Skin, Skeletal, and Muscular Systems: Muscles in Action

The video tutorial explains how skeletal muscles enable movement by contracting and shortening in length. It describes how muscles work in pairs to move bones in opposite directions, using the arm as a model to illustrate the contraction of biceps and relaxation of triceps. The structure of skeletal muscle is detailed, highlighting muscle fibers, myofibrils, and filaments. The sliding filament theory is introduced, explaining how nerve impulses stimulate muscle contraction through the interaction of thin and thick filaments.

Describe the structure of muscle fibers.

What is the sliding filament theory?