Body Systems

3. Tiny, colorless pieces of cells that help clot your blood.
7. This type of digestion is done by enzymes and acids.
10. Your sternum is this type of bone, named for its shape.
11. The blood cells that give blood its color.
12. When your body does it automatically, your cardiac muscle is an example.
15. This is the type of bone that is on the outside and makes them hard.
16. Soft connective tissue, like your ears and the tip of your nose.
17. The blood cells that fight disease.
18. A muscle shaped like a ring. Closes off areas, like between your esophagus and stomach.
19. This is a joint that cannot move, such as the skull.
20. The upper chambers of the heart.
21. Your body needs to breathe to take this gas in.

1. Your muscles that attach to bones.
2. A type of blood vessel that carries blood back to the heart.
4. Mammals need their body ___________ to stay within a certain range.
5. This mineral makes your bones strong and healthy.
6. The liquid part of your blood, 90% is water.
8. The lower chambers of the heart.
9. Soft connective tissue that is found in the spaces between your bones.
13. Muscles work by _____________ or shortening.
14. Largest of the blood vessels.
18. These types of muscles line the inside of your body and work without you having to think about it.