1. Spinal Cord What is the name of the bundle of nerves that runs down your back?

2. Cells What are the smallest living structures in the human body?

3. Involuntary What kind of muscles are being used when you digest food, breathe, or pump blood around your body? (voluntary or involuntary)

4. Cardiac What kind of muscle is the heart made of?

5. lungs Where do red blood cells pick up oxygen?

6. Bones What tissue makes red and white blood cells?

7. Smooth Muscle What kind of muscle helps you breathe (diaphragm) and moves food through the digestive system?

8. Brain Which organ receives and sends messages to all parts of your body?

9. Blood Cells What kind of cells do bones make?

10. Skeletal System Which body system protects your vital organs?

11. White Blood Cells What kind of blood cells fight pathogens?

12. Skeletal System What system supports your body?

13. Muscular System What body system moves your body parts?

14. Skeletal System What body system makes blood cells?

15. Respiratory System Which system takes in oxygen and removes carbon dioxide from your body?

16. Skin What organ helps to maintain your body temperature (by sweating)?

17. Voluntary What kind of muscles are being used when you kick a ball, swim, or hold a pencil? (voluntary or involuntary)

18. Alveoli What is the name of the tiny air sacs that exchange oxygen and carbon dioxide gases?

19. Oxygen and Glucose (food for the plant) What are the two products of photosynthesis?

20. Endocrine System Which body system sends hormones to make things happen in your body?

21. Circulatory System Which system moves blood around your body?

22. Reproductive System This system creates more individuals, babies.

23. Excretory System This system removes wastes from your body.

24. Hormones Chemical messengers They tell your body when and how much to grow

25. Endocrine System This system sends messages in the form of chemicals called hormones.