Sliding Filament Theory

The Sliding Filament Theory explains how muscles contract to produce movement. Inside muscle fibers, there are two types of proteins: actin (thin filaments) and myosin (thick filaments). When a muscle is stimulated, the myosin filaments pull the actin filaments closer together, causing the muscle to shorten and contract. This process requires energy from ATP and occurs in cycles, allowing for controlled movement. Essentially, the interaction between these filaments enables muscles to tense and relax, facilitating everything from walking to lifting objects.