Across
- 5. Chemical messengers created by glands (8)
- 10. Bleed on the brain (6)
- 11. Known as the windpipe (7)
- 13. Outside layer of the eye - becomes the cornea at the front (6)
- 14. Part of the central nervous system (5)
- 15. They stop blood from flowing backwards (6)
- 18. Where gas exchange takes place in the lungs (7)
- 19. Vitamin that helps the body absorb calcium (8)
- 22. Brings oxygenated blood to the kidneys (5, 6)
- 23. Where aerobic respiration takes place in the cell (12)
Down
- 1. A group of these work together to form a system (6)
- 2. Too much of this can cause heart problems (11)
- 3. The type of digestion that is not chemical (8)
- 4. A characteristic of living things (8)
- 6. Aerobic respiration uses this to release energy from food (6)
- 7. Mineral that enables oxygen to be carried in the blood (4)
- 8. Mineral that helps strengthen bones (7)
- 9. Changes shape to focus images onto the back of the eye (4)
- 11. Gland that controls metabolism (7)
- 12. The function of motor nerves (8)
- 15. Important vitamin for eyesight (8)
- 16. An excretory organ (4)
- 17. These group together to make tissues (5)
- 20. An excretory product (5)
- 21. Gland that produces adrenaline (7)