36.2 The Muscular System

Myosin

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

Actin

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

Neuromuscular Junction

• Point of contact between a motor neuron and a skeletal muscle cell.

Acetylcholine

• Neurotransm-itter that diffuses across a synapse and produces an impulse in the cell membrane of a muscle cell.

Tendon

• Tough connective tissue that joins skeletal muscles to bones.

Key Concept

• There are three different types of muscle tissue: skeletal, smooth, and cardiac.

Key Concept

• A muscle contracts when the thin filaments in the muscle fiber slide over the thick filaments.

Key Concept

• Regular exercise is important in maintaining muscular strength and flexibility.