Across
- 3. A small tube
- 4. process glucose broken down in cells for energy
- 6. a balloon like structure
- 9. the smallest airways
- 11. higher to lower concentration
- 12. near to the heart
Down
- 1. smallest blood vessels
- 2. filters hair
- 5. a red colour iron pigment
- 7. voicebox
- 8. carry impure blood to the heart
- 10. pumps blood