Skeletal Muscles

2. protein component of the thick myofilaments
4. when they connect thick filaments and thin filaments, the myosin heads are called _____
6. bundles of muscle fibers
7. the tropomyosin strands are held in position by molecules of _____
8. the area containing thick filaments
9. surrounds each skeletal muscle fiber and ties adjacent muscle fibers together
10. a layer of of collagen fibers that separates the muscle from surrounding tissues and organs
11. openings scattered across the surface of the sarcolemma lead into a network of narrow tubules called _____
14. where myofilaments are organized into repeating functional units
17. made up of proteins that connect the central portions of each thick filament to its neighbors
18. the boundaries of each sarcomere
19. cylindrical structures

1. nerve fibers
2. protein filaments consisting primarily of the proteins actin and myosin
3. electrical impulse in the sarcolemma
5. a chemical released by a neuron to communicate with other cells
12. a narrow space that separates the synaptic terminal from the sarcolemma
13. divides the skeletal muscle into bundles of muscle fibers
15. the cell membrane of a muscle fiber that surrounds the cytoplasm
16. the collagen fibers of all three layers come together to form either a bundle known as a ______