1. 36.2 The Muscular System

2. Myosin Protein that makes up thick filaments in striations in skeletal muscle cells.

3. Actin Protein that mainly makes up the thin filaments in striations in skeletal muscle cells.

4. Neuromuscular Junction Point of contact between a motor neuron and a skeletal muscle cell.

5. Acetylcholine Neurotransm-itterthat diffuses across a synapse and produces an impulse in the cell membrane of a muscle cell.

6. Tendon Tough connective tissue that joins skeletal muscles to bones.

7. Key Concept There are three different types of muscle tissue: skeletal, smooth, and cardiac.

8. Key Concept A muscle contracts when the thin filaments in the muscle fiber slide over the thick filaments.

9. Key Concept Regular exercise is important in maintaining muscular strength and flexibility.