Across
- 4. Muscle growth from heavy training
- 6. Prolonged activity; requires oxygen and nutrients
- 7. An alternate name for a mesodermal cell
- 8. Primary energy source for peak muscle activity
- 11. Red pigment that binds oxygen
- 13. Lengthwise subdivisions within muscle fibers
- 14. Hundreds of these are contained in skeletal muscle cells.
- 16. Thin, light filaments
- 18. Quick fatigue; strenuous activity
- 19. Bundles of muscle fibers
Down
- 1. The weakening of muscle due to lack of muscle activity
- 2. The color of fast fibers
- 3. The color of slow fibers
- 5. A fixed contraction after death
- 9. The chemical that forms the epimysium
- 10. Dark, thick filaments
- 12. Motor units contain hundreds of these.
- 13. The initial tension and firmness of a muscle at rest
- 15. An alternate name for a muscle cell
- 17. Provides energy for muscle contraction