Across
- 4. This system allows animals both to move and to control their movements.
- 8. This system includes mouth, nose, trachea, lungs and smaller airways.
- 11. Animals take it in, when breathe.
- 12. This system serves as a barrier to protect the body internal parts.
- 13. They bring blood back to the heart.
Down
- 1. A small glandular organ, which produces a hormone known as thymosin.
- 2. This system comprises the heart, vessels and lymphatic system.
- 3. They bring blood away from the heart.
- 5. The fluid is circulated by the heart, carrying oxygen and nutrients to and waste materials away from all body tissues.
- 6. This system is different in males and females.
- 7. This system absorbs and digests food and eliminates solid wastes from the body.
- 9. This system maintains the structural integrity of the body.
- 10. This system includes several glands that produce hormones.