Across
- 3. Considers as a secondary lymphoid organ
- 6. Specific defense system
- 7. A network of tissues and organs
- 10. Located low in the throat, overlying the heart
- 11. Destroy bacteria in the intestine
Down
- 1. Provide an immune response to antigens
- 2. Harmful materials that enter lymph vessels
- 3. Carried by lymphatic vessels
- 4. Engulf and destroy foreign substances
- 5. Filters the blood
- 7. Filter lymph before it is returned to the blood
- 8. Acts as a sentinel to protect respiratory and digestive tracts
- 9. Nonspecific defense system