The Lymphatic and Immune Systems

2. Tube-like structures that carry lymph. These are similar to veins.
6. Interstitial fluid that has entered lymphatic vessels.
9. These lymphocytes mature in the thymus.
11. These recognize a repeat invader and activate the immune system to prevent an infection.
13. A foreign substance that triggers an immune response, these can be found on surfaces of bacteria and viruses.
16. A type of WBC that becomes B and T cells. They are found in blood and lymphatic tissues.
18. These need a host to reproduce, so they hijack body cells and trick them into producing more of themselves, often destroying the host cell in the process.
20. The largest lymphatic organ that contains macrophages and other immune cells to fight pathogens in blood. It also gets rid of old erythrocytes and stores oxygen-rich blood.
22. Free-living or parasitic, very simple single-celled organisms that reproduce by cell division. Some produce toxins that damage the body, while some are helpful or even necessary for good health.
24. The type of immunity you are born with. It is nonspecific.
26. Part of the lymphatic system where lymphocytes are made.
27. Tiny hairs on cells that can remove foreign invaders from the respiratory system.
28. These are the smallest lymphatic vessels that first collect lymph.
29. These are a type of T-cell that activates B cells and killer T cells.

1. Created from B cells, these make antibodies.
3. An immune response that dilates blood vessels to increase blood flow thereby more quickly bringing immune cells to the site of an infection.
4. First line of defense against pathogens.
5. These are a type of T-cell that attacks infected and cancer cells that have been tagged with antigens.
7. Produce plasma cells and B memory cells.
8. A sticky substance produced in the nose and mouth and other areas that can capture harmful invaders.
10. Small encapsulated tissues that filter lymph.
12. The ability to protect against a pathogen the body has previously been exposed to.
14. A microscopic organism that causes sickness, such as some bacteria and viruses.
15. Plasma that has left blood capillaries and is surrounding the cells of body tissues.
17. These attach to antigens and mark them for phagocytes to destroy. They can also neutralize toxins and incapacitate viruses.
19. The type of immunity your body develops as you are exposed to antigens. It is specific in that it responds to specific pathogens, not just any foreign invader.
21. A type of WBC that “eats” pathogens via phagocytosis.
23. These are two small masses of lymphoid tissue in the back of the throat to protect you from things you inhale or swallow.
25. This gland is both part of the lymphatic system and endocrine system. It is where T-Cells mature.