Immunity Crossword

6. Initiates blood clotting
9. Blood cells that perform the function of destroying disease-causing microorganisms
10. fluid that circulates within the lymphatic vessels
11. Human Immunodeficiency Virus, the virus that causes A.I.D.S.
12. A weakened or inactive version of a pathogen that stimulates the body's production of antibodies.
13. a substance produced by the body that destroys or inactivates an antigen that has entered the body
16. An individual does not produce his or her own antibodies, but rather receives them directly from another source
18. single-celled prokaryotic organism
20. A disease causing agent

1. Cells that use phagocytosis to engulf foreign organisms
2. White blood cells
3. a form of acquired immunity in which the body produces its own antibodies against disease-causing antigens
4. Defenses against any pathogen
5. "Cell eating"
7. Bean-shaped filters that cluster along the lymphatic vessels of the body
8. White blood cells that are involved in the immune response
14. A non-cellular infectious agent
15. A system that protects the body from foreign substances and pathogenic organisms by producing the immune response
17. A protein that, when introduced in the blood, triggers the production of an antibody
19. Acute, contagious respiratory infection