Immune System

2. red blood cells
3. immune sentinels
6. any substance that antagonizes or stimulates the immune system
7. a form of small leukocyte
10. treatment with a vaccine to produce immunity against a disease
14. a complex biological system endowed with the capacity to recognize and tolerate whatever belongs to the self
15. a breakdown or inability of certain parts of the immune system to function
17. a type of immune cell that can surround and kill microorganisms
19. blood cells that are essential to clotting
20. a type of white blood cell that makes antibodies

1. a mean by which the body is given immunity to a disease by intentional exposure to small quantities of it
4. medicines that fight bacterial infections in people and animals
5. part of the immune system and develop from stem cells in the bone marrow
8. a protein produced by the body's immune system when it detects harmful substances
9. any infectious disease
11. one of the white blood cells
12. the natural or genetic ability of an organism to avoid or repel attack by biotic agents
13. complex system of cells, tissues, organs, and the substances that help the body fight infections
16. a chemical messenger protein
18. “Cell suicide”