Across
- 3. spinal column
- 6. windpipe
- 9. the pH in the stomach
- 12. the movement of food down the oesophagus
- 13. diffusion of oxygen into cells and carbon dioxide into blood
- 15. organelle in which photosynthesis occurs
- 17. first part of the small intestine
- 18. pump with four chambers
- 20. prevent the back-flow of blood in the heart
Down
- 1. site of cellular respiration
- 2. plural of bronchus
- 4. site of gaseous exchange in lungs
- 5. heart chambers that receive blood
- 7. the flap the prevents food entering the lungs
- 8. skull
- 10. wall gives the plant cells structure and support
- 11. jelly-like substance in which the organelles are suspended
- 14. breastbone
- 16. knee cap
- 19. lobes in right lung