Across
- 1. Small air sacks in the lungs.
- 4. Main organ in the circulatory system.
- 5. The level between cells and organs.
- 6. Blood vessels that carry blood towards the heart.
- 7. Small things that make up an organism.
- 11. The tube that food travels through and breaks down.
- 13. Main organ of the digestive system.
- 14. Longest bone in the human body.
- 15. Organ that filters your blood.
- 16. Passageway of air into the lungs.
- 18. The organ that is involved in the last step of excretion.
- 20. Organ that holds urine.
- 22. Small hairs that filter the air that enter your nose.
- 23. Allows blood to enter the heart.
- 26. Main organ of the respiratory system.
- 27. Lining of the stomach.
Down
- 2. Another word for a voice box.
- 3. A cell in your bone.
- 8. The powerhouse of a cell.
- 9. Collections of lymphoid tissue facing into the aerodigestive tract.
- 10. Flexible tissue for interior bones.
- 12. Largest artery in the human body.
- 16. Solid that protects your organs.
- 17. The set of bones that protect the lungs.
- 19. A carbohydrate that contains lots of glucose.
- 21. Two small bones that make up the leg bone.
- 24. Blood vessels that carry blood away from the heart.
- 25. Little bumps inside the intestine.