2. THE HUMAN BODY Vocabulary Unit II achilles tendon, involuntary muscle joint ligament marrow muscle nerves reflex voluntary musclex-ray

3. x-rays waves that can be used to take an image of and observe the condition of bone and, in some instances, tissue

4. reflex involuntary movements as a result of unexpected stimulus grasp reflex

5. involuntary muscle a muscle that you cannot consciously move

6. ligament tissue that connects a bone to other bones or to cartilage and helps to support joints

7. achilles tendon a tendon at the back of the ankle that connects the calf muscles and the heel; named after the mythical Greek hero Achilles

8. muscle tissue that works with the skeleton to make movement possible

9. joint the point where two bones meet

10. marrow a tissue that fills many bones and makes most blood cells, including disease-fighting white blood cells

11. nerves the specialized cells or bundled fibers that send signals from one body part to another Yellow part are nerves

12. voluntary muscle a muscle that you can consciously move