Immune System

2. A group of molecules on cell surfaces that display fragments of proteins for recognition by immune cells.
4. The ability to resist or recover from infection or disease.
9. A cell that targets and destroys infected or cancerous cells without prior activation.
10. A small organ near the large intestine that contains immune tissue and may support gut immunity.
12. Signaling proteins released by infected cells that help defend against viral spread
13. A cell that activates other immune cells by releasing signaling molecules.
15. The process of engulfing and digesting pathogens or debris.
17. A cell that processes and presents antigens to activate other immune cells.

1. A cell that captures antigens and presents them to other immune cells to trigger a response.
3. A cell that directly attacks and destroys infected or abnormal cells.
5. A non-specific, immediate form of defense present from birth.
6. An organ that filters blood, removes old cells, and helps mount immune responses.
7. A type of defense that is specific, develops over time, and creates long-term protection.
8. A cell that remains in the body after an infection to provide a faster response if re-exposed.
11. A type of white blood cell involved in recognizing and responding to specific invaders.
14. A branch of defense involving substances in body fluids, primarily targeting extracellular pathogens.
16. A protein that binds to foreign substances to help neutralize or eliminate them.