired active immunity?

6. Lymphoid organs include the

7. One purpose of lymph nodes is to:

8. B-cell lymphocytes mature in the:

9. A role of immunoglobulin G (IgG) is to:

10. Cytokines are chemical messengers which: