Across
- 2. fatty stuff that lives inside the bones where the body makes blood cells
- 4. fight off germs
- 5. type of lymph organs where the mature Tcells are stored
- 6. infection fighting white blood cells that help build the immunity
Down
- 1. used by the immune system to identify and neutralize a foreign substance in the body
- 3. can recognise particular germs and respond quickly
- 6. a small organ behind the breast bone where the tcells formed in the marrow mature