Across
- 1. pacemaker cells of the heart
- 5. a muscle under conscious control
- 7. the plasma membrane of muscle cells
- 9. fibers are organized into bundles
- 10. a muscle that is not under conscious control
- 12. folded area of the sarcolemma where the muscle and neuron communicate
- 14. found in the walls of hollow organs
- 17. the boundary between sarcomeres
- 18. Composed of individual heart muscle cells
- 19. cells contain a lot of mitochondria
- 20. gap between the neuron and motor end plate
Down
- 2. each muscle is surrounded by a membrane
- 3. where thick and thin filaments overlap
- 4. Protects internal organs and produces heat
- 6. each muscle has smaller fibers called
- 8. what bones are attached to
- 11. the functional unit inside of a muscle fiber
- 13. enzyme that breaks down ACH
- 15. a single muscle cell
- 16. excessive stretching and possible tearing of the muscle or tendon